U.S. patent application number 10/310652 was filed with the patent office on 2003-08-21 for plunger-based flow immunoassay assembly.
Invention is credited to Foley, Thomas J., Liang, Greg, Smith, Dave, Smith, Mike, Tatum, Roger, Waltzer, Eric.
Application Number | 20030157564 10/310652 |
Document ID | / |
Family ID | 27613202 |
Filed Date | 2003-08-21 |
United States Patent
Application |
20030157564 |
Kind Code |
A1 |
Smith, Dave ; et
al. |
August 21, 2003 |
Plunger-based flow immunoassay assembly
Abstract
Assemblies and methods are provided for flowing sample through a
flow immunoassay assembly using one or more plungers. The flow
immunoassay assembly includes an immunoassay reaction chamber, a
sample distribution chamber in fluid communication with the
immunoassay reaction chamber, and a sample dispense plunger being
movable within the sample distribution chamber to dispense the
sample from the sample distribution chamber into the immunoassay
reaction chamber. The flow immunoassay assembly can further include
a buffer chamber in fluid communication with the immunoassay
reaction chamber, and a buffer dispense plunger movable within the
buffer chamber to dispense buffer from the buffer chamber into the
immunoassay reaction chambers. The flow immunoassay assembly can
further include a read cell in fluid communication with the
immunoassay reaction chamber for providing a means to measure a
reaction within the reaction chamber (which may be a displacement
type immunoassay reaction chamber) and a waste chamber in fluid
communication with the read cell for storage of hazardous
biological fluid. Upper and lower seals can be provided on the
buffer chamber for storage of the buffer prior to use, in which
case, the buffer dispense plunger can be provided with a stylus
that is configured to puncture the upper seal when the buffer
dispense plunger is moved toward the upper seal. To automate the
immunoassay flow assembly, it can further include a drive assembly
mechanically coupled to the sample dispense plunger, and if
applicable, the buffer dispense plunger.
Inventors: |
Smith, Dave; (Highland,
CA) ; Smith, Mike; (Redlands, CA) ; Tatum,
Roger; (Riverside, CA) ; Waltzer, Eric;
(Riverside, CA) ; Liang, Greg; (Rancho Cucamonga,
CA) ; Foley, Thomas J.; (Mission Viejo, CA) |
Correspondence
Address: |
JONES DAY
555 WEST FIFTH STREET, SUITE 4600
LOS ANGELES
CA
90013-1025
US
|
Family ID: |
27613202 |
Appl. No.: |
10/310652 |
Filed: |
December 4, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60336596 |
Dec 4, 2001 |
|
|
|
Current U.S.
Class: |
435/7.1 ;
435/287.2 |
Current CPC
Class: |
B01F 35/754251 20220101;
B01F 35/7137 20220101; B01L 2400/0478 20130101; G01N 33/48714
20130101; B01L 2400/0622 20130101; G01N 1/02 20130101; B01F 33/812
20220101; Y10T 156/1002 20150115; B01F 2101/23 20220101; B01L 3/502
20130101; B01L 2300/041 20130101; B01F 33/81 20220101; Y10T
436/2575 20150115; Y10T 137/7036 20150401; B01L 2300/0864 20130101;
G01N 33/54366 20130101; B01F 35/713 20220101; G01N 33/54373
20130101; G01N 33/98 20130101; B01F 35/7161 20220101; B01L
2400/0644 20130101; B01F 35/7163 20220101; B01L 2300/0825 20130101;
Y10T 436/11 20150115; G01N 33/54313 20130101; B01F 35/7174
20220101; B01L 3/5023 20130101; B01L 2200/0689 20130101; A61B
10/0051 20130101; B01F 33/452 20220101; A61B 10/0283 20130101; G01N
2035/00158 20130101 |
Class at
Publication: |
435/7.1 ;
435/287.2 |
International
Class: |
G01N 033/53; C12M
001/34 |
Claims
What is claimed:
1. A flow immunoassay assembly for testing a sample, comprising: an
immunoassay reaction chamber; a sample distribution chamber
configured for containing said sample, and being in fluid
communication with said immunoassay reaction chamber; and a sample
dispense plunger disposed within said sample distribution chamber,
and being movable to dispense said sample from said sample
distribution chamber into said immunoassay reaction chamber.
2. The flow immunoassay assembly of claim 1, further comprising a
sample/buffer mixing assembly in fluid communication with said
sample distribution chamber, said mixing assembly configured for
mixing said sample and a buffer to form a buffered sample solution
and distributing said buffered sample solution into said sample
distribution chamber.
3. The flow immunoassay assembly of claim 1, further comprising: a
buffer chamber configured for containing a buffer, said buffer
chamber in fluid communication with said plurality of immunoassay
reaction chamber; and a buffer dispense plunger disposed within
said buffer chamber, and being movable within said buffer chamber
to dispense said buffer from said buffer chamber into said
plurality of immunoassay reaction chamber.
4. The flow immunoassay assembly of claim 3, wherein said buffer
chamber comprises a buffer and a seal that seals said buffer in
said buffer chamber.
5. The flow immunoassay assembly of claim 4, wherein said buffer
dispense plunger comprises a stylus that is configured to puncture
said seal when said buffer dispense plunger is moved toward said
seal.
6. The flow immunoassay assembly of claim 1, further comprising a
valve for selectively placing said sample distribution chamber in
fluid communication with said plurality of immunoassay reaction
chamber.
7. The flow immunoassay assembly of claim 1, further comprising a
read cell in fluid communication with said plurality of immunoassay
reaction chamber.
8. The flow immunoassay assembly of claim 7, further comprising a
waste chamber in fluid communication with said read cell.
9. The flow immunoassay assembly of claim 1, wherein said plurality
of immunoassay reaction chamber comprises a displacement
immunoassay reaction chamber.
10. The flow immunoassay assembly of claim 1, further comprising a
sample drive assembly mechanically coupled to said sample dispense
plunger.
11. The flow immunoassay assembly of claim 3, further comprising: a
sample drive assembly mechanically coupled to said sample dispense
plunger; and a buffer drive assembly mechanically coupled to said
buffer dispense plunger.
12. A flow immunoassay assembly for testing a sample, comprising: a
plurality of immunoassay reaction chambers; a plurality of sample
distribution chambers configured for containing said sample, and
being in fluid communication with said plurality of immunoassay
distribution chambers; and a plurality of sample dispense plungers
disposed within said plurality of sample distribution chambers, and
being movable to dispense said sample from said plurality of sample
distribution chambers into said plurality of immunoassay reaction
chambers.
13. The flow immunoassay assembly of claim 12, wherein each of said
plurality of sample distribution chambers, immunoassay reaction
chambers, and sample dispense plungers comprises five or more.
14. The flow immunoassay assembly of claim 12, wherein each of said
plurality of sample distribution chambers, immunoassay reaction
chambers, and sample dispense plungers comprises ten or more.
15. The flow immunoassay assembly of claim 12, further comprising a
sample/buffer mixing assembly in fluid communication with said
plurality of sample distribution chambers, said mixing assembly
configured for mixing said sample and a buffer to form a buffered
sample solution and distributing said buffered sample solution into
said plurality of sample distribution chambers.
16. The flow immunoassay assembly of claim 12, further comprising:
a plurality of buffer chambers configured for containing a buffer,
said plurality of buffer chambers being in fluid communication with
said plurality immunoassay reaction chambers; and a plurality of
buffer dispense plungers disposed within said plurality of buffer
chambers, and being movable within said plurality of buffer
chambers to dispense said buffer from said plurality of buffer
chambers into said plurality of immunoassay reaction chambers.
17. The flow immunoassay assembly of claim 6, wherein said
plurality of buffer chamber comprises a buffer and a plurality of
seals that seals said buffer in said plurality of buffer
chambers.
18. The flow immunoassay assembly of claim 7, wherein said
plurality of buffer dispense plungers comprises a respective
plurality of styluses that are configured to puncture said
plurality of seals when said buffer dispense plungers are moved
toward said plurality of seals.
19. The flow immunoassay assembly of claim 12, further comprising a
plurality of read cells in fluid communication with said plurality
of immunoassay reaction chambers.
20. The flow immunoassay assembly of claim 9, further comprising a
waste chamber in fluid communication with said plurality of read
cells.
21. The flow immunoassay assembly of claim 12, further comprising a
cassette case for containing said pluralities of immunoassay
reaction chambers, sample distribution chambers, and sample
dispense plungers.
22. The flow immunoassay assembly of claim 12, further comprising a
valve for selectively placing said plurality of sample distribution
chambers in fluid communication with said plurality of immunoassay
reaction chambers.
23. The flow immunoassay assembly of claim 12, wherein said valve
is a rotary valve.
24. The flow immunoassay assembly of claim 12, wherein said
plurality of immunoassay reaction chambers comprises a plurality of
displacement immunoassay reaction chambers.
25. The flow immunoassay assembly of claim 12, further comprising
one or more sample drive assemblies mechanically coupled to said
plurality of sample dispense plungers.
26. The flow immunoassay assembly of claim 6, further comprising:
one or more sample drive assemblies mechanically coupled to said
plurality of sample dispense plungers; and one or more buffer drive
assemblies mechanically coupled to said plurality of buffer
dispense plungers.
27. A method of analyzing a sample, comprising: distributing said
sample into a plurality of sample distribution chambers; flowing
said sample from said plurality of sample distribution chambers
through a plurality of immunoassay reaction chambers by moving a
plurality of sample dispense plungers within said plurality of
sample distribution chambers; and measuring a reaction within each
of said plurality of immunoassay reaction chambers.
28. The method of claim 27, further comprising flowing a buffer
from a plurality of buffer chambers through said plurality of
immunoassay reaction chambers by moving a plurality of buffer
dispense plungers within said plurality of buffer chambers.
29. The method of claim 27, wherein said buffer is flowed through
said plurality of immunoassay reaction chambers during said sample
distribution.
30. The method of claim 27, wherein said buffer is flowed through
said plurality of immunoassay reaction chambers prior to said
sample flow.
31. The method of claim 28, wherein said buffer is flowed through
said plurality of immunoassay reaction chambers during said sample
flow.
32. The method of claim 28, wherein said buffer is flowed through
said plurality of immunoassay reaction chambers prior to said
sample flow.
33. The method of claim 27, wherein said sample flow produces a
analyte detectable sample solution within said plurality of
immunoassay reaction chambers, and said reaction measuring
comprises flowing said analyte detectable sample solution through a
plurality of read cells and measuring an analyte indicator in said
analyte detectable sample solution.
34. The method of claim 33, wherein said analyte indicator
comprises a labeled antigen.
35. The method of claim 27, wherein said sample comprises
saliva.
36. The method of claim 27, wherein said sample comprises a bodily
fluid.
Description
RELATED APPLICATIONS
[0001] The present application claims priority under 35 U.S.C.
119(e) to U.S. Provisional Application No. 60/336,596 filed Dec. 4,
2001, which is incorporated herein by reference.
TECHNICAL FIELD OF THE INVENTION
[0002] The present inventions generally relate to systems, methods,
and devices for the identification of analytes in bodily fluids,
and in particular, for the identification of drugs, alcohol, and
other toxic substances in saliva.
BACKGROUND OF THE INVENTION
[0003] The collection of body fluids for diagnostic analysis has
long been used in medical, diagnostic, forensic, veterinary medical
and other fields to test and monitor for the presence of specific
molecules within the fluid. Results of such analyte testing can be
used to diagnose medical conditions, and to measure the
concentration of pharmaceutical and other drugs or toxic substances
in a human or animal subject. Analyte test results can also be used
to monitor appropriate levels of therapeutic agents, or for other
purposes. A subject's oral fluids may be used to test for a wide
variety of types of molecules whose concentration in saliva is
related to the circulating concentration of those molecules or
related metabolites of substances in the blood. (Malamud, D, Saliva
as a diagnostic fluid, Br. Med. J., 305, 207-208 (1990); Mandel, I.
D, The diagnostic uses of saliva, J. Oral Pathol. Med., 19, 119-125
(1990); Mandel, I. D., Salivary Diagnosis: Promises, Promises,
Malamud, D. and Tabak, L. (eds.); Saliva as a Diagnostic Fluid,
Vol. 694: Annals of the New York Academy of Sciences, New York: The
New York Academy of Sciences (1993), pp. 1-8).
[0004] Use of saliva as a medium for analysis is desirable since it
can be obtained by noninvasive methods, unlike blood product
collection methods that involve trained medical personnel and use
venipuncture or finger-stick methods of collection. Oral fluid
collection can also be done in public without requiring privacy
booths, bathroom facilities, and careful subject monitoring
otherwise required to avoid adulteration, sample replacement,
sample dilution and other problems associated with urine
collection. A number of sample collection assemblies and methods
have been disclosed. For example, U.S. Pat. No. 6,022,326 issued to
Tatum et al., which is fully and expressly incorporated herein by
reference, describes a device and method for automatically
collecting saliva from a subject through aspiration using a wand
with an associated saliva collection tip and a vacuum that flows
the saliva from the tip, through the wand, and into a collection
chamber. After the saliva sample is collected, it is typically sent
to a specialized laboratory for analysis.
[0005] Many different assay methods for measuring an analyte in a
sample are known in the art. Many of such methods are immunological
based, i.e., they involve measuring the binding of an antibody or
antibody fragment to a complementary ligand, e.g., a drug or other
molecule. Immunoassay methods, in general, are based on the
competition between a specific analyte, the concentration of which
is to be measured in a sample, and a known amount of tracer, which
is generally the analyte or an appropriate analog antigen thereof
in labeled form, with the analyte and tracer competing for a
limiting number of available binding sites on a binder. U.S. Pat.
Nos. 5,183,740 and 5,354,654 issued to Ligler et al., which are
hereby fully and expressly incorporated herein by reference,
disclose these immunoassay methods in further detail.
[0006] Typically, semi-automated or automated systems are used to
load and perform immunoassay tests on the saliva samples. The
majority of the systems on the market comprise a loading tray for
loading multiple samples, which are not necessarily of the same
nature or having the same assay performed on them. There is also a
reagent tray that holds a number of reagent cartridges for the
various different tests to be performed. In the machine, the
samples are transferred, normally by pipetting into an assay cell,
where the sample is combined with the necessary reagent or
reagents. The assay cell is then transferred to a part of a machine
where it can be held for sufficient time for the reagent and the
sample to combine. Thereafter, the sample cell is transferred to
the detector, which detects the presence of a known indicator to
determine whether or not the sample contained a particular
component and/or how much of that component was present in the
assay.
[0007] Recent systems have employed flow injection technology,
which involves combining the sample in a fluid stream that passes
through a reaction column containing a support medium on which
antibodies are bound and saturated with a labeled antigen. The
fluid stream passes over the support media, where competition
between any analytes and the labeled antigen occur. Any displaced
labeled antigen passes out through the reaction chamber and into a
transparent detection chamber where it is detected and quantified,
e.g., by fluorescent means, as an indication of the presence and
quantity of the specific analyte to be tested. U.S. Pat. Nos.
5,370,842, 5,779,978, 6,120,734, 6,159,426, as well as previously
mentioned U.S. Pat. No. 5,183,740, discuss this flow injection
technology in some detail.
[0008] The above-described methodologies are sufficient for some
applications, e.g., those applications in which time is not
critical. For other applications that require portability and/or
real-time testing of the sample, e.g., in police stations,
emergency rooms, etc., sending a sample to a laboratory for
analysis is simply not practical. In response to the need to
decrease the amount of time required to obtain test results from a
sample, as well as the need to provide more convenient and less
expensive diagnostic methods, there have been efforts to develop
simple tests to allow unskilled persons to perform certain
analytical procedures outside of the laboratory. For example, U.S.
Pat. No. 5,145,789 describes a method for testing urine. As
previously mentioned, however, there are various problems that are
associated with urine collection and testing.
[0009] Other methods, such as those described in U.S. Pat. Nos.
4,703,017, 5,556,789, and 5,714,341, require a two-step process,
which involves collecting the specimen, and then manually applying
the collected specimen to the analytical device. Thus, at least two
operations and devices are necessary with these previous methods.
First, collection of the saliva specimen with some type of
collection device and, second, application of the saliva specimen
to the analytical device described in those inventions. Thus, these
methods are disadvantageous in that they are not performed in real
time and requires additional handling by users, posing a risk that
errors may be unknowingly introduced into the test results.
[0010] U.S. Pat. No. 6,248,598 describes a method that collects the
saliva and initiates an assay or assays of the saliva in one step.
This method, however, requires the use of a saliva absorption
technique, which has significant limitations, including slow
collection times, risk of irreversible absorption into the carrier
membrane, inability to obtain quantitative results, and a
limitation of the number of different tests that can be performed
on the small sample size.
[0011] There thus remains a need for improved systems, methods, and
assemblies that test or facilitate in testing bodily fluids for
target analytes, e.g., drugs in saliva.
SUMMARY OF THE INVENTION
Tester for Automated Identification of Analytes in Bodily
Fluids
[0012] The present inventions are also directed to systems,
methods, and assemblies for identifying one or more analytes within
bodily fluids, such as saliva.
[0013] In accordance with a first aspect of the present inventions,
a system comprises an analyte tester, an oral aspirator, a conduit
that is in fluid communication between the oral aspirator and the
tester, and a pump in fluid communication with the conduit. In this
manner, the aspirated oral fluid can be pumped directly from the
aspirator into the analyte tester for identification of one or more
oral fluid analytes. In a non-limiting preferred embodiment, the
analyte tester can be a flow immunoassay tester that identifies the
five NIDA drugs-of-abuse, and can be configured to identify up to
ten different drugs or other analytes. The analyte tester can also
be portable, so that it can be conveniently used areas remote from
laboratories. The tester may comprise a chemistry cassette and a
test console configured for receiving the chemistry cassette. In
this case, the conduit may be in fluid communication with the
chemistry cassette. A user interface may also be provided for
entering test information (e.g., a specific test selection or test
panel customization) and for conveying test results (e.g., using a
display or printer).
[0014] In accordance with a second aspect of the present
inventions, a system comprises an analyte tester that is configured
to identify one or more analytes in less than 1 ml of bodily fluid,
a sample collection interface device, a conduit that is in fluid
communication between the sample collection interface device and
the tester, and a pump in fluid communication with the conduit. In
this manner, the system can be conveniently used to test for
analytes in a subject without the use of a substantial amount of
bodily fluid. In a non-limiting preferred embodiment, the pump may
be configured for pumping bodily fluid through the conduit at a
rate of less than 200 .mu.L/min. Although other types of bodily
fluid can be collected, the sample collection interface device
comprises an oral aspirator for collecting saliva from the test
subject in the preferred embodiment. Other previously described
features can also be incorporated into an embodiment constructed in
accordance with the second aspect of the present inventions.
[0015] In accordance with a third aspect of the present inventions,
a method comprises pumping an oral fluid sample from a subject to
an analyte tester, and identifying one or more analytes contained
in the oral fluid sample. In a non-limiting preferred method, a
flow immunoassay technique can be used to semi-quantitatively or
quantitatively identify the five NIDA drugs-of-abuse, and can be
modified to test up to ten different drugs or other analytes. The
sample can be aspirated from the test subject, and the time that it
takes to complete the method can take less than ten minutes.
[0016] In accordance with a fourth aspect of the present
inventions, a method comprises pumping less than 1 ml of a bodily
fluid sample from a subject to an analyte tester, and identifying
the one or more analytes contain in the sample. In a non-limiting
preferred method, the sample can be pumped at a rate of less than
200 .mu.L/min. Although other types of bodily fluid can be pumped
from the test subject, oral fluid can be used as the sample. Other
previously described features can also be incorporated into a
method performed in accordance with the fourth aspect of the
present inventions.
[0017] In accordance with a fifth aspect of the present inventions,
a cassette assembly comprises a chemistry cassette receivable
within a test console, and a bodily fluid sample collection
assembly configured for being in fluid communication with the
chemistry cassette. The chemistry cassette enables the test console
to identify one or more bodily fluid analytes. In a non-limiting
preferred embodiment, the chemistry cassette can be a fluid
immunoassay cassette, and the bodily fluid sample collection
assembly can be an oral fluid sample collection assembly that
includes an oral aspirator, sample collection chamber, and a
conduit in fluid communication between the oral aspirator and the
sample collection chamber.
PLUNGER-BASED FLOW IMMUNOASSAY ASSEMBLY
[0018] The present inventions are also directed to assemblies and
methods for flowing sample through a flow immunoassay assembly
using one or more plungers.
[0019] In accordance with a first aspect of the present inventions,
a flow immunoassay assembly comprises an immunoassay reaction
chamber, a sample distribution chamber in fluid communication with
the immunoassay reaction chamber, and a sample dispense plunger
being movable within the sample distribution chamber to dispense
the sample from the sample distribution chamber into the
immunoassay reaction chamber.
[0020] In a non-limiting preferred embodiment, the flow immunoassay
assembly can further include a buffer chamber in fluid
communication with the immunoassay reaction chamber, and a buffer
dispense plunger movable within the buffer chamber to dispense
buffer from the buffer chamber into the immunoassay reaction
chambers. The preferred flow immunoassay assembly can further
include a read cell in fluid communication with the immunoassay
reaction chamber for providing a means to measure a reaction within
the reaction chamber (which may be a displacement type immunoassay
reaction chamber) and a waste chamber in fluid communication with
the read cell for storage of hazardous biological fluid. Upper and
lower seals can be provided on the buffer chamber for storage of
the buffer prior to use, in which case, the buffer dispense plunger
can be provided with a stylus that is configured to puncture the
upper seal when the buffer dispense plunger is moved toward the
upper seal. To automate the preferred immunoassay flow assembly, it
can further include a drive assembly mechanically coupled to the
sample dispense plunger, and if applicable, the buffer dispense
plunger.
[0021] In accordance with a second aspect of the present
inventions, a flow immunoassay assembly comprises a plurality of
immunoassay reaction chambers, a plurality of sample distribution
chambers in fluid communication with the plurality of immunoassay
reaction chambers, and a plurality of sample dispense plungers
being movable within the plurality of sample distribution chambers
to dispense the sample from the plurality of sample distribution
chambers into the plurality of immunoassay reaction chambers.
[0022] In a non-limiting preferred embodiment, the flow immunoassay
assembly can further include many of the other features described
above, such as buffer chambers, read cells, a waste chamber, and a
drive assembly, but can also comprise other features that
facilitate the multiple flow paths. For example, the preferred flow
immunoassay assembly can include a valve, such as a rotary valve,
to selectively place the plurality of sample distribution chambers
in fluid communication with the plurality of immunoassay reaction
chambers, and if applicable, the plurality of buffer chambers in
fluid communication with the plurality of immunoassay reaction
chambers. The preferred flow immunoassay assembly can further
include a sample/buffer mixing assembly in fluid communication with
the plurality of sample distribution chambers, in which case, the
mixing assembly is configured for mixing sample and buffer to form
a buffered sample solution and distributing the buffered sample
solution amongst the sample distribution chambers. The number of
sample flow paths, i.e., the number of sample distribution chambers
and corresponding immunoassay reaction chambers, can equal five or
more, or even ten or more. Similarly, if applicable, the number of
buffer flow paths, i.e., the number of buffer chambers and
corresponding immunoassay reaction chambers, can equal five or
more, or even ten or more.
[0023] In accordance with a third aspect of the present inventions,
a method of analyzing a sample comprises distributing the sample
into a plurality of sample distribution chambers, flowing the
sample from the plurality of sample distribution chambers through a
plurality of immunoassay reaction chambers by moving a plurality of
sample dispense plungers within the plurality of sample
distribution chambers, and measuring a reaction with each of the
plurality of immunoassay reaction chambers. In a non-limiting
preferred method, buffer can be flowed from a plurality of buffer
chambers through the plurality of immunoassay reaction chambers by
moving a plurality of buffer dispense plungers within the plurality
of buffer chambers. The buffer can be flowed through the plurality
of immunoassay reaction chambers prior to, during, after the sample
flow, and even during sample distribution. The sample flowing
through the plurality of immunoassay reaction chambers can produce
a analyte detectable sample solution, in which case, the preferred
method can further comprise flowing the analyte detectable sample
solution through a plurality of read cells and measuring an analyte
indicator, such as a labeled antigen, in the analyte detectable
sample solution. The sample tested can be bodily fluid, such as
saliva.
AUTOMATED PLUNGER-BASED SAMPLE/BUFFER MIXING ASSEMBLY
[0024] The present inventions are also directed to assemblies and
methods for mixing a sample and a buffer.
[0025] In accordance with a first aspect of the present inventions,
a sample/buffer mixing assembly comprises a sample collection
chamber, a buffer chamber containing a buffer, a mixing chamber,
and one or more plungers. The sample collection chamber is in fluid
communication with a sample collection interface device. The mixing
chamber comprises a sample port adjacent the sample collection
chamber, and a buffer port adjacent the buffer chamber. The one or
more plungers is in fluid communication with the sample collection
chamber and the buffer chamber, and can be moved to dispense the
buffer from the buffer chamber into the mixing chamber via the
sample port, and the sample from the sample collection chamber into
the mixing chamber via the buffer port. In this manner, the
dispensed sample and buffer form a buffered sample solution within
the mixing chamber.
[0026] In a non-limiting preferred embodiment, the one or more
plungers can include a buffer dispense plunger that is movable
within the buffer chamber towards the buffer port to dispense the
buffer from the buffer chamber into the mixing chamber under
positive pressure via the buffer port. The one or more plungers can
also include a sample dispense plunger that is movable within the
mixing chamber away from the sample port to dispense the sample
from the sample collection chamber into the mixing chamber via the
sample port. The preferred sample/buffer mixing assembly can be
automated by mechanically coupling drive assemblies to the sample
and buffer dispense plungers. To ensure that the sample and buffer
are mixed, a ferrous element can be provided within the mixing
chamber, and a mixing motor can be magnetically coupled to the
ferrous element to agitate the buffered sample solution. The
preferred sample/buffer mixing assembly can also be used to mix
saliva and buffer, in which case, the sample collection chamber is
a saliva collection chamber.
[0027] In accordance with a second aspect of the present
inventions, a method of buffering a sample comprises dispensing the
sample into a mixing chamber via a sample port, dispensing buffer
into the mixing via a buffer port, and mixing the sample and the
buffer in the mixing chamber to form a buffered sample solution.
Sample and buffer chambers are moved in fluid communication with
the mixing chamber to dispense the sample and buffer within the
mixing chamber.
[0028] In a non-limiting preferred method, the buffered sample
solution may be dispensed from the mixing chamber via a dispense
port by moving buffered sample dispense plunger in fluid
communication with the mixing chamber, e.g., by moving the buffered
sample dispense plunger within the mixing chamber towards the
dispense port. The buffered sample solution can be mixed within the
mixing chamber simply through the dispensing process, or
additionally by a mixing motor. The preferred method can be
automated by mechanically coupling drive assemblies to the sample
and buffer dispense plungers.
[0029] In accordance with a third aspect of the present inventions,
a mixing assembly comprises a first chamber containing a first
solution, a second chamber containing a second solution, and a
third chamber comprising a first port in fluid communication with
the first chamber, a second port in fluid communication with the
second chamber, and a third port. The mixing assembly further
comprises a first plunger disposed within the first chamber, which
is movable to dispense the first solution from the first chamber
into the third chamber via the first port. The mixing assembly
further comprises a second plunger disposed within the third
chamber, which is movable to dispense the second solution from the
second chamber into the third chamber via the second port to form a
fluid mixture with the first and second solutions. The mixing
assembly further comprises a third plunger disposed within the
third chamber, which is movable to dispense the fluid mixture from
the third chamber via the third port.
[0030] In a non-limiting preferred embodiment, the mixing assembly
can be a sample/buffer mixing assembly, wherein the first, second,
and third chambers can be buffer, sample collection, and mixing
chambers, the first and second solutions can be buffer and sample,
the first, second, and third ports can be buffer, sample, and
dispense ports, and the first, second, and third plungers can be
buffer, sample, and dispense plungers. The buffer port can have a
seal to hold the buffer within the buffer chamber. In this case,
the buffered sample dispense plunger can be provided with a stylus
that punctures the seal when the buffered sample dispense plunger
is moved towards the buffer port. The dispense port can also be
provided with one or more through ports for allowing the buffer to
flow from the buffer chamber into the mixing chamber. The buffer
dispense plunger can be mated with one side of the buffered sample
dispense plunger to move the buffered sample dispense plunger
towards the dispense port, and the sample dispense plunger can be
mated with the other side of the buffered sample dispense plunger
to move the buffered sample dispense plunger towards the buffer
port to puncture the seal. The mixing chamber can be in axial
alignment with the buffer chamber to allow the buffer dispense
plunger to engage the buffered sample dispense plunger within the
mixing chamber. The buffer chamber can also have a plug that is
receivable within the through port of the buffered sample dispense
plunger to prevent leakage when the buffered sample dispense
plunger is moved towards the dispense port to dispense the buffered
sample solution. The buffer port may be a longitudinal port and the
sample port may be a lateral port, in which case, one surface of
the buffered sample dispense plunger may be adjacent the buffer
port and the opposite surface of the buffered sample dispense
plunger may be adjacent the sample port. Other previously described
features can also be incorporated into an embodiment constructed in
accordance with the second aspect of the present inventions.
[0031] In accordance with a fourth aspect of the present
inventions, a method of mixing first and second fluid using first,
second, and third chambers comprises a disposing the first fluid in
a first chamber, and disposing the second fluid in a second
chamber. The method further comprises moving the first plunger
within the first chamber towards first port to dispense the first
solution from the first chamber into the third chamber, moving a
second plunger within the third chamber away from a second port to
dispense the second solution from the second chamber into the third
chamber to form a fluid mixture from the first and second
solutions, and moving a third plunger within the third chamber
towards the third port to dispense the fluid mixture from the third
chamber out through the third port.
[0032] In a non-limiting preferred embodiment, the first, second,
and third chambers can be buffer, sample collection, and mixing
chambers, the first and second solutions can be buffer and sample,
the first, second, and third ports can be buffer, sample, and
dispense ports, and the first, second, and third plungers can be
buffer, sample, and dispense plungers. The buffered sample dispense
plunger can also be used to puncture a seal on the buffer port
prior to dispensing the buffer into the mixing chamber. The
buffered sample dispense plunger can be moved towards the dispense
port by pushing it with the buffer dispense plunger, or moved
towards the buffer port by pushing it with the sample dispense
plunger. The sample and buffer can be simultaneously dispensed into
the mixing chamber by moving the sample and buffer dispense
plungers simultaneously. Other previously described features can
also be incorporated into an embodiment constructed in accordance
with the second aspect of the present inventions.
HYDROPHOBIC/HYDROPHILIC SAMPLE COLLECTION TIP
[0033] The present inventions are also directed to assemblies for
collecting oral fluid from a mouth of a subject using a
hydrophobic/hydrophilic sample collection tip.
[0034] In accordance with a first aspect of the present inventions,
a sample collection assembly comprises a sample collection tip
configured for being placed within the mouth, and a conduit in
fluid communication with the sample collection tips. The sample
collection tip comprises a hydrophobic interior and a hydrophilic
outer surface. In this manner, the tendency of analytes within the
sample to stick to the interior of the sample collection tip is
minimized, while allowing wetting of the outer surface of the
sample collection tip with the sample to facilitate its
collection.
[0035] In a non-limiting preferred embodiment, the sample
collection assembly can further include a hand piece that has a tip
on which the sample collection tip is mounted, and through which
the conduit can extend. The sample collection tip can have a bore
in which the conduit is disposed, e.g., by bonding. The hydrophobic
interior of the sample collection tip can be composed of a
microporous material, such as high density polyethylene, and the
hydrophobic outer surface of the sample collection can comprise a
surfactant. The sample collection tip can have any suitable shape,
e.g., hemi-dome shaped.
[0036] In accordance with a second aspect of the present
inventions, a sample collection assembly comprises a sample
collection tip configured for being placed within the mouth, and a
conduit in fluid communication with the sample collection tips. The
sample collection tip comprises a hydrophobic body and a
hydrophilic surfactant disposed on an outer surface of the
hydrophobic body. In a non-limiting preferred embodiment, the
afore-described features can be incorporated into the sample
collection assembly.
[0037] In accordance with a third aspect of the present invention,
a sample collection assembly comprises a sample collection tip
configured for being placed within the mouth, a sample collection
chamber, a conduit in fluid communication with between the sample
collection tip and the sample collection chamber, and a pump
configured to pump sample from the sample collection tip, through
the conduit, and into the sample collection chamber. The sample
collection tip comprises a hydrophobic interior and a hydrophilic
outer surface, which facilitates the wetting of the entire outer
surface of the sample collection tip, thereby facilitating pumping
of the sample. In a non-limiting preferred embodiment, the
afore-described features can be incorporated into the sample
collection assembly. Additionally, the pump can use relatively low
air flow rates, e.g., between 5-50 ml/min at 350 mmHg absolute, to
pump the sample.
METHOD FOR ACCURATELY MIXING SAMPLE AND BUFFER SOLUTIONS
[0038] The present inventions are also directed to methods for
accurately mixing two solutions, e.g., buffer and sample
solutions.
[0039] In accordance with an aspect of the present inventions, a
method of mixing first and second fluids using first, second, and
third chambers comprises selecting a fluid mixture r, providing the
first chamber with a first cross-sectional area A.sub.1, providing
the third chamber with a second cross-sectional area A.sub.2,
disposing the first fluid in the first chamber, disposing the
second fluid in the second chamber, moving a first plunger within
the first chamber at a speed S.sub.1 towards a first port to
dispense the first solution from the first chamber into the third
chamber, and moving a second plunger substantially simultaneously
with the first plunger within the third chamber at a speed S.sub.2
away from the second port to dispense the second solution from the
second chamber into the third chamber, wherein
A.sub.2S.sub.2=A.sub.1S.sub.1(1+1/r).
[0040] In a non-limiting preferred method, the sample and buffer
can be mixed, in which case, the first, second, and third chambers
can be buffer, sample collection, and mixing chambers, and the
first and second ports can be buffer and sample ports. The sample
and buffer can be equally mixed, in which case, r=1. To effect
equal mixing of the sample and buffer, S.sub.1.congruent.S.sub.2
and 2A.sub.1.congruent.A.sub.2, or alternatively,
A.sub.1.congruent.A.sub.2 and 2S.sub.1.congruent.S.sub.2 The mixing
chamber can include a dispense port, in which case, the preferred
method can further moving a third plunger, such as buffered sample
dispense plunger, towards the dispense port to dispense the fluid
mixture from the mixing chamber out through the dispense port,
e.g., by pushing it with the buffer dispense plunger. The buffered
sample dispense plunger can also be moved within the mixing chamber
against the buffer port, e.g., by pushing it with the sample
dispense plunger.
[0041] The buffer port may include a seal, in which case, the
buffered sample dispense plunger can include a stylus that breaks
the seal when the buffered sample dispense plunger is seated
against the buffer port. When the sample dispense plunger is mated
with the buffered sample dispense plunger, it can be adjacent the
sample port, allowing the sample to flow through the sample port
immediately upon movement of the sample dispense plunger. The
buffered sample dispense plunger can include a through port, in
which case, the buffer can be dispensed from the buffer chamber
into the mixing chamber via the through port. The buffered sample
solution can be mixed within the mixing chamber simply through the
dispensing process, or additionally by a mixing motor. The
preferred method can be automated by mechanically coupling one or
more drive assemblies to the sample and buffer dispense
plungers.
FLOW IMMUNOASSAY ASSEMBLY WITH ROTARY VALVE
[0042] The present inventions are also directed methods and
assemblies for selectively distributing and dispensing fluids using
a rotary valve for purposes such as performing immunoassay
testing.
[0043] In accordance with a first aspect of the present invention,
a rotary valve comprises a stator and rotor disposed within the
stator. The rotor is clockable between a dispense configuration, a
first auxiliary dispense configuration, and a second auxiliary
dispense configuration. When the rotor is clocked in the dispense
configuration, it comprises a plurality of dispense channels
connected between a plurality of entry dispense ports and a
plurality of exit dispense ports disposed in the stator. When the
rotor is clocked in the first auxiliary dispense configuration, the
rotor comprises a first plurality of auxiliary dispense channels
connected between a plurality of auxiliary entry dispense ports
disposed on the stator and the plurality of exit dispense ports.
When the rotor is clocked in the second auxiliary dispense
configuration, the rotor comprises a second plurality of auxiliary
dispense channels connected between the plurality of entry dispense
ports and the plurality of exit dispense ports. In this manner, a
fluid can be flowed through the rotary valve when the rotor is
clocked in the dispense configuration, and another fluid can be
flowed through the rotary valve when the rotor is clocked in either
the first auxiliary or the second auxiliary dispense
configuration.
[0044] In a non-limiting preferred method, the dispense
configuration can be clocked substantially 90.degree. from the
first auxiliary dispense configuration and substantially 0.degree.
from the second auxiliary dispense configuration, i.e., the
dispense configuration and second auxiliary dispense configuration
are the same, so that a first and second fluid can be flowed
through the rotary valve without requiring rotation of the rotor.
The plurality of exit dispense ports can be clocked substantially
180.degree. from the plurality of entry dispense ports and
substantially 90.degree. from the plurality of auxiliary entry
dispense ports. In this case, the plurality of dispense channels
can comprise a plurality of through channels connecting the
plurality of entry dispense ports and the plurality of exit
dispense ports. The first plurality of auxiliary dispense channels
can comprise a plurality of through channels connected to the
plurality of auxiliary entry dispense ports, and a plurality of
substantially 90.degree. arcuate surface channels connected between
the plurality of through channels and plurality of exit dispense
ports. The second plurality of auxiliary dispense channels can
comprise a plurality of substantially 90.degree. arcuate surface
channels connected between the plurality of auxiliary entry
dispense ports and the plurality of exit dispense ports.
[0045] In accordance with a second aspect of the present
inventions, a rotary valve comprises a stator and a rotor disposed
within the stator. The rotor is clockable in a distribution
configuration, in which case, the rotor comprises a feed channel
connecting a feed port to an entry distribution port of a first
distribution port pair disposed on the stator. The rotor further
comprises a plurality of distribution channels connecting an exit
distribution port of each previous distribution port pair to an
entry distribution port of each next distribution port pair. In
this manner, fluid can be distributed amongst several chambers
through a single feed port.
[0046] In a non-limiting preferred embodiment, the feed port can be
clocked substantially 90.degree. from the first distribution port
pair, in which case, the feed channel comprises a through channel
connected to the feed port, and a substantially 90.degree. arcuate
feed surface channel connected between the through channel and the
entry distribution port of the first distribution port pair. The
distribution channels can be a plurality of longitudinal surface
channels that connect a rectilinear pattern of distribution port
pairs. The rotor can further include a vent channel that connects
an exit distribution port of the last distribution port pair with a
vent port disposed on the stator. The vent port can be clocked
substantially 180.degree. from the last distribution port pair, in
which case, the vent channel can comprise a first substantially
90.degree. arcuate vent surface channel connected to the exit
distribution port of the last distribution port pair, a second
substantially 90.degree. arcuate vent surface channel connected to
the vent port, and a through channel connecting the first and
second arcuate vent channels.
[0047] The rotor can further be clocked between the dispense
configuration, first auxiliary dispense configuration, and second
auxiliary configuration, as hereinbefore described. In this case,
the dispense configuration may be clocked 90.degree. from the
distribution configuration, the first auxiliary dispense
configuration and the distribution configuration may be clocked
substantially 0.degree. from each other, and the second auxiliary
dispense configuration and dispense configuration may be clocked
substantially 0.degree. from each other. Thus, the first auxiliary
dispense configuration and the distribution configuration can be
the same, so that a fluid can be distributed amongst several
chambers and another fluid can be dispensed without rotating the
rotor, and the second auxiliary dispense configuration and dispense
configuration can be the same, so that the both fluids can be
dispensed without rotating the rotor.
[0048] In accordance with a third aspect of the present inventions,
a flow immunoassay assembly for testing a sample comprises a
plurality of sample distribution chambers, a plurality of buffer
chambers, and a plurality of immunoassay reaction chambers. The
flow immunoassay assembly further comprises a stator and a rotor
disposed within the stator. That stator includes a plurality of
entry dispense ports in fluid communication with the plurality of
sample distribution chambers, a plurality of auxiliary entry
dispense ports in fluid communication with the plurality of buffer
chambers, and a plurality of exit dispense ports in fluid
communication with the plurality of immunoassay reaction chambers.
The rotor is clockable between a dispense configuration and a first
auxiliary dispense configuration.
[0049] When the rotor is clocked in the dispense configuration, it
comprises a plurality of dispense channels connected between a
plurality of entry dispense ports (and thus, the plurality of
sample distribution chambers) and the plurality of exit dispense
ports (and thus, the plurality of immunoassay reaction chambers).
When the rotor is clocked in the first auxiliary dispense
configuration, the rotor comprises a first plurality of auxiliary
dispense channels connected between the plurality of auxiliary
entry dispense ports (and thus, the plurality of buffer chambers)
and the plurality of exit dispense ports (and thus, the immunoassay
reaction chambers). In this manner, sample can be flowed from the
plurality of sample distribution chambers, through the rotary
valve, and into the plurality of immunoassay reaction chambers,
when the rotor is clocked in the dispense configuration, and buffer
can be flowed from the plurality of buffer chambers, through the
rotary valve, and into the plurality of immunoassay reaction
chambers, when the rotor is clocked in the first auxiliary dispense
configuration.
[0050] In a non-limiting preferred embodiment, the rotor can be
further clocked in a second auxiliary dispense configuration, in
which case, the rotor comprises a second plurality of auxiliary
dispense channels connected between the plurality of auxiliary
entry dispense ports (and thus, the plurality of buffer chambers)
and the plurality of exit dispense ports (and thus, the immunoassay
reaction chambers). The different configurations and ports and be
clocked in relation to each other in a manner similar to that
hereinbefore described, so that a buffer flow can be performed, a
sample flow can be performed after clocking the rotor 90.degree.,
and then another buffer flow can be performed without clocking the
rotor.
[0051] In accordance with a fourth aspect of the present
inventions, a method of controlling the flow of a sample within a
flow immunoassay assembly having a rotary valve, comprises flowing
buffer from a plurality of buffer chambers through the plurality of
immunoassay reaction chambers while the rotary valve is in a first
auxiliary dispense configuration, and flowing the sample from a
plurality of sample distribution chambers through the plurality of
immunoassay reaction chambers while the rotary valve is in a
dispense configuration. In a non-limiting preferred method, the
dispense configuration comprises a sample flow configuration, and
the first auxiliary dispense configuration comprises a buffer
pre-wash configuration, in which case, the plurality of immunoassay
reaction chambers is pre-washed with the buffer while the rotary
valve is in the buffer pre-wash configuration. The buffer can also
be flowed from the plurality of buffer chambers through the
plurality of immunoassay reaction chambers while the rotary valve
is in a second auxiliary dispense configuration, e.g., a buffer
post-wash configuration.
[0052] In accordance with a fifth aspect of the present invention,
a flow immunoassay assembly comprises a plurality of sample
distribution chambers and a plurality of immunoassay reaction
chambers. The flow immunoassay assembly further comprises a stator
and a rotor disposed within the stator. The stator comprises a feed
port, and plurality of distribution port pairs in fluid
communication with the plurality of sample distribution chambers,
with each of the distribution port pairs comprises an entry
distribution port and an exit distribution port. The stator further
comprises a plurality of exit dispense ports in fluid communication
with the plurality of immunoassay reaction chambers. The rotor is
clockable in a distribution configuration, in which case, the rotor
comprises a feed channel connecting the feed port to an entry
distribution port of a first distribution port pair (and thus, the
first sample distribution chamber), and a plurality of distribution
channels connecting an exit distribution port of each previous
distribution port pair (and thus, the previous sample distribution
chamber) to an entry distribution port of each next distribution
port pair (and thus, the next sample distribution chambers).
[0053] In a non-limiting preferred embodiment, the stator may
comprise a vent port, and the rotor may comprise a vent channel
connecting an exit distribution port of the last distribution port
pair (and thus, the last sample distribution chambers). To provide
for sample and buffer flows, the rotor can further be clocked
between the dispense configuration, first auxiliary dispense
configuration, and second auxiliary configuration, as hereinbefore
described. Also, the different configurations and ports can be
clocked in relation to each other in a manner similar to that
hereinbefore described, so that the sample can be distribution to
the sample distribution chambers, the buffer can be flowed through
the immunoassay reaction chambers, the sample can be flowed from
the sample distribution chambers through the immunoassay reaction
chambers after clocking the rotor 90.degree., and the buffer can be
again flowed from the buffer chambers through the immunoassay
reaction chambers.
[0054] In accordance with an eighth aspect of the present
inventions, a method of controlling the flow of sample within a
flow immunoassay assembly comprises placing a rotary valve in a
distribution configuration, and flowing sample from a sample feed
port into a plurality of sample distribution chambers while the
rotary valve is in the distribution configuration. In a
non-limiting preferred method, the sample can be cascaded into the
plurality of sample distribution chambers. Air can further be
vented from the plurality of sample distribution chambers via the
rotary valve during the sample distribution. The sample can also be
prevented from flowing through a plurality of immunoassay reaction
chambers when the rotary valve is in the distribution configuration
to prevent premature dispensing of the sample. The rotary valve can
also be placed into dispense, first auxiliary dispense, and second
auxiliary dispense configuration, e.g., sample dispense, buffer
pre-wash, and buffer post-wash configurations, to effect the
aforementioned sample and buffer flows through the plurality of
immunoassay reaction chambers. The distribution and first auxiliary
dispense configurations can be clocked substantially 0.degree. from
each other, so that the sample distribution and buffer pre-wash can
be performed without rotating the rotor. Similarly, the dispense
and second auxiliary dispense configuration can be clocked
substantially 0.degree. from each, so that the sample dispense and
buffer post-wash can be performed without rotating the rotor.
[0055] In accordance with a seventh aspect of the present
inventions, a flow immunoassay assembly comprises a plurality of
sample distribution chambers, a plurality of immunoassay reaction
chambers, and a rotary valve clockable between a distribution
configuration to place a sample feed port in fluid communication
with the plurality of sample distribution chambers, and a dispense
configuration to place the plurality of sample distribution
chambers in fluid communication with the plurality of immunoassay
reaction chambers. In a non-limiting preferred embodiment, the flow
immunoassay assembly can further comprise a plurality of buffer
chambers, in which case, the rotary valve can be clockable in a
first auxiliary dispense configuration to place the plurality of
buffer chambers into fluid communication with the plurality of
immunoassay reaction chambers, and a second auxiliary dispense
configuration to further place the plurality of buffer chambers
into fluid communication with the plurality of immunoassay reaction
chambers. The rotary valve can be clocked in the distribution
configuration to further prevent fluid communication between the
plurality of distribution chambers and the plurality of immunoassay
reaction chambers, and in the dispense configuration to further
prevent fluid communication between the sample feed ort and the
plurality of sample distribution chambers.
[0056] In accordance with an eighth aspect of the present
inventions, a flow immunoassay assembly comprises a plurality of
sample distribution chambers, a plurality of buffer chambers, a
plurality of immunoassay reaction chambers, and a rotary valve
clockable between a dispense configuration to place the plurality
of sample distribution chambers into fluid communication with the
plurality of immunoassay reaction chambers, and a different first
auxiliary dispense configuration to place the plurality of buffer
chambers into fluid communication with the plurality of immunoassay
reaction chambers. In a non-limiting preferred embodiment, the
rotary valve can be placed into a second auxiliary dispense
configuration to further place the plurality of buffer chambers in
fluid communication with the plurality of immunoassay reaction
chambers.
METHOD OF MANUFACTURING A SELF-SEALING CHAMBER
[0057] The present inventions are also directed to methods for
manufacturing self sealing chambers by interference fitting
barriers within the chambers.
[0058] In accordance with a first aspect of the present inventions,
a method of substantially sealing a chamber, comprises providing a
die plate through which a channel extends and a compression plate
through which a tapered channel extends. The tapered channel
includes a first opening and a second opening opposite the first
opening. The second opening is equal to or smaller than the chamber
opening. The method further comprises providing a chamber adapter
that has a female portion and a passage extending therethrough The
method further comprises mating the chamber adapter female portion
with a compression plate male portion, and associating the chamber
with the chamber adapter passage, e.g., by disposing the chamber
within the chamber adapter passage. The method further comprises
disposing a compressible material on the die plate and forming the
barrier by pushing a pin through the compressible material into the
die plate passage. The method further comprises pushing the barrier
into the first tapered channel opening, through the tapered channel
and into the chamber adapter passage via the second tapered channel
opening. Lastly, the method further comprises pushing the barrier
through the chamber adapter passage into the chamber opening.
[0059] In a non-limiting preferred method, the barrier is pushed
through the compression plate tapered channel and chamber adapter
passage using the pin. The passages through which the barrier
passes are preferably geometrically similar, e.g., circular. In the
preferred method, the barrier can be composed of a porous material,
suitable for constructing an immunoassay reaction chamber. These
steps can be repeated to dispose another barrier within an opening
located at the other end of the chamber.
[0060] In accordance with a second aspect of the present
inventions, a method of substantially sealing a chamber comprises
providing a barrier having an uncompressed size larger than an
opening at one of the chamber. The method further comprises
providing a tool through which a tapered passage extends. The
tapered passage includes a first opening and a second opening
opposite the first opening. The second opening is equal to or
smaller than the chamber opening. The method further comprises
associating the chamber opening with the second tapered passage
opening, introducing the barrier into the first tapered passage
opening, and passing the barrier through the tapered passage, and
into the chamber opening via the second tapered passage opening. In
this manner, a barrier within an uncompressed diameter greater than
the chamber opening can be placed therein and allowed to expand
into a compression fit with the chamber. In a non-limiting
preferred method, the afore-described details can be incorporated
therein.
[0061] In accordance with a third aspect of the present inventions,
a method of manufacturing an immunoassay reaction chamber comprises
providing a hollow column with a channel, interference fitting a
first porous frit within the column channel, disposing reagent
within the column channel, and interference fitting a second porous
frit within the column channel, wherein the reagent is contained
between the first and second frits. In a non-limiting preferred
method, each of the frits has an uncompressed size that is larger
than the column channel, and each frit is interference fit within
the column channel by disposing the frit within the column channel
in a compressed stated, and allowing the frit to expand to generate
a compressive force between it and the column channel. Preferably,
the compressive force generated by the frit and the column channel
is sufficient to hold the frit in place when fluid is flowed
through the column channel. Each frit can be disposed within the
column in a compressed state by associating the column channel with
a tapered passage having a first opening and a second opening equal
to or smaller than the column channel. The frit can then be pushed
into the first tapered passage opening, through the tapered passage
and into the column channel via the second tapered passage opening.
The column channel can be cylindrical, in which case, the first and
second frits will be circular.
[0062] In accordance with a fourth aspect of the present
inventions, an immunoassay reaction chamber comprises a hollow
column with a channel, a first and second porous frits interference
fit within the column channel, and reagent contained within the
column channel between the first and second frits. In a
non-limiting preferred embodiment, each of the frits has an
uncompressed size larger than the column channel, in which case,
each frit can be interference fit within the column channel by a
compressive force between each frit and the column channel. The
column channel can be cylindrical, in which case, the first and
second frits will be circular.
ROTARY VALVE WITH COMPLIANT LINING
[0063] The present inventions are also directed to rotary valves
that provide a rotor with a compliant lining.
[0064] In accordance with a first aspect of the present inventions,
a rotary valve comprises a rigid hollow stator and a rotor disposed
within the stator. The rotor comprises a rigid core and a compliant
lining injection molded onto the rigid core, wherein the compliant
lining is sealingly engaged with an inner bearing surface of the
stator and comprises one or more surface channels that can be
placed into fluid communication with one or more ports disposed on
the stator. In a non-limiting preferred embodiment, the rigid core
is composed of polycarbonate and the compliant lining is composed
of polyurethane. The surface channels can be, e.g., arcuate or
longitudinal surface channels. The rigid core can comprise one or
more through channels, in which case, the one or more surface
channels can intersect the one or more through channels to form a
continuous channel.
[0065] In accordance with a second aspect of the present
inventions, a rotor for a rotary valve comprises a rigid core and a
compliant lining injection molded onto the rigid core, wherein the
compliant lining comprises one or more surface channels. In a
non-limiting preferred embodiment, the previously mentioned
detailed features can be incorporated into the rotor.
[0066] In accordance with a third aspect of the present inventions,
a rotary valve comprises a rigid hollow stator and a rotor disposed
within the stator. The rotor comprises a rigid core including a
ridge and a compliant lining injection molded onto the ridge to
form a surface channel. The compliant lining is sealingly engaged
with an inner bearing surface of the stator, and the surface
channel can be placed into fluid communication with the flow
port.
[0067] In a non-limiting preferred embodiment, the rigid core can
comprise a plurality of equidistant arcuate ridges, in which case,
the compliant lining can be injection molded onto the plurality of
arcuate ridges to form a plurality of arcuate surface channels that
can be placed into fluid communication with a plurality of flow
ports disposed on the stator. The rigid core can also comprise a
longitudinal ridge that intersects the plurality of arcuate ridges,
in which case, the compliant lining can be injection molded onto
the longitudinal ridge to form a longitudinal surface channel that
can be placed into fluid communication with another flow port
disposed on the stator, or even a plurality of longitudinal surface
channels that can be placed into fluid communication with another
plurality of flow ports disposed on the stator.
[0068] Each ridge can have a pair of opposing lateral surfaces and
an adjacent circumferential surface. The compliant lining can be
injection molded onto the opposing lateral surfaces of the ridge,
while leaving the circumferential surface of the ridge exposed, to
form the surface channel. The compliant lining can also have a
surface channel stop, in which case, the ridge has another pair of
opposing lateral surfaces and another adjacent circumferential
surface. The compliant lining can be can be injection molded onto
the other opposing lateral surface and the other adjacent
circumferential surface of the ride to form the surface channel
stop.
[0069] In accordance with a fourth aspect of the present
inventions, a rotor for rotary valve comprises a rigid core
including a ridge, and a compliant lining injection molded onto the
ridge to form a surface channels. In a non-limiting preferred
embodiment, the previously mentioned detailed features can be
incorporated into the rotor.
FLOW IMMUNOASSAY ASSEMBLY WITH MULTIPLE FLOW CHANNELS
[0070] The present inventions are also directed to methods and
assemblies for flowing a single sample through a plurality of
immunoassay reaction chambers.
[0071] In accordance with a first aspect of the present inventions,
a flow immunoassay assembly for testing a single sample, comprises
a sample feed port, a plurality of immunoassay reaction chambers
for performing a plurality of different assays on the sample, a
plurality of sample flow channels in fluid communication between
the sample feed port and the plurality of immunoassay reaction
chambers, and one or more sample drive assemblies configured to
pump the sample through the plurality of sample flow channels into
the plurality of immunoassay reaction chambers. In this manner,
several immunoassay tests can be simultaneously performed on the
sample.
[0072] In a non-limiting preferred embodiment, the flow immunoassay
assembly can further comprise a plurality of buffer flow channels
in fluid communication with the plurality of immunoassay reaction
chambers, and one or more buffer drive assemblies configured to
pump the buffer through the plurality of buffer flow channels into
the plurality of immunoassay reaction chambers. The preferred flow
immunoassay assembly can further comprise a plurality of sample
distribution chambers configured to receive the sample from the
sample feed port, and a plurality of buffer chambers containing the
buffer. The preferred flow immunoassay assembly can further
comprise a plurality of sample dispense plungers disposed within
the plurality of sample distribution chambers, and a plurality of
buffer dispense plungers disposed within the plurality of buffer
chambers, in which case, the one or more sample drive assemblies
can have a plurality of sample dispense plunger drivers that are
configured to move the plurality of sample dispense plungers within
the plurality of sample distribution chambers to pump the sample,
and the one or more buffer drive assemblies can have a plurality of
buffer dispense plunger drivers that are configured to move the
plurality of buffer dispense plungers within the plurality of
buffer chambers to pump the buffer.
[0073] A valve, such as a rotary valve, can be used to selectively
place the sample feed port in fluid communication with the
plurality of sample distribution chambers, for selectively placing
the plurality of distribution chambers in fluid communication with
the plurality of immunoassay reaction chambers, and for selectively
placing the plurality of buffer chambers in fluid communication
with the plurality of immunoassay reaction chambers. The number of
sample flow channels and buffer flow channels can be, e.g. five or
more.
[0074] In accordance with a second aspect of the present
inventions, a method of analyzing a single sample comprises pumping
sample from a sample feed port into a plurality of sample
distribution chambers, and pumping the sample from the sample
distribution chambers through a plurality of immunoassay reaction
chambers for performing a plurality of different assays on the
sample, and measuring a reaction occurring in the plurality of
immunoassay reaction chambers. In a non-limiting preferred method,
a plurality of analyte detectable sample solutions are produced
within the plurality of immunoassay reaction chambers, in which
case, the reactions can be measured by flowing the plurality of
analyte detectable sample solutions through a plurality of read
cells, and measuring a plurality of analyte indicators, e.g.,
different labeled antigen, in the plurality of analyte detectable
sample solutions. The preferred method further comprises pumping
buffer from a plurality of buffer chambers through the plurality of
immunoassay reaction chambers.
[0075] In accordance with a third aspect of the present inventions,
a flow immunoassay assembly for testing a single sample, comprises
a sample feed port, a first plurality of immunoassay reaction
chambers, a first plurality of sample flow channels in fluid
communication with the first plurality of reaction chambers, and a
first sample drive assembly configured to pump the sample through
the first plurality of sample flow channels into the first
plurality of immunoassay reaction chambers. The flow immunoassay
assembly further comprises a second plurality of immunoassay
reaction chambers, a second plurality of sample flow channels in
fluid communication with the second plurality of reaction chambers,
and a second sample drive assembly configured to pump the sample
through the second plurality of sample flow channels into the
second plurality of immunoassay reaction chambers. In this manner,
the sample flow rate and volume can be independently controlled
through the first and second pluralities of sample flow
channels.
[0076] In a non-limiting preferred embodiment, the flow immunoassay
assembly can further include a first plurality of buffer flow
channels in fluid communication with the first plurality of
reaction chambers, and a first buffer drive assembly configured to
pump the buffer through the first plurality of buffer flow channels
into the first plurality of immunoassay reaction chambers. The
preferred flow immunoassay assembly can further include a second
plurality of buffer flow channels in fluid communication with the
second plurality of reaction chambers, and a second buffer drive
assembly configured to pump the buffer through the second plurality
of buffer flow channels into the second plurality of immunoassay
reaction chambers. In this manner, the buffer flow rate and volume
can be independently controlled through the first and second
pluralities of buffer flow channels. The preferred flow immunoassay
assembly can further include many of the other features described
above, such sample distribution chambers, buffer chambers, read
cells, sample dispense plungers, sample dispense plunger drivers,
buffer dispense plungers, and buffer dispense plunger drivers.
[0077] In accordance with a fourth aspect of the present
inventions, a method of analyzing a sample comprises pumping sample
through a first plurality of immunoassay reaction chambers using a
first sample drive assembly, pumping the sample through a second
plurality of immunoassay reaction chambers using a second sample
drive assembly, and measuring a reaction within each of the first
and second pluralities of immunoassay reaction chambers.
[0078] In a non-limiting preferred method, a first plurality of
analyte detectable sample solutions can be produced within the
first plurality of immunoassay reaction chambers, and a second
plurality of result solutions can be produced within the second
plurality of immunoassay reaction chambers, in which case, the
reactions can be measured by flowing the first and second
pluralities of analyte detectable sample solutions through first
and second pluralities of read cells, and measuring first and
second pluralities of analyte indicators, e.g., different labeled
antigen, in the first and second pluralities of analyte detectable
sample solutions. The sample can be pumped through the first and
second pluralities of immunoassay reaction chambers at
substantially different rates and/or different quantities. The
preferred method may further comprise pumping buffer through the
first plurality of immunoassay reaction chambers using a first
buffer drive assembly, and pumping buffer through the second
plurality of immunoassay reaction chambers using a second buffer
drive assembly.
IMMUNOASSAY CHEMISTRY CASSETTE BARCODE FOR SYSTEM CUSTOMIZATION
[0079] The present inventions are also directed to assemblies,
systems, and methods for using a chemistry cassette barcode to
obtain information associated with the cassette.
[0080] In accordance with a first aspect of the present inventions,
a barcode assembly for use with an analyte testing system comprises
a barcode affixed to the chemistry cassette, and the barcode
assembly further comprises a barcode reader mounted within a test
console of an analyte testing system. The barcode comprises
information associated with the chemistry cassette, and the barcode
reader is configured for scanning the barcode when the chemistry
cassette is received within the test console. In the non-limiting
preferred embodiment, the barcode information can indicate a test
panel contained within the chemistry cassette, e.g., the NIDA
drugs-of-abuse test panel, a date of manufacture of the chemistry
cassette, test calibration information, and/or information
indicating whether the chemistry cassette has been previously used,
e.g., a checksum code.
[0081] In accordance with a second aspect of the present
inventions, a method of obtaining information within an analyte
testing system comprises receiving a chemistry cassette within a
test console, and scanning a barcode containing information
associated with the chemistry cassette. In the non-limiting
preferred method, the barcode information can indicate the
previously described parameters of the system. The preferred method
may further comprise preventing the chemistry cassette from being
used within the test console if the barcode information indicates
that the chemistry cassette has been previously used.
[0082] In accordance with a third aspect of the present inventions,
a self-customizing analyte testing system comprises a test console,
a chemistry cassette receivable within the test console, a barcode
affixed to the chemistry cassette, a barcode reader configured for
scanning the barcode, and circuitry electrically coupled to the
barcode reader for modifying one or more operational parameters of
the testing system based on information contained in the
barcode.
[0083] In a non-limiting preferred embodiment, the barcode reader
and circuitry, which can be a CPU, can be contained in the test
console, and the barcode reader can be configured to scan the
barcode while the chemistry cassette is received within the test
console. The circuitry can be configured to modify one or more
testing parameters for each analyte of a multi-analyte test panel.
For example, if the barcode information comprises test calibration
information, the circuitry can be configured to calibrate the test
panel using the test calibration information. If the testing system
comprises a flow immunoassay assembly, the circuitry can be
configured to modify each of the plurality of flow channels, e.g.,
by modifying the flow volume or flow rate.
[0084] In accordance with a fourth aspect of the present
inventions, a method of customizing an analyte testing system
comprises receiving a chemistry cassette within a test console,
scanning a barcode containing information associated with the
chemistry cassette, and modifying one or more operational
parameters based on the barcode information. In a non-limiting
preferred method, the testing system can be customized by modifying
one or more testing parameters for each analyte of a multi-analyte
test panel as previously described. For example, a test panel can
be calibrating using test calibration information obtained from the
barcode, or a plurality of flow channels within a flow immunoassay
assembly can be modified.
[0085] In accordance with a fifth aspect of the present inventions,
a self-customizing multi-analyte flow immunoassay testing system
comprises a flow immunoassay assembly, a barcode comprising
information associated with the flow immunoassay assembly, a
barcode reader configured for scanning the barcode, and control
circuitry electrically coupled to the barcode reader. The flow
immunoassay assembly comprises a plurality of flow channels
corresponding to a plurality of analytes to be tested, and the
control circuitry is configured to modify one or more flow channel
parameters for each of the plurality of flow channels, based on the
barcode information. In the non-limiting preferred embodiment, the
control circuitry comprises a CPU that is configured for modifying
the flow rate and/or volume of the flow channels.
[0086] In accordance with a sixth aspect of the present inventions,
a method of customizing a multi-analyte flow immunoassay testing
system comprises scanning a barcode comprising information
associated with the flow immunoassay assembly, and modifying one or
more flow channel parameters for each of a plurality of flow
channels based on the barcode information. In a non-limiting
preferred method, the flow rate and/or flow volume of the flow
channels are modified.
DRUG AND ALCOHOL ASSAY ASSEMBLY
[0087] The present inventions are also directed to assemblies and
methods for performing an assay on a sample for drugs and
alcohol.
[0088] In accordance with a first aspect of the present inventions,
a drug and alcohol assay assembly comprises a sample feed port, and
immunoassay reaction chamber containing a drug reagent, and a first
sample flow channel in fluid communication between the sample feed
port and the immunoassay reaction chamber. The assembly further
comprises an alcohol reaction chamber configured for containing an
alcohol reagent, and a second sample flow channel in fluid
communication between the sample feed port and the alcohol reaction
chamber.
[0089] In a non-limiting preferred embodiment, the assembly can
further comprise a first buffer flow channel in fluid communication
with the immunoassay reaction chamber, a second buffer flow channel
in fluid communication with the alcohol reaction chamber, and a
reagent chamber disposed within the buffer flow channel. The
reagent chamber can contain dry alcohol reagent. In this case, the
alcohol reagent can comprise a reagent solution, where the reagent
chamber is configured to produce the reagent solution for
dispensing in the alcohol reaction chamber when buffer flows
through the buffer flow channel. The drug reagent can be specific
to one of the NIDA drugs-of-abuse.
[0090] In accordance with a second aspect of the present
inventions, a drug and alcohol assay assembly comprises an
immunoassay reaction chamber containing a drug reagent, a first
sample chamber in fluid communication with the immunoassay reaction
chamber, and being configured for containing sample, an alcohol
reaction chamber configured for containing an alcohol reagent, and
a second sample chamber in fluid communication with the immunoassay
reaction chamber, and being configured for containing the
sample.
[0091] In a non-limiting preferred embodiment, the assembly can
further comprises a sample feed port in fluid communication with
the first and second sample chamber. The preferred assembly can
further comprise a sample dispense plunger disposed within the
first sample chamber, and can be movable to dispense the sample
from the first sample chamber into the immunoassay reaction
chamber. The preferred assembly can further comprise an air flow
port in communication with the second sample chamber, and can be
configured to dispense the sample from the second sample chamber
into the alcohol reaction chamber when air is flowed through the
air flow port. The preferred assembly can further comprise a valve
for selectively placing the first sample chamber in fluid
communication with the immunoassay reaction chamber, and for
selectively placing the second sample chamber in fluid
communication with the alcohol reaction chamber. The valve can be a
rotary valve, in which case, it can include a stator and a rotor
disposed within the stator, wherein the second sample chamber
comprises a shear valve formed within the rotor.
[0092] The preferred assembly can further comprise a first buffer
chamber that contains buffer and is in fluid communication with the
immunoassay reaction chamber, a second buffer chamber, and a
reagent chamber in fluid communication between the second buffer
chamber and the alcohol reaction chamber. In this case, the
preferred assembly can further comprise a first buffer dispense
plunger movable within the first buffer chamber to dispense buffer
from the first buffer chamber into the immunoassay reaction chamber
to hydrate dry drug reagent therein. The preferred assembly can
further comprise a second a second buffer dispense plunger movable
within the second buffer chamber to dispense the buffer from the
second buffer chamber through the immunoassay reaction chamber to
hydrate dry alcohol reagent therein, wherein a reagent solution is
produced and dispensed into the alcohol reaction chamber.
[0093] In accordance with a third aspect of the present inventions,
a method of performing a drug and alcohol assay, comprises flowing
sample into an immunoassay reaction chamber containing a drug
reagent, reacting the sample and the drug reagent, flowing the
sample into an alcohol reaction chamber containing an alcohol
reagent, and reacting the sample and the alcohol reagent.
[0094] In a non-limiting preferred method, the method can further
comprise flowing a first buffer into the immunoassay reaction
chamber to produce a hydrated drug reagent, flowing a second buffer
through a reagent chamber to produce an alcohol reagent solution,
and flowing the alcohol reagent solution into the alcohol reaction
chamber. The sample and first buffer can be pumped into the
immunoassay reaction chamber, and the sample and second buffer can
be pumped into the alcohol reaction chamber.
[0095] In accordance with a fourth aspect of the present
inventions, a flow immunoassay and alcohol detection assembly
comprises an immunoassay reaction chamber containing a drug
reagent, a first sample chamber in fluid communication with the
immunoassay reaction chamber, a read cell in fluid communication
with the immunoassay reaction chamber, a first energy source
configured to transmit energy through the read cell, and a first
energy detector configured to receive energy from the read cell.
The assembly further comprises an alcohol reaction chamber
configured for containing an alcohol reagent, a second sample
chamber in fluid communication between the sample feed port and the
immunoassay reaction chamber, a second energy source configured to
transmit energy through the alcohol reaction chamber, and a second
energy detector configured to receive energy from the alcohol
reaction chamber. The assembly also comprises processing circuitry
configured for determining a presence of a drug in the sample based
on the energy received by the first energy detector, and configured
for determining a presence of alcohol in the sample based on the
energy received by the second energy detector.
[0096] In a non-limiting preferred embodiment, the afore-described
features can be incorporated into the assembly. The preferred
assembly can further comprise a calibrator chamber in fluid
communication with the alcohol reaction chamber, and a calibrator
dispense plunger movable within the calibrator chamber dispense
calibrator solution having a predetermined quantity of alcohol from
the calibrator chamber into the alcohol reaction chamber to react
with the reagent solution. The first and second energy sources can
be optical sources, and the first and second energy detectors can
be optical detectors.
[0097] In accordance with a fifth aspect of the present inventions,
a method of analyzing a sample comprises flowing the sample through
an immunoassay reaction chamber, wherein the immunoassay reaction
chamber produces a drug detectable sample solution containing a
drug indicator, measuring the drug indicator, and determining a
presence of a drug analyte within the sample based on the measured
drug indicator. The method further comprises flowing the sample
into an alcohol reaction chamber containing an alcohol reagent,
wherein the alcohol reaction chamber produces an alcohol detectable
sample solution containing an alcohol indicator, measuring the
alcohol indicator, and determining a presence of alcohol within the
sample based on the measured alcohol indicator.
[0098] In a non-limiting preferred method, the drug indicator can
emit optical energy when excited, and the alcohol indicator
measuring comprises optically exciting the displaced labeled
antigen to emit optical energy and measuring the emitted optical
energy. The alcohol indicator can exhibit an optical absorbance
value at a specific optical wavelength, wherein the alcohol
indicator measuring comprises transmitting optical energy through
the alcohol detectable sample solution at the specified wavelength,
and measuring the transmitted optical energy after it is
transmitted through the alcohol detectable sample solution. The
preferred method can further comprise flowing a first buffer into
the immunoassay reaction chamber to produce a hydrated drug
reagent, wherein the sample reacts with the hydrated drug reagent
to produce the drug detectable sample solution, flowing a second
buffer through a reagent chamber to produce an alcohol reagent
solution, and flowing the alcohol reagent solution into the alcohol
reaction chamber, wherein the sample reacts with the alcohol
reagent solution to produce the alcohol detectable sample solution.
The method can further comprising flowing a calibrator solution
containing a predetermined quantity of alcohol into said alcohol
reaction chamber to produce an alcohol detectable calibration
solution containing an initial alcohol indicator, measuring the
initial alcohol indicator, and calibrating the alcohol detectable
sample solution.
FLOW IMMUNOASSAY SCANNING ASSEMBLY
[0099] The present inventions are also directed to methods and
assemblies for scanning a flow immunoassay assembly.
[0100] In accordance with a first aspect of the present inventions,
a flow immunoassay scanning assembly comprises a plurality of
immunoassay reaction chambers, a plurality of read cells in fluid
communication with the plurality of immunoassay reaction chambers,
a detector having a sensing beam, and a scanning drive assembly
configured to translate the detector to intersect the plurality of
read cells with the sensing beam. In a non-limiting preferred
embodiment, the detector comprises an optical detector, and each of
the immunoassay reaction chambers contains fluorescent labeled
antigen that is displaced when an analog to the fluorescent labeled
antigen flows through the immunoassay reaction chamber. Thus, the
fluorescent labeled antigen can be detected by the optical detector
when flowed through the corresponding read cell. The detector can
also be configured, such that the sensing beam intersects the
plurality of read cells at an angle substantially perpendicular to
the longitudinal axes of the read cells. The scanning drive
assembly can be configured to translate the detector to repeatedly
intersect the plurality of read cells with the sensing beam.
[0101] In accordance with a second aspect of the present
inventions, a method of testing the presence of a plurality of
target analytes in a sample comprises producing a plurality of
immunoassay flow paths containing the sample, wherein an analyte
indicator is produced in each of the plurality of immunoassay flow
paths in the presence of a corresponding target analyte. The method
further comprises detecting any of the plurality of analyte
indicators in the plurality of immunoassay flow paths by scanning a
sensing beam across the plurality of immunoassay flow paths.
[0102] In a non-limiting preferred method, the sensing beam
comprises an optical sensing beam, and the analyte indicator
comprises a fluorescent labeled antigen. The sensing beam can be
scanned substantially perpendicular to the direction of the flow
paths and repeatedly across the plurality of flow paths. The
preferred method can further comprise outputting a plurality of
signals based on the detection of any analyte indicators within the
plurality of immunoassay flow paths, and processing the output
signals to detect the present of the plurality of target analytes
within the sample. The preferred method can further comprise
detecting a location of each of the plurality of read cells, in
which case, the detected analyte indicator is only processed when a
location of a corresponding one of the plurality of read cells is
detected.
[0103] In accordance with a third aspect of the present inventions,
a flow immunoassay scanning assembly comprises a plurality of
immunoassay reaction chambers, a plurality of read cells in fluid
communication with the plurality of immunoassay reaction chambers,
and a detector having a sensing beam. The flow immunoassay scanning
assembly further comprises a scan head mechanism to which the
detector and transmitter are mounted, and a scanning drive assembly
configured to translate the detector and the transmitter to
intersect the plurality of read cells with the sensing beam and
energy beam.
[0104] In a non-limiting preferred embodiment, the detector can be
an optical detector, and the transmitter can be an optical source,
e.g., a laser, in which case, the analyte indicator can comprise
fluorescent labeled antigen that is exited by the laser beam into
fluorescence. The detector may be configured, such that the sensing
beam intersects the plurality of read cells at an angle
substantially perpendicular to the longitudinal axes of the read
cells, and the transmitter is configured, such that the laser beam
travels through the read cells at an angle substantially parallel
to the longitudinal axes of the read cells. The scanning drive
assembly can be configured to translate the detector and
transmitter to repeatedly intersect the plurality of read cells
with the sensing beam and energy beam. The preferred embodiment may
also comprise a read cell detector fixably coupled to the scan head
mechanism and configured to sense a location of each of the
plurality of read cells, and processing circuitry for processing an
output of the detector only when the read cell detector senses the
location of each of the plurality of read cells. To facilitate
detection of the read cells, read cell indicators, e.g., notches,
can be spaced a distance equal to the distance in which the read
cells are spaced. The scanning drive assembly can further comprise
a rail that extends along the plurality of read cells, and a runner
on which the scan head mechanism is fixably coupled.
[0105] In accordance with a fourth aspect of the present
inventions, a method of detecting the presence of a plurality of
target analytes in a sample comprises producing a plurality of
immunoassay flow paths containing the sample, wherein an analyte
indicator is produced in each of the plurality of immunoassay flow
paths in the presence of a corresponding target analyte, exciting
the plurality of analyte indicators by scanning an energy beam
across the plurality of immunoassay flow paths, and detecting any
of the plurality of excited analyte indicators in the plurality of
immunoassay flow paths by scanning a sensing beam across the
plurality of immunoassay flow paths. In a non-limiting preferred
method, the sensing beam can comprise an optical sensing beam, and
the energy beam can comprise an optical energy beam, such as a
laser beam. The preferred method can further include scanning the
sensing beam substantially perpendicular to the direction of the
flow paths, and the energy beam scanned substantially parallel to
the direction of the flow paths. The preferred method can further
include scanning the sensing and energy beams simultaneously and
repeatedly across the plurality of immunoassay flow paths.
ORTHOGONAL READ ASSEMBLY
[0106] The present inventions are also directed to methods and
assemblies for transmitting and detecting energy within a read
cell.
[0107] In accordance with a first aspect of the present inventions,
an orthogonal read assembly comprises an immunoassay reaction
chamber, a read cell having a lumen in fluid communication with the
immunoassay reaction chamber, a transmitter configured to transmit
energy through the lumen, and a detector configured to sense energy
emitted transversely from the lumen. In a non-limiting preferred
embodiment, the transmitter can comprise an optical transmitter,
such as a laser, and the detector can comprise an optical detector,
e.g., a silicon diode. The optical transmitter can transmit optical
energy at an oblique entry angle to the lumen, e.g., 45.degree.,
and the optical energy can be sensed by the optical detector at an
angle substantially perpendicular to the lumen. The read cell can
be composed of a transparent plastic and can be parallel-pipe
shaped. The lumen can be cylindrically shaped and may include an
optical transmission port, in which case, the optical transmitter
can be configured to transmit the optical energy through the lumen
via the optical transmission port.
[0108] In accordance with a second aspect of the present
inventions, an orthogonal read assembly comprises an immunoassay
reaction chamber containing labeled antigen that is displaced when
an analog to the labeled antigen flows through the immunoassay
reaction chamber, a read cell comprising a lumen in fluid
communication with the immunoassay reaction chamber, a transmitter
configured to transmit energy through the lumen to excite the
labeled antigen to transversely emit energy from the lumen, and a
detector configured to sense the transversely emitted energy from
the labeled antigen. In a non-limiting preferred embodiment, any of
the afore-described detail features can be incorporated into the
orthogonal read assembly.
[0109] In accordance with a third aspect of the present inventions,
a method of sensing an analyte within a sample comprises flowing
the sample through an immunoassay reaction chamber to displace
labeled antigen from the immunoassay reaction chamber, flowing
displaced labeled antigen through a lumen of a read cell,
transmitting energy along the lumen to excite the labeled antigen
into transversely emitting energy from the lumen, and sensing the
transversely emitted energy. In a non-limiting preferred method,
any of the afore-described detailed features can be incorporated
into the steps of the method.
INTEGRAL SAMPLE COLLECTION TIP
[0110] The present inventions are also directed to assemblies for
collecting a sample from a mouth using an integrated sample
collection tip.
[0111] In accordance with a first aspect of the present inventions,
a sample collection assembly comprises a sample collection body
configured for being placed within the mouth, wherein the sample
collection body comprises a bore and one or more pores. The sample
collection assembly further comprises a conduit that disposed
within the bore of the sample collection body and that is in fluid
communication with the one or more pores. In a non-limiting
preferred embodiment, the conduit is bonded within the bore. The
sample collection assembly can further include a hand piece that
has a tip on which the sample collection body is mounted, and
through which the conduit can extend. For example, the rear surface
of the sample collection body can be bonded to the front surface of
the sample collection tip. The one or more pores can comprise a
plurality of micropores. The sample collection body can be
hydrophobic, and a hydrophilic surfactant can be disposed on the
outer surface of the sample collection body.
[0112] In accordance with a second aspect of the present
inventions, a sample collection assembly comprises a sample
collection body configured for being placed within the mouth,
wherein the sample collection body comprises a bore and one or more
pores. The sample collection assembly further comprises a conduit
that bonded within the bore of the sample collection body and that
is in fluid communication with the one or more pores. The adhesive
force between the conduit and the bore is greater than the cohesive
force of the sample collection body. In a non-limiting preferred
embodiment, the sample collection assembly can further include a
hand piece that has a tip on which the sample collection body is
mounted, and through which the conduit can extend. For example, the
rear surface of the sample collection body can be bonded to the
front surface of the sample collection tip. The adhesive force
between the rear surface of the sample collection body and the
front surface of the hand piece tip can be greater than the
cohesive force of the sample collection body. The one or more pores
can comprise a plurality of micropores. The sample collection body
can be hydrophobic, and a hydrophilic surfactant can be disposed on
the outer surface of the sample collection body.
[0113] In accordance with a third aspect of the present invention,
a sample collection assembly comprises a sample collection body
configured for being placed within the mouth, a sample collection
chamber, a conduit in fluid communication with between the sample
collection body and the sample collection chamber, and a pump
configured to pump sample from the sample collection body, through
the conduit, and into the sample collection chamber. The sample
collection body comprises a bore and one or more pores, and the
conduit is bonded within the bore of the sample collection body in
fluid communication with the one or more pores. The adhesive force
between the conduit and the bore is greater than the cohesive force
of the sample collection body. In a non-limiting preferred
embodiment, the afore-described features can be incorporated into
the sample collection assembly.
ALCOHOL DETECTION ASSEMBLY
[0114] The present inventions are also directed to assemblies and
methods for detecting alcohol using a reconstituted reagent
solution.
[0115] In accordance with a first aspect of the present inventions,
an alcohol reaction assembly comprises an alcohol reaction chamber,
a reagent chamber in fluid communication with the alcohol reaction
chamber, and a buffer chamber in fluid communication with the
reagent chamber. The alcohol reaction assembly further includes a
buffer dispense plunger disposed within the buffer chamber for
dispensing buffer from the buffer chamber, through the reagent
chamber, and into the alcohol reaction chamber, where it hydrates
dry reagent therein to produce a reagent solution. The alcohol
reaction assembly further includes a calibrator chamber in fluid
communication with the alcohol reaction chamber, and a calibrator
dispense plunger disposed within the calibrator chamber to dispense
a predetermined quantity of alcohol into the alcohol reaction
chamber. The alcohol reaction assembly also includes a sample
chamber in fluid communication with the alcohol reaction chamber,
and being configured for containing a sample.
[0116] In a non-limiting preferred embodiment, the alcohol reaction
assembly comprises buffer and calibrator drive assemblies can be
mechanically coupled to the buffer and calibrator dispense plungers
to automate them. The components of the alcohol reaction assembly
can also be arranged in a cassette and test console. For example,
the chambers and plungers can be contained with the cassette,
whereas the drive assemblies can be contained within the test
console. In this case, the buffer drive assembly can include a
cassette loading drive assembly that is configured to load the
cassette into the test console, and a buffer driver that is fixed
within the test console and is configured to move the buffer
dispense plunger within the buffer chamber as the cassette is being
loaded into the test console. The alcohol reaction assembly can
further include an air blower and air flow port in communication
with the sample chamber to dispense the sample into the alcohol
reaction chamber when air is pumped through the air flow port from
the air blower. The alcohol reaction assembly can further include a
vent port (which may be the same as the air flow port) in
communication with the alcohol reaction chamber to vent air from
the alcohol reaction chamber when the reagent solution and the
calibrator solution are dispensed within the alcohol reaction
chamber. The alcohol reaction assembly may further include a mixing
drive assembly that is magnetically coupled to a ferrous element
within the alcohol reaction chamber to ensure reactions proceed to
completion within the alcohol reaction chamber.
[0117] In accordance with a second aspect of the present
inventions, an alcohol reaction assembly comprises an alcohol
reaction chamber, a reagent chamber in fluid communication with the
alcohol reaction chamber, and a buffer chamber in fluid
communication with the reagent chamber. The alcohol reaction
assembly further includes a buffer dispense plunger disposed within
the buffer chamber for dispensing buffer from the buffer chamber,
through the reagent chamber, and into the alcohol reaction chamber,
where it hydrates dry reagent therein to produce a reagent
solution.
[0118] In a non-limiting preferred embodiment, the dry reaction in
the reaction chamber comprises lyophilized alcohol dehydrogenase
(ADH) and nicotinamide adenine dinucleotide (NAD). The buffer
chamber can also include a seal that seals the buffer from the
reagent chamber, in which case, the buffer dispense plunger can
include a stylus that is configured to puncture the seal when the
buffer dispense plunger is moved toward the seal. The previously
described features can also be incorporated into the preferred
alcohol reaction assembly.
[0119] In accordance with a third aspect of the present inventions,
an alcohol detection assembly comprises an alcohol reaction
chamber, a reagent chamber in fluid communication with the alcohol
reaction chamber, and a buffer chamber in fluid communication with
the reagent chamber. The alcohol detection assembly further
includes a buffer dispense plunger disposed within the buffer
chamber for dispensing buffer from the buffer chamber, through the
reagent chamber, and into the alcohol reaction chamber, where it
hydrates dry reagent therein to produce a reagent solution. The
alcohol detection assembly further includes a sample chamber in
fluid communication with the alcohol reaction chamber, and is
configured for containing and dispensing a sample into the alcohol
reaction chamber to produce a detectable alcohol sample solution.
The alcohol detection assembly further includes an energy source
that is configured for transmitting an energy beam through the
alcohol reaction chamber, an energy detector configured for
receiving the energy beam from the alcohol reaction chamber and
outputting a signal based on the received energy beam; and
processing circuitry configured for determining the presence of
alcohol within the sample based on the output signal.
[0120] In a non-limiting preferred embodiment, the energy source
can comprise an optical source, e.g., a light emitting diode (LED),
the energy detector can comprise an optical detector, e.g., a
silicon diode detector, and the processing circuitry can comprise a
central processor unit (CPU). The preferred alcohol detection
assembly can further comprise a splitter for splitting energy from
the energy source into the energy beam and a reference energy beam
that bypasses the alcohol reaction chamber, a reference energy
detector for receiving the reference energy beam, and outputting a
reference signal based on the reference energy beam, and a
controller configured for using the reference output signal for
maintaining the magnitude of the energy beam at a substantially
uniform level.
[0121] The preferred alcohol detection assembly can also comprises
a calibrator chamber in fluid communication with the alcohol
reaction chamber, and a calibrator dispense plunger disposed within
the calibrator chamber for dispensing a predetermined quantity of
alcohol from the calibrator chamber into alcohol reaction chamber.
In this case, the energy source can be configured for transmitting
an initial energy beam through the alcohol reaction chamber, energy
detector can be configured for receiving the initial energy beam
from the alcohol reaction chamber, and outputting an initial signal
based on the initial received energy beam, and the processing
circuitry can be configured for calibrating the alcohol detection
assembly based on the initial output signal. Previously described
features can also be incorporated into the preferred alcohol
detection assembly.
[0122] In accordance with a fourth aspect of the present
inventions, a method of detecting the presence of alcohol in a
sample comprises flowing buffer from a buffer chamber through a
reagent chamber to produce and dispense a reagent solution into an
alcohol reaction chamber, and dispensing the sample within the
alcohol reaction chamber to produce an alcohol detectable sample
solution. The method further comprises transmitting energy through
the alcohol detectable sample solution, receiving the energy from
the alcohol detectable sample solution, and determining a presence
of alcohol within the sample based on the received energy.
[0123] In a non-limiting preferred method, the alcohol detectable
sample solution is mixed to complete reaction between the sample
and the reagent solution. The transmitted energy can be optical
energy, in which case, the detectable alcohol sample solution may
comprise an alcohol indicator exhibiting an optical absorbance
value in the presence of the transmitted optical energy, and the
presence of alcohol in the sample can be determined by determining
the optical absorbance value based on the optical energy received.
The alcohol indicator may be nicotinamide adenine dinucleotide with
high energy hydrogen (NADH), in which case, the reagent solution
may comprise alcohol dehydrogenase (ADH) and nicotinamide adenine
dinucleotide (NAD), and detectable alcohol sample solution can be
produced by reacting the NAD and the sample alcohol in the presence
of the ADH to produce the NADH. The optical absorbance value of the
alcohol indicator can be proportional to the quantity of alcohol
reacted with the reagent solution, in which case, the preferred
method may further comprise determining a concentration of the
alcohol in the sample based on the optical absorbance value of the
alcohol indicator. The preferred method may further comprise
calibrating prior to dispensing the sample within the reagent
solution.
[0124] In accordance with a fifth aspect of the present inventions,
a method of detecting the presence of alcohol in a sample comprises
flowing buffer from a buffer chamber through a reagent chamber to
produce and dispense a reagent solution within an alcohol reaction
chamber, and dispensing the sample within the alcohol reaction
chamber to produce an alcohol detectable sample solution having an
alcohol indicator. The method further comprises determining an
optical energy absorbance of the alcohol indicator at a specified
optical wavelength, and determining a presence of the alcohol in
the sample based on the optical energy absorbance measurement.
[0125] In a non-limiting preferred method, the alcohol indicator
can comprise nicotinamide adenine dinucleotide with high energy
hydrogen (NADH), in which case, the reagent solution can comprise
alcohol dehydrogenase (ADH) and nicotinamide adenine dinucleotide
(NAD), which reacts with the sample alcohol to produce the NADH. In
the preferred method, the optical absorbance value of the alcohol
indicator can be proportional to a quantity of alcohol reacted with
the reagent solution, in which case, the concentration of the
alcohol in the sample can be based on the optical absorbance value
of the alcohol indicator. The sample alcohol concentration can be
determined by dispensing a predetermined quantity of alcohol from a
calibrator chamber into the alcohol reaction chamber prior to
dispensing the sample, thereby producing an alcohol detectable
calibrator solution having a known alcohol concentration C, and
measuring a first optical absorbance value A.sub.0 of the reagent
solution. a second optical absorbance value A.sub.1 of the alcohol
detectable calibration solution, and a third optical absorbance
value A.sub.3 of the alcohol detectable sample solution, at the
specific wavelength, wherein the sample alcohol concentration is
determined in accordance with the factor
C(A.sub.2-A.sub.0)/(A.sub.1-A.sub.0). The specified wavelength used
in the preferred method to determine absorbance of the solutions
can be an ultraviolet wavelength, e.g., 365 nm.
BRIEF DESCRIPTION OF THE DRAWINGS
[0126] In order to better appreciate how the above-recited and
other advantages and objects of the present inventions are
obtained, a more particular description of the present inventions
briefly described above will be rendered by reference to specific
embodiments thereof, which are illustrated in the accompanying
drawings. Understanding that these drawings depict only typical
embodiments of the invention and are not therefore to be considered
limiting of its scope, the invention will be described and
explained with additional specificity and detail through the use of
the accompanying drawings in which:
[0127] FIG. 1 is a front-right perspective view of an on-site
analyte testing system constructed in accordance with a preferred
embodiment of the present inventions, wherein the testing system
comprises a portable test console and a loaded single-use
disposable test loaded cassette assembly;
[0128] FIG. 2 is a rear-right perspective view of the cassette
assembly;
[0129] FIG. 3 is a front-right perspective view of the cassette
assembly;
[0130] FIG. 4 is a bottom-left perspective view of the cassette
assembly;
[0131] FIG. 5 is a top perspective view of the cassette
assembly;
[0132] FIG. 6 is a front-left perspective view of the inner
components of the test console with cassette assembly;
[0133] FIG. 7 is a front-right perspective view of the inner
components of the test console with the cassette assembly;
[0134] FIG. 8 is a rear-right perspective view of the inner
components of the test console with the cassette assembly;
[0135] FIG. 9 is a top perspective view of the inner components of
the test console with the cassette assembly;
[0136] FIG. 10 is a bottom-front perspective view of the inner
components of the test console with the cassette assembly;
[0137] FIG. 11 is a bottom-rear perspective view of the inner
components of the test console with the cassette assembly;
[0138] FIG. 12 is a schematic block diagram of various components
of the testing system and their interaction with a central
processor unit (CPU);
[0139] FIG. 13 is a rear-left perspective view of the inner
components of the test console without the cassette assembly,
wherein a cassette carriage is shown fully loaded into the test
console;
[0140] FIG. 14 is a rear-right perspective view of the inner
components of the test console without the cassette assembly,
wherein the cassette carriage is shown fully deployed from the test
console;
[0141] FIG. 15 is a close-up perspective view of a cassette loading
assembly and a rotary valve drive assembly used in the test
console;
[0142] FIG. 16 is a close-up perspective view of the test console
portion of a sample collection assembly, and particularly, a vacuum
port drive assembly;
[0143] FIG. 17 is a perspective view of the cassette portion of the
sample collection assembly associated, and particularly, an oral
aspirator, sample collection chamber, and flexible conduit, wherein
a cover/extended handle is shown used as a cover;
[0144] FIG. 18 is a perspective view of the oral aspirator, sample
collection chamber, and flexible conduit, wherein the
cover/extended handle is shown used as an extended handle;
[0145] FIG. 19 is a longitudinal sectional view of the oral
aspirator;
[0146] FIG. 20 is a perspective view of a bottom chamber base used
to construct the sample collection chamber;
[0147] FIG. 21 is a perspective view of a top chamber cap used to
construct the sample collection chamber;
[0148] FIG. 22 is a cut-away perspective view of the bottom chamber
base;
[0149] FIG. 23 is a cut-away perspective view of the top chamber
cap;
[0150] FIG. 24 is a perspective view of the cassette portion of a
sample mixing assembly;
[0151] FIG. 25 is a perspective view of the buffer chamber and
mixing chamber of the sample mixing assembly;
[0152] FIG. 26 is a cut-away perspective view of the buffer chamber
and mixing chamber;
[0153] FIG. 27 is a cutaway perspective view of the sample mixing
assembly shown in a home position;
[0154] FIG. 28 is a cutaway perspective view of the sample mixing
assembly shown in a pre-sample and buffer dispensing position;
[0155] FIG. 29 is a cutaway perspective view of the sample mixing
assembly shown in a buffered sample solution mixing position;
[0156] FIG. 30 is a cutaway perspective view of the sample mixing
assembly shown in a pre-buffered sample solution dispensing
position;
[0157] FIG. 31 is a cutaway perspective view of the sample mixing
assembly shown in a post-buffered sample solution dispensing
position;
[0158] FIG. 32 is a perspective view of a buffer plunger for use in
the mixing assembly;
[0159] FIG. 33 is a cutaway perspective view of the buffer
plunger;
[0160] FIG. 34 is a perspective view of a sample dispense plunger
for use in the mixing assembly;
[0161] FIG. 35 is a cutaway perspective view of the sample dispense
plunger;
[0162] FIG. 36 is a perspective view of a buffered sample dispense
plunger for use in the mixing assembly;
[0163] FIG. 37 is a cutaway perspective view of the buffered sample
dispense plunger;
[0164] FIG. 38 is a close-up perspective view of the test console
portion of the mixing assembly, and particularly, the sample and
buffer drive assemblies;
[0165] FIG. 39 is a front-left perspective view of the cassette
portion of an immunoassay flow assembly;
[0166] FIG. 40 is a rear-left perspective view of the cassette
portion of the immunoassay flow assembly;
[0167] FIG. 41 is a perspective view of a distribution chamber for
use in the immunoassay flow assembly;
[0168] FIG. 42 is a cutaway perspective view of the distribution
chamber;
[0169] FIG. 43 is a perspective view of a buffer chamber for use in
the immunoassay flow assembly;
[0170] FIG. 44 is a cutaway perspective view of the buffer
chamber;
[0171] FIG. 45 is a front-right perspective view of the cassette
portion of a sample/buffer flow assembly for use in the immunoassay
flow assembly;
[0172] FIG. 46 is a rear-right perspective view of the cassette
portion of the sample/buffer flow assembly;
[0173] FIG. 47 is a side view of the cassette portion of the
sample/buffer flow assembly;
[0174] FIG. 47A is a longitudinal-sectional view taken along the
line 47A-47A of FIG. 47;
[0175] FIG. 47B is a magnified view taken along the line 47B of
FIG. 47A;
[0176] FIG. 48 is another side view of the cassette portion of the
sample/buffer flow assembly;
[0177] FIG. 48C is a longitudinal-sectional view taken along the
line 48C-48C of FIG. 48;
[0178] FIG. 48D is a magnified view taken along the line 48D of
FIG. 48C;
[0179] FIG. 49 is a bottom view of a rotary valve for use in the
sample/buffer flow assembly;
[0180] FIG. 50 is a rear-left perspective view of the rotary
valve;
[0181] FIG. 51 is a top view of the rotary valve;
[0182] FIG. 52 is one perspective view of a rotor for use in the
rotary valve;
[0183] FIG. 53 is another perspective view of the rotor;
[0184] FIG. 53A is a magnified view taken along the line 53D of
FIG. 53;
[0185] FIG. 54 is a perspective view of a rotor core used to
construct the rotor;
[0186] FIG. 55 is front-left perspective view of the cassette
portion of the sample/buffer flow assembly, particularly showing
sample distribution and venting flow paths when the rotary valve is
clocked in a sample distribution configuration;
[0187] FIG. 56 is rear-left perspective view of the cassette
portion of the sample/buffer flow assembly, particularly showing
the sample and distribution venting flow paths when the rotary
valve is clocked in the sample distribution configuration;
[0188] FIG. 57 is a longitudinal-sectional view of the rotary
valve, particularly showing distribution channels;
[0189] FIG. 58 is a front-left perspective view of the cassette
portion of the sample/buffer flow assembly, particularly showing
sample dispense flow paths when the rotary valve is clocked in a
sample flow configuration;
[0190] FIG. 59 is a longitudinal-sectional view of the rotary
valve, particularly showing sample dispense channels;
[0191] FIG. 60 is a side view of the cassette portion of the
sample/buffer flow assembly, particularly showing a sample dispense
channel;
[0192] FIG. 61 is a front-left perspective view of the cassette
portion of the sample/buffer flow assembly, particularly showing
buffer dispense flow paths when the rotary valve is clocked in a
buffer pre-wash configuration;
[0193] FIG. 62 is a rear-left perspective view of the cassette
portion of the sample/buffer flow assembly, particularly showing
the buffer dispense flow paths when the rotary valve is clocked in
the buffer pre-wash configuration;
[0194] FIG. 63 is a side view of the cassette portion of the
sample/buffer flow assembly, particularly showing the buffer
dispense channel;
[0195] FIG. 64 is a rear-left perspective view of the cassette
portion of the sample/buffer flow assembly, particularly showing
the buffer dispense flow paths when the rotary valve is clocked in
a buffer post-wash configuration;
[0196] FIG. 65 is a side view of the cassette portion of the
sample/buffer flow assembly, particularly showing the buffer
dispense channel;
[0197] FIG. 66 is a rear-right perspective view of the test console
portion of the sample/buffer flow assembly mounted within the main
base of the test console;
[0198] FIG. 67 is a perspective view of the test console portion of
the sample/buffer flow assembly;
[0199] FIG. 68 is a perspective view of a motor drive assembly for
use in the sample/buffer flow assembly;
[0200] FIG. 69 is a perspective view of a reaction chamber for use
in an immunoassay reaction assembly;
[0201] FIG. 70 is a cutaway perspective view of the reaction
chamber;
[0202] FIG. 71 is a cross-section of a frit tool assembly used to
install frits within a plurality of reaction chambers;
[0203] FIG. 72 is a cross-section of one bore of the frit tool
assembly, particularly showing the newly cut frit within the die
plate;
[0204] FIG. 73 is a cross-section of the frit tool assembly bore,
particularly showing the frit passing through the compression
plate;
[0205] FIG. 74 is a cross-section of the frit tool assembly bore,
particularly showing the frit mounted within the reaction
chamber;
[0206] FIG. 75 is a front-right perspective view of the immunoassay
reaction assembly for use in the immunoassay flow assembly;
[0207] FIG. 76 is a rear perspective view of the immunoassay
reaction assembly;
[0208] FIG. 77 is a front view of the immunoassay reaction
assembly;
[0209] FIG. 78 is a front view of the immunoassay flow assembly,
particularly showing the filling of the distribution chambers with
sample during the sample distribution process;
[0210] FIG. 79 is a rear view of the immunoassay flow assembly,
particularly showing the dispensing of buffer from the buffer
chambers during the buffer pre-wash process;
[0211] FIG. 80 is a front view of the immunoassay flow assembly,
particularly showing the dispensing of sample from the distribution
chambers during the sample dispense process;
[0212] FIG. 81 is a rear view of the immunoassay flow assembly,
particularly showing the dispensing of buffer from the buffer
chambers during the buffer post-wash process;
[0213] FIG. 82 is a top perspective view of the immunoassay
scanning assembly and associated cassette for use within the test
console;
[0214] FIG. 83 is a front-right perspective view of the immunoassay
scanning assembly, particularly showing a scanner head mechanism in
an end position;
[0215] FIG. 84 is a front-right perspective view of the immunoassay
scanning assembly, particularly showing the scanner head mechanism
in a home position;
[0216] FIG. 85 is a front view of the immunoassay scanning
assembly;
[0217] FIG. 86 is a schematic diagram of an optical excitation
assembly and optical detection assembly associated with an optical
read cell of the immunoassay reaction assembly;
[0218] FIG. 87 is a diagram plotting the gated voltage levels of a
measured reaction within the channels of the immunoassay reaction
assembly as measured by the immunoassay scanning assembly during a
single scan;
[0219] FIG. 88 is a diagram plotting the voltage level of a
measured reaction within a channel of the immunoassay reaction
assembly during the buffer pre-wash, sample flow, and buffer post
wash processes;
[0220] FIG. 89 is a rear-right perspective view of the cassette
portion of an alcohol reaction assembly mechanically associated
with the cassette portion of the immunoassay flow assembly;
[0221] FIG. 90 is a front-left perspective view of the cassette
portion of an alcohol reaction assembly mechanically associated
with the cassette portion of the immunoassay flow assembly;
[0222] FIG. 91 is front perspective view of the cassette portion of
the alcohol reaction assembly;
[0223] FIG. 92 is a rear perspective view of the cassette portion
of the alcohol reaction assembly;
[0224] FIG. 93 is a top view of the cassette portion of the alcohol
reaction assembly;
[0225] FIG. 93A is a longitudinal-sectional view taken along the
line 93A-93A of FIG. 93;
[0226] FIG. 94 is a front view of the cassette portion of the
alcohol reaction assembly;
[0227] FIG. 94A is a cross-sectional view taken along the line
94D-94D of FIG. 94;
[0228] FIG. 95 is a cross-sectional view of the cassette portion of
the alcohol reaction assembly when the rotary valve is in the
sample flow/buffer post-wash configuration;
[0229] FIG. 96 is a cross-sectional view of the cassette portion of
the alcohol reaction assembly when the rotary valve is clocked in
the sample distribution/buffer pre-wash configuration;
[0230] FIG. 97 is a perspective view of a heater assembly for use
in a temperature control assembly of the test console;
[0231] FIG. 98 is a perspective view of the inside of a front panel
used to construct a cassette case of the cassette assembly;
[0232] FIG. 99 is a perspective view of the front panel with the
cassette portion of the immunoassay flow assembly mounted
therein;
[0233] FIG. 100 is a perspective view of the inside of a rear panel
used to constructed the cassette case;
[0234] FIG. 101 is a perspective view of the rear panel with the
cassette portion of the immunoassay flow assembly mounted
therein;
[0235] FIG. 102 is a flow diagram illustrating the initialization
process of the system; and
[0236] FIG. 103 is a flow diagram illustrating the administration,
operation, and recall modes of the system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0237] With reference to FIG. 1, an on-site analyte testing system
100 will be briefly described. The system 100 utilizes flow
immunoassay technology and the collection of saliva as a specimen
to screen, quantitatively, or semi-quantitatively detect the
presence of any number of analytes, and specifically drugs and
beverage alcohol (both illegal and legal), in a test subject. For
the purposes of this specification, a test subject is any human or
animal whose bodily fluids (in this case, a saliva sample) is to be
collected and analyzed for drug/alcohol content using the system
100. A screening test is a test that provides for quantitation of
results with sufficient accuracy and precision to permit positive
determination of whether the level of analyte present in the sample
is at or below a predefined cutoff level, in which case the test is
declared to be a negative result, or whether the analyte is above
the predefined cutoff level, in which case the test is declared to
be a positive result. A quantitative test is a test that provides
for legally-defined quantitation of results for an analyte over a
defined range (for ethanol 0.04-0.20%) at or above defined accuracy
(for ethanol .gtoreq.95%) and precision (for ethanol .gtoreq.95%)
levels. A semi-quantitative test is a test that provides for
quantitation of results for an analyte over manufacturer-defined
limits of accuracy, precision, and range of results.
[0238] The system 100 is a relatively small self-contained device,
and thus, can be conveniently used in a broad range of areas,
including long term therapeutic drug monitoring, disease-state
testing, wellness-health screening, and all rapid diagnostic
testing where a non-invasive specimen collection and/or rapid
analytic result is desired. In the preferred embodiment, the system
100 can selectively provide up to ten specific immunoassay tests in
a single test panel on a single, small volume, saliva sample. The
system 100 manages all function related to the running of a test on
a subject, including automatic quality control validation, specimen
collection, specimen adequacy test, specimen processing, reagent
addition, optical readout, test result analysis and a quantitative
results printout with interpretation. The system 100 automatically
generates a hardcopy of the test results and interpretation to
provide the necessary documentation of test results. Thus, the
system 100 is fully or semi-automated in that minimal interaction
by the operator is required.
[0239] The preferred embodiment of the system 100 provides the
following advantages: (1) it is user friendly to non-technical
personnel; (2) it collects a single specimen and generates ten test
results in less than ten minutes; (3) it is non-invasive; (4) it
generates blood-equivalent tests results in non-medical
environments equal to centralized laboratory test results; (5)
provides quantitative and evidentiary results; (6) can be
customized to a broad list of applications by using multiple panels
with multiple formats; (7) it is completely automated and requires
no user intervention, thereby providing for legally defensible
results; (8) reagents used in system can be stored for a relatively
long period of time; (9) it can be applied to saliva, urine, and
whole blood or plasma assays; and (10) it is portable in that it
can be carried and transported by a single person and can fit into
a compact place. Succinctly, the system is a highly sensitive,
rapid, non-invasive, easy-to-use, on-site diagnostic tool.
[0240] The preferred system 100 generally includes a relatively
small, portable test console 102 and a single-use disposable test
cassette assembly 150 (shown in FIGS. 2-5), which is received by
the test console 102 via a cassette port 106, as will be described
in further detail below. The test console 102 includes a case 108,
which contains all of the componentry (e.g., the circuitry, motors,
sensors, detection and illumination devices, etc.) necessary to
effect the control, electromechanical, optical, and computational
functions performed on the cassette assembly 150 and essential for
the analysis of the analytes within the test subject's saliva
sample. In the illustrated embodiment, the case 108 is structurally
divided into a bottom case portion 110 and a top case portion 112.
As can be seen in FIGS. 6-11, the test console 102 also includes a
main base 114, which provides the necessary support for the inner
components of the console 102, integrating the assembly into a
single unit. In the illustrated embodiment, the main base 114
includes a top flange 116, a bottom flange 118, and two side
flanges 120 and 122, which are arranged to form a hollow three
dimensional rectangular rigid structure mounted inside the bottom
case portion 110. The main base further includes a distribution
flange 124 on which various motors and associated components are
distributed, and a pair of spacer flanges 126 to space the main
base 114 from the bottom case portion 110.
[0241] Referring to FIGS. 2 and 3, the cassette assembly 150
includes an external sample collection interface device, and
specifically an oral aspirator 402, and an associated flexible
sample collection conduit 410, which is used to collect saliva from
a subject via aspiration. The cassette assembly 150 further
comprises a chemistry cassette 152 that includes a case 154, which,
for purposes of reference, has a front 156, rear 158, top 160, and
bottom 162. The cassette case 154 houses all the chemical reagents
needed to perform a panel of immunoassay tests for drugs, as well
as an enzymatic test for ethanol, on the test subject's saliva
sample. In the illustrated embodiment, the cassette case 154
contains prepackaged quantities of lyophilized stable solid
reagents and stabilized liquid buffer reagents having a shelf-life
of twelve months under defined storage conditions. The cassette
case 154 further contains all required components to provide for
defined flow rate and for optical quantitation of the alcohol
concentration and fluorimetric semiquantitation of the drug levels.
The cassette case 154 also contains all materials, surfaces,
chambers, and components that will be wetted by the saliva sample
by aspiration into the chemistry cassette 152 and subsequently
analyzed by the test console 102. The cassette case 154 is further
designed to self-contain all chemical reagents and the biological
sample after their chemical reaction, and to treat the saliva
sample with an antibacterial to obviate any biological hazard of
the physiological sample. Other than the chemical reagents, the
chemistry cassette 152 is made entirely of common injection-molded
polymers (plastics) and aluminum foil. Therefore it can be disposed
of simply as solid waste.
[0242] Thus, the chemistry cassette 152, when installed within the
test console 102, enables it to identify a multitude of oral fluid
analytes and is available in a variety of formats to provide the
various markets with the specific test panels they require. For
example, the chemistry cassette 152 may provide a five drug test
panel to screen or semi-quantitatively identify the National
Institute on Drug Abuse (NIDA) required drugs-of-abuse, which is
currently identified as cocaine, opiates (heroin, morphine, and
codeine), phencyclidine (PCP), amphetamines/methamphetamines, and
marijuana (tetrahydrocannabinol or THC). The chemistry cassette 152
also provides screening or semi-quantitative analysis of beverage
alcohol (ethanol or EtOH). As another example, the chemistry
cassette 152 may provide up to ten tests for overdose or disease
panel testing. Thus, the chemistry cassette 152 can be customized
to any one of a variety of applications. Thus, the combination of
the test console 102 and chemistry cassette 152 provides for a
fully operational flow immunoassay analyte tester.
[0243] It should be noted that a confirmation cassette, which does
not perform any immunoassay tests, can be optionally used with the
test console 102 to merely collect the aspirated saliva sample from
the test subject. Typically, it will be used subsequent to the
administration of a drug-of-abuse test on a subsequently collected
saliva sample in order to confirm the results of the test.
Confirmatory tests use advanced instrumentation to provide for
sufficiently specific results to eliminate the possibility of
interfering or cross-reacting species that might provide incorrect
results, either false-positive or false-negative results, when
tested with a screening test using less complex and more
inexpensive technology. For example, for use by its agencies, the
U.S. Government requires that screening tests for drug-of-abuse be
confirmed with a test specifically incorporating gas
chromatography/mass spectrometry for confirmation of results.
[0244] Having generally described the system 100, the various
assemblies located in the chemistry cassette 152 and/or test
console 102 will now be described. It should be noted, however,
that the functional organization of this discussion into various
assemblies is provided to facilitate in the understanding of the
system 100, and is not meant to limit the structure of the
assemblies in any way. For example, assemblies located in both the
chemistry cassette 152 and the test console 102 may be divided into
a cassette portion and a tester portion in the subsequent
discussion. This does not mean, however, that the combination of
these two portions cannot be considered a single assembly. Also,
many of the components described herein bear on the functionality
of several assemblies. Thus, the organization of components into a
particular assembly does not mean that any such components cannot
be considered a part of another assembly.
[0245] I. Electrical Assembly
[0246] Referring to FIG. 12, an electrical assembly 200 provides
the necessary electrical and sensing functions to the system 100.
To this end, the electrical assembly 200 comprises an AC/DC power
supply 202 that plugs into normal AC power mains (85-240 VAC, 50-60
Hz) and supplies a nominal single DC voltage of 12 VDC (or multiple
DC voltages of +5 and .+-.15 VDC) to the test console 102 at
sufficient current to provide electrical power for all operations
of the test console 102. All power requirements of the test console
102 may also be supplied by an external battery (not shown) of a
sufficient ampere-hours rating to supply electrical power for all
operation of the test console 102 when remote from AC supplies,
such as on a ship, in an ambulance, or in a police car.
[0247] In the illustrated embodiment, the test console 102 provides
sufficient internal shielding and power supply decoupling
capacitors (not shown) to minimize susceptibility to external
interference caused by electrostatic (ESI), electromagnetic (EMI)
and radio frequency-interference (RFI) sources. The test console
102 is also sufficiently shielded and filtered to minimize
generation of interference from ESI, EMI or RFI sources within the
instrument. The test console 102 thus produces no more electrical
noise than other common household appliances, such as television
receivers or home computers. Analog and digital grounds are kept
separate through the test console 102 and only joined at a single
reference point within the device to minimize noise and possible
error sources caused by potential ground loops within the test
console 102. Similarly, all low-level, high impedance inputs are
shielded and isolated to minimize noise sources within the test
console 102.
[0248] The electrical assembly 200 further includes a central
processor unit (CPU) 204, which controls all operations of the test
console 102, with the exception of the cassette temperature
controller (described below), which is under dedicated hardware
control. In this regard, the CPU 204 is coupled via an input/output
(I/O) controller 206 to a multitude of sensors 208 and motors 210
located throughout the test console 102. In this manner, the CPU
204 can control the motors 210 to effect the various functions
performed within the test console 102, and can read the sensors 212
to determine the status of such functions. As will also be
described in further detail below, the CPU 204 also performs
intelligence functions, such as performing an analysis on the
sample and interfacing with the operator.
[0249] II. Cassette Loading Assembly
[0250] Referring to FIGS. 13 and 14, the system 100 comprises a
cassette loading assembly 300, the purpose of which is to allow the
operator to load and unload the chemistry cassette 152 into and out
of the test console 102. The cassette loading assembly 300
comprises a cassette carriage 302 for receiving the chemistry
cassette 152. To this end, the cassette carriage 302 includes a
front support flange 304 and a bottom flange 306, which are
profiled to seat and receive the chemistry cassette 152. To ensure
that the chemistry cassette 152 is firmly seated, the cassette
carriage 302 comprises a pair of homing pins 308 extending from the
front support flange 304, which are sized and spaced to mate with a
corresponding pair of homing pin holes 164 formed in the front 156
of the cassette case 154 (see FIG. 3). As can be seen by FIGS. 13
and 14, the cassette carriage 302 linearly translates in relation
to the main base 114. To this end, the cassette loading assembly
300 further includes a rail 307 (shown in FIGS. 8 and 15), which is
suitably mounted on the top main base flange 116, and a mating
runner 309 (shown also in FIGS. 8 and 15), which is suitably
mounted to the bottom of the cassette carriage 302, thus allowing
the cassette carriage 302 to smoothly ride on the main base 114
between a fully extended position (FIG. 13) and a fully closed or
home position (FIG. 14). The cassette carriage 302 includes a door
310 mounted to its end, such that when the cassette carriage 302 is
fully loaded, the door 310 is shut against the cassette port 106,
forming a light block that substantially eliminates stray ambient
light from the interior of the test console 102, the importance of
which will be described in further detail below.
[0251] Referring also to FIG. 15, the cassette loading assembly 300
further includes a cassette loading drive assembly 312, which
automates the reciprocal movement of the cassette carriage 302 in
relation to the main base 114. The cassette loading drive assembly
312 includes a rotational stepper motor 314 with an associated
drive pulley 316, and a drive screw 318 with an associated idler
pulley 320. The drive screw 318 includes a threaded portion 322
(best shown in FIG. 14) and opposing unthreaded portions 324 (only
one shown in FIG. 13). The cassette loading drive assembly 312
further includes a drive belt (not shown) mounted around the
respective drive and idler pulleys 316 and 320 for operably
connecting the stepper motor 314 to the drive screw 318. The
cassette loading drive assembly 312 further includes a motor mount
328 for affixing the motor 314 to the side main base flange 122,
and a pair of drive screw positioners 330 (shown also in FIG. 8)
having apertures 332 in which the unthreaded ends 324 of the drive
screw 324 are free to respectively rotate. The drive screw
positioners 330 are suitably mounted to the top main base flange
116, so that the rotating drive screw 318 is linearly fixed
relative to the main base 114. The cassette loading drive assembly
312 further includes a threaded flange 334, which is suitably
mounted to the exterior of the cassette carriage 302. The threaded
flange 334 includes a longitudinally disposed threaded hole 336
through which the threaded portion 322 of the drive screw 318 is
disposed. Thus, operation of the motor 314 rotates the drive pulley
316, which in turn rotates the idler pulley 320 and thus the drive
screw 318 via drive belt. The cassette carriage 302 is then
linearly translated with respect to the main base 114. Under
control of the CPU 204 and I/O controller 206 (see FIG. 12), the
motor 314 can be reciprocally operated to alternately translate the
cassette carriage 302 between the fully loaded and fully extended
positions.
[0252] Having described the structure of the cassette loading
assembly 300, its operation will now be described. In its home
position (FIG. 13), the empty cassette carriage 302 is fully loaded
into the test console 102 and the door 310 is shut against the
cassette port 106 of the test console 102 (FIG. 1). The cassette
carriage 302 is ejected by semi-automatically operating (i.e.,
prompted by the operator) the cassette loading drive assembly 312
to fully extend the cassette carriage 302 out the cassette port
106, allowing the operator to mount the cassette 152 within the
cassette carriage 302. The cassette 152 is then loaded into the
test console 102 by semi-automatically operating the cassette
loading drive assembly 312 to fully insert the cassette carriage
302 with the cassette 152 into the cassette port 106, returning the
cassette carriage 302 to its home position. The cassette 152 can be
ejected from the tester by again semi-automatically operating the
cassette loading drive assembly 312 to fully extend the cassette
carriage 302 and cassette 152 out the cassette port 106, allowing
the operator to remove the cassette 152 from the cassette carriage
302. A fully extended cassette carriage sensor, fully inserted
cassette carriage sensor, and door shut sensor (shown generally as
sensors 208 in FIG. 12) are used to ensure that the afore-described
steps have been fully effected.
[0253] III. Self-Customizing Assembly
[0254] Referring to FIG. 15, the system 100 comprises a
self-customizing assembly 350, the purposes of which is to
customize one or more operational parameters of the system as
dictated by the chemistry cassette 152. To this end, the
self-customizing assembly 350 comprises a barcode read assembly 352
and a customization assembly 354.
[0255] The purpose of the barcode read assembly 352 is to identify
information associated with the chemistry cassette 152. To this
end, the barcode read assembly 352 includes a unique barcode 356,
which is affixed to the rear 158 of the cassette case 154 (shown in
FIG. 2), and which contains information specific to the chemistry
cassette 152. The barcode read assembly 352 includes a standard
barcode reader 358, which is mounted to the top main base flange
116 via a mount 360, and is optically aligned with the barcode 356
when the chemistry cassette 152 is loaded within the test console
102 (FIG. 9). In the illustrated embodiment, the barcode 356
contains the following information: (1) type of cassette (e.g.,
NIDA drugs-of-abuse and alcohol cassette, confirmation cassette,
etc.); (2) date of manufacture; (3) various lot-specific
calibration information for each of the test channels; and (4)
checksum code.
[0256] The customization assembly 354 comprises circuitry, and
specifically the CPU 204, which is electrically coupled to the
barcode reader 358 and modifies the operational parameters, and
specifically the testing parameters, of the system 100 based on the
barcode information. The CPU 204 can optionally modify sample flow
parameters within the system 100 by, e.g., operating various motors
to provide for different sample flow rates and volumes within the
system 100 based on the type of cassette indicated in the barcode.
Optionally, information specifically indicating the sample flow
parameters can be contained within the barcode, in which case, the
CPU 204 need not infer the different flow rates and volumes from
the type of cassette. In addition, the CPU 204 can also calibrate a
test panel using the test calibration information containing with
the barcode. Further details on the customization of the system 100
will be described below.
[0257] The CPU 204 is also configured to operate the barcode reader
358 to destroy the barcode checksum code when the cassette 152 is
ejected from the test console 102. Thus, if the barcode information
and the checksum code do not correspond, the chemistry cassette 152
will not be able to be used, thereby preventing inadvertent or
intentional reuse of an invalid cassette 152. Also, the CPU 204
will prevent use of the cassette 152 if it is expired, e.g., 12
months after the date of manufacture.
[0258] In operation, when the cassette 152 is loaded into the test
console 102, the barcode reader 358 is automatically operated to
read the information from the barcode 356 disposed on the cassette
152. This information is then processed by the test console 102,
and specifically, the CPU 204. If the cassette 152 has expired or
has been previously used, the CPU 204 will operate the cassette
loading assembly 300 to eject the chemistry cassette 152.
Otherwise, the CPU 204 will customize the operational parameters of
the system 100 based on the barcode information. After completion
of the test, the CPU 204 operate the cassette loading assembly 300
to eject the cassette 152. Additionally, as cassette 152 is ejected
from the test console 102, the CPU 204 operates the barcode reader
358 to erase the checksum code from the barcode 356, so that the
cassette 152 cannot be reused.
[0259] IV. Sample Collection Assembly
[0260] Referring to FIGS. 2, 6, and 16, the system 100 comprises a
sample collection assembly 400, the purpose of which is to collect
the required amount of saliva (in the illustrated embodiment,
350.+-.35 .mu.L) semi-automatically by vacuum aspiration from the
mouth of the test subject. That is, the sample collection assembly
400 automatically draws saliva sample into the cassette 152,
measures the total volume accumulated within the cassette 152, and
notifies the operator when an adequate volume of sample has been
accumulated.
[0261] A. Sample Collection Assembly--Cassette Portion
[0262] Referring specifically to FIGS. 17-19, the portion of the
sample collection assembly 400 associated with the cassette
assembly 150 is illustrated. The sample collection assembly 400
includes the afore-mentioned oral aspirator 402, which includes a
hand piece 404, a sample collection tip 406 and a cover/extended
handle 408, the afore-mentioned flexible conduit 410, and a sample
collection chamber 412. As illustrated in FIG. 2, the oral
aspirator 402 and conduit 410 are external to the cassette 152,
whereas the sample collection chamber 412 is internal to the
cassette 152.
[0263] The hand piece 404 is composed of hollow rigid or semi-rigid
material of a suitable length and diameter. For example, the hand
piece 404 can be composed of white-colored, injection molded ABS
plastic, that is 15 cm in length, and 1 cm in diameter at a handle
414 that narrows to 0.5 cm diameter at a tip 414. To provide for
the best ergonomic use of the hand piece 404 in the mouth of the
test subject, the handle 414 is bent to a gentle obtuse angle,
e.g., 150.degree. at a distance of 5 cm from the tip 414, and has
two opposing molded finger grips 418, e.g., 10 cm from the tip
414.
[0264] The cover/extended handle 408 is also composed of a hollow
rigid or semi-rigid material of a suitable length and diameter to
fit over either the tip 414 of the hand piece 404 (FIG. 17) or the
handle 414 of the hand piece 404 (FIG. 18). For example, the
cover/extended handle 408 can be composed of a white-colored,
injection molded ABS plastic that is 5 cm in length and 1 cm in
diameter. As a cover, it can be initially placed over the sample
collection tip 406 to keep it clean during storage and just prior
to use, and can be held in place by a positive snap-action ribbed
holder 420. As an extended handle, it can be removed from the
sample collection tip 406 and slipped onto the handle 414 of the
hand piece 404, where it is held in place by another positive
snap-action ribbed holder 422. Thus, the length of the hand piece
404 is extended in additional amount (e.g., for a total length of
19 cm to keep the test subject's and operator's fingers away from
the sample collection tip 406, which will be coated with saliva.
Following use, the cover/extended handle 408 can be replaced over
the saliva-wetted tip 416 to prevent accidental contact of the test
subject and/or operator with potentially biologically-hazardous
saliva remaining on the tip 416.
[0265] The sample collection tip 406 has a size the allows it to
comfortably fit within a subject's mouth, and is constructed of a
non-toxic, non-analyte absorbing material. In the illustrated
embodiment, the sample collection tip 406 is cylindrical in shape
with a hemidome-shaped top surface, and has a length of 9 mm and a
diameter of 7 mm. The sample collection tip 406 comprises a sample
collection body 424 composed of a hydrophilic material, such as a
fused, nontoxic, high density polyethylene (HDPE) microporous
material. The outer surface 426 of the sample collection body 424
is treated with a surfactant, which reduces the surface tension of
the fluid in contact with the outer surface 426. Suitable
proprietary surfactants for this purpose can be obtained from Porex
Corporation located in Fairbum, Ga. Thus, the interior of the
microporous sample collection body 424 is hydrophobic, whereas its
outer surface 426 is hydrophilic. When in contact, even partially,
with a small pool of saliva in the mouth, the hydrophilic outer
surface 426 of the sample collection body 424 is sufficient to
cause capillary action to transport saliva into the hydrophobic
interior of the sample collection body 424. It is noted that with
purely hydrophobic tips, substantially the entire surface of the
tip must be in contact with saliva in order to flow saliva into the
interior of the tip, since exposing any portion of the hydrophobic
tip surface to air would tend to draw in the less viscous air.
[0266] Thus, a relatively small applied vacuum level, e.g., 350
mmHg absolute at an air flow rate of 5-50 ml/min, has been found to
be sufficient to draw saliva from the microporous sample collection
tip 406 through the flexible conduit 410. This is advantageous in
that a minimum air flow rate is necessary to maintain consistent
oral fluid collection, since too high of a flow rate causes a
greater volume of air to be transported through the system,
requiring removal of greater volumes of air in the sample
collection chamber 412. Also, where loss of volatile components in
the saliva must be controlled, maintaining a constant, minimal flow
of air through the sample collection assembly 400 at all times is
advantageous.
[0267] The micropores 428 of the sample collection tip 406 are of a
suitable diameter, e.g., 135 .mu.m, to facilitate collection of the
viscous saliva from the interior surface of the mouth. These
micropores 428 also function as a large pore-size depth filter to
prevent larger pieces of food, plaque or particles exogenous to the
mouth from being aspirated into the small interior diameter of the
flexible conduit 410, where they might possibly clog it and prevent
aspiration of the saliva therethrough. The sample collection tip
406 is bonded to the tip 416 of the hand piece 404 with a nontoxic,
medical-grade cyanoacrylate adhesive. Specifically, the rear
circular surface of the sample collection tip 406 is bonded to the
front surface of the hand piece tip 416, thereby sealing the rear
micropores of the sample collection tip 406 and forcing air to flow
from the sides and front surfaces of the sample collection tip,
406, where saliva is likely to be located once the tip 406 is
inserted into the mouth of the test subject for sample
collection.
[0268] Also, the central axis of the sample collection tip 406
contains a bore 428 into which one end of the flexible conduit 410
is inserted and bonded with a non-toxic, non-analyte absorbing
material, preferably the same as that used to bond the sample
collection tip 406 to the hand piece tip 416. This double bonding
with very strong adhesive causes the sample collection tip 406 to
be held to the hand piece tip 416 with more adhesive force than the
sample collection tip's own cohesive forces. Thus, under extreme
pressure, the sample collection tip 406 will fragment rather than
come loose from the hand piece 404, thereby minimizing the risk of
swallowing the sample collection tip 406.
[0269] The hollow-core flexible conduit 410 is made of a suitable
non-toxic hydrophobic slippery material, so that drugs, e.g., THC,
will not stick to its interior surface, and the flow of viscous
liquid saliva through the narrow-bore interior of the flexible
conduit is facilitated. Pure polytetrafluoroethylene (PTFE or
Teflon) has been found to be suitable for this purpose. To
facilitate bonding of the flexible conduit 410 to surfaces, such as
the bore 428 of the sample collection tip 406, the outer surface of
the PTFE can be etched to a depth of a few angstroms thick with a
hydrophilic surface. The inner diameter of the flexible conduit 410
is preferably selected based on the vacuum level and flow rates,
while maximizing retention of volatile ethanol in the saliva sample
as it is aspirated through the flexible conduit 410. An inner
diameter of, e.g., 0.5 mm has been empirically found to be suitable
for a vacuum level of 350 mmHg absolute and an air flow rate of
between 5-50 ml/min. The thickness of the wall of the flexible
conduit 410 is preferably suitable to prevent kinking, which may
otherwise clog the bore of the flexible conduit 410, and thereby
prevent collection of the saliva sample. Also, the specified wall
thickness should provide sufficient strength to prevent most
persons from being able to stretch or part the material, thereby
preventing sample collection. A wall thickness of 0.50 mm has been
found to be suitable for this purpose. The length of the flexible
conduit 410 is preferably suitable to facilitate collection of the
required volume of saliva from comfortably seated test subjects
when the test console 102 is placed on a bench-top. A length of
45-60 cm has been found to be suitable for this purpose.
[0270] Referring to FIGS. 20 and 21, the sample collection chamber
412 is composed of a suitable material, such as injection molded
ABS polymer, and is formed of a top chamber cap 430 and a bottom
chamber base 432, which are thermally welded together around their
circumference. The top chamber cap 430 includes a self-sealing
vacuum port 434 within which there is tightly disposed a
hydrophobic seal 436. In the illustrated embodiment, the seal 436
is composed of a self-sealing polyethylene membrane that comprises
small-diameter pores that are coated with a hydrophilic substance,
such as carboxymethlcellulose. When wetted, the hydrophilic pores
rapidly swell, closing the pore interiors, thereby preventing
liquid from passing through the membrane. This self-sealing vacuum
port 434, thus facilitates passing air, while preventing liquid or
spray droplets from passing from the cassette, which contains all
saliva-wetted parts of the system 100, into the test console 102,
which must remain dry in order to prevent even the remote
possibility of electrical shock hazard. The self-sealing vacuum
port 434 also serves to keep the potentially biologically hazardous
saliva from leaking out of the cassette 152 after its disposal
following use.
[0271] Referring further to FIGS. 22 and 23, the top chamber cap
430 further includes a sample input port 438 within which the end
of the flexible conduit 410 is bonded with a suitable material,
such as a medical grade cyanoacrylate adhesive. The diameter of the
input port 438 is of a suitable value, e.g., 1.5 mm, to facilitate
a tight fit with the flexible conduit 410. The sample input port
432 leads to an internal chamber 440 within the bottom chamber base
432, which in the illustrated embodiment, has a diameter of 1 cm
and holds an interior volume of 0.5 ml of saliva without wetting
the self-sealing vacuum port 434. The internal chamber 440 has an
inverted conical shape. Specifically, the internal chamber 440 is
cylinder-shaped at its upper rim and gradually narrows to small
diameter at its lower end, e.g., 0.5 mm, which leads to a sample
dispense port 442 having the same diameter. So that the sample
input port 438 is clocked in a predetermined rotational orientation
with respect to the chamber base 432, the chamber cap 430 and
chamber base 432 are provided with an alignment mechanism, and
specifically a mating detent 444 and slot 446. In this manner, the
portion of the flexible conduit 410 attached to the sample input
port 438 will be consistently positioned adjacent a routing slot
175 formed on the top 160 of the cassette case 154, thereby
allowing the flexible conduit 410 of the sample collection assembly
400 to be conveniently routed from the sample collection chamber
412 to the exterior of the cassette case 154.
[0272] B. Sample Collection Assembly--Tester Portion
[0273] Having just described the portion of the sample collection
assembly 400 associated with the cassette assembly, the portion of
the sample collection assembly 400 associated with the test console
102 will be discussed. Referring to FIGS. 6 and 16, the sample
collection assembly 400 further includes a vacuum port connector
450, vacuum port drive assembly 452, vacuum tubing 454, vacuum pump
456 with an associated vacuum inlet filter 458, and a fluid sensor
460 (shown in FIG. 8).
[0274] The vacuum port connector 450 is composed of a compliant
silicone rubber in the form of bellows, a compliant rim of which
forms a tight vacuum seal when engaged with the cassette vacuum
port 434. In the illustrated embodiment, the vacuum port connector
450 is 1.5 cm in length, and 1 cm in diameter, with its compliant
rim 2 mm in width. The vacuum port connector 450 is engaged with
the cassette vacuum port 434 by the vacuum port drive assembly 452,
which includes a linear stepper motor 462 and a motor mount 464.
The motor 462 is mounted to the motor mount 464, which is in turn
mounted to the distribution flange 124. The vacuum port drive
assembly 452 further includes a threaded drive pin 466 rotatably
coupled to the motor 462, and a threaded positioner 468 through
which the drive pin 466 extends. The vacuum port drive assembly 452
further includes a first drive flange 470 affixed to the threaded
positioner 468, and a second drive flange 472 on which the vacuum
port connector 450 is affixed. The second drive flange 472 is
mounted to the first drive flange 470, which includes a runner 474
that slidingly engages a rail 476 extending along the distribution
flange 124.
[0275] Thus, the vacuum port drive assembly 452 can be operated to
lower the vacuum port connector 450 from a home position (wherein
the vacuum port connector 450 is disengaged with the cassette
vacuum port 434 to a pre-collection position (wherein the compliant
rim of the connector 450 and the cassette vacuum port 434 coincide
and provide a tight seal. As shown in FIGS. 2 and 5, a vacuum port
access opening 166 is formed at the top 160 of the cassette case
154, thereby allowing the vacuum port connector 450 to engage the
vacuum port 434 of the sample collection chamber 412.
[0276] The other end of the vacuum port connector 450 is connected
to the vacuum tubing 454, which is composed of a suitable material,
such as Tygon tubing. The vacuum tubing 454 is in turn connected to
one port of the vacuum inlet filter 458, which is composed of a
suitable material, such as 0.1 .mu.m diameter port microporous
hydrophilic PTFE. This prevents dust, liquid droplets, or in the
event of a catastrophic failure, liquid saliva from contaminating
the vacuum pump 456. The other port of the inlet filter 458 is
connected to a vacuum inlet port 476 of the vacuum pump 456. In the
illustrated embodiment, the vacuum pump 456 is mounted to the
inside of the casing 108. Thus, the vacuum pump 456 can be operated
to create negative pressure within the sample collection assembly
400.
[0277] Referring to FIG. 8, the fluid sensor 460, which is used to
sense when a predetermined amount of saliva sample has been
collected in the sample collection chamber 412, is mounted to a
mounting flange 478, which is in turn mounted to the distribution
flange 124 to place the fluid sensor 460 into contact or near
contact (e.g., <0.5 mm or <0.20 in) with the outside wall of
the sample collection chamber 412 when the cassette 152 is fully
loaded into the test console 102. In the illustrated embodiment,
the fluid sensor 460 contains a 1 cm diameter sense electrode that
is placed at a height, such that a volume of 350 .mu.l saliva
sample is collected at the bottom of the sample collection chamber
412. As shown in FIG. 2, a sensor access opening 168 is provided in
the rear 158 of the cassette case 154 adjacent the sample
collection chamber 412, thereby allowing the fluid sensor 460 to be
in direct capacitive engagement with the sample collection chamber
412.
[0278] It should be noted that the vacuum port drive assembly 452
and vacuum pump 456 are all operated under control of a CPU 204 and
I/O controller 206 (FIG. 12). A vacuum motor drive sensor
(generally shown in FIG. 12) and the rail 474, which is indexed,
are used to provide independent confirmation of the position of the
vacuum port connector 450, while vacuum pressure and air flow
sensors (generally shown in FIG. 12) are used to measure vacuum
level and air flow rate within the vacuum pump 456.
[0279] C. Sample Collection Assembly--Operation
[0280] Having described the structure of the sample collection
assembly 400, its operation will now be described. After the
cassette 152 is fully loaded into the test console 102, and after
the hand piece 404 is placed into the mouth of the test subject,
the vacuum pump 456 is semi-automatically operated (i.e., prompted
by the operator) prior to engagement of the vacuum port connector
450 with the cassette vacuum port 434. During this time, the vacuum
level and flow rate are measured using the vacuum level and flow
rate sensors to determine if they fall within appropriate limits
(vacuum level .gtoreq.200 mmHg differential; vacuum flow rate
.gtoreq.100 ml/min). This measurement ensures that the vacuum pump
456 is operating properly. Simultaneous with these measurements,
the vacuum port drive motor 462 is operated to move the vacuum port
connector 450 downward from its home position to its pre-collection
position into sealing engagement with the cassette vacuum port 434.
Once the vacuum port connector 450 is in full contact with the
cassette vacuum port 434, the vacuum level and flow rate are again
measured by their respective sensors and again determined to be
within appropriate limits (vacuum level .gtoreq.300 mmHg
differential; vacuum flow rate .gtoreq.20 ml/min). This measurement
ensures that the cassette portion of the sample collection assembly
400 is operating properly.
[0281] If the vacuum level is less than the 300 mmHg differential,
than a vacuum leak at the cassette vacuum port 434 is determined.
In this case, the vacuum port connector 450 is disengaged and
repositioned over the vacuum port 434. The vacuum level is again
measured, and if less than the 300 mmHg differential, the vacuum
port connector 450 is disengaged, and the chemistry cassette 152 is
ejected from the test console 102 and then reloaded into the test
console 102. The vacuum level is again measured, and if less than
the 300 mmHg differential, the vacuum leak is considered fatal.
[0282] If the vacuum level is greater than the 300 mmHg
differential, but the air flow rate is less than 20 ml/min, than a
vacuum leak within the chemistry cassette 152 is determined, which
would typically be caused by a leak within the sample/buffer mixing
assembly, as will be described in further detail below. In this
case, the vacuum port connector 450 is disengaged, the chemistry
cassette 152 is ejected from the test console 102, and then, after
prompting the operator, another chemistry cassette 152 is loaded
into the test console 102. The vacuum level and air flow rate tests
are then repeated for the new chemistry cassette 152. If on the
other hand, the vacuum level is greater than the 300 mmHg
differential, but the air flow rate is less than 20 ml/min, it is
determined that the conduit 410 or sample collection tip 406 is
clogged. In this case, the vacuum port connector 450 is disengaged,
the chemistry cassette 152 is ejected from the test console 102,
and then, after prompting the operator, another chemistry cassette
152 is loaded into the test console 102. The vacuum level and air
flow rate tests are then repeated for the new chemistry cassette
152.
[0283] Once the vacuum level and air flow rate have been determined
to be within the control limits, saliva collection begins. Air is
drawn out of the cassette vacuum port 434, drawing a mixture of
saliva sample and air into the sample collection tip 406 from the
mouth of the test subject, through the flexible conduit 410, and
into the internal chamber 440 of the sample collection chamber 412,
where it is released from the turbulent flow conditions of the
small-bore port 438 into a laminar flow within the much larger
diameter internal chamber 440. Because the sample collection
chamber 412 is oriented in a vertical direction along the height
axis of the cassette 152, which is also held vertically by the test
console 102, gravity causes the more dense liquid saliva to settle
to the bottom of the internal chamber 440, while air is drawn from
the top of the internal chamber 440 through the vacuum port 434 as
a partial vacuum is applied thereto. The inverted conical shape of
the internal chamber 440 facilitates collection of all of the
liquid saliva from the sample collection chamber 412 as it funnels
down to the small diameter dispense port 442.
[0284] Saliva collection is continued until the sample collection
chamber 412 is filled with the predetermined quantity of saliva
sample, as measured by the fluid sensor 460, or until a
predetermined amount of time (in the illustrated embodiment, one
minute) elapses. If one minute has expired without collecting the
predetermined amount of saliva sample, the operator is prompted to
readjust the sample collection tip 406 within the test subject's
mouth, and saliva collection commences until the sample collection
chamber 412 is filled with the predetermined quantity of saliva
sample, as measured by the fluid sensor 460, or until another
predetermined amount of time (in the illustrated embodiment, one
minute) elapses. If the second minute has expired without
collecting the predetermined amount of saliva sample, the process
is repeated again. Sample collection is aborted if the third
attempt at collecting the saliva fails. If, however, a
predetermined quantity of saliva sample has been collected, the
vacuum pump 456 is turned off, and the operator, after prompted,
removes the aspirator 402 from the test subject and re-caps it.
[0285] V. Sample/Buffer Mixing Subassembly
[0286] Referring to FIGS. 8 and 24-38, the system 100 further
comprises a sample/buffer mixing assembly 500, the purpose of which
is to pipette predetermined volumes of collected saliva sample and
buffer solution and mix them into a less viscous and higher volume
buffered saliva sample solution. Mixing equal volumes of saliva
sample and buffer also tends to equalize the pH and ionic strength
of the saliva sample to minimize sudden changes during the
immunoassay test that could cause the antibody to falsely release
bound antigen in the absence of the analyte.
[0287] A. Sample/Buffer Mixing Subassembly--Cassette Portion
[0288] Referring specifically to FIGS. 24-26, the portion of the
sample/buffer mixing assembly 500 that resides in the cassette 152
includes a buffer chamber 502, the previously described sample
collection chamber 412, and a mixing chamber 504. In the
illustrated embodiment, the buffer chamber 502 and mixing chamber
504 are combined into a cylindrically shaped unibody design
composed of a suitable material, such as injection molded
polypropylene polymer, but alternatively can be separate and
distinct bodies that are suitably mated to each other. The buffer
chamber 502 and mixing chamber 504 are in axial alignment with each
other, which as will be described in further detail, facilitates
interaction between plungers. The buffer chamber 502 contains a
neutral buffer solution, e.g., phosphate buffered saline (PBS)
buffer solution (pH 6.9), and the sample collection chamber 412
contains saliva as a result of the sample collection process. In
the illustrated embodiment, the buffer chamber 502 holds 300 .mu.l
of buffer, and as previously mentioned, the sample collection
chamber 412 collects 350 .mu.l of saliva sample. Assuming equal
parts of the buffer and saliva sample are mixed, the mixing chamber
504 holds at least 600 .mu.L of the mixed and buffered saliva
solution.
[0289] The sample collection chamber 412 is removably affixed to
the mixing chamber 504. Specifically, the sample dispense port 442
of the sample collection chamber 412 is mated with a sample inlet
port 506 of the mixing chamber 504. So that an integral
sample/buffer mixing assembly 500 is formed, the chamber base 432
of the sample collection chamber 412 includes a radially extending
ridge 480 (shown best in FIG. 20), which mates with a slot 508
formed between two vertical radially extending ridges 510 on the
buffer chamber 502, thus providing three-axis rotational stability.
In addition, a chamber stand 482 is formed on the exterior of the
chamber base 432 of the sample collection chamber 412, which as
will be described in further detail below, rests on a ledge within
the cassette 152, thereby minimizing the shearing and bending
stress created at the connection between the sample dispense port
442 and the sample inlet port 506.
[0290] Referring to FIG. 27, the mixing assembly 500 further
includes a buffer dispense plunger 512, which is disposed in the
buffer chamber 502, a sample dispense plunger 514, which is
disposed within the mixing chamber 504, and buffered sample
dispense plunger 516, which is also disposed within the mixing
chamber 504. The buffer chamber 502 comprises a cylindrical bearing
surface 518 with which the buffer dispense plunger 512 sealingly
mates. The buffer chamber 502 comprises puncturable upper and lower
seals 520 and 522 (shown in FIG. 26) at the top and bottom of the
buffer chamber 502 to completely seal the buffer within the buffer
chamber 502 until the mixing process has commenced. The upper and
lower seals 520 and 522 prevent water vapor from escaping the
confines of the buffer chamber 502 during storage of the cassette
152, and are composed of a suitable material, such as aluminum
foil-lined/polymer bilayer seals. The buffer chamber 502 further
includes a buffer chamber access port 524, which provides
mechanical access to the buffer chamber 502.
[0291] The mixing chamber 504 comprises a plunger bearing surface
526 with which the sample dispense plunger 514 and buffered sample
dispense plunger 516 sealingly mate. The mixing chamber 504 further
comprises three ports: (1) a buffer port 528, which facilitates the
flow of buffer from the buffer chamber 502 into the mixing chamber
504; (2) the previously described sample port 506, which is mated
with the dispense port 442 of the sample collection chamber 412,
and thus facilitates the flow of saliva from the sample collection
chamber 412 into the mixing chamber 504; and (3) a dispense port
530, which is mated with a feed port of a flow immunoassay assembly
(as will be described in further detail below), and thus
facilitates the flow of buffered sample solution from the mixing
chamber 504 into the flow immunoassay assembly. As illustrated, the
buffer port 528 is located at the top of the mixing chamber 504,
the sample port 506 is located near the top of the mixing chamber
504 but below the buffer port 528, and the dispense port 530 is
located at the bottom of the mixing chamber 504. For the purposes
of this specification, the buffer port 528 can be considered a
longitudinal port, since it is parallel to the plunger bearing
surface 526 of the mixing chamber 504. In contrast, the sample and
dispense ports 506 and 530 can be considered lateral ports, since
they are perpendicular to the plunger bearing surface 506 of the
mixing chamber 504.
[0292] The plungers are used to dispense the buffer and sample
within the mixing chamber 504 to form the buffered sample solution,
and then to dispense the buffered sample solution from the mixing
chamber 504. Specifically, the movement of the buffer dispense
plunger 512 within the buffer chamber 502 towards the buffer port
528 dispenses the buffer from the buffer chamber 502 into the
mixing chamber 504 via the buffer port 528 under positive pressure.
Movement of the sample dispense plunger 514 within the mixing
chamber 504 away from the sample port 506 dispenses the sample from
the sample collection chamber 412 into the mixing chamber 504 via
the sample port 506 under negative pressure. Movement of the
buffered sample dispense plunger 516 within the mixing chamber 504
towards the dispense port 530 dispenses the buffered sample
solution out of the mixing chamber 504 via the dispense port 530
under positive pressure.
[0293] The mixing assembly 500 provides for the accurate dispensing
of buffer and saliva into the mixing chamber 504 in accordance with
a selected fluid mixing ratio r, which in the illustrated
embodiment, has been selected to be 1:1. Specifically, the
cross-sectional area A.sub.1 of the buffer chamber 502,
cross-sectional area A.sub.2 of the mixing chamber, buffer dispense
plunger speed S.sub.1, and sample dispense plunger speed S.sub.2,
are selected in accordance with the equation
A.sub.2S.sub.2=A.sub.1S.sub.1(1+1/.sub.r). For example, if the
buffer dispense plunger speed S.sub.1 and sample dispense plunger
speed S.sub.2 are equal, a 1:1 mixing ratio r can be achieved by
providing a mixing chamber cross-sectional area A.sub.2 that is
twice as great as the buffer chamber cross-section area A.sub.1. On
the other hand, if mixing chamber cross-sectional area A.sub.2 is
equal to the buffer chamber cross-sectional area A.sub.1, a 1:1
mixing ratio r can be achieved by providing a sample dispense
plunger speed S.sub.2 that is twice is great as the buffer dispense
plunger speed S.sub.1. In either case, the greater the ratio
between the cross-sectional areas A.sub.2 and A.sub.1 or the
greater the ratio between the plunger speeds S.sub.2 and S.sub.1,
the more saliva is drawn into the mixing chamber 504 relative to
the buffer.
[0294] Referring to FIGS. 32-37, buffer, sample, and buffered
sample dispense plungers 512, 514, and 516 will now be described.
Referring specifically to FIGS. 32 and 33, the buffer dispense
plunger 512 comprises a rigid plunger head 532, which includes an
O-ring groove 534 for seating of an O-ring (not shown). The O-ring
of the buffer dispense plunger 512 facilitates a sealing
relationship between the buffer dispense plunger 512 and the
bearing surface 518 of the buffer chamber 502, which preferably is
coated with a silicone based substance to further facilitate this
sealing relationship. Prior to use, the buffer dispense plunger 512
is completely sealed within the buffer chamber 502 between the
upper and lower seals 520 and 522 As will be described in further
detail below, the buffer dispense plunger 512 can be moved down
within the buffer chamber 502 after the top seal 520 of the buffer
chamber 502 is punctured, and then down within the mixing chamber
504 after the bottom seal 522 of the buffer chamber 502 is
punctured.
[0295] Referring specifically to FIGS. 34 and 35, the sample
dispense plunger 514, like the buffer dispense plunger 512,
comprises a rigid plunger head 536, which includes an O-ring groove
538 for seating of an O-ring (not shown). The O-ring of sample
dispense plunger 514 facilitates a sealing relationship between the
sample dispense plunger 514 and the bearing surface 526 of the
mixing chamber 504, which preferably is coated with a silicone
based substance to further facilitate this sealing relationship.
The sample dispense plunger 514 further includes a rigid plunger
body 540 and a plunger arm 542, which includes a 90.degree. angled
end 544. As will be described in further detail below, the sample
dispense plunger 514 may be moved up or down within the mixing
chamber 504.
[0296] Referring specifically to FIGS. 36 and 37, the buffered
sample dispense plunger 516, like the buffer and sample dispense
plungers 512 and 514, also comprises a rigid plunger head 546,
which includes an O-ring groove 548 for seating of an O-ring (not
shown). Like with the sample dispense plunger 514, the O-ring of
the buffered sample dispense plunger 516 facilitates a sealing
relationship between the buffered sample dispense plunger 516 and
the bearing surface 526 of the mixing chamber 504. The buffered
sample dispense plunger 516 further includes a stylus 550, which
punctures the bottom seal 522 of the buffer chamber 502 when seated
against the buffer port 528, and a through port 552, which allows
buffer from the buffer chamber 502 to flow into the mixing chamber
504. The through port 552 is of a suitable size, e.g., 1 mm. The
buffered sample dispense plunger 516 also comprises a ferrous
element relief 554, which temporarily stores a magnetic mixing flea
(not shown). The buffered sample dispense plunger 516 is moved up
or down within the mixing chamber 504 with the buffer and sample
dispense plungers 512 and 514. The buffered sample dispense plunger
516 serves to space the sample dispense plunger 514 a distance away
from the top of the mixing chamber 504, so that it is adjacent to
the sample port 506, the purpose of which will be described in
further detail below.
[0297] To this end, and referring generally to FIGS. 34-37, the
buffered sample dispense plunger 516 has a top thrust surface 556,
which mates with a bottom thrust surface 558 of the buffer dispense
plunger 512, and a bottom thrust surface 560, which mates with a
top thrust surface 562 of the sample dispense plunger 514.
Specifically, the bottom thrust surface 558 of the buffer dispense
plunger 512 forms a stylus relief 564, which receives the stylus
550 of the buffered sample dispense plunger 516 in a complementary
fashion, and a plug 566, which fits within and seals the through
port 552 of the buffered sample dispense plunger 516. The top
thrust surface 562 of the sample dispense plunger 514 forms a
concave recess 570, which receives a convex protrusion 572 of the
bottom thrust surface 560 of the buffered sample dispense plunger
516 in a complementary fashion. Thus, the buffer dispense plunger
512 can mate with and push the buffered sample dispense plunger
down within the mixing chamber 504 as an integral unit, and the
sample dispense plunger 514 can mate with and push the buffered
sample dispense plunger up within the mixing chamber 504 as an
integral unit.
[0298] B. Sample/Buffer Mixing Subassembly--Tester Portion
[0299] Referring to FIGS. 8 and 38, the portion of the
sample/buffer mixing assembly 500 that resides in the test console
102 comprises a buffer drive assembly 574, a sample drive assembly
576, and a mixing drive assembly 578.
[0300] The buffer drive assembly 574 includes the previously
described linear stepper motor 462, motor mount 464, threaded drive
pin 466, threaded positioner 468, and first drive flange 470. The
buffer drive assembly 574 further includes a buffer driver 580 that
is mounted through the first flange 470. The buffer driver 580 is
aligned with the buffer chamber access port 524, so that when the
buffer driver 580 is driven downward from a pre-mix position to a
dispense position, it engages and pushes the buffer dispense
plunger 512 downward into the buffer chamber 502 after the upper
seal 520 of the buffer chamber 502 is punctured. A buffer chamber
access opening 170 is formed at the top 160 of the cassette case
154 (shown in FIGS. 2 and 5), thereby allowing the buffer driver
580 to engage the buffer dispense plunger 512 within the buffer
chamber 502.
[0301] The sample drive assembly 576 includes a linear stepper
motor 582 and a motor mount 584. The motor 582 is mounted to the
motor mount 584, which is in turn mounted to the distribution
flange 124. The sample drive assembly 576 further includes a
threaded drive pin 586 rotatably coupled to the motor 582, and a
threaded positioner 588 through which the drive pin 586 extends.
The sample drive assembly 576 further includes a first drive flange
590 affixed to the threaded positioner 588. The first drive flange
590 includes a runner 592 that slidingly engages the rail 476
extending along the distribution flange 124. The sample drive
assembly 576 further includes a 90.degree. angled driver 594, which
can be alternately driven upward and downward by the motor 582 a
predetermined stepped distance. The angled sample driver 594 has a
pronged tip 596, which engages the angled end 544 of the plunger
arm 542 as the cassette 152 (as illustrated in FIG. 2) is loaded
into the test console 102.
[0302] A horizontal access slot 172 is formed within the rear 158
of the cassette case 154 (shown in FIG. 2), terminating adjacent
the angled end 544 of the plunger arm 542 to facilitate its
engagement with the pronged tip 596 of the sample driver 594. When
engaged, downward and upward movement of the sample driver 594
correspondingly moves the sample dispense plunger 514 downward and
upward into the mixing chamber 504. A vertical access slot 174 is
formed within the rear 158 of the cassette case 154 (shown in FIG.
2) adjacent the angled end 544 of the plunger arm 542, thereby
allowing angled sample driver 594 to vertically displace the sample
dispense plunger 514.
[0303] The mixing drive assembly 578 includes a rotary mixing motor
598, which is mounted to the mounting flange 478, and a mixing
coupling (not shown) that is rotatably coupled to the mixing motor
598, which is located adjacent the mixing chamber 504 of the mixing
assembly 500 when the cassette 152 is loaded into the test console
102. The mixing coupling contains two magnets (also not shown),
which when rotated by the mixing motor 598 magnetically interact
with the ferrous element (not shown) within the mixing chamber
504.
[0304] It should be noted that the sample drive assembly 576,
buffer drive assembly 574, and mixing drive assembly 578 are all
operated under control of a CPU 204 and I/O controller 206 (shown
in FIG. 12), with sample and buffer motor sensors (generally shown
in FIG. 12) used to provide independent confirmation of the
positions of the sample and buffer drivers 580 and 594.
[0305] C. Sample/Buffer Mixing Subassembly--Operation
[0306] Referring generally to FIGS. 27-31, with general reference
to FIG. 38, the operation of the mixing assembly 500 will now be
described. During operation of the mixing assembly 500, the
respective sample and buffer drive assemblies 574 and 576 are
operated to move the buffer, sample, and buffered sample plungers
512, 514, and 516 upward and downward within the chambers of the
mixing assembly 500.
[0307] Referring specifically to FIG. 27, the mixing assembly 500
is shown in its shipping or home position. The buffer is completely
sealed within the buffer chamber 502 with the top and bottom seals
520 and 522 of the buffer chamber 502 yet to be punctured. The
buffer dispense plunger 512 is located at the top of the buffer
chamber 502, so that mixing chamber 504 contains the maximum amount
of buffer. The buffered sample dispense plunger 516 is at the top
of the mixing chamber 504, but is not seated against the buffer
port 528, and has therefore not yet punctured the bottom seal 522
of the buffer chamber 502. The sample dispense plunger 514 is mated
with the buffered sample dispense plunger 516. The O-ring of the
buffered sample dispense plunger 516 seals the sample port 506 in
this position to ensure that there is no vacuum leak during the
previously described sample collection process.
[0308] Referring specifically to FIG. 28, the sample drive assembly
576 is semi-automatically operated (i.e., prompted by the operator)
to move the sample dispense plunger 514, and thus the mated
dispense plunger 514, upward within the mixing chamber 504 towards
the buffer port 528 until the buffered sample dispense plunger 516
is seated against the buffer port 528, thereby puncturing the
bottom seal 522 of the buffer chamber 502. At this point, the
thickness of the buffered sample dispense plunger 516 spaces the
top thrust surface 570 of the sample dispense plunger 514 a
predetermined distance from the top of the mixing chamber 504, so
that it is just below the sample port 506. It should be noted that
at this point time, the saliva sample has already been collected in
the sample collection chamber 412, and thus, the sample port 506
need not be sealed at this point.
[0309] Referring specifically to FIG. 29, the buffer drive assembly
574 is then automatically operated (i.e., prompted by the CPU) to
engage the buffer driver 466 with the buffer chamber access port
524, puncturing the upper seal 520, and then moving the buffer
dispense plunger 512 downward within the buffer chamber 502 towards
the buffer port 528. Simultaneously, the sample drive assembly 576
is operated to move the sample dispense plunger 514 downward within
the mixing chamber 504 towards the dispense port 530. Thus, buffer
flows from the buffer chamber 502, through the buffer port 528 and
then through the through port 552 and ferrous element relief 554 of
the buffered sample dispense plunger 516, into the mixing chamber
504. At the same time, saliva sample flows from the sample
collection chamber 412, through the sample port 506, into the
mixing chamber 504, thereby forming a buffered sample solution
within the mixing chamber 504. During this dispensing process, the
sample dispense plunger 514 remains above the dispense port 530,
thus sealing it off from the buffered sample solution. It should be
noted that partial mixing of the buffer and saliva sample occurs as
they are dispensed into the mixing chamber 504.
[0310] Referring specifically to FIG. 30, downward movement of the
buffer dispense plunger 512 automatically ceases after the buffer
dispense plunger 512 is mated with the buffered sample dispense
plunger 516, and when the integral unit intersects the sample port
506 to seal it. Similarly, downward movement of the sample dispense
plunger 514 ceases when the sample dispense plunger 514 is located
at the bottom of the mixing chamber 504 intersecting the dispense
port 530 to seal it. At this point, the ferrous element (not shown)
is also released from the ferrous element relief 554 of the
buffered sample dispense plunger 516 into the mixing chamber 504.
The mixing drive assembly 578 is operated to rapidly move the
ferrous element within the mixing chamber 504, thereby agitating,
and thus, homogeneously mixing the buffered sample solution.
Because the sample and dispense ports 506 and 530 are both sealed,
none of the buffered sample solution leaks out the mixing chamber
504 during this enhanced mixing process.
[0311] Referring specifically to FIG. 31, the buffer drive assembly
574 is automatically operated again to move the buffer dispense
plunger 512, and thus the buffered sample dispense plunger 516,
downward within the mixing chamber 504 towards the dispense port
530. Simultaneous with this, the sample drive assembly 576 is
automatically operated to move the sample dispense plunger 514
downward within the mixing chamber 504 until the entire sample
dispense plunger 514 is below the dispense port 530. At this point,
the dispense port 530 is exposed to the buffered sample solution
within the mixing chamber 504, and downward movement of the sample
dispense plunger 514 automatically ceases. Downward movement of the
mated buffer and buffered sample dispense plungers 512 and 516, on
the other hand, continues, thereby dispensing the buffered sample
solution from the mixing chamber 504 out through the dispense port
530. Downward movement of the mated buffer and buffered sample
dispense plungers 512 and 516 continues until the buffered sample
dispense plunger 516 mates with the sample dispense plunger 514,
and thus when the buffered sample solution has been completely
dispensed from the mixing chamber 504. Anytime prior to the
ejection of the cassette 152 from the test console 102, the sample
and buffer drive assemblies 574 and 576 are automatically moved
back to their home positions (i.e., disengaged from the cassette
152).
[0312] VI. Flow Immunoassay Assembly
[0313] Referring generally to FIGS. 39-65, the system 100 comprises
a flow immunoassay assembly 600, the purpose of which is to
generate and exhibit a measurable immunoassay reaction for each
targeted drug (ten in the illustrated embodiment) that is found in
the buffered sample solution received from the sample/buffer mixing
assembly 500. In performing this function, the flow immunoassay
assembly 600 includes a sample/buffer flow assembly 602 and an
immunoassay reaction assembly 604. The flow immunoassay assembly
600 comprises a plurality of sample flow channels 606 (ten in the
illustrated embodiment) and a plurality of buffer flow channels 608
(ten in the illustrated embodiment), which are respectively used to
flow sample and buffer therethrough in effecting the proper
immunoassay reaction for each targeted drug.
[0314] A. Sample/Buffer Flow Assembly
[0315] The purpose of the sample/buffer flow assembly 602 is to
provide appropriate volumes, flow rates, and flow times for
continuous buffer pre-wash, sample, and buffer post-wash solutions
to flow through the immunoassay reaction assembly 604.
[0316] 1. Sample/Buffer Flow Assembly--Cassette Portion
[0317] Referring specifically to FIGS. 39 and 40, the portion of
the sample/buffer flow assembly 602 that resides in the cassette
152 includes a rotary valve 610 and an equal number (ten in the
illustrated embodiment) of sample distribution chambers 612, buffer
chambers 614, and a sample feed port 628. For purposes of context,
the immunoassay reaction assembly 604, and specifically, an equal
number of reaction chambers 616, a read cell assembly 618
comprising an equal number of read cells 620, and a waste chamber
622, are also illustrated.
[0318] The rotary valve 610 includes a generally cylindrical hollow
stator 624 and a generally cylindrical rotor 626, which is inserted
into the stator 624 in a rotatably sealing relationship.
Preferably, the stator 624 is slightly lubricated with silicone oil
to provide for a smooth rotary relationship between the stator 624
and rotor 626. The rotary valve 610 is of a suitable length to
support the sample and buffer flow channels, which in the
illustrated embodiment, is 13 cm. The rotor 626 can be clocked
within the stator 624 to place the rotary valve 610 into a various
configurations to effect predefined flow paths between the
afore-described mixing chamber 504 of the mixing assembly 500 and
the sample distribution chambers 612, between the sample
distribution chambers 612 and the immunoassay reaction chambers
616, and between the buffer chambers 614 and the immunoassay
reaction chambers 616.
[0319] In the illustrated embodiment, the rotary valve 610 can be
clocked between a distribution configuration (sample distribution
configuration), dispense configuration (sample flow configuration),
first auxiliary dispense configuration (buffer pre-wash
configuration), and second auxiliary dispense configuration (buffer
post-wash configuration). In the illustrated embodiment, the sample
distribution and buffer pre-wash configurations are simultaneously
effected by placing the rotary valve 610 in a first position, and
the sample dispense and buffer post-wash configurations are
simultaneously effected by placing the rotary valve 610 in a second
position clocked 90.degree. from the first position.
[0320] Specifically, the rotary valve 610, when in the sample
distribution configuration, places the sample feed port 628 in
fluid communication with the sample distribution chambers 612,
while preventing fluid communication between the sample
distribution chambers 612 and reaction chambers 616, thus
facilitating distribution of the buffered sample solution
(hereinafter, sample) from the mixing assembly 500 into the sample
distribution chambers 612 without prematurely exposing the
immunoassay reaction chambers 616 to the sample. The rotary valve
610 also provides for proper venting of air displaced from the
sample distribution chambers 612 during the distribution process.
In the illustrated embodiment, a single vertical flow path 630 and
a single horizontal flow path 632 accomplishes this by connecting
the sample feed port 628 with the sample distribution chambers 612
using the vertical flow path 630, and connecting the sample
distribution chambers 612 in series and filling them in a cascading
manner using the horizontal flow path 632. In this manner, each of
the sample distribution chambers 612 are filled with
precisely-measured prevolumes of sample. Another single vertical
flow path 634 connects the sample distribution chambers 612 to a
vent port (not shown). It should be noted that for the purposes of
this specification, elements are in fluid communication with each
other when configured such that fluid flowing through one element
correspondingly flows through the other element.
[0321] The rotary valve 610, when in the sample flow configuration,
places the sample distribution chambers 612 in fluid communication
with the immunoassay reaction chambers 616, while preventing fluid
communication between the sample distribution chambers 612 and
sample feed port 628, thus facilitating the flow of the sample from
the sample distribution chambers 612 through the immunoassay
reaction chambers 616, and preventing the flow of the sample out
through the sample feed port 628. In the illustrated embodiment,
ten parallel vertical flow paths 634 are formed between the sample
distribution chambers 612 and the immunoassay reaction chambers 616
when the rotary valve 610 is in the sample flow configuration.
[0322] The rotary valve 610, when in either of the buffer pre-wash
or buffer post-wash configurations, places the buffer chambers 614
in fluid communication with the immunoassay reaction chambers 616,
thus facilitating the flow of the buffer from the buffer chambers
614 through the immunoassay reaction chambers 616. In the
illustrated embodiment, two different sets of ten parallel vertical
flow paths 636/638 are formed between the buffer chambers 614 and
the immunoassay reaction chambers 616. The structure and operation
of the afore-described flow paths will be described in further
detail below.
[0323] In the illustrated embodiment, the sample distribution
configuration is clocked 0.degree. from the buffer pre-wash
configuration, i.e., the rotary valve 610 is clocked in the same
position for the distribution and buffer pre-wash configurations.
Thus, the buffer can be flowed from the buffer chambers 614 through
the immunoassay reaction chambers 616, and the sample can be
distributed to the sample distribution chambers 612 without
clocking the rotary valve 610 between the buffer dispense and
sample distribution functions. Likewise, the sample flow
configuration is clocked 0.degree. from the buffer post-wash
configuration, i.e., the rotary valve 610 is clocked in the same
position for the sample dispense and buffer post-wash
configurations. Thus, the buffer can be flowed from the buffer
chambers 614 through the immunoassay reaction chambers 616, and the
sample can be flowed from the sample distribution chambers 612
through the immunoassay reaction chambers 616 without clocking the
rotary valve 610 between the sample dispense and buffer dispense
functions. The sample flow configuration is clocked 90.degree. from
the sample distribution configuration, thus requiring movement of
the rotary valve 610 when switching from the sample distribution
function to the sample dispense function.
[0324] The sample distribution chambers 612, in combination, are
sized to contain at least an amount equal to the entire sample
dispensed from the mixing chamber 504. For example, each of the
sample distribution chambers 612 has a nominal 250 .mu.L fluid
capacity. Referring now to FIG. 41, each of the sample distribution
chambers 612 is cylinder-shaped and is composed of a suitable
material, e.g., injection molded polycarbonate. The sample
distribution chamber 612 comprises a plunger bearing surface 640
with which an associated sample dispense plunger 642 sealingly
mates. Like the previously described buffer dispense plunger 512
used in the mixing assembly 500, each of the sample dispense
plungers 642 comprises a rigid plunger head 644, which includes an
O-ring groove 646 for seating of an O-ring 648. The O-ring 648 of
the sample dispense plunger 642 facilitates a sealing relationship
between the sample dispense plunger 642 and the bearing surface 640
of the sample distribution chamber 612, which preferably is coated
with a silicone-based substance to further facilitate this sealing
relationship. As will be described in further detail below,
movement of the sample dispense plunger 642 upward within the
sample distribution chamber 612 flows the sample from the sample
distribution chambers 612, through the associated reaction chambers
616 and read cells 620, and into the waste chamber 622, when the
rotary valve 610 is placed in the sample flow configuration.
[0325] Referring now to FIGS. 43 and 44, each of the buffer
chambers 614 is cylindrical-shaped and is composed of a suitable
material, e.g., injection molded polypropylene. Since the cassette
152 contains stabilized lyophilized enzyme and immunoassay
reagents, as will be described below, it is essential to prevent
migration of water vapor through the walls of the buffer chambers
614. To this end, the walls of each buffer chambers 614 are
sufficiently thick and impermeable to water vapor during the
storage lifetime of the cassette 152. Each buffer chamber 614
contains a suitable neutral buffer solution, e.g., phosphate
buffered saline (PBS) buffer solution (pH 6.9) containing protein
(0.2% BSA) and 0.05%.sub.w/v sodium azide (NaN.sub.3) stabilizers,
and has a capacity suitable to effectively facilitate the buffer
pre- and post-wash functions. For example, each buffer chamber 614
has a capacity of 1.0 ml. Each buffer chamber 614 comprises an
angled rigid tube 650, and puncturable upper and lower seals 652
and 654 bonded at the top and bottom of the buffer chamber 614 to
completely seal the buffer within the buffer chamber 614 until the
dispensing process has commenced. The upper and lower seals 652 and
654 prevent water vapor from escaping the confines of the buffer
chamber 614 during storage of the cassette 152, and are composed of
a suitable material, such as aluminum foil-lined/polymer bilayer
seals.
[0326] Each of the buffer chambers 614 comprises a cylindrical
bearing surface 656 with which an associated buffer dispense
plunger 658 sealingly mates. The buffer dispense plunger 658, like
the sample dispense plunger 642, comprises a rigid plunger head
660, which includes an O-ring groove 662 for seating of an O-ring
664 The O-ring 664 of the buffer dispense plunger 658 facilitates a
sealing relationship between the buffer dispense plunger 658 and
the bearing surface 656 of the buffer chamber 614. The buffer
dispense plunger 658 further includes a stylus 666, which is
configured to puncture the top seal 654 of the buffer chamber 614.
As will be described in further detail below, movement of the
buffer dispense plunger 658 upward within the sample distribution
chamber 612 (after puncturing the lower seal 654), causes the
stylus 666 to puncture the upper seal 654, allowing the buffer to
flow from the buffer chambers 614, through the associated reaction
chambers 616 and read cells 620, and into the waste chamber 622,
when the rotary valve 610 is placed in the buffer pre-wash or
buffer post-wash configurations.
[0327] Having already described the general function of the rotary
valve 610, its detailed structure will now be described. Referring
to FIGS. 45-51, the stator 624 is composed of a suitable material
that is able to endure the large rotary torque that will be applied
in order to rotate the closely toleranced multi-channel rotor 626
therein. In the illustrated embodiment, the stator 624 is composed
of an injection-molded polycarbonate, which exhibits the required
mechanical strength and rigidity. The stator 624 comprises a hollow
cylindrical wall 668 having an inner bearing surface 670 with which
the rotor 626 is rotatably associated, and an outer surface 672
with which a variety of chamber seats and ports are associated.
[0328] Specifically, the stator 624 comprises the afore-described
sample feed port 628 (best shown in FIG. 48D), which extends
through the cylindrical wall 668, and a sample feed seat 674, which
extends from the cylindrical wall 668 and surrounds the sample feed
port 628. The mixing chamber dispense port 530 is firmly, but
removably, seated within the sample feed seat 674, thereby placing
the mixing chamber 504 in fluid communication with the sample feed
port 628. The stator 624 further comprises a number of distribution
port pairs 676 (best shown in FIGS. 47B and 49) equal to the number
of sample distribution chambers 612, which in the illustrated
embodiment is ten. Each of the distribution port pairs 676 includes
a entry distribution port 678 and a distribution exit port 680. The
distribution port pairs 676 extend through the cylindrical wall 668
and are disposed along one side of the cylindrical wall 668 in a
equidistant rectilinear fashion. In the illustrated embodiment,
there are no seats for the sample distribution chambers 612, but
rather the distribution chambers 642 are molded directly onto the
outer surface 672 of the cylindrical wall 668 over the distribution
port pairs 676, thereby respectively placing the sample
distribution chambers 612 in fluid communication with the
distribution port pairs 676. As will be described in further detail
below, the distribution port pairs 676 facilitate distribution of
the sample into the sample distribution chambers 612 in a cascading
manner. It should be noted that the distribution exit ports 680 are
also used as sample entry dispense ports 681 during sample flow, as
will be described in further detail below.
[0329] The stator 624 further comprises a number of auxiliary entry
dispense ports (buffer entry dispense ports) 682 (best shown in
FIGS. 48D and 50) and a number of corresponding auxiliary seats
(buffer chamber seats) 684 equal to the number of buffer chambers
614, which in the illustrated embodiment is ten. The buffer entry
dispense ports 684 extend through the cylindrical wall 668 and are
disposed along another side of the cylindrical wall 668 in an
equidistant rectilinear fashion. The buffer chamber seats 684
extend from the cylindrical wall 668 and respectively circumscribe
the corresponding buffer entry dispense ports 684. The angled tubes
650 of the corresponding buffer chambers 614 are firmly, but
removably, seated within the buffer chamber seats 684, thereby
placing the buffer chambers 614 in fluid communication with the
buffer entry dispense ports 684.
[0330] The stator 624 further comprises a number of exit dispense
ports 686 and a number of exit dispense seats (reaction chamber
seats) 688 (best shown in FIGS. 47B and 51) equal to the number of
immunoassay reaction chambers 616. The exit dispense ports 686
extend through the cylindrical wall 668 along still another side of
the cylindrical wall 668 in an equidistant rectilinear fashion. The
reaction chamber seats-688 extend from the cylindrical wall 668 and
respectively circumscribe the corresponding exit dispense ports
686. The corresponding reaction chambers 616 are firmly, but
removably, seated within the reaction chamber seats 688, thereby
placing the immunoassay reaction chambers 616 in fluid
communication with the exit dispense ports 686. Significantly, it
should be noted that the exit dispense ports 686 are clocked
180.degree. from the entry distribution ports 678 and 90.degree.
from the buffer entry dispense ports 684. It should also be noted
that the last exit dispense port 686 also serves as the previously
mentioned vent port 687, as will be described in further detail
below.
[0331] Referring now to FIGS. 52-54, the rotor 626 comprises a
honeycombed rotor core 690 and a rotor lining 692 disposed on the
rotor core 690. Like the stator 624, the rotor core 690 is composed
of a material that is able to endure the large rotary torque that
will be applied to, which in the illustrated embodiment, is
injection-molded polycarbonate. The rotor core 690 forms a number
of equidistant arcuate ridges 694 and a number of longitudinal
ridges 696 on which the various channels will be formed, as will be
described in further detail below. The rotor core 690 further forms
four radially equidistant sets of alignment apertures 698 between
the arcuate and longitudinal ridges 694 and 696. These apertures
698 are engaged by the mandrel of the injection molding machine
during the injection molding process. The compliant lining 692 is
the portion of the rotor 626 that sealingly engages the inner
bearing surface 670 of the stator 624. The compliant lining 692 is
composed of a suitably compliant material, such as, polyurethane,
which is injection molded over the outer periphery of the rotor
core 690, and specifically, onto the various ridges formed by the
honeycombed configuration of the rotor core 690. The end of the
rotor core 690 forms four radially extending ridges 700 for
engagement with a rotary valve drive assembly, as will be discussed
in further detail below.
[0332] As will now be described, surface channels 702, surface
channel stops 704, and through channels 706 associated with the
rotor core 690 effect the afore-described flow paths, as specified
by the various configurations in which the rotary valve 610 can be
placed. Referring specifically to FIG. 53A, a compliant sealing
material is formed onto the ridges of the rotor core 690. If a
surface channel 702 is to be formed, the sealing material is formed
on the opposing lateral surfaces 708 (shown best in FIG. 54) of the
ridge 694/696, while leaving the adjacent circumferential surface
710 of the ridge 694/696 exposed. If a surface channel stop 704 is
to be formed, the sealing material is formed on both the lateral
surfaces 708 and the adjacent circumferential surface 710 of the
ridge 694/696. Thus, when the rotor 626 is firmly disposed within
the stator 624, fluid will flow within the surface channels 702
between the exposed circumferential surface of the associated ridge
and the inner bearing surface 670 of the stator 624. For the
purposes of this specification, the surface channels 702 associated
with the arcuate ridges 694 are considered arcuate surface
channels, and the surface channels 702 associated with the
longitudinal ridges 696 are considered longitudinal surface
channels.
[0333] During the injection molding process, the inner surface of a
mandrel will be in high pressure contact with the circumferential
surfaces 710 of the ridges 694/696 where surface channels 702 are
to be formed. The inner surface of the mandrel will not be in
contact at all with the circumferential surfaces 710 of the ridges
694/696 where surface channel stops 704 are to be formed. For
purposes of alignment and stability, the mandrel will also be in
contact with the apertures 698 of the rotor core 690 between the
ridges 694/696. It should be noted that when forming surface
channels 702 on the ridges of the rotor core 690 via injection
molding, the mandrel will preferably in high pressure contact with
the circumferential surface of the ridge opposite (i.e.,
180.degree.) that of the ridge on which the surface channel 702 is
to be formed to ensure that the mandrel holds the rotor core 690
firmly in place during the high pressure injection molding process.
Thus, unused surface channels 702 may be formed opposite the used
surface channels as a result of this process. It should be noted
that the injection molding process allows the rapid high volume
assembly of a uniform leak-proof rotor 626 without the need for
gaskets or O-rings.
[0334] The through channels 706 are formed transversely through the
longitudinal axis of the rotor core 690, with one end of the
through channel 706 formed through a ridge 694/696, and the other
end of the through channel 706 being formed through an oppositely
disposed ridge 694/696. A surface channel 702 is connected to a
through channel 706 by forming the surface channel 702 adjacent an
end of the through channel 706.
[0335] Referring further to FIGS. 52 and 55-57, the rotary valve
610, when clocked in the sample distribution configuration, is
channeled to place the sample feed port 628 and distribution port
pairs 676 of the stator 624 in fluid communication with each other,
and thus, the sample distribution chambers 612 in fluid
communication with the sample feed port 628. The rotor 626 is also
configured to place the distribution port pairs 676 in fluid
communication with the vent port 687 of the stator 624, and thus
the sample distribution chambers 612 in fluid communication with
the waste chamber 622. To this end, the rotor 626 comprises a feed
channel 712, which connects the sample feed port 628 and the first
distribution port pairs 676 to each other, and a plurality of
distribution channels 714 (sample distribution channels), which
connect the distribution port pairs 676 to each other. The rotor
626 further comprises a vent channel 716, which connects the last
distribution port pair 676 to the vent port 687.
[0336] The feed channel 712 specifically comprises a through
channel 706(1) and a 90.degree. arcuate surface channel 702(1). One
end of the through channel 706(1) connects to the sample feed port
628, and the 90.degree. arcuate surface channel 702(1) is connected
between the other end of the through channel 706 and the entry
distribution port 678 of the first distribution port pair 676. The
sample distribution channels 714 specifically comprise longitudinal
surface channels 702(2) that connect the distribution exit port 680
of each distribution port pair 676 with the entry distribution port
678 of the next distribution port pair 676. The vent channel 716
includes a 90.degree. arcuate surface channel 702(3), a through
channel 706(2), and another 90.degree. arcuate surface channel
702(4). One end of the 90.degree. arcuate surface channel 702(3) is
connected to the exit distribution port 680 of the last
distribution port pair 676, one end of the through channel 706(2)
is connected to the other end of the 90.degree. arcuate surface
channel 702(3), and the other 90.degree. arcuate surface channel
702(4) is connected between the other end of the through channel
706(2) and the vent port 687. It should be noted that there are
preferably no channels, other than the vent channel 716, that
places the sample distribution chambers 612 in fluid communication
with the immunoassay reaction chambers 616 when the rotor 626 is
clocked in the sample distribution configuration, thereby
preventing sample from being prematurely dispensed from the sample
distribution chambers 612 into the immunoassay reaction chambers
616.
[0337] Referring to FIGS. 52 and 58-60, the rotary valve 610, when
clocked in the sample flow configuration, is channeled to place the
sample entry dispense ports 681 (which as previously discussed
coincide with the exit distribution ports 680) and exit dispense
ports 686 of the stator 624 in fluid communication with each other,
and thus, the sample distribution chambers 612 in fluid
communication with the immunoassay reaction chambers 616. To this
end, the rotor 626 comprises dispense channels (sample dispense
channels) 718, and specifically through channels 706(3), which
connect the corresponding sample entry dispense ports 681 and exit
dispense ports 686 with each other. It should be noted that the
sample dispense channels 718 are oriented in relation to the sample
distribution channels 714 to correspond to the 90.degree. clocking
difference between the sample distribution and sample flow
configurations.
[0338] Referring to FIGS. 53 and 61-63, the rotary valve 610, when
clocked in the buffer pre-wash configuration, is channeled to place
the buffer entry dispense ports 684 and exit dispense ports 686 of
the stator 624 in fluid communication with each other, and thus,
the buffer chambers 614 in fluid communication with the immunoassay
reaction chambers 616. To this end, the rotor 626 comprises first
auxiliary dispense channels 720 (buffer pre-wash channels), which
connect the buffer entry dispense ports 684 and exit dispense ports
686 to each other. Each of the buffer pre-wash channels 720
specifically comprises a through channel 706(4) and a 90.degree.
arcuate surface channel 702(5). One end of the through channel 706
is connected to the corresponding buffer entry dispense port 682,
and the 90.degree. arcuate surface channel 702 is connected between
the other end of the through channel 706 and the corresponding exit
dispense port 686. It should be noted that the buffer pre-wash
channels 720 are oriented in relation to the sample distribution
channels 714 to correspond to the 0.degree. clocking difference
between the buffer pre-wash configuration and the sample
distribution configuration.
[0339] Referring to FIGS. 53, 64, and 65, the rotary valve 610,
when clocked in the buffer post-wash configuration, is channeled to
place the buffer entry dispense ports 684 and exit dispense ports
686 of the stator 624 in fluid communication with each other, and
thus, the buffer chambers 614 in fluid communication with the
immunoassay reaction chambers 616. To this end, the rotor 626
comprises second auxiliary dispense channels 722 (buffer post-wash
channels), which connect the buffer entry dispense ports 684 and
exit dispense ports 686 to each other. Each of the buffer post-wash
channels 722 specifically comprises the aforementioned 90.degree.
arcuate surface channel 702(5) connected between the corresponding
buffer entry dispense port 682 and the corresponding exit dispense
port 686. It should be noted that the buffer post-wash channels 722
are oriented in relation to the sample dispense channels 718 to
correspond to the 0.degree. clocking difference between the buffer
post-wash configuration and the sample flow configuration.
[0340] 2. Sample/Buffer Flow Assembly--Tester Portion
[0341] Having just described the portion of the sample/buffer flow
assembly 602 associated with the cassette 152, the portion of the
sample/buffer flow assembly 602 associated with the test console
102 will be discussed. Referring to FIGS. 11, 13-15, and 66-68, the
sample/buffer flow assembly 602 further includes a rotary valve
drive assembly 730, a number of sample drive assemblies 732, and a
number of buffer drive assemblies 734.
[0342] Referring specifically to FIGS. 11 and 13-15, the rotary
valve drive assembly 730 functions to provide the large amount of
torque (in the illustrated embodiment, .gtoreq.5.5 N-m) necessary
to clock the multi-channel rotary valve 610 90.degree. from the
sample distribution/buffer pre-wash configuration (its home
position) and the sample dispense/buffer post-wash configuration
(its actuated position). Specifically, the rotary valve drive
assembly 730 comprises a linear stepper motor 736, and a motor
mount 738 for affixing the linear motor 736 to the side main base
flange 122. The rotary valve drive assembly 730 further includes a
rotor driver 740, which is linearly displaced by the motor 736. The
rotary valve drive assembly 730 further includes a crank arm 742,
one end of which is hingedly connected to the rotor driver 740, and
the other end of which is affixed to a rotary pin 744. The rotary
pin 744 has a pronged end 746 (best shown in FIG. 14) that engages
the end of the rotor 626 of the rotary valve 610 between the
radially extending ridges 700.
[0343] The shaft of the rotary pin 744 rotatably extends through an
aperture 748 formed in a pin alignment flange 750, which is
suitably mounted to the top main base flange 116 to align the
rotary pin 744 with the rotor 626 of the rotary valve 610. Thus,
operation of motor 736 linearly translates the rotor driver 740,
rotating the crank arm 742, and thus the rotary pin 744 and rotor
626.
[0344] It should be noted that the rotary valve drive assembly 730
is operated under control of a CPU 204 and I/O controller 206
(shown in FIG. 12), with a rotary valve home sensor (generally
shown in FIG. 12) used to provide independent confirmation that the
end of the rotary pin 744 rotationally aligns with the end of the
rotor 626. It should be noted that the cassette case 154 comprises
a rotary valve access opening 176 (shown in FIG. 3) formed on the
side of the cassette case 154 adjacent one end of the rotary valve
610, thereby allowing the rotary valve drive assembly 730 to
operably associate with the rotor 626 of the rotary valve 610.
[0345] Referring specifically to FIGS. 11 and 66-68, the sample
drive assemblies 732 function to move the sample dispense plungers
642 upward within the respective sample distribution chambers 612.
The number of sample drive assemblies 732 may vary, but in the
illustrated embodiment, is four, with (1) the first sample drive
assembly 732(1) being operably associated with the first two sample
distribution chambers 612; (2) the second sample drive assembly
732(2) being operably associated with the next three sample
distribution chambers 612; (3) the third sample drive assembly
732(3) being operably associated with the next three sample
distribution chambers 612; and (4) the fourth sample drive assembly
732(4) being operably associated with the last two sample
distribution chambers 612. The sample drive assemblies 732 are
arranged in a rectilinear series, so that they are properly aligned
with the rectilinear series of sample distribution chambers
612.
[0346] The buffer drive assemblies 734 similarly function to move
the buffer dispense plungers 658 upward within the respective
buffer chambers 614. The number of sample drive assemblies 732 may
vary, but in the illustrated embodiment, equals four, with (1) the
first buffer drive assembly 734(1) being operably associated with
the first two buffer chambers 614; (2) the second buffer drive
assembly 734(2) being operably associated with the next three
buffer chambers 614; (3) the third buffer drive assembly 734(3)
being operably associated with the next three buffer chambers 614;
and (4) the fourth buffer drive assembly 734(4) being operably
associated with the last two buffer chambers 614. The buffer drive
assemblies 734 are arranged in a rectilinear series, so that they
are properly aligned with the rectilinear series of buffer chambers
614.
[0347] Each sample/buffer drive assembly includes a linear stepper
motor 752 with an associated motor driver 754, and a ganged plunger
drive assembly 756. Each motor 752 is mounted to the bottom surface
of the bottom main base flange 118, with the associated motor
driver 754 extending through a respective aperture 758 formed
through the bottom main base flange 118. The motor driver 754
includes a rotational bearing (not shown) mounted thereon adjacent
the top surface of the bottom main base flange 118 for association
with the ganged plunger assembly 756.
[0348] The ganged plunger assembly 756 includes a gang base 760
with a common aperture (not shown) formed at the bottom of the gang
base 760 and in which the rotational bearing of the motor driver
754 is firmly mounted. The gang base 760 further includes three
equally spaced sample dispense plunger drive seats 762 disposed
along the center of gang base 760 opposite the common aperture 762.
The ganged plunger assembly 756 further includes two or three
sample/buffer dispense plunger drivers 764 seated within the
respective plunger drive seats 762. The sample/buffer dispense
plunger drivers 764 extend from the plunger drive seats 762 and up
through apertures 766 formed through the top main base flange 116.
For purposes of compactness, two sample/buffer dispense plunger
drivers 764 occupy the second and third plunger drive seats 762
with respect to the first sample drive assembly 732(1); three
sample/buffer dispense plunger drivers 764 will occupy all three of
the plunger drive seats 762 with respect to the third sample drive
assembly 732(2); three sample/buffer dispense plunger drivers 764
will occupy all three of the plunger drive seats 762 with respect
to the third sample drive assembly 732(3); and two sample/buffer
dispense plunger drivers 764 will occupy the first and second
plunger drive seats 762 with respect to the fourth sample drive
assembly 732(4).
[0349] The sample/buffer dispense plunger driver 764 extending from
the second (or center) plunger drive seat 762 includes a linear
bearing (not shown), and the remaining sample/buffer dispense
plunger drivers 764 include a bushing (not shown), which are firmly
mounted within the aperture 766 in the top main base flange 116.
This arrangement prevents the sample/buffer dispense plunger
drivers 764 from binding within the apertures 766 of the top main
base flange 116 that may otherwise occur due to manufacturing
tolerances. The apertures 766 within the top main base flange 116
align the sample/buffer dispense plunger drivers 764 with the
corresponding sample dispense plungers 642 within the distribution
chambers 612, such that operation of the respective sample and
buffer drive assemblies 732 and 734 correspondingly engage the
sample dispense plungers 642 with the sample dispense plunger
drivers 764, and the buffer dispense plungers 658 with the buffer
dispense plunger drivers 764. It should be noted that the sample
and buffer drive assemblies 732 and 734 are considered to be in
their home positions when the ends of the respective sample/buffer
dispense plunger drivers 764 are below the bottom flange 118 of the
cassette carriage 302, and in their pretest positions when the ends
of the respective sample/buffer dispense plunger drivers 764 are
disposed through apertures 768 (shown in FIG. 13) within the bottom
flange 306 of the cassette carriage 302 and engaged with the
respective sample and buffer dispense plungers 642 and 658 within
the sample distribution and buffer chambers 612 and 614.
[0350] Thus, the ganging of the plunger drivers 764 provides
flexibility in selecting different flow rates and volumes of the
sample and buffer dispensed from the respective sample distribution
and buffer chambers 612 and 614. For example, if the accurate
testing of two or three drugs requires a relatively high volume,
slow flow rate, the flow paths associated with these tests can be
associated with a single gang assembly, while other flow paths can
be associated with the other gang assemblies. It should be noted
that the sample drive assemblies 732 and buffer drive assemblies
734 are all operated under control of a CPU 204 and I/O controller
206 (shown in FIG. 12). Sample and buffer motor assembly home and
pre-test sensors (generally shown in FIG. 12) are provided to
ensure that the respective sample and buffer drive assemblies 732
and 734 are placed into their home and pre-test positions when
desired. In the illustrated embodiment, a pair of printed circuit
boards (PCB's) 770 (one for the set of sample drive assemblies 732
and one for the set of buffer drive assemblies 734) and
corresponding indicators 734 mounted to each of the gang bases 760
are used to convey this information.
[0351] It should also be noted that the cassette case 154 (shown in
FIGS. 3 and 4) comprises for providing mechanical access to the
sample and buffer chambers 612 and 614. Specifically, a series of
ten distribution chamber access openings 178 is formed on the
underside of a ledge 180 above the bottom 162 of the cassette case
154, thereby allowing the sample dispense plunger drivers 764 to
engage the sample dispense plungers 642 within the sample
distribution chambers 612. Likewise, a series of ten buffer chamber
access openings 182 is formed on the bottom 162 of the cassette
case 154, thereby allowing the buffer dispense plunger drivers 764
to engage the buffer dispense plungers 658 within the buffer
chambers 614.
[0352] B. Immunoassay Reaction Assembly
[0353] Referring generally to FIGS. 69-77, the purpose of the
immunoassay reaction assembly 604 is to: 1) perform a dynamic,
continuous-flow immunoassay reaction on the sample in each of the
drug channels; (2) present the reacted sample to scanning detector;
and (3) collect and permanently store fluids that have flowed
within the immunoassay reaction assembly 604. The immunoassay
reaction assembly 604 comprises the afore-mentioned immunoassay
reaction chambers 616, read cell assembly 618, and waste chamber
622.
[0354] Referring specifically to FIGS. 69 and 70 (close up of
reaction chamber) each reaction chamber 616 is configured to
provide the biochemical reaction necessary to detect analytes in
the sample when flowed therethrough. It should be first noted that
although the present inventions can employ various types of assays
(e.g., direct binding, sandwich, and competition assays), the
illustrated embodiment utilizes displacement assays to facilitate
the detection of analytes in the sample. Specifically, the
immunoassay reaction chambers 616 perform exchange reactions
between the sample and immobilized antibody proteins, which have
been previously saturated with labeled antigen (and then stabilized
by lyophilization).
[0355] To this end, each immunoassay reaction chamber 616 comprises
a cylindrical column 774 composed of a suitable chemically insert
material, such as injection molded polypropylene polymer. The
column 774 can be of any suitable size and form that allows it to
compactly fit within the cassette 152. In the illustrated
embodiment, the column 774 is 10 mm (0.4 in) in length and has a 2
mm (0.080 in) inner diameter channel 780. The reaction chamber 616
further comprises a read cell seat 775 in which ends of the read
cells 620 will be seated, as will be described in further detail
below. Each column 774 contains dried drug reagent, and
specifically, a support medium that carries lyophilized
antibody-antigen complexes that react in the presence of a target
drug analyte. In the illustrated embodiment, the support medium
comprises beads 776 that are composed of a material that is neutral
to the target drug analytes, so that a false positive or negative
signal is not created. Sephacryl S-1000 beads having a 60 .mu.m
median diameter have been found to be suitable for this purpose.
Among other suitable materials are silica or glass beads, hollow
fibers, and activated polymers. In further embodiments, the hollow
fibers or bundles of capillary tubes may serve simultaneously as
the reaction chamber 616 and support medium.
[0356] The antibody-antigen complexes are formed by covalently
bonding immobilized antibodies on the beads 776 for the appropriate
drug to be tested. In the illustrated embodiment, approximately 10%
of the active surface of each bead is covered with the antibody.
The immobilized antibody is then saturated with labeled antigen,
which form the drug tracer. Any suitable labeled antigen (such as,
e.g., radiolabels, fluorophores, chromophores, electroactive
groups, and electron spin label) can be used in the process, but in
the illustrated embodiment, the labeled antigen comprises
covalently bonded fluorescent CY5 dye, which excites best at 650 nm
and fluoresces at 655-700 nm. The tracer-saturated antibody beads
are stabilized with protein (BSA) and trehalose, and then packed as
a known volume slurry into the column 774. The column 774 is washed
to remove any excess labeled dye, and then lyophilized to provide
for stability of one year under appropriate storage conditions. In
the illustrated embodiment, each column 774 contains 3 mg of dried
reagent. Further details on preparing lyophilized antibody-antigen
complexes are disclosed in U.S. Pat. No. 5,354,654, entitled
"Lyophilized Ligand-Receptor Complexes for Assays and Sensors,"
which is fully and expressly incorporated herein by reference.
[0357] In order to contain the beads 776, while allowing the flow
of liquid through the reaction chamber 616, circular-shaped porous
barriers or screens (frits) 778 are provided at the bottom and top
of the column channel 780. The frits 778 also serve to prepare the
sample by filtering out all particles larger than the pore size (in
the illustrated embodiment, 30 .mu.m) from the saliva. It is noted
that larger particles (e.g., 135 .mu.m) are initially filtered by
the sample collection tip 406 of the previously described sample
collection assembly 400. In the preferred embodiment, the frits 778
are advantageously self-sealing in that they are held in place by
interference fit within the column channel 780.
[0358] With reference to FIG. 71, a preferred method of
manufacturing the immunoassay reaction chamber 616 using a frit
tool assembly 850 will now be discussed. The frit tool assembly 850
is capable of simultaneously manufacturing, compressing, and
installing frits 778 within a plurality reaction columns 774, which
in the illustrated embodiment, is accomplished for an 12.times.96
array of immunoassay reaction chambers 616. The compressed frits
778 when disposed within the column 774 are allowed to expand,
thereby creating compressive forces between the first and the
column channel 780. For purposes of clarification and brevity, the
manufacture of only one immunoassay reaction chamber 616 will be
discussed in detail.
[0359] The frit tool assembly 850 generally comprises a punch plate
852, stripper plate 854, die plate 856, frit compression plate 858,
chamber adapter plate 860, and base plate 861. The punch plate 852
includes a number of cylindrical punch plate pins 855 extending
therefrom. The stripper plate 854 includes an equal number of
circular passages 862 passing therethrough. Likewise, the die plate
856 includes an equal number of circular shearing passages 864
passing therethrough. Disposed between the stripper and die plates
854 and 856 is a frit material 866. As illustrated in FIG. 72, a
motor assembly (not shown) operably coupled to the punch plate 852
is configured to drive the punch pins 855 (each of which has a
diameter equal to the diameter of the die plate shearing passages
862) through the strip plate passages 862 and into the die plate
shearing passages 864 to shear off the frits 778 within the die
plate shearing passages 864. It is noted that the diameter of the
uncompressed frit 778 will be approximately equal to the diameter
of the die plate shearing passages 864, which in the illustrated
embodiment, is 0.082 in.
[0360] The frit compressing plate 858 includes an equal number of
conical passages 868 passing therethrough. The conical passages 868
have upper openings 870, which are configured to receive the newly
cut frits 778 from the die plate shearing passages 864. In the
illustrated embodiment, the diameters of the upper openings 870 are
greater than that of the die plate shearing passages 864 to
compensate for manufacturing and alignment tolerances, thereby
ensuring that the upper openings 870 can receive the frits 778 from
the die plate shearing passages 864. In the illustrated embodiment,
the upper openings 870 have diameters of 0.084 in. The conical
passages 868 naturally taper to lower openings 872, the diameters
of which are less than that of the uncompressed frit 778 and column
channel 780. In the illustrated embodiment, the diameters of the
lower openings 872 are 0.074 in, which are less than the 0.082 in.
diameters of the uncompressed frits and 0.080 in. diameters of the
column channels 780. Thus, as illustrated in FIG. 73, when the
punch pins 855 are further driven down into the conical passages
868 of the frit compression plate 858, the frits 778 are pushed
through the conical passages 868, where they are laterally
compressed by the lower openings 872.
[0361] The frit compression plate 858 further includes an equal
number of male portions 874 in which the conical passages 868
terminate. The chamber adapter 860 includes an equal number of
corresponding female portions 876, which are configured to be
received by the male portions 874 of the frit compression plate
858. The chamber adapter 860 further includes an equal number of
cylindrical passages 878, which terminate adjacent the lower
openings 872 of the frit compression plate 858. The cylindrical
passages 878 are sized to firmly receive the columns 774, such that
the ends of the columns 774 abut the lower passages 780 of the frit
compression flange 858 when mounted therein. Thus, as illustrated
in FIG. 74, when the punch pins 855 are further driven down through
the cylindrical passages 878 of the chamber adapter 860, the
compressed frits 778 are pushed into the column channels 780, where
they expands into compression with the column channel 780 to form
an interference fit.
[0362] The punch plate pins 855 are then pulled out of the chamber
adapter 860, frit compression plate 858, die plate 856, and
stripper plate 854, with the stripper plate 854 functioning to hold
the frit material 866 in place as the punch plate pins 855 are
pulled from the frit material 866. The columns 774 are then
suitably flipped upside down and filled with the reagent. The
afore-described process is then repeated to interference fit other
frits 778 within the opposite ends of the columns 774 to form
complete immunoassay reaction chambers 616, with the exception that
the frit material is preferably displaced a predetermine distance
to move unused frit material 866 over the shearing passages 864 of
the die plate 856.
[0363] Referring now to FIGS. 75-77, the read cell assembly 618 is
configured to present the reacted sample to a light source, where
any labeled antigen will be exited into fluorescent emission, the
intensity of which can be measured by a suitable detector. The read
cell assembly 618 is molded from a single piece of transparent,
e.g., injection molded, bubble-free, acrylic polymer, which
includes vertical and horizontal disposed flanges 782 and 784.
[0364] The vertical flange 782 of the read cell assembly 618 forms
the number of optical read cells 620 with internal lumens 786
(which in the illustrated embodiment, equals ten). The transparent
material is selected to have especially low endogenous fluorescence
(e.g., .lambda.exc=636 nm, .lambda.em=670 em) and no UV inhibitors
or plasticizers as additives. In the illustrated embodiment, each
of the molded read cells 620 is rectangular parallel-piped in
shape, and has a width, depth, and length equal to 2.0 mm, 2.0 mm,
and 10 mm, respectively. The read cell lumen 786 is
cylindrically-shaped and has diameter of 1.0 mm. Each of the
optical read cells 620 includes an input port 788 configured to be
inserted into the read cell seat 775 of the corresponding reaction
chamber 616. Each of the optical read cells 620 comprises an energy
transmission port 790 located opposite the input port 788, which as
will be described in further detail below, is used to transmit
optical energy, and specifically laser energy, through the read
cell lumen 786.
[0365] The horizontal flange 784 of the read cell assembly 618
forms a number of drain channels 792 (ten in the illustrated
embodiment), which are in fluid communication with the optical read
cells 620, and a single common drain channel 794, which is fluid
communication with the drain channels 792. This common drain
channel 794 is further in fluid communication with two outlet drain
ports 796 that exit out the bottom of the horizontal flange 784
into the waste chamber 622.
[0366] The fluorescent labeled antigens are excited by transmitting
laser energy down the longitudinal axis of the read cell lumen 786
using a light source, and specifically a laser, thereby exciting
any labeled antigen into fluorescence. Thus, the laser beam enters
the optical read cell 620 through the energy transmission port 790
and penetrates down the longitudinal axis of the read cell lumen
786, illuminating the sample stream, as well as the wall of the
read cell lumen 786, with the laser light. The fluorescent emission
within the optical read cell 620 is then detected by a detector,
the intensity of which is indicative of the quantity of the target
drug analyte within the sample, thereby allowing the sample to be
quantitatively analyzed. It should be noted that the transmission
of laser energy down the longitudinal axis of the optical read cell
620, as opposed to perpendicular to the longitudinal axis of the
cell 620, allows the detector to view a greater quantity of the
labeled antigen at one time, thereby increasing the accuracy of the
measurement and subsequent analysis of the sample.
[0367] In order to quantitate low-intensity fluorescent photons
within the labeled antigen, stray light must be eliminated from the
cassette 152. The test console 102, which surrounds the cassette
152, provides the first level of stray light protection and removes
99% of ambient light. Each optical read cell 620 is masked by an
optical read slit 184 formed on the front 156 of the cassette case
154 (shown in FIGS. 3-5). In the illustrated embodiment, this slit
184 is 1.2 mm in width and 10 mm in length. The end of each optical
read cell 620 is also masked by an optical excitation aperture 186
formed on the top 160 of the cassette case 154 (shown in FIGS. 3
and 5). The cassette case 154 is also manufactured from
light-absorbing dark pigmented plastic, and together with the
optical read slits 184 and optical excitation apertures 186,
eliminates 99% of the remaining stray ambient light from the
exterior environment. No exposed source of red light, such as
red-colored light emitting diodes (LEDs), are contained within the
test console 102. At the top and sides of the optical read cell
620, a highly light-absorbent black plastic light shield 798 with
interior baffles is used to absorb as much of the scattered light
beam and unwanted fluorescent light as possible. Only multiple
reflections from black and dark surfaces of the light shield and
cassette case 154 can cause stray light. Thus, the undesirable
channel-to-channel stray light pickup is minimized.
[0368] The waste chamber 622 is configured to collect and
permanently store the buffer- and saliva-containing sample fluids,
so that they cannot leak from the confines of the cassette case
154. The cassette 152 can then be disposed of simply as solid waste
without hazard from leakage of potentially biologically hazardous
saliva samples. The waste chamber 622 is composed of a suitable
leak proof material, such as black polycarbonate, and is configured
to be nested within the angled read cell assembly 618. The waste
chamber 622 includes a pair of drain inlet ports 799 that
positionally correspond with, and are configured to receive, the
drain outlet ports 796 of the read cell assembly 618. The waste
chamber 622 includes a self-sealing vent port (not shown) within
which there is tightly disposed a hydrophobic seal (not shown). In
the illustrated embodiment, the seal is composed of a self-sealing
polyethylene membrane that comprises small-diameter pores (e.g., 25
.mu.m diameter) that are coated with a hydrophilic substance, such
as carboxymethlcellulose. When wetted, the hydrophilic pores
rapidly swell, closing the pore interiors, thereby preventing
liquid from passing through the membrane. This self-sealing vent
port, thus facilitates passing air, while preventing the
biologically hazardous saliva from leaking out of the cassette 152
after its disposal following use. Further, the buffer dispensed
during buffer pre- and post-wash contain a 0.05% solution of sodium
azide (NaN3) antibacterial preservative to prevent the growth of
bacteria in the fluid medium.
[0369] C. Flow Immunoassay Assembly--Operation
[0370] Having described the detail structure of the flow
immunoassay assembly 600, its detailed operation will now be
described. When the cassette 152 is loaded into the test console
102, the recess formed within the end of the rotary pin 744 engages
the ridged end of the rotor 626 of the rotary valve 610 (FIG. 38).
Additionally, the sample and buffer drive assemblies 734 and 736
(FIG. 66) are automatically (i.e., prompted by the CPU) moved from
their home positions to their pre-test positions, such that the
sample dispense plunger drivers 764 are engaged with the respective
sample dispense plungers 642 (FIG. 78), and the buffer dispense
plunger drivers 764 are engaged with the respective buffer dispense
plungers 658 (FIG. 79). For purposes of brevity, only one sample
dispense plunger 642 and one buffer dispense plunger 658 is shown
engaged with the respective plunger drivers 764.
[0371] Turning to FIGS. 55, 56, and 78, the sample distribution is
performed in order to fill the sample distribution chambers 612
prior to flowing the sample through the immunoassay reaction
chambers 616. Specifically, the rotary valve 610 is first placed
into the sample distribution configuration, and the sample is
pumped from the dispense port 530 of the mixing assembly 500 into
the sample feed port 628, which as previously described, is
accomplished by operating the buffer drive assembly 574 associated
with the buffered sample dispense plunger 516 of the mixing
assembly 500. It should be noted that the rotary valve 610 is
preferably manufactured and stored in the sample
distribution/buffer pre-wash configuration, in which case, the
rotary valve drive assembly 730 need not be operated to clock the
rotor 626 prior to the sample distribution process.
[0372] It should also be noted that, during the manufacturing
process, the sample dispense plungers 642 are preferably pushed all
the way to the top of those sample distribution chambers 612
(blanked out) that will not be used. For example, if the five
drugs-of-abuse are to be tested, the remaining five sample
distribution chambers 612 will be blanked out. In the illustrated
embodiment, distribution chambers 2-3, 6, 8, and 10 are shown
blanked out. In this manner, the sample is not distributed into
unused sample distribution chambers 612, and thus wasted. To allow
the sample to traverse across blanked out sample distribution
chambers 612, a divot (not shown) is preferably made in the top of
each sample dispense plunger 642 to ensure fluid communication
between the entry and exit ports 678 and 680 of the distribution
port pair 676 associated with any blanked out sample distribution
chamber 612. In the case where a sample distribution chamber 612
need not be completely filled, the corresponding sample dispense
plunger 642 can be pushed up into the sample distribution chamber
612 a predefined distance as dictated by the amount of sample that
will be dispensed from the sample distribution chamber 612. In the
illustrated embodiment, the sample dispense plungers 642 are shown
displaced a predetermined distance from the bottoms of the
distribution chambers 5 and 9.
[0373] Optionally, the sample drive assemblies 732 associated with
the sample distribution chambers 612 to be blanked out or partially
filled are operated under control of the CPU 204 and I/O controller
206 (FIG. 12) to push the sample dispense plungers 642 up into
those sample distribution chambers 612 the required distance, such
that the amount of sample distributed into each sample distribution
chamber 612 is performed in accordance with a quantity of sample
required for the corresponding sample flow channel, if any. This
information can be derived from the barcode affixed to the
chemistry cassette 152. If the sample drive assemblies 732 are
operated to adjust the sample dispense plungers 642, it is
preferable that those sample distribution chambers 612 that are to
be filled with the same quantity of sample should be associated
with the same sample drive assembly 576.
[0374] During sample distribution, the sample flows from sample
feed port 628, through the feed channel 712 and into the first
distribution chamber 612 via the entry distribution port 678 of
first distribution port pair 676. Once the first distribution
chamber 612 fills up, the sample flows out through the exit
distribution port 680, through the sample distribution channel 714,
and into the next available distribution chamber 612 via the entry
distribution port 678 of the next distribution port pair 676. This
cascading process continues until the last available distribution
chamber 612 is filled with the sample. FIG. 78 illustrates that
distribution chamber 7 is currently being filled, with distribution
chambers 1, 4, and 5 having already been filled, and distribution
chambers 2, 3, and 6 being blanked out. During the sample
distribution process, air is vented from the sample distribution
chambers 612. Specifically, as the sample distribution chambers 612
are being filled with the sample, the remaining air with each
distribution chamber 612 is forced out through the corresponding
exit distribution port 680, through the sample distribution channel
714 and into the next available distribution chamber 612 via the
next entry distribution port 678. The air within the last available
distribution chamber 612 is forced out the exit distribution port
680, through the vent channel 716, through the corresponding
reaction chamber 616 and read cell 620, and into the waste chamber
622. As illustrated, since distribution chamber 7 is currently
being filled and distribution chambers 8 and 10 are blanked out,
air (dashed line) escapes from the exit distribution port 680 of
distribution chamber 7, into and out of the entry distribution port
pair 676 of distribution chamber 9, and out through the vent
channel 716.
[0375] Referring to FIGS. 61-63 and 79, buffer pre-wash is
performed to (1) rehydrate the immobilized antibody proteins,
thereby conditioning the stabilized lyophilized column to be ready
to accept liquid sample and kinetically release labeled antigen for
each of the assays in response to the presence of any drug
molecules in the sample; (2) wash away nonspecifically bound
labeled antigen and other unwanted molecules (such as trehalose
stabilizing agent); (3) pre-equilibrates the column with buffer of
the appropriate pH and ionic strength in preparation for the
sample; and (4) provides a convenient means to calibrate the
fluorescent read out from the read cell assembly 618. It should be
noted that the buffer pre-wash can be performed at any time in
relation to the sample distribution process, but preferably is
accomplished prior to the sample dispensing process.
[0376] At the beginning of the buffer pre-wash, the rotary valve
610 is placed into the buffer pre-wash configuration, which in the
illustrated embodiment, is the same as the sample distribution
configuration. Thus, the distribution and buffer pre-wash can be
conveniently accomplished simultaneously, or at the least, the
rotary valve 610 need not be rotated between sample distribution
and buffer pre-wash. In any event, the buffer drive assemblies 734
are automatically operated, placing the buffer dispense plunger
drivers 764 into contact with the buffer dispense plungers 658
after puncturing the bottom seals 654, and thereafter pushing the
buffer dispense plungers 658 up within the buffer chambers 614,
puncturing the top seals 652 with the styluses 666. The buffer is
dispensed out of the buffer chambers 614, through the rigid tubes
650, buffer entry dispense ports 684, buffer pre-wash channels 720,
and exit dispense ports 686. The buffer then flows through and
conditions the immunoassay reaction chambers 616, where the
afore-described pre-conditioning takes place, through the optical
read cells 620, where the buffer is exposed to laser light and its
corresponding fluorescence is measured to calibrate the read out,
and then finally into the waste chamber 622, where the buffer is
permanently stored.
[0377] The flow of buffer through the immunoassay reaction chambers
616 is of a suitable flow rate and volume. For example, for the
drugs-of-abuse, a buffer pre-wash using a buffer volume of 400
.mu.l at a flow rate of 400 .mu.l/min has been found to be
suitable. In this case, it will take 60 seconds to complete the
buffer pre-wash.
[0378] Turning to FIGS. 58-60 and 80, the sample flow is performed
in order to flow the sample through the immunoassay reaction
chambers 616. The purpose of the sample flow is to expose the
immunoassay reaction chambers 616 to any drug present within the
sample. Thus, the sample, which may contain drug-of-abuse
molecules, flows past the bound, antibody-antigen complex, causing
an exchange reaction between the labeled antigen and the unbound
drug molecules. Since the native drug antigen molecules bind more
tightly to their corresponding antibody molecules, than the more
bulky labeled antigen molecules, the reaction chamber 616
preferentially exchanges the labeled antigen with the real
drug-of-abuse molecules. The net result is an increase in the
concentration of fluorescent labeled antigen.
[0379] Specifically, the rotary valve 610 is automatically clocked
90.degree. from the sample distribution configuration (buffer
pre-wash configuration) into the sample flow configuration (buffer
post-wash configuration). The sample drive assembly 734 is
automatically operated, pushing the sample dispense plungers 642 up
within the sample distribution chambers 612. The sample is
dispensed out of the sample distribution chambers 612, through the
sample entry dispense ports 681 (which are the same as the exit
distribution ports 680), dispense channels 718, and exit dispense
ports 686. The sample then flows through the immunoassay reaction
chambers 616, where the exchange immunoassay reaction occurs,
through the optical read cells 620, where the sample is exposed to
laser light and its corresponding fluorescence is measured, and
then finally into the waste chamber 622, where the sample is
permanently stored. The sample flow is performed until the entirety
of the sample has been emptied from the sample distribution
chambers 612. It should be noted that the construction of the
rotary valve 610 allows the sample to be injected as a contiguous
band into the buffer flow, i.e., it prevents, or at least
minimizes, the amount of air introduced into the flow that may
otherwise be caused by the operation of a traditional valve between
the buffer pre-wash and sample dispense processes.
[0380] The flow of the sample through the immunoassay reaction
chambers 616 is of a suitable flow rate and volume. For example, a
flow rate of 100 .mu.l/min for all of the drug-of-abuse, and sample
volumes of 50 .mu.l, 50 .mu.l, 100 .mu.l, 250 .mu.l, and 50 .mu.l
for cocaine, opiates (heroin, morphine, and codeine), phencyclidine
(PCP), amphetamines/methamphetamines, and marijuana
(tetrahydrocannabinol or THC), respectively, has been found to be
suitable. Thus, in this case, it will take about 21/2 minutes to
complete the sample dispense process. It is noted that the sample
distribution chambers 612 corresponding to the 50 .mu.l and 100
.mu.l sample volumes will be partially filled, in which case, the
sample dispense plungers 642 will have been pushed up within these
sample distribution chambers 612 either during the manufacturing
process or by operation of the corresponding drive assemblies 734
and 736. For example, assuming a 250 .mu.l capacity, a sample
dispense plunger 642 will be pushed up 4/5 of the way for a sample
distribution chamber 612 that will be partially filled with 50
.mu.l of sample and 3/5 of the way for a sample distribution
chamber 612 that will be partially filled with 100 .mu.l of sample.
Optionally, the sample drive assemblies 732 can be operated under
control of the CPU 204 and I/O controller 206 (FIG. 12) to move the
sample dispense plungers 642 at different speeds, thus effecting
different flow rates for the sample flow channels. The information
on the desired flow rates for the sample flow channels can be
derived from the barcode affixed to the chemistry cassette 152.
[0381] Referring to FIGS. 64, 65, and 81, the buffer post-wash is
performed to push the remaining sample through the immunoassay
reaction chambers 616 and read cells 620. Specifically, the rotary
valve 610 is placed into the buffer post-wash configuration, which
in the illustrated embodiment, is the same as the sample flow
configuration. The buffer drive assemblies 734 are automatically
operated again, further pushing the buffer dispense plungers 658 up
within the buffer chambers 614. The remaining buffer is dispensed
out of the buffer chambers 614, through the rigid tubes 650, buffer
entry dispense ports 684, buffer post-wash channels 722, exit
dispense ports 686, reaction chambers 616, read cells 620, and
finally into the waste chamber 622. This is performed until the
entirety of the buffer has been dispensed from the buffer chambers
614. The volume of the buffer chambers 614, and the speed of the
buffer dispense plungers 658, are such that buffer continues to
flow through the immunoassay reaction chambers 616 even after the
sample is no longer flowing. In this manner, the buffer will push
any remaining sample residing in the rotary valve 610 out through
the immunoassay reaction chambers 616 and read cells 620, providing
for a more efficient use of the sample.
[0382] The flow of the buffer through the immunoassay reaction
chambers 616 are of a suitable flow rate and volume. For example, a
flow rate of 100 .mu.L/min and 250 .mu.L volume for all of the
drug-of-abuse has been determined to be suitable. Thus, in this
case, it will take about 21/2 minutes to complete the buffer
post-wash.
[0383] Prior to the ejection of the cassette 152 from the test
console 102, automatic operation of the sample drive assemblies 732
move the sample dispense plunger drivers 764 downward, disengaging
them from the sample distribution chambers 612 and cassette
carriage 302 until they are back in their home positions. Likewise,
automatic operation of the buffer drive assemblies 734 moves the
buffer dispense plunger drivers 764 downward, disengaging them from
the buffer chambers 614 and cassette carriage 302 until they are
back in their home positions.
[0384] VII. Optical Flow Immunoassay Scanning Assembly
[0385] Referring generally to FIGS. 13, and 82-88, the system 100
comprises an optical flow immunoassay scanning assembly 900, the
purpose of which is to measure the amount of labeled antigen, and
specifically fluorescent CY5 dye, flowing through each of the
optical read cells 620. In performing this function, the optical
flow immunoassay assembly 600 includes a dynamic scanning assembly
902, an optical excitation assembly 904, and an optical detection
assembly 906.
[0386] A. Dynamic Scanning Assembly
[0387] The purpose of the dynamic scanning assembly 902 is to
translate the positions of the optical excitation assembly 904 and
optical detection assembly 906, so that they can interact with the
optical read cells 620 of the flow immunoassay assembly 600. To
this end, the dynamic scanning assembly 902 comprises a vertically
extending rigid mechanical bench 908 mounted to the top flange 116
of the main base 114. The dynamic scanning assembly 902 further
includes a scanner head mechanism 910 that rides on top of the
mechanical bench 908. Specifically, the dynamic scanning assembly
902 includes a runner 912, which is mounted to the scanner head
mechanism 910, and a rail 914, which is mounted to the top of the
mechanical bench 908. Thus, the runner 912 rides on the rail 914,
such that the scanner head mechanism 910 rides smoothly along the
top of the mechanical bench 908.
[0388] The scanner head mechanism 910 includes a horizontal flange
916 and a vertical flange 918 for mounting various components.
Specifically, the horizontal flange 916 extends along the top of
the chemistry cassette 152 when loaded into the test console 102,
and includes a laser aperture 918 (shown best in FIG. 13) with
which the optical excitation assembly 904 is associated to interact
with the optical read cells 620. The horizontal flange 916 is used
to mount a position sensor 920, which as will be described in
further detail below, aids in determining the location of the
scanner head mechanism 910 in relation to each optical read cell
620. In addition, the previously described runner 912 is mounted to
the vertical flange 918. The vertical flange 918 extends along the
front of the chemistry cassette 152 when loaded into the test
console 102 and includes a detector aperture 922 with which the
optical detection assembly 906 is associated to interact with the
optical read cells 620. The vertical flange 918 comprises a sensor
actuator 924 (shown best in FIG. 13), which as will be described
below, aid in determining the extreme limits of the scanner head
mechanism 910 in relation to the mechanical bench 908.
[0389] The dynamic scanning assembly 902 further includes a
scanning drive assembly 926, which automatically scans the scanner
head mechanism 910 in relation to the mechanical bench 908, and
thus, the loaded cassette 152. The scanning drive assembly 926
includes a rotational stepper motor 928 and a motor mount 930,
which affixed the motor 928 to the mechanical bench 908. The
scanning drive assembly 926 further includes a driver pulley 932,
which is rotatably mounted to the motor 928, and an idler pulley
934, which is rotatably mounted to the front of the mechanical
bench 908. The scanning drive assembly 926 further includes a
circular, notched drive belt (not shown) mounted around the
respective driver and idler pulleys 932 and 934. The scanner head
mechanism 910 is affixed to the drive belt, such that operation of
the motor 928 moves the drive belt, thus linearly translating the
scanner head mechanism 910 in relation to the mechanical bench 908,
which linear translation is ensured by the rail and runner
arrangement.
[0390] It should be noted that one scan cycle of the dynamic
scanning assembly 902 consists of one scan in the forward direction
(left-to-right, referred to simply as the "forward scan")
immediately followed by one scan in the reverse direction
(right-to-left, referred to simply as the "reverse scan"). To
ensure that the scanner head mechanism 910 does not translate to
far, the scanning drive assembly 926 includes a scanner home
position sensor 936, which is mounted to one end of the mechanical
bench 908, and a scanner end position sensor 938, which is mounted
to the other end of the mechanical bench 908, to independently
indicate the position of the scanner head mechanism 910 near the
extreme limits of travel during each scan cycle. The sensor
actuator 924 mounted to the vertical flange 918 of the scanner head
mechanism 910 triggers the scanner home and end position sensors
936 and 938 to facilitate this determination. The forward and
reverse scans of the scanner head mechanism 910 are performed under
control of the CPU 204 (FIG. 12). Specifically, the CPU 204
generates instructions used to program the I/O controller 206 for
the motor 928, which in the illustrated embodiment, is performed at
a linear rate of 20 cm/s, thus performing a single scan of all ten
channels in one second (1 s).
[0391] To indicate the location of the optical read cells 620, the
scanning drive assembly 926 further includes an indexed flange 940,
which is mounted to the front of the mechanical bench 908, and the
position sensor 922, which, as previously described, is mounted to
the horizontal flange 916 of the scanner head mechanism 910. To
this end, the indexed flange 940 comprises notches 942 (ten, in the
illustrated embodiment) that are spaced apart the same distance in
which the optical read cells 620 are spaced apart, i.e., each notch
942 spaced from an adjacent notch 942 a distance equal to the
distance in which each optical read cell 620 is spaced from an
adjacent read cell 620. Thus, when the position sensor 922
associated with the scanner head mechanism 910 senses a notch 942
within indexed flange 940, a certain portion of the scanner head
mechanism 910 will be aligned with a read cell 620, which as will
be described in further detail below, indicates that the optical
read cell 620 is currently being scanned.
[0392] B. Optical Excitation Assembly
[0393] The purpose of the optical excitation assembly 904 is to
provide constant wavelength, constant intensity light to the
optical read cells 620, so that each of the labeled antigen, and
specifically fluorescent CY5 dye, flowing therethrough are excited
by photons of the correct wavelength. To this end, the optical
excitation assembly 904 comprises a laser module 944 (best shown in
FIG. 13), which is mounted within the laser aperture 918 formed
through the horizontal flange 916 of the scanner head mechanism
910. The optical excitation assembly 904 further includes a heat
sink 946 and fan 948, which provide heatsinking functionality to
the optical excitation assembly 904.
[0394] As illustrated in FIG. 86, the laser module 944 includes a
modular housing 950, which contains a laser source 952 and a
thermocontroller 954 that are configured to provide constant output
controlled laser energy to the optical read cells 620. The laser
source 952 is rigidly mounted within the modular housing 950, which
aligns the laser source 952 with the optical transmission port 790
of the read cell 620. Thus, the laser source 952 transmits laser
energy through the optical transmission port 790 of each read cell
620, and through the corresponding lumen 786.
[0395] In the illustrated embodiment, the laser source 952 is
mounted, such that the resultant laser beam 956 intersects the
longitudinal axis 958 of the read cell lumen 786 at an oblique
entry angle. If this oblique angle is, e.g., 45.degree. a two times
(2.times.) overscan of each optical read cell 620 in the vertical
axis (and many times overscan in the horizontal axis due to the
linear translation of the scanner head mechanism 910) is provided.
This assures that some portion of the cross-section of the laser
beam 956 intersects the transmission ports 790 of the read cell
lumens 786, even if some displacement of the optical read cells 620
along the length of the cassette 152 exists, e.g., if the cassette
152 is slightly warped, or otherwise due to manufacturing
tolerances in the injection molded plastic read cell assembly 618.
The laser source 952 specifically comprises a 5 mW solid-state
laser diode that nominally operates at 636 nm and has a resultant
laser beam 956 with a 2 mm.times.4 mm rectangular beam profile.
[0396] Thus, operation of the dynamic scanning assembly 902,
mechanically scans the resultant laser beam across each optical
read cell 620 through the transmission port 790 and down the
longitudinal axis of the lumen 786, thereby illuminating the sample
stream, as well as the walls of the optical read cells 620, with
laser light. Thus, at a linear scan rate of 20 cm/s, some portion
of each 2 mm wide optical read cell 620 will be exposed to the
laser beam for approximately 0.020 s.
[0397] The thermocontroller 950 controls the temperature of the
heat sink 946, thereby controlling the operating wavelength of the
laser source 948. The thermocontroller 950 is a 4W Peltier
thermocontroller, which ensures that the output wavelength of the
laser source 948 is maintained substantially constant. The optical
excitation assembly 904 further includes a laser controller 960 to
control the operating current of the laser source 948. The laser
controller 960 comprises an internal reference optical diode (not
shown) that samples a small portion of the laser output and
provides a reference voltage that is input to the laser controller
960 and used to control the current to the laser source 948 as a
feedback signal from an amplifier (not shown) in the laser
controller 960.
[0398] The optical excitation assembly 904 further comprises a
laser filter 962, which is mounted between the laser source 948 and
the optical read cell 620 to provide adequate rejection of
scattered light produced by the turbid saliva samples (turbidity of
human saliva samples can vary by as much as 20-to-1) and by the
read cell assembly 618. Since solid-state laser diodes typically
contain a light emitting diode (LED) with a high-Q resonant cavity,
the LED produces a relatively low intensity broad band of radiation
approximately 200 nm in width on which is superimposed a high
intensity, narrow band (.congruent.1 nm) of resonant laser energy.
For example, the laser energy can be about 106 (a million times, or
6 orders of magnitude) more intense than the low energy broadband
radiation. Consequently, the low energy broadband radiation of a
solid-state laser diode is typically ignored. Since fluorescence,
however, 10.sup.4-10.sup.5 times less intense than scattering due
to the low efficiency of the fluorescent radiation process,
scattered light outside the nominal laser wavelength that reaches
the laser source 948 from the sample can be even more intense than
the fluorescent light generated within each optical read cell
620.
[0399] Thus, in order to eliminate significant error due to light
scattering by the sample, and thereby ensure that detected light is
due to the fluorescence of CY5 dye found within the optical read
cell 620, rather than to high turbidity of the saliva sample,
scattered light must be highly rejected from the optical detection
assembly 906. To this end, the laser filter 962 comprises a 636
nm.+-.5 nm FWHM (full width at half maximum height) bandpass filter
with steep rolloff (20 db) of its bandpass, thus assuring that
light outside the desired excitation band is prevented from
reaching the optical read cells 620, and ultimately the optical
detection assembly 906. Further, the laser filter 962 is preferably
mounted at an oblique angle off of its normal axis, e.g.,
5.degree., so that the reflected light from the front and back
surfaces of the laser filter 962 cannot reenter the resonant laser
cavity and modulate the laser activity of the laser source 948.
[0400] C. Optical Detection Assembly
[0401] The purpose of the optical detection assembly 906 is to
detect the excited labeled antigen, and specifically fluorescent
radiation from the CY5 dye, and produce a voltage signal that is
directly proportional to the concentration of dye in the optical
read cell 620, and thus directly proportional to the concentration
of target drug analyte in the sample. To this end, the optical
detection assembly 906 comprises an optical detector module 964
mounted within the detector aperture 922 formed through the
vertical flange 918 of the scanner head mechanism 910. The optical
detector module 964 includes a modular housing 966, which contains
an optical detector 968 and an integral high-gain preamplifier 970
(shown in FIG. 86). The optical detector 968 includes a silicon
diode, and the high-gain preamplifier 970 is mounted on the same
dye to minimize noise and thermal effects of the high impedance
detector circuit. The high-gain integral preamplifier 970 has a 600
M.OMEGA. internal feedback resistor (not shown), giving the circuit
a relatively large internal gain. The optical detector 968 is
mounted within the modular housing 966, such that its sensing beam
976 intersects the optical read cells 620 at an angle transverse to
the longitudinal axes of the optical read cells 620. In the
illustrated embodiment, this transverse angle is 90.degree. to
maximize the amount of light sensed by the optical detector
968.
[0402] The optical detection assembly 906 further comprises an
external amplifier 972, which takes the preamplified signal (e.g.,
10.sup.4 gain) from the preamplifier 970, and amplifies it by an
additional factor, e.g., 10.sup.2. The combined detector circuitry
gain has a gain of one million (10.sup.6 gain) in order to produce
an output voltage of 1.4 volts for a CY5 dye concentration of
1.0.times.10.sup.-9 M. This is a combined gain within a factor of 2
of what is obtainable with a highly sensitive photomultiplier tube
detector. Thus, the power supply for optical detection assembly 906
preferably has a very low noise.
[0403] It should be noted that CY5 dye molecules absorb photons
most efficiently at 650 nm (.lambda..sub.ex max=650 nm) and emit
fluorescent photons most efficiently at 655 nm (.lambda..sub.em
max=655 nm). This gives a Stokes shift of only 5 nm, which is a
relatively demanding optical requirement. As a result, the optical
detection assembly 906 must be capable of detecting fluorescent
photons with great sensitivity, while simultaneously rejecting
incident light photons with high selectivity. To this end, the
optical detection assembly 906 comprises a three-stage filter 974,
which includes two stages of 670 nm bandpass filters (.+-.5 nm
FWHM) to permit detection of fluorescent photons, and a single
stage 655 nm reject filter, which rejects light <655 nm and
passes light >655 nm with a steep slope between the two.
Together these filters reject incident photons of scattered light
(<655 nm) while passing photons of fluorescent light (>655
nm) with at least 50% efficiency for the three-stage filter
974.
[0404] Together, the optical excitation assembly 904 and optical
detection assembly 906 provide a Stokes shift of approximately 35
nm (670 nm-635 nm). While this is only about 50% as sensitive for
fluorescent light detection as the optimal 5 nm Stokes shift, it
does permit acceptable rejection of scattered light (>10.sup.8:1
limit). This is equivalent to a background light of about
10.sup.-12 M (i.e., 1 pM) CY5 dye. The combined optical excitation
and optical detection assemblies 904 and 906 has a linear dynamic
range of about 10.sup.-11 to 5.times.10.sup.-9 M CY5 dye or about
2.5 decades of linear response to CY5 dye molecules. The flow
immunoassay assembly 600 has been optimized, so that the cutoff
points for each of the assay occur well within this range of CY5
dye concentration.
[0405] D. Optical Flow Immunoassay Scanning Assembly-Operation
[0406] Having now described the detail structure of the optical
flow immunoassay scanning assembly 900, its operation will now be
described. During the afore-described buffer pre-wash, sample
dispense, and buffer post-wash cycles, the optical flow immunoassay
scanning assembly 900 senses any displaced labeled antigen flowing
through the read cells 620 and processes this information
accordingly.
[0407] Specifically, the scanning drive assembly 926 is operated to
translate the scanner head mechanism 910, and thus, the laser beam
of the laser source 948 and sensing beam of the optical detector
968 simultaneously across the immunoassay flow channels. That is,
the laser source 948 transmits laser energy at an oblique entry
angle, e.g., 45.degree., to the longitudinal axes of the read cells
620 lumens. The laser energy enters the optical transmission ports
790 of the read cell lumens 786, which is then transmitted down the
longitudinal axes 958 of the read cells lumens 786. In response,
any fluorescent labeled antigen flowing through the optical read
cells 620 is excited into fluorescence, which optical energy is in
turn transversely emitted from the fluoresced labeled antigen
through the walls of the read cells 620. At the same time, the
optical detector 968 senses the transversely emitted optical energy
at an angle substantially perpendicular to the longitudinal axes of
the read cell lumens 786.
[0408] Referring to FIG. 87, the optical detector 968 outputs a
signal indicative of the sensed fluorescence level of the optical
energy, which is then received by the CPU 204 (FIG. 12). Because
the optical detector 968 scans through the immunoassay flow
channels, a discrete output signal is generated for each of the
immunoassay flow channels during a single scan. As illustrated in
FIG. 87, the CPU 204 takes these discrete output signals and
constructs, for each immunoassay flow channel, a fluorescence
magnitude level waveform over time, i.e., over several forward and
reverse scans.
[0409] The position sensor 922 is gated to the CPU 204, such that
the CPU 204 only processes the data for each immunoassay reaction
chamber when a corresponding optical read cell 620 is detected,
i.e., when the sensing beam of the optical detector 968 intersects
the corresponding optical read cell 620. That is, as the position
sensor 922 senses a position indicator 942, which in the
illustrated embodiment is a notch, it outputs a high signal to the
CPU 204, indicating that the sensing beam 976 of the optical
detector 968 is currently passing through the corresponding optical
read cell 620. As long as this signal is high, the CPU 204
processes the output signal received from the optical detector 968.
In contrast, when the position sensor 922 no longer senses a
position indicator 942, it outputs a low signal to the CPU 204,
indicating that the sensing beam of the optical detector 968 is
currently passing through a region between optical read cells 620.
As long as the signal is low, the CPU 204 will not process the
output signal received from the optical detector 968.
[0410] Turning now to the analysis of the detector signals, during
the buffer pre-wash, the buffer is flowed through the immunoassay
reaction chambers 616 to wash out any displaced labeled antigen
from the immunoassay reaction chambers. The analyte detectable
sample solution is then flowed through the read cells 620. The
buffer pre-wash continues until all immunoassay flow channels have
caused the requisite volume of buffer to flow through the
immunoassay reaction chambers 616, so that each has come to
equilibrium, as demonstrated by each immunoassay flow channel
having achieved a constant background fluorescence level readout of
approximately 100 mV. As previously discussed, the illustrated
embodiment flows 400 .mu.l of buffer from the buffer chambers 614,
which has been found to achieve equilibrium. This phenomenon is
illustrated in FIG. 88, which shows a sharp increase in the
fluorescence level detected from the excited labeled antigen, and a
drop off of the fluorescence level to a fluorescence reference
level when the immunoassay reaction chamber 616 comes to
equilibrium. The fluorescence reference level is used to establish
normalization parameters for each of the respective immunoassay
flow channels by using the immunoassay flow channel having the
greatest mean intensity as a reference value of 1.000 and
determining the ratio of each immunoassay flow channel to this
reference immunoassay flow channel. This provides a separate
normalization parameter for each immunoassay flow channel. For
example, Table 1 illustrates exemplary pre-wash reference values
for five immunoassay flow channels and the respective calculated
normalization factors for each. As shown, immunoassay flow channel
#3 exhibits the greatest mean fluorescence reference level, and is
thus assigned a normalization factor of 1.00. The remaining
immunoassay flow channels exhibit lesser fluorescent levels, and
are thus assigned a normalization factor less than 1.00.
[0411] During sample flow after the buffer pre-wash, the sample is
flowed through the immunoassay reaction chambers 616, which if it
contains the target drug analyte, displaces any remaining bound
labeled antigen from the corresponding immunoassay reaction chamber
616. In any event, the analyte detectable sample solution then
flows through the read cells 620. The sample flow continues until
all of the sample has flowed from the sample distribution chambers
612. If the sample does contain the target drug analyte, the
detected fluorescent level will increase to a relatively high
level, as illustrated in FIG. 88. If the sample does not contain
the target drug analyte, the detected fluorescent level will remain
at the relatively low reference level.
[0412] After sample flow is completed, buffer post-wash is
performed until all of the remaining sample has been pushed through
the immunoassay flow channels and into the waste chamber 622. As
previously discussed, the illustrated embodiment flows 250 .mu.l
more of buffer from the buffer chambers 614, which has been found
to be suitable to push the remaining sample through the immunoassay
flow channels. In the case, where the sample does contain the
target drug analyte, the detected fluorescence level will
eventually decrease to the relatively low reference level when the
sample has indeed been flowed out of the read cells 620, as
illustrated in FIG. 88. Of course if the sample does not contain
the target drug analyte, the detected fluorescence level will have
already been at the relatively low reference level, and will remain
as such through the duration of the buffer post-wash.
[0413] After the buffer post-wash is completed, the amount of
target drug analyte within the sample is quantified by first
obtaining the mean fluorescent intensity of each of the immunoassay
flow channels. The mean intensity of each of the immunoassay flow
channels is then divided by their respective normalization factors,
providing for a ratio-metric readout that tends to cancel
channel-to-channel optical differences arising from slight optical
differences caused by manufacturing tolerances in the injection
molded plastic optical read cell assembly 618. Table 1 illustrates
exemplary sample mean values for the sample for the five
immunoassay flow channels, and the and the calculated ratiometric
values for each. It is noted that although the means signal values
for immunoassay flow channels #"s 1, 4, and 5 were less than that
of immunoassay flow channel #3, their ratiometric output signals
are greater than that of immunoassay flow channel #3 due to their
relatively low channel normalization factors.
1TABLE 1 Channel No. Ch. #1 Ch. #2 Ch. #3 Ch. #4 Ch. #5 Mean 95 mV
98 mV 100 mV 97 mV 99 mV Pre-wash Reference Value Channel 0.950
0.980 1.00 0.970 0.990 Normal- ization Factor Sample 1500 mV 1450
mV 1570 mV 1533 mV 1610 mV Mean Value Ratiometric 1579 1480 1570
1580 1626 Value
[0414] It is noted that since immunoassay agglomerization reactions
require minutes/hours to reach completion, and the continuous flow
immunoassay reactions used in the system 100 occur within 3-5
minutes, the reactions are performed in kinetic/dynamic mode far
from equilibrium conditions. Nevertheless, careful control of
reaction parameters ensures that the concentration of the labeled
antigen in the analyte detectable sample solution is representative
of the original concentration of the target drug analyte contained
in the original pure saliva sample. As previously discussed,
appropriate proportionality constants permitting calibration of
each of the immunoassay flow channels are contained in the barcode
information, which can be used in addition to the previously
discussed internally measured channel-to-channel normalization
factors.
[0415] VIII. Alcohol Detection Assembly
[0416] Referring to FIGS. 6-8 and 89-96, the system 100 comprises
an alcohol detection assembly 1000, the purpose of which is to
conduct a quantitative analysis of the concentration of ethanol in
the buffer sample solution and determine the mass-per-volume
percentage (%.sub.w/v) of ethanol in the original sample of
collected, undiluted saliva. In the illustrated embodiment, the
alcohol detection assembly 1000 conducts an endpoint alcohol
dehydrogenase (ADH) enzymatic assay on the sample in order to
quantitatively detect the alcohol in the sample. The alcohol
detection assembly 1000 generally comprises an alcohol reaction
assembly 1002 and an alcohol reader assembly 1004.
[0417] A. Alcohol Reaction Assembly-Cassette Portion
[0418] The purpose of the alcohol reaction assembly 1002 is to
provide a reaction between any alcohol in the sample and reagents,
and then presenting this reaction for analysis. Referring
specifically to FIGS. 89-96, the portion of the alcohol detection
assembly 1000 associated with the cassette 152 is illustrated. As
can be seen, the alcohol detection assembly 1000 is integrated with
the previously described flow immunoassay assembly 600, and
specifically, the rotary valve 610, which is operated to dispense
the same sample to the alcohol detection assembly 1000 as is
distributed to the flow immunoassay assembly 600. The alcohol
detection assembly 1000 generally includes a manifold 1002, an
alcohol reaction chamber 1004, a reagent chamber 1006, a buffer
chamber 1008 with an associated buffer dispense plunger 1010, a
calibrator chamber 1012 with an associated calibrator dispense
plunger 1014, a sample chamber 1015 (which is the same as the
through channel 706(1) shown in FIG. 55), and a vent/air flow
assembly 1016.
[0419] The manifold 1002 is configured to provide the necessary
interface, e.g., fluid and air transfer, between the alcohol
reaction chamber 1004 and the other components. Specifically, the
manifold 1002 comprises a main body 1018 that is composed of a
suitable material, such as polycarbonate. The manifold main body
1018 is mounted to the bottom of the stator 624 of the rotary valve
610 underneath the sample feed port 628, which as will be described
in further detail below, allows for indirect receipt of the sample
from the feed port 628. To the end, the manifold main body 1018
includes an arcuate surface 1020 that complements the outer surface
of the stator 624. The various channels disposed within the
manifold 1002 will be described in further detail below.
[0420] Referring specifically to FIG. 93A, the reagent chamber 1006
comprises a cylindrical column 1022 composed of a suitable
chemically insert material, such as injection molded polypropylene
polymer. The reagent chamber 1006 is configured to provide the
components that react in the presence of alcohol to produce an
alcohol indicator. In the illustrated embodiment, the reagent
chamber 1006 contains dry alcohol reagent, which is specifically
produced by disposing 0.2 mM N-acetyl cyseine, 1.8 .mu.M
nicotinamide adenine dinucleotide (NAD), 500 U/ml alcohol
dehydrogenase (ADH), 0.01 M phosphate buffer (pH=7.5), 0.01% BSA,
and 2% trehalose, and lyophilizing the components to stabilize them
during transportation and storage of the cassette 152. The reagent
chamber 1006 is in fluid communication with the alcohol reaction
chamber 1004 through the manifold 1002. To this end, the manifold
1002 is seated within a reaction chamber seat 1024 formed within
the manifold 1002. The manifold 1002 comprises a reagent channel
1026 that extends perpendicularly between a stylus bore 1028, which
extends from the reagent chamber seat 1028, and a reagent exit port
1030 leading to the alcohol reaction chamber 1004. To prevent
permeation of water vapor, a pair of puncturable seals 1032 and
1034 are bonded at the opposite ends of the reagent chamber 1006.
The seals 1032 and 1034 are composed of a suitable material, such
as an aluminum foil-lined/polymer bilayer seal.
[0421] The buffer chamber 1008 is longitudinally disposed along the
side of the rotary valve 610 underneath the buffer chamber seats
684, and is configured to rehydrate the lyophilized reagent within
the reagent chamber 1006. The buffer chamber 1008 is
cylindrical-shaped and is composed of a suitable material, e.g.,
injection molded polypropylene. The buffer chamber 1008 is in fluid
communication with the reagent chamber 1006, and to this end, is
suitably mated with the extreme end of the reagent chamber 1006. As
with the other buffer chambers, the walls of the buffer chamber
1008 are sufficiently thick and impermeable to water vapor during
the storage lifetime of the cassette 152. The buffer chamber 1008
has a 1 ml capacity and contains a buffer solution suitable for
reconstituting the reagents within the reaction chamber 1005, e.g.,
0.6 M TRIS/0.4 M lysine buffer (pH=9.7).
[0422] Referring specifically to FIG. 93A, the buffer chamber 1008
comprises a cylindrical bearing surface 1038 with which the
associated buffer dispense plunger 1010 sealingly mates. The buffer
dispense plunger 1010 comprises a rigid plunger head 1040, which
includes an O-ring groove 1042 for seating of an O-ring (not
shown). The O-ring of the buffer dispense plunger 1010 facilitates
a sealing relationship between the buffer dispense plunger 1010 and
the bearing surface 1036 of the buffer chamber 1008. Originally,
the buffer dispense plunger 1010 is disposed within the buffer
chamber 1008 at its extreme end, while a puncturable seal 1042 is
bonded to the end of the buffer chamber 1008 opposite the buffer
dispense plunger 1010. The combination of the buffer dispense
plunger 1010 and seal 1042 prevent water vapor from escaping the
confines of the buffer chamber 1008 during storage of the cassette
152. The seal 1042 is composed of a suitable material, such as an
aluminum foil-lined/polymer bilayer seal.
[0423] The buffer dispense plunger 1010 further includes a stylus
1046, which is configured to puncture the seal 1044 at the other
end of the buffer chamber 1008. Movement of the buffer dispense
plunger 1010 towards the seal 1044, causes the stylus 1046 to
puncture the seal 1044, allowing the buffer to flow from the buffer
chamber 1008 through the reagent chamber 1006. During the buffer
dispensing process, the stylus 1046 extends through the reagent
chamber 1006 and reagent chamber seat 1028 (after puncturing the
seals 1032 and 1034), coming to rest in the stylus bore 1028 at the
end of the dispensing process. The flow of buffer through the
reagent chamber 1006 rehydrates the lyophilized reagent, producing
a reconstituted reagent therein, which is in turn, dispensed into
the alcohol reaction chamber 1004.
[0424] Referring specifically to FIG. 94D, the calibrator chamber
1012 contains a calibrator solution having a inown quantity of
alcohol, which in the illustrated embodiment, is 0.1 ml calibrator
solution with a concentration of 0.01% concentration of alcohol.
The calibrator chamber 1012 is cylindrical-shaped and is composed
of a suitable material, e.g., injection molded polypropylene. The
calibrator chamber 1012 is in fluid communication with the alcohol
reaction chamber 1004 via the manifold 1002. To this end, the
manifold 1002 includes a calibrator chamber seat 1048 in which one
end of the calibrator chamber 1012 is seated. The manifold 1002
further includes an alcohol channel 1050 perpendicularly extending
between a stylus bore 1028, which extends from the seat 1048, and
an alcohol exit port 1054 leading to the alcohol reaction chamber
1004.
[0425] The calibrator chamber 1012 comprises a cylindrical bearing
surface 1056 with which the associated calibrator dispense plunger
1014 sealingly mates. The calibrator dispense plunger 1014
comprises a rigid plunger head 1058, which includes an O-ring
groove 1060 for seating of an O-ring (not shown). The O-ring of the
calibrator dispense plunger 1014 facilitates a sealing relationship
between the calibrator dispense plunger 1014 and the bearing
surface 1056 of the calibrator chamber 1012. Originally, the
calibrator dispense plunger 1014 is disposed within the calibrator
chamber 1012 at its extreme end, while a puncturable seal 1062 is
bonded within the calibrator chamber 1012 opposite the calibrator
dispense plunger 1014. The combination of the calibrator dispense
plunger 1014 and seal 1062 prevent the calibrator solution from
escaping the confines of the calibrator chamber 1012 and manifold
1002 during storage of the cassette 152. The seal 1062 is composed
of a suitable material, such as an aluminum foil-lined/polymer
bilayer seal.
[0426] The calibrator dispense plunger 1014 further includes a
stylus 1064, which is configured to puncture the seal 1062 at the
other end of the calibrator chamber 1012. Movement of the
calibrator dispense plunger 1014 towards the seal 1062, causes the
stylus 1064 to puncture the seal 1062 and extend through an
aperture 1066 at the end of the calibrator chamber 1012, allowing
the calibrator solution to flow through the alcohol channel 1050
into the alcohol reaction chamber 1004. At the end of the alcohol
dispensing process, the stylus 1064 comes to rest in the stylus
bore 1052.
[0427] The sample chamber 1015 is the same as the through channel
706(1) (shown in FIG. 59) that extends through the rotor 626 and
forms part of the feed channel 712 in the flow immunoassay assembly
600. In the illustrated embodiment, the sample chamber 1015
contains 20 .mu.l of sample. When the rotary valve 610 is clocked
in the sample flow/buffer post-wash configuration, the sample
chamber 1015 is rotated to a vertical position, where it placed
into fluid communication with the alcohol reaction chamber 1004,
thereby acting as a shear valve. Specifically, the sample chamber
1015 communicates with a sample dispense port 1068 disposed through
the bottom of the stator 624 (shown in FIG. 59). The manifold
includes an access channel 1070 through which a sample/vent tube
1071 extends. One end of the sample/vent tube 1071 is connected to
the sample dispense port 1068, while the other end of the
sample/vent tube 1071 extends into the alcohol reaction chamber
1004. The sample remains in the sample chamber 1015 even when in
the vertical position, due to the surface tension of the sample. As
will be described in further detail below, the sample is forced out
of the sample chamber 1015 into the alcohol reaction chamber 1004
using air pressure, as will be described below.
[0428] The alcohol reaction chamber 1004 is configured to collect
the sample from the sample chamber 1015, the alcohol from the
calibrator chamber 1012, and the reconstituted reagent solution
from the reagent chamber 1006, and exhibit the analyte detectable
sample solution to the alcohol reader assembly 1004 for calibration
and detection of the alcohol within the sample. It is noted that
the reagent solution, which contains NAD and ADH will react with
the alcohol to produce an optical energy absorbing substance, and
specifically, NAD with high energy hydrogen (NADH). As will be
described in further detail below, the optical energy absorbed by
the NADH can be optically detected by the alcohol reader assembly
1004 to perform the calibration and detection functions. To this
end, the reaction chamber 1004 is composed of a suitably clear
material, such as, acrylic polymer, and is rectangular in shape,
which in the illustrated embodiment, has a pathlength of 0.500 cm,
a width of 0.8 cm, and a height of 2.5 cm. The top of the reaction
chamber 1004 is open and is friction fit around the bottom of the
manifold main body 1018.
[0429] The vent/air flow assembly 1016 is configured to perform
three functions: (1) provide venting of air from the alcohol
reaction chamber 1004 during the dispensing processes; (2)
providing air flow to the sample chamber 1015 to dispense the slug
of sample into the alcohol reaction chamber 1004; and (3) sealing
the sample within the sample chamber 1015 and alcohol reaction
chamber 1004 after the cassette 152 is discarded. Specifically, the
vent/air flow assembly 1016 comprises a vent manifold 1072 composed
of a suitable material, such as polycarbonate. The vent manifold
1072 is mounted to the top of the stator 624 of the rotary valve
610 above the sample feed port 628. To the end, the vent manifold
1072 includes an arcuate surface 1074 that complements the outer
surface of the stator 624.
[0430] The vent/air flow assembly 1016 further comprises a
channeled barb fitting 1076 that is screwed into vent seat 1077
formed within the vent manifold 1072. The vent manifold 1072
includes a vent channel 1078, which extends from the vent seat 1077
down through the vent manifold 1072, where it communicates with an
air entry port 1080 disposed through the stator 624. When the
rotary valve 610 is clocked in the sample flow/buffer post-wash
configuration (FIG. 95), thereby vertically positioning the sample
chamber 1015, the top of the sample chamber 1015 is aligned with
and communicates with the air entry port 1080 located at the top of
the stator 624, and the bottom of the sample chamber 1015, as
previously described, is aligned with and communicates with the
sample dispense port 1068 located at the bottom of the stator 624,
which as will be described in further detail below, facilitates
conveyance of air flow through the sample chamber 1015 to dispense
the sample into the alcohol reaction chamber 1004. In contrast,
when the rotary valve 610 is clocked in the sample
distribution/buffer pre-wash configuration (FIG. 96), the air entry
port 1080 and sample dispense port 1068 are exposed to the space
1082 within the stator 624, which as will be described in further
detail below, facilitating venting of air from the alcohol reaction
chamber 1004.
[0431] The vent/air flow assembly 1016 further includes a flexible
conduit 1084, such as Tygon tubing, one of which is mated to the
vent fitting 1076. The vent/air flow assembly 1016 further includes
a vent/air flow port 1086, which is suitably affixed to the other
end of the flexible conduit 1084. The flexible conduit 1084 is of a
suitable length, e.g., 13 cm., to allow the vent/air flow port 1086
to be mounted within an vent/air flow port mounting aperture 188 on
the side of the cassette case 154 (FIG. 3). Optionally, the
vent/air flow port 1086 may be self-sealing in that it includes a
tightly disposed a hydrophobic seal (not shown), which allows air
to pass therethrough, while preventing the biologically hazardous
saliva from leaking out of the cassette 152 after its disposal
following use.
[0432] Thus, when the rotary valve 610 is clocked in the sample
flow/buffer post-wash configuration (FIG. 95), the vent/air flow
port 1086 is placed into communication with the alcohol reaction
chamber 1004 via the flexible conduit 1084, vent fitting 1076, vent
channel 1078, air entry port 1080, sample chamber 1015, sample
dispense port 1068, and sample/vent tube 1071, thereby facilitating
the dispensing of the sample from the sample chamber 1015 into the
alcohol reaction chamber 1004 when air is blown into the vent/air
flow port 1086. When the rotary valve 610 is clocked in the sample
distribution/buffer pre-wash configuration (FIG. 96), the vent/air
flow port 1086 is placed into communication with the alcohol
reaction chamber 1004 via the flexible conduit 1084, vent fitting
1076, vent channel 716, air entry port 1080, the interior of the
stator 624, the sample dispense port 1068, and the sample/vent tube
1071, thereby facilitating the venting of air out through the
alcohol reaction chamber 1004 during the dispensing process.
[0433] B. Alcohol Reaction Assembly-Tester Portion
[0434] Having just described the portion of the alcohol reaction
assembly 1002 associated with the cassette 152, the portion of the
alcohol reaction assembly 1002 associated with the test console 102
will be discussed. Referring to FIGS. 6-8, 13, and 14, the alcohol
reaction assembly 1002 further includes a buffer driver 1102,
calibrator drive assembly 1104, a vacuum port connector 1106, the
previously described cassette loading assembly 300 and vacuum pump
456, and a mixing drive assembly 1110.
[0435] The buffer driver 1002 (best shown in FIG. 14), which is
affixed to the pin alignment flange 750 in a manner that aligns the
buffer driver 1002 with the buffer dispense plunger 1010 disposed
within the buffer chamber 1008. Thus, as the cassette loading
assembly 300 is operated to load the cassette 152 into the test
console 102, the buffer driver 1002 engages and displaces the
buffer dispense plunger 1010 within the buffer chamber 1008. A
buffer driver access opening 190 is formed on the side of the
cassette case 154 (shown in FIG. 3), thereby allowing the buffer
driver 1002 to engage the buffer dispense plunger 1010.
[0436] The calibrator drive assembly 1104 includes a linear stepper
buffer motor 1114, which is mounted to the motor mount 1116, and a
calibrator driver 1118, which is aligned with the calibrator
dispense plunger 1014 within the calibrator chamber 1012 when the
cassette 152 is loaded into the test console 102. Thus, when the
calibrator driver 1118 is driven towards the cassette 152, it
engages and displaces the calibrator dispense plunger 1014 within
the calibrator chamber 1012. A calibrator chamber access opening
192 is formed on the front 156 of the cassette case 154 (shown in
FIGS. 3 and 4), thereby allowing the calibrator driver 1118 to
engage the calibrator dispense plunger 1014.
[0437] The vent/air flow port connector 1106 is mounted within an
aperture 1112 disposed within the pin alignment flange 750 (best
shown in FIGS. 13 and 14). In the illustrated embodiment, the
vent/air flow port connector 1106 is similar to the previously
described vacuum port connector 450. Thus, the vent/air flow port
connector 1106 is composed of a compliant silicone rubber in the
form of bellows, a compliant rim of which forms a tight vacuum seal
when engaged with the cassette vent/air flow port. In the
illustrated embodiment, the vent/air flow port connector 1106 is
1.5 cm in length, and 1 cm in diameter, with its compliant rim 2 mm
in width.
[0438] The afore-described cassette loading assembly 300 is used as
the vent/air flow port drive assembly. Thus, as the cassette 152 is
loaded into the test console 102, the vent/air flow port connector
1106 is engaged with the vent/air flow port 1086 located on the
side of the cassette case 154, so that the compliant rim of the
connector and the vent/air flow port 1086 coincide and provide a
tight seal. The previously described vent/air flow port mounting
aperture 188 (shown in FIG. 3) allows vent/air flow port connector
1106 to engage the vent/air flow port 1086.
[0439] The other end of the vent/air flow port connector 1106 is
connected to vacuum tubing 1120, which is composed of a suitable
material, such as Tygon tubing. The vacuum tubing 1120 is in turn
connected to one port of a vacuum outlet filter 1122, which is
composed of a suitable material, such as 0.1 .mu.m diameter port
microporous hydrophilic PTFE. The other port of the outlet filter
1122 is connected to a vacuum outlet port 1124 of the vacuum pump
456. Thus, the vacuum pump 456 can be operated to create positive
pressure within the vent/air flow assembly 1016. It should be noted
that the vent/air flow port drive assembly 1108 and vacuum pump 456
are both operated under control of a CPU 204 and I/O controller 206
(FIG. 12). A vent/air flow port drive home sensor (generally shown
in FIG. 12) is used to provide independent confirmation that the
vent/air flow port drive assembly 1108 has moved from or into its
home position.
[0440] The mixing drive assembly 1110 includes a rotary mixing
motor 1126, which is mounted to the inside of the door 310, and a
mixing coupling (not shown) that is rotatably coupled to the mixing
motor 1126, which is located adjacent the alcohol reaction chamber
1004 when the cassette 152 is loaded into the test console 102. The
mixing coupling contains two magnets (not shown), which when
rotated by the mixing motor 1126 magnetically interact with a
ferrous element (not shown) within the alcohol reaction chamber
1004. In the illustrated embodiment, the ferrous element is a 1.6
mm diameter stainless steel ball. It should be noted that the
mixing drive motor assembly 1110 is operated under control of a CPU
204 and I/O controller 206 (FIG. 12). A mixing motor 1126 home
sensor (generally shown in FIG. 12) is used to provide independent
confirmation that the coupling is in the home position, i.e., the
magnet is located at it lowest point to ensure that the ferrous
element is disposed in the bottom portion of the alcohol reaction
chamber 1102, so that dispensing operations are not interfered
with.
[0441] C. Alcohol Reader Assembly
[0442] The purpose of the alcohol reader assembly 1004 is to
measure the reaction that takes place in the alcohol reaction
chamber 1004 and to quantify any alcohol contained in the sample
based on this measured reactions. In the illustrated embodiment,
the alcohol reader assembly 1004 uses spectrophotometry to
determine the absorbance level of the reacted solution, which
absorbance level is proportional to the amount of alcohol in the
reacted solution. To this end, the alcohol reader assembly 1004
generally comprises an optical transmission assembly 1150, an
optical detection assembly 1152, and processing circuitry, which in
the illustrated embodiment, is the CPU 204.
[0443] The optical transmission assembly 1150 comprises an optical
transmission module 1154 and a mount 1156 mounted to the main base
side flange 120. The mount 1156 has an aperture 1158 through which
the optical transmission module 1154 is mounted. The optical
transmission module 1154 includes a housing 1160 in which there is
housed an optical source (not shown) that is aligned with and is
configured to transmit optical energy through the alcohol reaction
chamber 1004, and thus the analyte detectable sample solution, from
the rear 158 of the cassette case 154. An optical viewing window
194 is formed through the cassette case 154 (shown in FIGS. 3 and
4) to expose the alcohol reaction chamber 1004 on both sides of the
cassette case 154, thereby allowing the transmission of optical
energy from the rear 158 of the cassette case 154 where the optical
transmission assembly 1150, out the front 156 of the cassette case
154.
[0444] The optical transmission assembly 1150 further includes a
optical bandpass filter (not shown) housed within the housing 1160,
so that the optical energy passing through the alcohol reaction
chamber 1004 and analyte detectable sample solution exhibits
approximately monochromatic light of suitable wavelength. In the
illustrated embodiment, the optical source comprises a 0.75 mW UV
light emitting diode (LED) with maximum light emission at 375 nm,
and the optical bandpass filter passes an optical frequency of 365
nm (.+-.5 nm FWHM). The optical transmission assembly 1150 further
comprises an optical 50:50 splitter 1160, which splits the energy
beam from the optical bandpass filter into two energy beams, one of
which is a reference energy beam that bypasses the alcohol reaction
chamber 1004, and the other of which is the energy beam that passes
through the alcohol reaction chamber 1004. As will be described, in
further detail below, the reference energy beam is used to ensure
that the optical source transmits a uniform quantity of optical
energy through the alcohol reaction chamber 1004.
[0445] The optical detection assembly 1152 comprises a first
optical detection module 1164 located at the front 156 of the
cassette case 154 adjacent the optical viewing window 194. The
optical detection module 1164 is mounted within an aperture 1166
formed within the mechanical bench 908, such that it receives the
optical energy beam transmitted through the alcohol reaction
chamber 1004. The optical detection assembly 1152 further comprises
a second optical detection module 1168 mounted within a beam
splitter 1170 in which the optical transmission module 1164 is
associated. Thus, the second optical detection module 1168 receives
half of the optical energy from the optical transmission module
1154 in the form of a reference optical energy beam.
[0446] In the illustrated embodiment, each of the optical detection
modules 1164 and 1168 comprises a blue-sensitive silicon diode. The
first optical detection module 1164 receives the energy beam from
the alcohol reaction chamber 1004 and outputs a signal indicative
of the amount of optical energy received by it. As will be
described in further detail, this output signal is processed by the
CPU 204 to calibrate the alcohol detection assembly 1000 and
quantify the amount of alcohol in the sample. The second optical
detection module 1168 receives the reference energy beam directly
from the optical transmission module 1154 and also outputs a signal
indicative of the amount of optical energy received by it. This
output signal is used as feed back to a voltage-controlled current
source controller module (not shown), which ensures that the
optical transmission module 1154 is outputting a uniform optical
energy intensity.
[0447] D. Alcohol Detection Assembly-Operation
[0448] Having now described the detail structure of the alcohol
detection assembly 1000, its operation will now be described. In
general, the alcohol detection assembly 1000 reacts the sample with
the reagent solution to produce an alcohol detectable sample
solution having an alcohol indicator. In the illustrated
embodiment, any alcohol within the sample is reacted in the
presence of NAD, using ADH to effect the oxidation of the alcohol
to acetaldehyde with a simultaneous reduction of NAD to NADH. When
reacted to completion, a number of moles of NADH equal to the
number of moles of alcohol is produced. Thus, the concentration of
NADH is proportional to the concentration of alcohol within the
sample.
[0449] The concentration of the NADH in the alcohol detectable
sample solution can be measured by determining the change in
absorbance between the blank reagent solution, which does not
contain alcohol, and the alcohol detectable sample solution, which
does contain alcohol if the sample does. That is, according to the
Beer-Lambert Law (commonly known as Beer's law), the common
logarithm of the intensity of signal (i.e., voltage output) from an
optical detector is inversely proportional to the concentration of
NADH in the alcohol detectable sample solution. To eliminate any
unknown parameters from the sample quantification calculation, the
system is first calibrated by reacting the calibrator solution with
the reagent solution to produce an alcohol detectable calibrator
solution.
[0450] Thus, the concentration of alcohol in the sample can be
calculated using the following equations:
F=C/(A.sub.1-A.sub.0);
P=F*(A.sub.2-A.sub.0)*1.02,
[0451] where F is the calibration factor; C is the concentration of
alcohol in the alcohol detector calibrator solution, which is 0.001
in the illustrated embodiment; A0 is the measured absorbance of the
blank reagent solution, A1 is the measured absorbance of the
alcohol detectable calibrator solution, A2 is the measured
absorbance of the alcohol detectable calibrator solution; and P is
the weight-per-volume concentration of alcohol in the alcohol
detector sample solution. It is noted that the factor 1.02 corrects
for the dilution of the alcohol detectable sample solution by the
sample. The weight-per-volume concentration of alcohol in original
sample can then be obtained from the weight-per-volume
concentration of alcohol in the alcohol detector sample solution
(P), keeping in mind that the buffered sample solution dispensed in
the alcohol reaction chamber 1004 has been diluted 1:1 by a
buffer.
[0452] Thus, as will now be described in further detail, the
alcohol detection assembly 1000 is operated to (1) produce and
measure the absorbance of the blank reagent solution; (2) produce
and measure the absorbance of the alcohol detectable calibrator
solution; and (3) produce and measure the absorbance of the alcohol
detectable sample solution.
[0453] The blank reagent solution is produced by operating the
cassette loading assembly 300 to move the cassette carriage 302,
and thus the cassette 152, towards the buffer driver 1002 affixed
within the test console 102. As the buffer driver 1002 engages and
displaces the buffer dispense plunger 1010 within the buffer
chamber 1008, the stylus 1046 punctures the seal 1044 in the buffer
chamber 1008, and the seals 1032 and 1034 in the reagent chamber
1006. This allows the buffer to flow through the alcohol reaction
chamber 1004, thereby hydrating the dry reagent, and exiting the
reagent chamber 1006 as reconstituted reagent solution. The blank
reagent solution then flows through the reagent channel 1026 within
the manifold 1002 and into the reagent chamber 1006 via the reagent
exit port 1030. The mixing drive assembly 1110 is then operated for
a period of time, e.g., 1 minute, to move the ferrous element
within the alcohol reaction chamber 1004, thereby quantitatively
mixing the blank reagent solution.
[0454] The absorbance of the blank reagent solution is measured by
operating the alcohol detection assembly 1000. Specifically,
optical energy is transmitted from the optical transmission module
1154 through the blank reagent solution, where it is received by
the first optical detection module 1164. The first optical
detection module 1164 then outputs a signal, which is received and
used by the CPU 204 to determine the absorbance of the blank
reagent solution. It is noted that the second optical detection
module 1168 continuously receives the reference optical energy to
provide feedback and effect uniform transmission of optical energy
from the optical source.
[0455] The alcohol detectable calibrator solution is produced by
operating the calibrator drive assembly 1104 to move the calibrator
driver 1118 into engagement with the calibrator dispense plunger
1014, which is displaced within the calibrator chamber 1012. During
displacement of the calibrator dispense plunger 1014, the stylus
1064 punctures the seal 1062 within the calibration chamber 1012,
allowing the calibrator solution to flow from the calibrator
chamber 1012, through the alcohol channel 1050 within the manifold
1002, and into the alcohol reaction chamber 1004 via the alcohol
exit port 1054. The mixing drive assembly 1110 is again operated
for a period of time, e.g., 1 minute, to move the ferrous element
within the alcohol reaction chamber 1004, thereby mixing the
unreacted calibrator solution and the blank reagent solution to
form a fully reacted alcohol detectable calibrator solution.
[0456] The absorbance of the alcohol detectable calibrator solution
is measured by operating the alcohol detection assembly 1000 again.
Specifically, optical energy is transmitted from the optical module
1154 through the alcohol detectable calibrator solution, where it
is received by the first optical detection module 1164. The first
optical detection module 1164 then outputs a signal, which is
received and used by the CPU 204 to determine the absorbance of the
alcohol detectable calibrator solution.
[0457] The alcohol detectable sample solution is produced by
operating the rotary valve drive assembly 730 to clock the rotary
valve 610 into the sample flow/buffer post-wash configuration,
thereby placing the sample chamber 1015 into the vertical position.
The vent/air flow connector drive assembly is operated to engage
the vent/air flow port connector with the vent/air flow port 1086.
It is noted that this can be performed during the previous steps.
The vacuum pump 456 is then operated to provide a short burst of
compressed air, e.g., 1 second, to force air through the vent/air
flow assembly 1016, and thus, the sample out of the sample chamber
1015, through the sample/vent tube 1071 and into the alcohol
reaction chamber 1004. The mixing drive assembly 1110 is then
operated to move the ferrous element within the alcohol reaction
chamber 1004, thereby mixing the unreacted sample and the alcohol
detectable calibrator solution to form a fully reacted alcohol
detectable sample solution. It is noted that if the sample contains
alcohol, additional NADH is produced.
[0458] The absorbance of the alcohol detectable sample solution is
measured by again operating the alcohol detection assembly 1000.
Specifically, optical energy is transmitted from the optical module
1154 through the alcohol detectable calibrator solution, where it
is received by the first optical detection module 1164. The first
optical detection module 1164 then outputs a signal, which is
received and used by the CPU 204 to determine the absorbance of the
alcohol detectable sample solution.
[0459] With knowledge of the measured absorbances of the blank
reagent solution (A.sub.1), alcohol detectable calibrator solution
(A.sub.2), and alcohol detectable sample solution (A.sub.3), as
well as the known mass of alcohol in the calibrator solution (M),
the CPU 204 calculates the weight-per-volume percentage of alcohol
in the alcohol detectable sample solution (P), and thus, the
original sample.
[0460] IX. Temperature Control Assembly
[0461] Referring to FIGS. 7, 8, and 97, the system 100 comprises a
temperature control assembly 1200, the purpose of which is to bring
the internal assemblies of the cassette 152 to a desired controlled
constant temperature, thus providing consistency and predictability
to the chemical reactions that occur within the cassette 152. The
temperature control assembly 1200 is an independent hardware-only
assembly that functions independently of the CPU 204. This permits
temperature control to function continuously while the CPU 204
performs other housekeeping functions, such as sensor QC control
tests.
[0462] The temperature control assembly 1200 includes a heater
assembly 1202 and a heater controller (not shown) that periodically
turns the heater assembly 1202 on and off to maintain the
temperature of the system 100 as measured by temperature sensors
(not shown) disposed at strategic locations within the test console
102. The heater assembly 1202 includes internal heating elements
1208, a heat shroud adapter 1210, and a heat vent adapter 1212. The
temperature control assembly 1200 further includes a cooler (not
shown), which remains on to provide a constant level of cooling of
the cassette 152 sufficient to lower the ambient temperature of the
cassette 152 from its maximum initial ambient temperature
(10-40.degree. C. in the illustrated embodiment) to the desired
cassette control temperature (37.degree. C. in the illustrated
embodiment).
[0463] The temperature control assembly 1200 further include a fan
1216, which is mounted to a fan bracket 1228, a flexible heat vent
1218, and a heat shroud 1220 to provide recirculation of the
controlled temperature air. One end of the heat vent 1218 is
connected to the fan 1216, while the other end of the heat vent
1218 is connected to the heat vent adapter 1212 of the heater
assembly 1202. The heat shroud adapter 1210 of the heater assembly
1202 is in turn connected to the heat shroud 1220. The heat shroud
1220 tapers to a rectangular tapered end 1222, which mates with a
complementary rectangular opening 1224 (FIG. 85) formed in the
mechanical bench 908 of the dynamic scanning assembly 902. A
complementary rectangular opening 1226 (FIG. 14) is also formed in
the front support flange 304 of the cassette carriage 302. Thus,
the rectangular tapered end 1222 of the heat shroud 1220 aligns
with various openings formed in the cassette case 154 for providing
thermal access to the internal components with the cassette
152.
[0464] Referring to FIGS. 3-5, a first series of heat vents 196 is
formed on the front 156 of the cassette case 154 adjacent the
buffer chambers 614. A second series of heat vents 198 is formed on
the front 156 of the cassette case 154 adjacent the sample
distribution chambers 612. A third series of heat vents 199 is
formed on the rear 158 of the cassette case adjacent the angled
rigid tubes 650 of the buffer chambers 614. Thus, thermally
controlled air exiting the rectangular tapered end 1222 of the heat
shroud 1220 enters the cassette case 154 through the first and
second series of heat vents 196 and 198, thereby exposing the
internal components of the chemistry cassette 152 to the air, which
then exits the cassette case 154 out through the third series of
heat vents 199 on the rear 158 of the cassette case 154.
[0465] In the illustrated embodiment, the heater assembly 1202
comprises a 350W resistive heater, and the heater controller is a
proportional/differential/integral solid-state heater controller.
The temperature sensors are thermistors that are placed in
mechanical contact with the cassette case 154, thereby providing
intimate thermal conductivity with the cassette case 154, or
alternatively, IR-sensitive thermocouples or thermopiles (shown as
thermopile 1214 in FIG. 9) that are optically coupled to the buffer
chambers 614 near the middle of the cassette 152. Thus, if the
cassette 152 is determined to be below the desired temperature, the
heater controller places the temperature control assembly 1200 in
heat mode by turning on the heater assembly 1202. As a result, heat
proportional to the difference between the desired cassette
temperature and the ambient measured temperature of the cassette
case 154 is produced.
[0466] The heater controller controls the amount of heat added to
the constantly recirculating air through the closed loop
temperature control assembly 1200 by incorporating sufficient
anticipation to ramp down the heat added to the temperature control
assembly 1200, so that the temperature of the cassette 152 does not
stray outside (i.e., overshoot or undershoot) a transitional
temperature range (e.g., .+-.2.degree. C.) on the initial thermal
cycle, and does not stray outside a lesser steady-state temperature
range (e.g., .+-.1.degree. C.) during subsequent thermal cycles.
Once the temperature of the cassette 152 is determined to be in
this smaller range, only sufficient heat is added to keep the
cassette 152 within the control range, which provides a
counteracting effect to the constantly operating cooler 1208.
[0467] X. Cassette Case
[0468] Turning now to FIGS. 98-101, the internal structural details
of the cassette case 154 will now be described. The cassette case
154 can be generally divided into front and rear panels 1302 and
1304 that fit together in a clam-shell fashion. For the purposes of
this discussion, the relative terms "upward" and "downward" will
respectively mean towards the top and bottom sides of the cassette
case; "leftward" and "rightward" will respectively mean towards the
left and right sides of the cassette case looking towards the back
of the cassette case 154; and "forward" and "rearward" means
towards the front and back of the cassette case 154.
[0469] The cassette case 154 comprises an internal mixing assembly
compartment 1306, which is formed when the front and rear panels
1302 and 1304 are mated together. The mixing assembly compartment
1306 can be divided into a separate buffer chamber compartment
1308, sample collection chamber compartment 1310, mixing chamber
compartment 1312, and sample dispense plunger compartment 1314,
which respectively contain and support the buffer chamber 502,
sample collection chamber 412, mixing chamber 504, and plunger body
520 of the mixing assembly 500. It will appreciated that structure
disclosed as providing mechanical support to a particular component
of the mixing assembly 500 will provide similar mechanical support
to the entire mixing assembly 500 to some extent, since the mixing
assembly 500 can, in general, be considered a rigid body.
[0470] The mixing chamber compartment 1312 comprises first and
second support flanges 1316 and 1318, which extend from the rear
panel 1304 at the top and bottom of the mixing chamber compartment
1312. The bottom surface of the first flange 1316 abuts the top of
the mixing chamber 504, and the top surface of the second flange
1318 abuts the bottom of the mixing chamber 504, thereby supporting
the mixing chamber 504 in the presence of force applied to it in
the upward and downward directions. Of significance is the
prevention of the upward and downward movement of the mixing
chamber 504 when the sample and buffer drive assemblies 732 and 734
are operably associated with mixing assembly 500. The sample
dispense plunger compartment 1314 further comprises an actuate
opening 1320 provided within the second flange 1318 through which
the sample dispense plunger body 520 is disposed.
[0471] The buffer chamber compartment 1308 comprises the
afore-described first support flange 1316 and a third support
flange 1322, which is formed by complementary support flange
sections 1324 and 1326 extending from the tops of the front and
rear panels 1302 and 1304. An arcuate seat 1328 is formed within
the flange section 1326, and an opposing arcuate seat 1330 is
formed within a fourth flange 1332 extending from the front panel
1302. Thus, when the front and rear panels 1302 and 1304 are mated
together, the arcuate section 1330 receives the bottom of the
buffer chamber 502, and the arcuate section 1328 receives the top
of the buffer chamber 502, thereby supporting the buffer chamber
502 in the presence of force applied to it in the leftward,
rightward, forward, and rearward directions.
[0472] The sample collection chamber compartment 1310 comprises the
afore-described third support flange 1322, and a fifth support
flange 1334 extending from the rear panel 1304 at the bottom of the
sample collection chamber compartment 1310. The chamber stand 482
of the sample collection chamber 412 rests on the fifth support
flange 1334, thereby supporting the sample collection chamber 412
in the presence of force applied to it in the downward direction.
Of significance is the prevention of any downward movement of the
sample collection chamber 412 when the vacuum port connector 450 is
operably associated with the mixing assembly 500. As a result, any
shear or bending stress otherwise created between the sample
dispense port 530 and the sample inlet port 506 of the mixing
chamber 504 is minimized.
[0473] The cassette case 154 further comprises an internal flow
immunoassay assembly compartment 1336, which is formed when the
front and rear panels 1302 and 1304 are mated together. The flow
immunoassay assembly compartment 1336 can be divided into a
separate buffer chamber, rigid tube, distribution chamber, upper
chamber, and rotary valve compartments 1338, 1340, 1342, 1344, and
1346, which respectively contain the buffer chambers 614, the rigid
tubes 650, the sample distribution chambers 612, the immunoassay
reaction chambers 616, read cell assembly 618 and waste chamber
622, and the rotary valve 610. It will appreciated that structure
disclosed as providing mechanical support to a particular component
of the flow immunoassay assembly 600 will provide similar
mechanical support to the entire flow immunoassay assembly 600 to
some extent, since the flow immunoassay assembly 600 can, in
general, be considered a rigid body.
[0474] The buffer chamber compartment 1338 comprises sixth and
seventh support flanges 1348 and 1350, which extend from the rear
panel 1304 at the top and bottom of the buffer chamber compartment
1338. The bottom surface of the sixth support flange 1348 abuts the
top of the buffer chambers 614, and the top surface of the seventh
support flange 1350 abuts the bottom of the buffer chambers 614,
thereby supporting the buffer chambers 614 in the presence of force
applied to them in the upward and downward directions.
Significantly, upward movement of the buffer chambers 614 are
prevented when the buffer drive assemblies 734 are in operable
association with the flow immunoassay assembly 600. An eighth
flange 1352 extends from the front panel 1302 at the bottom of the
buffer chamber compartment 1338. The buffer chamber compartment
1338 comprises a series of ten buffer chamber seats 1354, which are
formed from a series of ten arcuate openings 1356 formed on top of
the seventh flange 1350 and a complementary series of ten arcuate
ledges 1358 formed on the eighth flange 1352 at the bottom of the
front panel 1302. When the front and rear panels 1302 and 1304 are
mated together, the complementary arcuate openings 1356 and ledges
1358 abut each other to form the completed buffer chamber seats
1352. Thus, the bottoms of the buffer chambers 614 can be seated
within the corresponding seats 1352, thereby supporting the buffer
chambers 614 in the presence of force applied to them in the
leftward, rightward, forward, and rearward directions.
[0475] The rigid tube compartment 1340 comprises the
afore-described sixth support flange 1348 and a ninth support
flange 1356, which extend from the rear panel 1304 at the top and
bottom of the rigid tube compartment 1340. The bottom surface of
the ninth support flange 1356 abuts the angled portion of the rigid
tubes 650, thereby supporting the rigid tubes 650 in the presence
of force applied to them in the upward direction. Of significance,
upward movement of the rigid tubes 650 is prevented when the buffer
drive assemblies 734 are in operable association with the flow
immunoassay assembly 600. The rigid tube compartment 1340 also
comprises a first and second series often arcuate seats 1358 and
1360 respectively formed in the sixth and ninth support flanges
1348 and 1356 at the bottom and top of the rigid tube compartment
1340. The first and second series of arcuate seats 1358 and 1360
receive the rigid tubes 650 at their top and bottom, thereby
supporting the rigid tubes 650, and thus further supporting the
flow immunoassay assembly 600 in the left, right, and back lateral
directions.
[0476] The sample distribution chamber compartment 1342 comprises
the previously described ledge 180, which is formed by the front
panel 1302. The top surface of the ledge 180 abuts the bottom of
the sample distribution chambers 612, thereby supporting the sample
distribution chambers 612 in the presence of force applied to them
in the downward direction. The sample distribution chamber
compartment 1342 also comprises a tenth flange 1362 extending from
the front panel 1302 in the middle of the sample distribution
chamber compartment. A series of ten arcuate seats 1364 are formed
in the tenth flange 1362, and receive the sample distribution
chambers 612, thereby supporting the sample distribution chambers
612 in the presence of force applied to them in the leftward and
rightward directions.
[0477] The upper chamber compartment 1344 comprises a front wall
1366 an eleventh flange 1368 formed by the upper portion of the
front panel 1302, and a ridge 1370 formed on the upper portion of
the rear panel 1304. The front surface of the read cell assembly
618 abuts the surface of the front wall 1366, and the top back
surface of the read cell assembly 618 abuts the ledge 180. Thus,
the read cell assembly 618 is supported against any force applied
to it in the forward and rearward directions. The bottom surface of
the eleventh flange 1368 abuts the top of the read cell assembly
618, thereby supporting the read cell assembly 618 against any
force applied to it in the upward direction. Significantly, the
upward movement of the read cell assembly 618 is prevented when the
sample drive assemblies 732 are operably associated with the flow
immunoassay assembly 600.
[0478] The rotary valve compartment 1346 comprises an annular
relief 1370 formed within the inner surface of the front panel
1302. The annular relief 1370 receives one side of the cylindrical
wall 668 of the stator 624, thereby supporting the rotary valve 610
in the presence of force applied to it in the forward direction.
The rotary valve compartment 1346 also a series of ten arcuate
seats 1374 that are formed in the eleventh flange 1368, and receive
the immunoassay reaction chamber seats 688 of the stator 624,
thereby supporting the rotary valve 610 in the presence of force
applied to it in the leftward and rightward directions.
[0479] The cassette case 154 further comprises various openings for
providing thermal access to the various components of the flow
immunoassay assembly 600, including the previously mentioned first,
second, and third series of heat vents 196, 198, and 199, which are
formed on the front and rear panel 1302 and 1304. The cassette case
154 also comprises the previously described pair of homing pin
holes 164 on the front panel 1302. The cassette case 154 further
comprises various openings for providing access to the internal
components of the chemistry cassette 152, including the previously
mentioned vertical access slot 174, horizontal access slot 172,
routing slot 175, sample distribution chamber access openings 178,
sensor access opening 168, optical read slits 184, optical
excitation apertures 186, vent/air flow port mounting aperture 188,
calibrator chamber access opening 192, and optical viewing window
194. These openings can be easily understood from a review of the
intact cassette case 154, and will not be discussed further.
[0480] The cassette case 154 further includes the previously
mentioned buffer chamber access opening 170, vacuum port access
opening 166, buffer chamber access openings 182, rotary valve
access opening 176, and buffer driver access opening 190 which will
now be described in further detail. The buffer chamber access
opening 170 and vacuum port access opening 166 are formed by
cooperation between the front and rear panels 1302 and 1304.
Specifically, the buffer chamber access opening 176 is formed from
the previously described arcuate opening 1328 formed in the flange
section 1326 of the rear panel 1304, and a complementary arcuate
opening 1372 formed on the flange section 1324 of the front panel
1302 when the front and rear panels 1302 and 1304 are mated
together. The vacuum port access opening 166 is also formed from
complementary arcuate openings 1374 and 1376 formed within the
flange sections 1324 and 1326 when the front and rear panels 1302
and 1304 are mated together.
[0481] The buffer chamber access openings 182 are formed from
arcuate openings 1378 formed in the eighth flange 1352 at the
bottom of the buffer chamber compartment 1308, and complementary
arcuate openings 1380 formed in a thirteen flange 1382 directly
below the seventh flange 1350 when the front and rear panels 1302
and 1304 are mated together. The rotary valve access opening 176 is
formed from complementary arcuate openings 1384 and 1386 within the
side walls of the front and rear panels 1302 and 1304 when mated
together. The buffer driver access opening 190 is formed from
complementary arcuate openings 1388 and 1390 within the side walls
of the front and rear panels 1302 and 1304 when mated together. In
addition, a series of five guiding holes (not shown) extend through
the cassette case 154 in longitudinal alignment with buffer drive
access opening 190, thus receiving the buffer driver 1002 when
inserted into the buffer driver access opening 190. The guiding
holes are formed from complementary arcuate openings (not shown)
formed from opposing flanges (not shown) extending respectively
from the inside surfaces of the front and rear panels 1302 and
1304.
[0482] XI. User Interface Assembly
[0483] Referring to FIG. 1, the system 100 includes a user
interface 150 for providing information to, and receiving
information from, an administrator/operator. The user interface 150
includes an LCD display screen 152, which displays menu items,
information request prompts, and test results to the operator, and
an internal printer 154, which provides the test results on
hardcopy upon request by the operator. The user interface 150
further includes a keyboard (not shown) and keys 156 for entering
requested information into the system 100. The keys 156 include (1)
a set of alpha-numeric keys 158 for entering numerical information
into the user interface 150; (2) a set of arrow keys 160 for
scrolling between menu items; and (3) a set of four soft function
keys 162, which, depending on the menu item displayed, may be
assigned "cont," "accept," "menu," "return," "cancel," "previous,"
"next," "back," "yes," "no," "print," or "done" functions, which
appear at the bottom of the display screen 152 for viewing by the
administrator/operator.
[0484] Specifically, depression of the following soft function keys
162 will provide the following functions: (1) "cont" will accept a
selected menu item (highlighted by manipulation of the arrow keys
160) and take the user to the next screen or menu; (2) "accept"
will accept the properly entered information and take the user to
the next screen or menu; (3) "menu" will take the user back to the
main menu if in the test mode or the administration menu if in the
administration mode; (4) "return" will return the user to the next
higher level menu; (5) "cancel" will place the system in cancel
mode; (6) "previous" will take the user to a previous same level
menu or screen; (7) "next" will take the user to the next same
level menu or screen; (8) "back" will return the user to a
previously selected same level menu or screen; (9) "yes" will give
an affirmative answer to a posed question and take the user to the
next menu or screen; (10) "no" will give a negative answer to a
posed question and take the user to the next menu or screen; (11)
"print" will print test results; and (12) "done" will be return the
user to the main menu. The CPU 204 is programmed to implement the
menu-driven user interface 150.
[0485] XII. System and User Level Operation
[0486] Having described the detailed structure and operation of the
assemblies of the system 100, the overall operation of the system
100 will now be described. Referring to FIG. 102, the system 100
runs through a battery of tests and monitoring processes. The
system 100 is first initialized at action block 1400, e.g.,
immediately upon power-up (cold-start), or after any interruption
of normal operations or system reset (warm-start). During system
initialization, the CPU 204 performs an initialization process in
which all software variable parameters are initialized, including
counters and pointers to data tables, with values necessary for
correction operation of the software. The core BIOS provides the
initialization of all hardware resources and provides a flag to the
power on self-test that the initialization process has occurred
satisfactorily.
[0487] At action block 1402, the CPU 204 performs a power on
self-test during which the various assemblies are tested to
determine that the test console 102 is capable of performing the
desired functions for its correct operation. Any failure of a
assembly component causes a QC message to indicate the type of
failure and not allow the operator to run a test. Immediately
following successful completion of the power on self-test, the CPU
204, at action block 1404, performs an initial sensor/interlock
test during which all of the sensors will be read by the CPU 204
for proper initial state/operation.
[0488] Following the completion of the foregoing tests, the system
100 is placed into a Ready mode at action block 1408 during which
all assemblies are fully powered and chemical testing can be
initiated immediately upon insertion of a cassette 152 into the
cassette port 106 on the front of the test console 102. If no
cassette insertion or keypad or keyboard operation is sensed within
a predetermined period of time (decision block 1406), e.g., 5
minutes, the CPU 204 will place the system 100 into Standby mode
(action block 1408) during which only the cassette port 106 and the
keypad/keyboard ports are power on. Insertion of the chemistry
cassette 152 or pressing any key on the keypad or keyboard will
cause the CPU 204 to place the system 100 back into Ready mode
(action block 1404).
[0489] When the system 100 is placed into Ready or Standby mode,
the CPU 204 continuously monitors power supply voltages and
sensor/interlock functions for satisfactory operation. A fault in
any of the power supply voltages and sensor/interlock functions
generates a fault condition, which generates an error flag on the
display screen 152 and halts any further analytical operation of
the test console 102 until the fault condition has been cleared.
Any error flags indicative of faults in the system 100 are
permanently logged into the nonvolatile memory of the reader
device. Further, during idle operation time, the test console 102
will periodically perform a diagnostic self test to determine
proper function of the various assemblies and certify the system's
ability to conduct the testing functions. In the event that a new
cassette 152 is inserted into the test console 102, any diagnostic
self-test currently underway will be cancelled, and the test
console 102 will then immediately return to its normal Ready
(analytical) mode of operation.
[0490] Referring now to FIG. 103, once the system 100 has been
powered on and has run through various initialization tests, the
administrator/operator is given the option to place the system 100
in an administrative mode, an operation mode, and a recall mode
(action block 1410). In the administration mode, an authorized
administrator may define the operational parameters of the system
100, e.g., record specific operator and facility information,
customize test panels, change the test parameters, setup display
and printer options, etc. In the operation mode, an authorized
operator may input test subject information and conduct tests using
the system 100, but may not alter predefined parameters that change
the function of the system 100 (which can only be accomplished by
the administrator). In the recall mode, an authorized operator may
recall previously performed and stored tests along with
corresponding subject information.
[0491] If at action block 1410, the user selects the
"Administrative Mode," the system 100 first prompts the
operator/administrator for his or her user name and password
(action block 1412). Thus, only authorized administrators can
modify the operational parameters of the system 100. Upon entry of
his or her correct user name and password, the system 100 is
prompted to select a specific language (e.g., English, Spanish,
French, and German) that the operator will use to communicate with
the system 100 (action block 1414). In alternative embodiments, the
specific language will not be selectable, but rather will default
to the language of the country in which the system 100 is
ultimately shipped. Upon selection of the language, the system 100
prompts the administrator to select the type of administration
information (e.g., facility information, general setup information,
date/time information, authorized operator, test panel,
units/threshold, and output option information) to be programmed
into the system 100 (action block 1416).
[0492] Specifically, selection of the "Facility" choice prompts the
administrator to enter facility specific information, such as the
name and location of the facility where the test is being run, as
well as any comments. Selection of the "General Setup" choice
prompts the administrator to input general setup information, such
as whether an operator password and/or subject identification
information is required. For example, if test results are to be
used as evidentiary purposes, e.g., at a police station or
workplace, the administrator would likely require an operator
password and subject information to be entered. If, on the other
hand, the test results are to be used merely to determine the state
of the test subject, e.g., in an emergency hospital room, the
administrator would likely not require an operator password and
subject information to be entered. The administrator may also
select whether an operator must enter the operator password/subject
identification at the beginning of every test. Selection of the
"Date/Time" choice prompts the administrator to enter date/time
information, such as the current date, time, and daylight savings
information.
[0493] Selection of the "Authorized Operator" choice prompts the
administrator to further select the operators authorized to operate
the system 100. Specifically, the administrator may add an operator
to a list of those authorized to operate the system 100 by entering
an operator user ID and associated password that is to be assigned
to the added operator. The administrator may select whether the
added operator also has administrative privileges, i.e., whether
the operator can modify the administrative parameters of the system
100. The administrator may also remove an operator from the
authorization list.
[0494] Selection of the "Test Panel" choice prompts the
administrator to further select the specific tests that are to be
run within each of a multitude of specific test panels. Thus, the
system 100 allows the administrator to customize test panels that
are to be run on the system 100. These test panels can be
preprogrammed into the system 100, but ultimately can be modified
by the administrator. For example, the administrator may customize
the test panels to a workplace environment. Here, the workplace
test panels may include, e.g., pre-employment, post-accident,
random, or reasonable cause (the name of which has been
preprogrammed or typed in by the administrator), as well as custom
tests. It should be noted, however, that the system 100 can be
customized to other scenarios besides the workplace, e.g., at a
police station or hospital emergency room. Selection of one of the
test panels, whether it be specifically named or one the custom
test panels, allows the administrator to select the specific drugs
that are to be tested for the selected test panel.
[0495] Selection of the "Units/Threshold" prompts the administrator
to input unit and threshold information for each of the list of
specific tests that can be run on the system 100. Selection of the
"Output Option" prompts the administrator to further select how the
test results will be exhibited and stored. For example, the
administrator may select the type of data that will be displayed as
the test results, e.g., quantitative, threshold level,
interpretative, or no display at all. Likewise, the administrator
may select the type of data that will be printed as the test
results, e.g., quantitative, threshold level, or interpretative.
Additionally, the administrator may select other types of
information to be printed, e.g., operator signature line, subject
signature line, select the number of copies to be printed, and the
specific printer that will be used to print the test results, e.g.,
internal printer, parallel printer, or serial printer. The
administrator may also select if the test results will be saved
internally within the system 100 or externally to, e.g., another
computer via an RS232 port.
[0496] If at action block 1410, the user selects the "Operation
Mode," the operator, if previously required by the administrator,
enters an operator ID and password, as well as the subject name and
ID (action block 1420). Upon correct entry of this information, the
operator selects one of the specific test panels to be run on the
system 100 (action block 1422). If the operator only desires to
collect a sample for subsequent testing at a laboratory, the
operator will select a confirmatory test. Once a test panel, if
any, has been selected, the chemistry cassette 152 is loaded into
the test console 102 (action block 1424) (See Section II). By
virtue of the loading action of the chemistry cassette 152, the
buffer drive assembly 1102 is operated to hydrate the dry reagent
within the alcohol reagent chamber 1006 of the alcohol reaction
assembly 1002, producing and dispensing the alcohol reagent
solution within the alcohol reaction chamber 1004 of the alcohol
reaction assembly 1002 (action block 1426) (Section VIII.D). All of
the drive assemblies are then placed into their home position
(action block 1428). Once the chemistry cassette 152 has been
loaded, it is brought from its ambient temperature (10-40.degree.
C.) to the optimum operating temperature (37.degree. C.) (action
block 1430) (See Section IX). At the same time, the system 100
determines if the chemistry cassette 152 has been previously used
(decision block 1432). If the chemistry cassette 152 has been
previously used, the cassette loading assembly 300 is operated to
eject the chemistry cassette 152 from the test console 102, and the
system 100, via the user interface 150, informs the operator that
the chemistry cassette 152 has been previously used and to load
another chemistry cassette 152 (action block 1434). If the
chemistry cassette 152 has not been previously used, the system 100
customizes the operational parameters of the test console 102 to
the specific chemistry cassette 152 and calibrates the test panel
(action block 1436) (See Section III).
[0497] The sample collection assembly 400 is then operated to
collect the saliva sample from the test subject (action block 1438)
(See Section IV.C). The system 100 determines whether the cassette
is a confirmation cassette (decision block 1440). If it is, the
confirmation cassette is ejected and processed accordingly (action
block 1442). It should be noted that if the cassette is a
confirmation cassette, action block 1426 will not have been
completed since there is no test to be run. If the cassette is not
a confirmation cassette, the sample is buffered and mixed at action
block 1444 (See Section V.C). The sample collection assembly 400 is
then operated to dispense the sample into the flow immunoassay
assembly 600, and specifically, to distribute the sample amongst
the multitude of immunoassay flow paths within the sample
distribution chambers 612, i.e., the sample distribution is
performed (action block 1446) (See Section VI.C). Simultaneous with
the sample distribution, the sample/buffer flow assembly 602 of the
immunoassay flow assembly 600, and specifically, the buffer drive
assemblies 576, is operated to flow the buffer through the
immunoassay flow paths to prepare the immunoassay reaction chambers
616, i.e., the buffer pre-wash is performed (action block 1448)
(See Section VI.C). During the buffer pre-wash, the optical flow
immunoassay scanning assembly 900 is operated to calibrate the
immunoassay flow paths (action block 1450) (See Section VII.D).
During the buffer pre-wash, the alcohol detection assembly 1000 is
also calibrated by (1) operating the alcohol reader assembly 1004
to measure the absorbance of the alcohol reagent solution
previously dispensed within the alcohol reaction chamber 1004; (2)
operating the alcohol reaction assembly 1002 to dispense the
calibrator solution into the alcohol reaction chamber 1004 to react
with the alcohol reagent solution and produce the alcohol
detectable calibrator solution; and (3) operating the alcohol
reader assembly 1004 again to measure the absorbance of the alcohol
detection calibrator solution (action block 1452) (See Section
VIII.D). The sample/buffer flow assembly 602 of the immunoassay
flow assembly 600, and specifically, the sample drive assemblies
574, is then operated to flow the sample through the immunoassay
flow paths to react within the immunoassay reaction chambers 616,
i.e., the sample flow is performed (action block 1454) (See Section
VI.C). During sample flow, the optical flow immunoassay scanning
assembly 900 is operated to quantitatively detect the presence of
any drug analytes within the sample (action block 1456) (See
Section VII.D). During sample flow, the vent/air flow assembly 1016
of the alcohol reaction assembly 1002 is also operated to dispense
the sample within the alcohol reaction chamber 1004 to react with
the alcohol reagent solution, thereby producing the alcohol
detectable sample solution (action block 1458) (See Section
VIII.D). The alcohol reader assembly 1004 is then operated to
quantitatively detect the presence of alcohol within the sample
(action block 1460) (See Section VIII.D).
[0498] Once the test is complete, the cassette loading assembly 300
is operated to eject the chemistry cassette 152 from the test
console 102, which is then discarded (action block 1462). The
system 100 then analyzes the collected data (action block 1464),
saves the results (action block 1466), and then displays the
results of the test (action block 1468), and optionally, the
operator prints the results (action block 1470).
[0499] If at action block 1410, the user selects the "Recall Mode,"
the user enters the specific test to be recalled (action block
1472), and the system 100 displays the results of the recalled test
(action block 1474), and optionally, prints the results (action
block 1476).
[0500] Although particular embodiments of the present inventions
have been shown and described, it will be understood that it is not
intended to limit the present inventions to the preferred
embodiments, and it will be obvious to those skilled in the art
that various changes and modifications may be made without
departing from the spirit and scope of the present inventions.
Thus, the present inventions are intended to cover alternatives,
modifications, and equivalents, which may be included within the
spirit and scope of the present inventions as defined by the
claims. All publications, patents, and patent applications cited
herein are hereby incorporated by reference in their entirety for
all purposes.
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