U.S. patent application number 11/312951 was filed with the patent office on 2007-06-21 for diagnostic test reader with disabling unit.
Invention is credited to Patrick T. Petruno.
Application Number | 20070143035 11/312951 |
Document ID | / |
Family ID | 38135972 |
Filed Date | 2007-06-21 |
United States Patent
Application |
20070143035 |
Kind Code |
A1 |
Petruno; Patrick T. |
June 21, 2007 |
Diagnostic test reader with disabling unit
Abstract
A diagnostic test reader including a test unit and a disabling
unit. The test unit is configured to perform one or more tests.
Each of the one or more tests employs a diagnostic assay to analyze
whether an analyte is present within a sample. The disabling unit
is coupled with the test unit and is configured to disable the test
unit based on a selected threshold number of tests.
Inventors: |
Petruno; Patrick T.; (San
Jose, CA) |
Correspondence
Address: |
AVAGO TECHNOLOGIES, LTD.
P.O. BOX 1920
DENVER
CO
80201-1920
US
|
Family ID: |
38135972 |
Appl. No.: |
11/312951 |
Filed: |
December 19, 2005 |
Current U.S.
Class: |
702/27 |
Current CPC
Class: |
G01N 35/00594 20130101;
G01N 35/00722 20130101 |
Class at
Publication: |
702/027 |
International
Class: |
G06F 19/00 20060101
G06F019/00 |
Claims
1. A diagnostic test reader comprising: a test unit configured to
perform one or more tests, wherein each of the one or more tests
employs a diagnostic assay to analyze whether an analyte is present
within a sample; and a disabling unit coupled with the test unit,
the disabling unit configured to disable the test unit based on a
selected threshold number of tests.
2. The diagnostic test reader of claim 1, wherein the disabling
unit includes: a counter configured to determine an actual number
of tests that have been performed by the test unit, a memory
configured to store the threshold number, and a processor
configured to compare the actual number of tests to the selected
threshold number.
3. The diagnostic test reader of claim 2, further comprising a
trigger coupled to the counter and configured to be activated after
a test has been performed by the test unit, wherein the counter
increments the actual number each time the trigger is
activated.
4. The diagnostic test reader of claim 2, wherein the selected
threshold number is commensurate with a predetermined sensitivity
level range.
5. The diagnostic test reader of claim 2, wherein the selected
threshold number is based on a probable sensitivity of the
diagnostic reader.
6. The diagnostic test reader of claim 1, further comprising: a
trigger configured to be activated after a test has been performed
by the test unit, wherein the activated trigger is configured to
instruct the disabling unit to disable the test unit.
7. The diagnostic test reader of claim 6, wherein the trigger is
mechanically activated.
8. The diagnostic test reader of claim 6, wherein the trigger is
electrically activated.
9. The diagnostic test reader of claim 6, wherein the trigger
includes a timer that begins when the test begins, and wherein the
trigger is activated when the timer reaches a predetermined
time.
10. The diagnostic test reader of claim 1, wherein the test unit
includes: an assay interface configured to receive the diagnostic
assay, a memory configured to store a program for analyzing the
diagnostic assay, and a test processor configured to execute the
program and analyze the assay.
11. The diagnostic test reader of claim 10, wherein the disabling
unit is coupled to the memory and is configured to disable the test
unit by deleting at least a portion of the program from the
memory.
12. The diagnostic test reader of claim 1, wherein the disabling
unit is configured to electrically disable the test unit.
13. The diagnostic test reader of claim 1, wherein the analyte is
human chorionic gonadotropin and the diagnostic assay is a lateral
flow assay.
14. The diagnostic test reader of claim 1, wherein the analyte
indicates drug use by a patient who provided the sample being
tested.
15. A diagnostic test system comprising: a diagnostic test reader
including: a test unit configured to perform one or more tests,
wherein each of the one or more tests employs a diagnostic assay to
analyze whether an analyte is present within a sample, and a
disabling unit coupled with the test unit, the disabling unit
configured to disable the test unit based on a selected threshold
number of tests; and a number of diagnostic assays equal to the
threshold number, wherein the diagnostic test reader and the
plurality of diagnostic assays are packaged together.
16. A diagnostic test reader comprising: means for performing one
or more tests, wherein each of the one or more tests uses a
diagnostic assay to analyze whether an analyte is present within a
sample received from a patient; and means for disabling the
diagnostic test reader when a threshold number of tests have
already been performed, wherein a disabled diagnostic test reader
is unable to perform additional tests.
17. A method of performing one or more tests employing a disposable
diagnostic test reader, the method comprising: performing one or
more tests employing the disposable diagnostic test reader
including determining with an assay if an analyte is present in a
sample introduced to the assay; and preventing use of the
diagnostic test reader based on a selected threshold number of
tests performed with the disposable diagnostic test reader.
18. The method of claim 17, further comprising: determining the
threshold number of tests that can be performed at a desired
sensitivity level.
19. The method of claim 17, further comprising: determining the
number of tests performed with the disposable diagnostic test
reader; and comparing the number of tests performed to the
threshold number; wherein preventing use of the disposable
diagnostic test reader occurs based on the comparison of the number
of tests performed to the threshold number.
20. The method of claim 17, wherein preventing use of the
disposable diagnostic test reader includes one of deleting a test
program from the disposable diagnostic test reader and electrically
disabling the disposable diagnostic test reader.
Description
BACKGROUND
[0001] Patient samples are often analyzed for the presence of
analytes to determine if a patient is carrying a disease, has an
infection, has been using drugs, etc. Analytes are typically
detected with immunoassay testing using antigen-antibody reactions.
Conventionally, such tests have been carried out in specialized
laboratories using relatively expensive reading equipment. However,
the need for on-site examination at the point-of-care, such as
hospitals, emergency rooms, nursing homes, practitioner offices,
and even at the home of a patient, is growing rapidly. Due to the
expense and size of many of the laboratory readers used to analyze
such tests, the conventional readers are not generally suitable for
use at the point-of-care.
[0002] Due to the limited sensitivity and breadth of available
point-of-care tests, turn around time of clinically significant
diagnostic test results typically requires three days time. More
specifically, tests must be completed at a central laboratory or be
transferred to the laboratory where they are placed in a queue to
be analyzed on one of a first in, first out or emergency basis. The
delay of clinically significant test results may result in a delay
of treatment until the presence of a particular ailment or level of
a particular condition has been verified. For example, in an
embodiment where a patient experiences the onset of a sore throat,
a streptococcus (strep) screen is typically performed. Currently
available rapid diagnostic, point-of-care test kits lack the
sensitivity to detect an early stage of strep, and therefore, the
patient typically waits two to three days for strep throat test
results. Since doctors typically will not prescribe antibiotics or
other remedies until the presence of strep has been verified in the
patient, the recovery of the patient will be delayed and, in the
meantime, the patient may come in contact with and infect a number
of other individuals. Concerns are magnified in cases involving
more serious medical conditions in which delayed treatment can have
devastating effects.
[0003] As noted above, conventional point-of-care test kits
generally lack the sensitivity to detect conditions in early stages
of their development. This lack of sensitivity is due in part to
the relatively low price points required for point-of-care testing.
The low price points have resulted in typical point-of-care tests
being less precise and less sensitive than desired. The lack of
sensitivity of such tests can result in early stages of an ailment
or condition not being detected. More specifically, as the level of
sensitivity of the reader decreases, the detectable level of
analyte in the test fluid typically increases. As such, in early
stages of diagnosis, although an analyte may be present in a
patient's system, the amount of a particular analyte within the
patient may not rise to a level sufficient to trigger a positive
test result in low sensitivity tests. Consequently, false negative
results will be obtained further delaying treatment. This lack of
sensitivity in point-of-care test kits further increases dependency
upon tests analyzed in the central laboratory.
[0004] Delayed treatment may lead to additional progression of an
ailment, increased contamination levels of new individuals having
contact with the patient, and other undesired effects. As such, a
need exists for a device and method for reading diagnostic tests
that provides a level of sensitivity configured to detect
relatively low levels of analytes while having a sufficiently low
price point to increase the availability of such tests at the point
of care. More specifically, a need exists for a test reader that is
sensitive, reliable, and relatively inexpensive.
SUMMARY
[0005] One aspect of the present invention relates to a diagnostic
test reader including a test unit and a disabling unit. The test
unit is configured to perform one or more tests. Each of the one or
more tests employs a diagnostic assay to analyze whether an analyte
is present within a test sample. The disabling unit is coupled with
the test unit and is configured to disable the test unit based on a
selected threshold number of tests.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Embodiments of the invention are better understood with
reference to the following drawings. Elements of the drawings are
not necessarily to scale relative to each other. Like reference
numerals designate corresponding similar parts.
[0007] FIG. 1 is a schematic diagram illustrating one embodiment of
a diagnostic test reader.
[0008] FIG. 2 is a flow chart illustrating one embodiment of a
method of using the diagnostic test reader of FIG. 1.
[0009] FIG. 3 is an exploded, perspective view illustrating one
embodiment of a diagnostic test reader and a sample container.
[0010] FIG. 4 is a partially exploded, perspective view
illustrating one embodiment a diagnostic test reader and a sample
container.
[0011] FIG. 5 is a perspective view illustrating one embodiment of
a set of packaged product including a diagnostic test reader.
DETAILED DESCRIPTION
[0012] In the following Detailed Description, reference is made to
the accompanying drawings, which form a part hereof, and in which
is shown by way of illustration specific embodiments in which the
invention may be practiced. In this regard, directional
terminology, such as "top," "bottom," "above," "over," etc., is
used with reference to the orientation of the Figure(s) being
described. Because components of embodiments of the present
invention can be positioned in a number of different orientations,
the directional terminology is used for purposes of illustration
and is in no way limiting. It is to be understood that other
embodiments may be utilized and structural or logical changes may
be made without departing from the scope of the present invention.
The following Detailed Description, therefore, is not to be taken
in a limiting sense, and the scope of the present invention is
defined by the appended claims.
[0013] FIG. 1 is a schematic diagram illustrating one embodiment of
a diagnostic test reader 10. In one embodiment, test reader 10
includes a test unit 12 and a disabling unit 14. Test unit 12 is
configured to interface with and read a diagnostic test or assay.
In order to keep the cost of test reader 10 below a desired level,
test unit 12 is designed to be disposable with no intermediate
upkeep or calibration. Test unit 12 is configured to read only a
certain number of tests, commensurate with a designed lifetime.
After such usable life, failure mechanisms may cause quality or
reliability effects, which may begin to degrade the sensitivity of
test unit 12. To prevent use of test unit 12 after degradation,
disabling unit 14 is coupled with test unit 12 and is configured to
disable test unit 12 prior to degradation. In particular, in one
embodiment, disabling unit 14 is configured to track the number of
actual tests performed by test unit 12 and to disable test unit 12
after a predetermined number of tests have been performed. In
particular, the disabling unit 14 is configured to disable test
unit 12 prior to degradation of the precision, reliability, or
sensitivity of test unit 12 in reading the particular diagnostic
test or assays associated with test reader 10. As such, a lower
cost test reader 10 can be supplied that delivers the more
sensitive test results desired by patients, caretakers, and other
healthcare workers.
[0014] In one embodiment, test unit 12 includes a diagnostic test
or assay interface 20, a test processor 22, and a memory 24. Assay
interface 20 is configured to receive any particular type of
diagnostic assay, such as a lateral flow assay, or can be brought
into the proximity of more difficult to handle assays, such as
liquid form ELIZA's performed in test tubes or microtiter plates,
or other assays in which handling might interrupt the function of
the assay. In one embodiment, assay interface 20 is configured to
receive an assay strip, such as a lateral flow assay strip, a
sample container including a diagnostic test or assay strip, or any
other suitable device configured to receive at least a portion of a
sample to be analyzed by test unit 12.
[0015] Assay interface 20 is coupled with test processor 22. Test
processor 22 is configured to analyze the assay received by assay
interface 20. Test processor 22 may include or be coupled with any
suitable device for detecting the assay result, such as an
opto-electronic detectors (PIN diodes, APD), cameras or other
imagers, etc. In addition, test processor 22 can include post
processing of detected data as well as mechanisms for timing and/or
detection of start and stop times. In one embodiment, test
processor 22 is coupled with memory 24, which stores a test program
26. Test program 26 outlines a procedure for analyzing a particular
assay to determine whether and/or how much of an analyte is
detected by the assay as being present in the fluid being tested.
In one embodiment, test program 26 further instructs test processor
22 to determine how the levels of analyte detected relate a
particular ailment or condition. Accordingly, test processor 22 is
configured to run test program 26 to analyze the particular assay
received by assay interface 20 and the fluid tested therein.
[0016] For example, in one embodiment, test program 26 outlines a
procedure for optically analyzing a lateral flow assay test for a
particular change in color of or appearance of a line in the assay
test, wherein a change of color or appearance of a line in the
assay test indicates the presence of the analyte being tested for.
In one embodiment in which test reader 10 is a pregnancy test, test
program 26 outlines a method for reviewing a lateral flow assay
strip for a change of color indicating the presence of human
chorionic gonadotropin, or HCG, to determine whether or not a
particular patient is pregnant. However, test program 26 may
include instructions for performing any method of analyzing a test,
such as an ELIZA test, a drugs-of-abuse test, or any other suitable
analyte test.
[0017] In general, by using test processor 22 to analyze the assay,
a more precise and accurate result can be determined as compared to
manual reading of the assay. For example, in a typical pregnancy
test, the degree of color change in an assay can vary greatly
depending upon the level of HCG included in the blood or urine of
the patient being tested. In early detection cases, the color
change of the assay strip is relatively minor and may be
undetectable to a user or may leave the user with questions
regarding whether or not there was actually a color change in the
assay strip. However, test processor 22 running test program 26 can
more precisely analyze the degree of color change and determine a
particular level of HCG within the assay. In this regard, a more
definite and sensitive test result can be achieved.
[0018] The precision and accuracy of test unit 12 is improved
dramatically over manual interpretation due to the use of complex
optical and electronic elements. However, the addition of more
complex elements to test unit 12 generally increases the amount of
maintenance used to keep the device reading correctly at the
desired sensitivity levels. Therefore, the complexity of the test
unit design will allow a certain level of sensitivity, however,
continued use of such a test unit 12 without maintenance will have
a statistical probability of failing or "drifting," which can
eventually cause catastrophic failure or gradual accuracy
degradation that would not overtly be detected by a user. In order
to statistically insure the desired level of sensitivity is
maintained for test unit 12, the number of tests that test unit 12
will be allowed to perform is limited to a number configured to be
completed well in advance of any statistical onset of the
above-described degrading or failing mechanisms. The number of
tests that can be performed is generally directly proportional to
the cost of test unit 12. Accordingly, as the price of test reader
10 is lowered to increase the availability of test reader 10, the
effective life span of test reader 10 typically decreases since
less robust and reliable components are utilized.
[0019] In one embodiment, test unit 12 is configured to perform
less than one of 100, 50, 10, 5, or any other number of tests
allowable by the test unit 12. The threshold number of tests for
which test unit 12 can be used depends on the particular
construction, the durability of the material, electronic
capabilities utilized, and safety factor for test unit 12. For
example, not only may the test processor 22 and/or other
electronics of test unit 12 only be configured for a limited number
of uses, but mechanical tabs or other devices physically
interacting with the assay or associated device break or corrode
and, therefore, are also only reliable for a limited number of
uses. As such, the threshold number is equal to or less than a
number of tests that would result in undesirable statistical
probability either electrical or mechanical degradation that
decreases the test reader sensitivity to be below a desired
level.
[0020] In one embodiment, test unit 12 optionally includes a
display 28 for indicating the results of performing test program
26, such as whether an analyte is present and/or what levels of an
analyte are present. Display 29 is any suitable indicator or
information display, such as a light emitting diode (LED) light, a
liquid crystal display (LCD) screen, etc.
[0021] Disabling unit 14 is coupled with test unit 12 and is
configured to disable test unit 12. In one embodiment, disabling
unit 14 is configured to disable test unit after a predetermined
number of tests have been performed. In one example, disabling unit
14 includes a memory storing a threshold number of tests 30, a test
complete trigger 32, a counter 34, a disabling processor 36, and a
disabling device 38. Threshold number of tests 30 is a number of
tests that the test unit 12 has been rated to be able to perform
reliably and with a particular sensitivity level desired for test
reader 10.
[0022] The threshold number of tests 30 may be selected with any
factor of safety desired to generally disable test unit 12 prior to
any statistical probability of either electrical or mechanical
degradation that decreases the test reader sensitivity to be below
a desired level. In particular, threshold number of tests 30 is
determined via calculations and/or experimentation in which a
number of test units 12 are tested during periods of repeated use.
The number of uses at which particular components of test unit 12
begin to fail or the sensitivity levels of the test fall below a
desired level are determined. The threshold number of tests 30
stored in disabling unit 14 is generally a number significantly
lower than the number of tests determined to cause degradation or
an undesired decrease in the sensitivity or reliability of test
unit 12. The desired level of sensitivity varies depending upon the
test being run with test unit 12. For example, pregnancy tests may
require less sensitivity or may allow higher error rates than a
test for an infectious disease where test errors may have a more
detrimental effect on the patient or others.
[0023] In one embodiment, the threshold number of tests 30 is
selected based upon a mean time to failure (MTTF) number of tests
completed. The MTTF occurs when half the units will give incorrect
test results when performing the MTTF number of tests. The
threshold value may be adjusted or decreased in appropriate orders
of magnitude to achieve an acceptable error rate for a particular
type of test. Acceptable levels to determine threshold numbers may
be based on such confidence levels and/or economics of test
production. However, any other suitable method of determining
threshold number of tests 30 may also be utilized.
[0024] For example, in one embodiment in which test unit 12 was
continually found to electrically and/or mechanically degrade
sensitivity to less than acceptable levels at or around fifty
tests, threshold number of test 30 is determined to be a fraction
of the fifty tests given a particular safety factor. For example,
threshold number of tests 30 may be determined to be forty tests
given an 80% safety factor. By using a safety factor or guard band,
the threshold number of tests 30 is positioned well below the
actual number of tests that cause test unit 12 to degrade, thereby,
guarding against failure or decreased sensitivity of test unit 12
prior to reaching the threshold number of tests 30. Given the
particular unit and the cost points of that unit, the threshold
number of tests 30 can range anywhere from 1 to 500 tests. Notably,
in one embodiment, threshold number of tests may be selected to
allow some sensitivity degradation of test unit 12, but is selected
to prevent use of test unit 12 below a predetermined level of
sensitivity.
[0025] Test complete trigger 32 is configured to recognize when
test unit 12 has completed analysis of an assay. Trigger 32 is
coupled with counter 34. Counter 34 receives notification from
trigger 32 that a test has been completed. Upon such notification,
counter 34 increments the actual number of tests stored by counter
34 by one. In this manner, counter 34 includes an up-to-date tally
of the number of tests that test unit 12 has actually
performed.
[0026] Trigger 32 can be any trigger suitable to determine when a
test has been completed by test unit 12. In one embodiment, trigger
32 detects when an assay has been loaded into test unit 12, which,
in turn, starts a timer in one of test unit 12 and disabling unit
14. When the timer indicates that a particular time period has
passed, which corresponds with a completion of the test, trigger 32
notifies counter 34. In other embodiments, trigger 32 may sense a
physical movement of the assay into or out of assay interface 20,
may optically and/or electronically sense the introduction of a
sample fluid to the assay strip or assay interface 20, may detect a
color change or other indicator of the assay strip, and/or may
detect any other suitable action or occurrence indicating that a
test has begun or has been completed. In one embodiment, triggers
conventionally used to begin a test or analysis are used as at
least a part of trigger 32. In one example, a button may be
included on the device to manually trigger counter 34. In one
embodiment, trigger 32 is automatically activated during
performance of a diagnostic test and does not require a separate
action by the user to trigger the device.
[0027] Disabling processor 36 is any suitable processor configured
to compare threshold number of tests 30 to the actual number of
tests performed as determined by counter 34. In particular,
following each use or otherwise periodically, disabling processor
36 is configured to compare the number of actual tests performed
from counter 34 to threshold number of tests 30 to determine if the
number of tests that have actually been performed is equal to or
greater than threshold number of tests 30. If the actual number of
tests performed is found to be below the threshold number of tests
30, the disabling processor 36 does nothing further. However, if
the disabling processor 36 determines the actual number of tests
performed to be equal to or greater than threshold number of tests
30, disabling processor 36 notifies disabling device 38 to disable
test unit 12.
[0028] Disabling device 38 can be any device configured to
effectively disable or deactivate test unit 12 to substantially
prevent use of test unit 12 to perform any further diagnostic
tests. In one embodiment, disabling device 38 is coupled with
memory 24. In this embodiment, disabling device 38 is configured to
erase memory 24 of test program 26 upon instruction from disabling
processor 36. As such, once test program 26 is deleted from memory
24, test processor 22 cannot analyze subsequent assays placed
within assay interface 20 since it no longer has instructions for
how to perform such analysis. As such, no subsequent diagnostic
test can be performed by test unit 12. In another embodiment,
disabling device 38 is configured to bum or otherwise de-activate a
fuse within test unit 12, thereby, preventing use of test unit 12
to diagnostically access an assay received by assay interface 20. A
fuse may be configured to deprive test unit 12 of power, to disrupt
communication between assay interface 20 and test processor 22,
and/or to disrupt communication between test processor 22 and
memory 24. However, any other suitable disabling device 38 is also
acceptable.
[0029] In one embodiment, in which test unit 12 is configured for
only one use before being disposed, trigger 32 may be directly
coupled with disabling device 38. As such, when trigger 32 senses
completion of the first use, trigger 32 notifies disabling device
38 to disable test unit 12. In such an embodiment, threshold number
of tests 30, counter 34, and disabling processor 36 may be
eliminated. In one embodiment, all of disabling unit 14 or any
portions of disabling unit 14 may be realized mechanically,
electrically, and/or optically.
[0030] In the above description, test unit 12 and disabling unit 14
are described as separate units in view of their function for
clarity. However, in one embodiment, test unit 12 and disabling
unit 14 are formed to utilize or share components. For example, a
single processor may serve as test processor 22 and disabling
processor 36, etc.
[0031] In this respect, test reader 10 is specifically configured
to prevent use of the test reader 10 beyond a particular number of
predetermined uses. For example, a unit that has only been rated
for use with ten tests generally cannot be used to perform an
eleventh test. Therefore, even if a particular patient, or
caregiver believes the test reader 10 to be reliable for a number
of tests greater than threshold number of tests 30, the patient or
caregiver cannot continue to use a test reader 10. It is important
to substantially prevent use of a test reader 10 beyond the
threshold number since any subsequently performed tests would
generally have an increased chance of error or decreased
sensitivity, or under an economic motivation, to prevent use of
test reader 10 for unpaid services.
[0032] Prevention of use for more than the threshold number of
tests is particularly important in practice areas where users do
not generally believe that test readers 10 are disposable. In
particular, in more complicated diagnostic tests, the test readers
are generally believed by healthcare workers and others to be
expensive pieces of equipment that are not generally disposable. As
such, healthcare workers or other individuals having this general
belief may not be comfortable with disposing of a test reader 10
that still appears to be working properly. Therefore, disabling
unit 14 protects against undesired or unreliable uses of test
reader 10. Furthermore, use of disabling unit 14 allows inexpensive
parts to be used with test unit 12 without a worry that such parts
will degrade and lead to unreliable test results or a desensitivity
of the test results.
[0033] FIG. 2 illustrates a method of using test reader 10
generally at 50 with reference to FIG. 1. At 52, test reader 10
receives a diagnostic assay via assay interface 20. At 54, the
diagnostic assay is read and analyzed by test unit 12. Upon
completion of the diagnostic analysis, counter 34 is triggered at
56. For example, as described above, the triggering of counter 34
may be caused by a passing of a predetermined period of time, a
mechanical interaction, an optical interaction, an electrical
interaction, or other sensor interaction. In one embodiment,
counter 34 is triggered by the removal of assay strips 78 from test
reader 10 following completion of a test.
[0034] At 58, it is determined if the actual number of diagnostic
tests performed by test unit 12 is less than threshold number 30
stored in disabling unit 14. If the actual number of tests
performed is less than threshold number 30, then additional tests
may be performed by test reader 10 and steps 52 through 58 are be
repeated accordingly with new assays. However, if the actual number
of diagnostic tests performed is not less than threshold number 30,
then the method 50 continues to operation 60.
[0035] At 60, disabling device 38 is triggered by disabling
processor 36 to disable test unit 12. In one embodiment, disabling
test unit 12 at 60 includes at least one of deleting test program
26 from memory 24, burning a fuse in test unit 12, or any other
suitable method of disabling test unit 12, which guards against
future use of test unit 12. In one embodiment, after being
disabled, test unit 12 is substantially useless. At 62, test reader
10 is disposed of accordingly.
[0036] FIG. 3 illustrates one embodiment of a particular diagnostic
test system 70 including a diagnostic test reader 72 similar to
test reader 10 of FIG. 1. In this embodiment, diagnostic test
system 70 further includes a sample collection cup 74 and a
diagnostic lid 76. Sample cup 74 is configured to receive test
fluids, such as urine, blood, etc. from a patient. Lid 76 is
configured to interface with an open end of cup 74 to substantially
enclose the sample fluid within cup 74. In one embodiment, lid 76
includes one or more diagnostic assays 78. For example, as
illustrated in FIG. 2, lid 76 is subsequently transparent and
includes a plurality of lateral flow assay strips 78 that are
generally visible through lid 76.
[0037] Test reader 72 is configured to interface with sample cup
74, more particularly, with lid 76 of sample cup 74. In one
embodiment, test reader 72 is adapted to optically analyze assay
strips 78 in lid 76. In one embodiment, test reader 72 is formed of
two parts, namely, an inner housing 80 and an outer housing 82.
Outer housing 82 is configured to coaxially receive inner housing
80.
[0038] In one embodiment, circuitry 88 of inner housing 80 is
mounted to a top surface of inner housing 80. In one example,
circuitry 88 includes test processor 22 (FIG. 1), a timer, an
opto-electronic camera positioned within inner housing 80, and/or
disabling unit 14 (FIG. 1). In one embodiment, test reader 72, in
particular, inner housing 80, includes a connection device 90 to a
computer processing unit or other device, in one embodiment,
connection device 90 is a universal serial bus (USB) connector.
[0039] Test reader 72 is configured to be aligned with and pushed
down and at least partially over lid 76 to secure test reader 72 to
lid 76. Upon coupling of test reader 72 with lid, in one
embodiment, a camera included in circuitry 88 is positioned to
optically capture assay strips 78 through lid 76. To facilitate
coupling in one embodiment, inner housing 80 includes tabs 84
circumferentially spaced around an open periphery of inner housing
80. Tabs 84 are bent toward lid 76 during use to grasp lid 76
locking test reader 72 to lid 76. In one embodiment, bending or
unbending of tabs 84 may trigger test reader 72 that a test has
been performed. In one example, springs 86 interact with inner and
outer housings 80 and 82 and facilitate decoupling of test reader
72 with lid 76.
[0040] In one embodiment, lid 76 includes a cavity 92 including an
aliquot plunger, and test reader 72 includes an index member 94.
After inner housing 80 is positioned on lid 76, outer housing 82 is
pushed toward inner housing 80, thereby, moving index member 94
down into cavity 92. Index member 94 interacts with the aliquot
plunger causing sample fluid in cup 74 to be aliquot to assays
78.
[0041] In one embodiment, once inner housing 80 grasps lid 76, the
timer begins a countdown of the predetermined time period required
to complete the analysis of assay strip 78 in lid 76. In
particular, in one embodiment, the opto-electro camera (not
pictured) of inner housing 80 views assays 78 through transparent
lid 76 to determine whether or not a particular analyte is present
by analyzing any color change of test trip 78. At the end of the
predetermined time period, if no analyte is detected, then the test
is negative. Regardless of whether or not the analyte was detected,
the test is generally complete upon the expiration of the
predetermined time period. Therefore, in one embodiment, the
expiration of the time period serves as the test complete trigger
32 (FIG. 1) and notifies counter 34 (FIG. 1) to increment the tally
of the actual tests performed by one.
[0042] As described with reference to FIG. 1, disabling processor
36 compares the actual number of tests completed as determined by
counter 34 with a threshold number of tests 30 previously stored to
test reader 72. If disabling processor 36 determines that the
actual number of tests completed by test reader 72 is equal to or
greater than the threshold number of tests 30, disabling device 38
is notified, and disabling device 38 subsequently deletes test
program 26 from memory 24, thereby, disabling test reader 72. Since
test reader 72 is disabled, a patient or healthcare worker is more
likely to dispose of the test reader 72 and will not generally
reuse the test reader 72 for additional tests beyond the number of
threshold tests 30.
[0043] Although described in the embodiments above as being a
sample cup 74 with assay strips 78 in lid 76, in one embodiment,
the lateral flow assay strip is directly configured to receive the
sample fluid being tested, such as urine, blood, etc. such as in a
pregnancy test. In these embodiments, the above described test
reader 72 functions in a similar manner wherein placement of the
lateral flow assay test into the pregnancy reader triggers a test
or performance of a test of a lateral flow assay mechanically,
electrically, or otherwise indicates to the trigger 32 that a test
has been complete and notifies counter 34 to increment by one the
number of actual tests completed.
[0044] For example, FIG. 4 is a schematic diagram of a diagnostic
test system 110 including a test reader 111, which functions
similar to test reader 10. Accordingly, test reader 111 includes a
test unit 112 and a disabling until 114 similar to units 12 and 14,
respectively. A lateral flow assay strip 116 is received by assay
interface of test unit 112. Receipt of assay strip 116 or some
subsequent event triggers disabling unit 114 to track the actual
number of assay strips 116 that have been analyzed by test reader
111. In a similar manner, as described above with test readers 10
and 72, disabling unit 114 is configured to disable test unit 112
when a predetermined threshold number of assay strips 116 have been
analyzed.
[0045] FIG. 5 illustrates one embodiment of packaged diagnostic
test system at 150. In one embodiment, packaged diagnostic test
system 150 includes a container or packaging 152, a test reader 10,
and a plurality of test strips or assays 154. In one embodiment,
the number of assays or test strips 154 packaged with a single test
reader 10 is equal to the threshold number of tests 30 (FIG. 1).
For example, where threshold number of tests 30 is ten, a single
test reader 10 is packaged with ten test assays 154. As such,
packaging 152 can be used in addition to or as an alternative to
counter 34 (FIG. 1) to determine when diagnostic test reader 10 has
performed threshold number of tests 30. For example, a test reader
10 is used with all diagnostic assays 154 packaged therewith. Upon
the use of all diagnostic assays 154 packaged with test reader 10,
test reader 10 is disposed of and a new diagnostic test system
product package 150 is opened and used. As such, such packaging can
be used in and of itself to monitor the use of test reader 10
and/or can be used a secondary or visual device indicating the
number of diagnostic assays remaining that may be completed on a
particular test reader 10 including disabling unit 14 (FIG. 1). In
one embodiment, the threshold number of tests may be set slightly
differently than the number of assays 154 to allow for inclusion of
spare assays 154 in packaged system 150, or for a few additional
uses if a user unintentionally triggers the counter or otherwise so
requires.
[0046] The embodiments described above provide relatively low cost
diagnostic test readers configured to analyze immunoassays with a
desired level of sensitivity. The low cost of the test readers
increases availability of such test readers at non-laboratory
locations, such as at the point of care. In addition, the disabling
unit included within the test readers polices use of the test
readers, substantially preventing use of the test readers to
perform tests after a threshold number of uses and well before
statistical probability of either electrical or mechanical
degradation of the test reader or before the legal life of the test
unit has expired. As such, a sensitive diagnostic test can be
performed at the point of care for a relatively low price.
[0047] Although specific embodiments have been illustrated and
described herein, it will be appreciated by those of ordinary skill
in the art that a variety of alternate and/or equivalent
implementations may be substituted for the specific embodiments
shown and described without departing from the scope of the present
invention. This application is intended to cover any adaptations or
variations of the specific embodiments discussed herein. Therefore,
it is intended that this invention be limited only by the claims
and the equivalents thereof.
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