U.S. patent application number 11/924033 was filed with the patent office on 2009-01-08 for portable apparatus for improved sample analysis.
Invention is credited to Jorn Gorlach, Edward W. Withrow, III.
Application Number | 20090010804 11/924033 |
Document ID | / |
Family ID | 39365198 |
Filed Date | 2009-01-08 |
United States Patent
Application |
20090010804 |
Kind Code |
A1 |
Withrow, III; Edward W. ; et
al. |
January 8, 2009 |
Portable apparatus for improved sample analysis
Abstract
The present invention is an improved apparatus for sample
analysis. The apparatus employs an assay component containing a
membrane having one or a plurality of analyte-specific binding
agents attached thereto, a means for absorbing liquid, and a piston
means for drawing analytes through said membrane into said means
for absorbing liquid. The apparatus is configured to be portable
and provide a detector for detecting binding of an analyte to an
analyte-specific binding agent, a plurality of data acquisition
components, and a computer for integrating, analyzing and storing
the detected analyte specific binding and acquired data.
Inventors: |
Withrow, III; Edward W.;
(Santa Barbara, CA) ; Gorlach; Jorn; (Manchester,
NJ) |
Correspondence
Address: |
Jane Massey Licata;Licata & Tyrrell P.C.
66 E. Main Street
Marlton
NJ
08053
US
|
Family ID: |
39365198 |
Appl. No.: |
11/924033 |
Filed: |
October 25, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60863241 |
Oct 27, 2006 |
|
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|
Current U.S.
Class: |
422/68.1 |
Current CPC
Class: |
A61B 5/418 20130101;
B01L 2300/0663 20130101; G01N 33/54366 20130101; A61B 5/14532
20130101; A61B 5/14546 20130101; B01L 2300/024 20130101; A61B 5/411
20130101; Y10S 435/809 20130101; B01L 3/5023 20130101; G16H 40/63
20180101; G01N 35/00871 20130101; B01L 2200/028 20130101; Y02A
90/26 20180101; A61B 5/1455 20130101; A61B 5/0002 20130101; A61B
5/416 20130101; G06F 19/00 20130101; B01L 2300/0636 20130101; B01L
2400/0478 20130101; A61B 5/415 20130101; B01L 2300/023 20130101;
Y02A 90/10 20180101 |
Class at
Publication: |
422/68.1 |
International
Class: |
B01J 19/00 20060101
B01J019/00 |
Claims
1. An improved sample analysis apparatus of the type having a
membrane with an analyte-specific binding agent attached thereto, a
means for absorbing liquid, and a piston means for drawing analytes
in a sample through the membrane into the means for absorbing
liquid, the improvement comprising a detector for detecting
analyte-specific binding to the analyte-specific binding agent, a
plurality of data acquisition components for acquiring data, and a
computer, wherein the computer integrates, analyzes and stores the
detected analyte-specific binding and acquired data thereby
providing improved sample analysis.
2. The apparatus of claim 1, wherein the apparatus comprises one or
a plurality of analyte-specific binding agents.
Description
INTRODUCTION
[0001] This application claims benefit of priority to U.S.
Provisional Patent Application Ser. No. 60/863,241, filed Oct. 27,
2006, the content of which is incorporated herein by reference in
its entirety.
BACKGROUND OF THE INVENTION
[0002] Diagnostic testing throughout the world is currently carried
out using a variety of different specimen types including whole
blood, serum, oral fluid, plasma, cerebrospinal fluid and others.
Testing for diseases under laboratory conditions typically involves
use of a blood serum specimen obtained by removing the blood cells
from an intravenous blood sample by centrifugation. The serum
sample so obtained is then tested under laboratory conditions using
one of a number of methodologies, such as Enzyme Linked Immuno
Sorbent Assay (ELISA), Immunofluorescence (IFA), Latex
Agglutination (LA), or any of a number of automated instrument
platforms employing chemiluminescence, fluorescence or other
sensitive technologies.
[0003] One such device for diagnostic testing employs a membrane
having a receptor (e.g., an antibody) physically attached to its
surface, wherein upon application of a sample, a piston means
creates a region of reduced pressure thereby drawing analytes
present in the sample through the membrane into a means for
absorbing liquid. In this regard, an analyte which specifically
binds to the receptor is readily detected. See, e.g., U.S. Pat.
Nos. 4,797,260 and 5,137,691, incorporated herein by reference in
their entireties.
[0004] Although serum testing under laboratory conditions has
traditionally constituted the technique of choice, there is now a
growing trend to move testing closer to the patient so that a
patient sample is processed and analyzed more rapidly, often while
the patient is still in attendance. The recent advance known as
"near-patient" or "point-of-care" testing has caused a shift in the
way testing is done.
[0005] In contrast to conventional testing, which requires a
waiting period of anywhere from several hours to weeks, during
which the specimens are transported to a centralized laboratory,
processed, and results sent to the physician, point-of-care (POC)
testing offers the advantage of giving the physician and/or the
patient immediate results. POC testing is particularly advantageous
in rural locals which may only have one centralized laboratory or
countries with limited resources, wherein centralized laboratories
do not exist.
[0006] In addition to human patient care, there are a variety of
other applications for immediate testing capabilities, including
veterinary applications, detection of bioterrorism agents,
contaminant detection in quality control and environmental sources,
and food safety.
[0007] While conventional benchtop testing devices such as TARGET
ANALYZER (Target System Diagnostics) are known in the art, such
devices are not adaptable to a point-of-care setting and require
advanced training to read and interpret results. Needed is a
portable handheld apparatus for providing a plurality of
measurements and data analysis tools for diagnostic, environmental
and quality control applications. Moreover, such a device
preferably also contains easy turn-key test calibration. The
present invention meets this need in the art.
SUMMARY OF THE INVENTION
[0008] The present invention is an improved apparatus for sample
analysis. The apparatus is of the type having a membrane with an
analyte-specific binding agent attached thereto, a means for
absorbing liquid, and a piston means for drawing analytes in a
sample through the membrane into the means for absorbing liquid.
The apparatus further contains a detector for detecting
analyte-specific binding to the analyte-specific binding agent, a
plurality of data acquisition components for acquiring data, and a
computer, wherein the computer integrates, analyzes and stores the
detected analyte-specific binding and acquired data thereby
facilitating sample analysis. In some embodiments the apparatus
contains one or a plurality of analyte-specific binding agents.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is an illustration of the portable, hand-held
apparatus of the invention.
[0010] FIG. 2 is an illustration of a keypad for manual data
acquisition.
DETAILED DESCRIPTION OF THE INVENTION
[0011] The present invention is an apparatus composed of a portable
hand-held detector/analyzer used in conjunction with an assay
component composed of a membrane having an analyte-specific binding
agent bound thereto, a means for absorbing liquid, and a piston
means for drawing sample analytes through said membrane into said
means for absorbing liquid. See, e.g., U.S. Pat. No. 4,797,250. The
apparatus provides a detection component, a plurality of data
acquisition components, a computer for integrating, analyzing and
storing data, and a display screen, which allows for data
visualization. In this regard, the instant apparatus can compile,
integrate and analyze data from the assay as well as multiple other
sources, thereby providing more relevant information to the
user.
[0012] As illustrated in FIG. 1, apparatus 10 includes housing 20
with chamber 22 for holding removable assay component 24. Housing
20 has disposed therein computer 28 for integrating, analyzing and
storing data and detector 30 for detecting binding of the analyte
to the analyte-specific binding agent in assay component 24. Manual
data acquisition components 32,34 for manually entering data are
mounted on housing 20, as is port 36 which provides connectivity
with peripheral data acquisition component 38 for acquisition of
external data. Visualization of data and other relevant information
(e.g., date and time) is via display screen 40 mounted on housing
20. In some embodiments, apparatus 10 includes output interface 42
(e.g., a SIM card) for data output, such as wired or wireless data
transfer interface or printer interface. Desirably, housing 20 has
a narrow width such that, apparatus 10 can be held in one hand and
operated by the thumb of that same hand or using the free hand.
Moreover, given the portability of the instant apparatus, housing
20 is made of a material which is durable and water-resistant or
water-proof for use in the field. Apparatus 10 is an improvement
over existing analyzers as it provides the user not only with the
capability to detect binding between the analyte and the
analyte-specific binding agent, but it also provides a plurality of
data acquisition components 32,34,38, as well as computer 28 for
integrating, analyzing and storing data. These and other elements
of the instant apparatus are provided in more detail below.
[0013] Data Acquisition. Manual input of data such as date, time,
user identification (e.g., entry of username or a password), test
number, patient information (e.g., name, age, weight, and medical
history) can be carried out using one or more manual data
acquisition components such as a keypad, touch-pad or
microphone/speaker as might be provided with a communicator. A
keypad can take any configuration suitable for manually entering
data. In general, the keypad can have 10-30 keys with number,
letters, or commands associated therewith. As illustrated in FIG.
2, manual data acquisition component 32 is illustrated as a keypad
containing seventeen keys 44, including one or more of which are
dedicated for a particular purpose 46 or have multiple uses 48,
e.g., number and letter entry. As an alternative, the instant
analyzer can contain touch-pads (or touch-sensitive areas) or icons
on a display screen, which can be touched by the user to enter
data. Those touch-pad areas can be dedicated to a particular
purpose (e.g., letters or numbers) or can be changeable based on
what is displayed in the area when touched (i.e., the indication on
the tab can be changed by the user in a suitable manner to display
something other than a keypad). In reference to FIG. 1, the
touch-pad areas can be part of display screen 40. As such, display
screen 40 includes not only a display structure but also suitable
sensors associated therewith which are responsive to touching
selected areas of the screen. In some embodiments, the instant
analyzer contains one manual data acquisition component. In other
embodiments, the instant analyzer contains at least two manual data
acquisition components. By way of illustration of this embodiment,
FIG. 1 shows manual data acquisition component 32, which is a
keypad, and also shows manual data acquisition component 34, which
is a biometric fingerprint reader. A biometric fingerprint reader
finds application in user verification as well as patient
identification. Fingerprint verification and sensors for the same
are well-known in the art (see, e.g., U.S. Pat. Nos. 7,116,805 and
7,099,497). Manual data acquisition components can be produced from
commercially available components well-known to those skilled in
the art. Manually entered data can be stored internally or
transferred to a printer interface if required for test
documentation.
[0014] Wired or wireless data transfer from peripheral data
acquisition components to the instant apparatus also provides
additional data which can be integrated, analyzed, stored,
displayed and/or printed. As illustrated in FIG. 1, one or more
peripheral data acquisition components 38 can be coupled to
apparatus 10 via one or more ports 36, which can provide wired
(e.g., USB or ethernet) or wireless connectivity with peripheral
data acquisition components 38. Peripheral data acquisition
components of use in conjunction with the instant apparatus include
servers (e.g., remote or local) which house databases containing
patient medical histories or environmental data, as well as any
monitor which measures physiological, biological, or environmental
conditions. For example, the instant apparatus can obtain data from
an electrocardiograph, a heart rate monitor, blood pressure
monitors, electronic blood glucose meters, a fetal monitor, a
balance, a pH meter, a conductometer, an osmometer, a thermometer,
a barometer, a photometer, a luminometer, a radioactivity meter, a
carbon dioxide or carbon monoxide meter, a voltmeter, or a device
for measuring toxic or volatile organic compounds. A barcode wand
or fingerprint reader is also contemplated as a peripheral data
acquisition component which can provide, e.g., patient-specific
data. One embodiment of the present invention embraces an apparatus
with at least one manual data acquisition component and at least
one peripheral data acquisition component. Another embodiment of
the present invention embraces an apparatus with at least two
manual data acquisition components and one peripheral data
acquisition component. Additional embodiments of the present
invention relate to wireless encrypted data transmission.
[0015] Data acquired from the assay component of the instant
apparatus can be achieved using any detector. Such data can pertain
to the presence or absence of a single analyte in a sample or a
plurality of analytes in a sample. In this regard, the membrane of
the instant assay component can contain one binding agent or a
plurality of binding agents, wherein the term analyte-specific
binding agent is intended to include an antibody, an antibody
fragment, or an antibody derivative (e.g., an aptamer) which
specifically binds to a cognate analyte. Specific binding between
two entities generally refers to an affinity of at least 10.sup.6,
10.sup.7, 10.sup.8, 10.sup.9, or 10.sup.10 M.sup.-1. Affinities
greater than 10.sup.8 M.sup.-1 are desired to achieve specific
binding.
[0016] When the binding agent is an antibody, the antibody can be
produced by natural (i.e., immunization) or partial or wholly
synthetic means. Antibodies can be monoclonal or polyclonal and
include commercially available antibodies, against known,
well-characterized analytes. An antibody can be a member of any
immunoglobulin class, including any of the human classes: IgG, IgM,
IgA, IgD, and IgE. Bispecific and chimeric antibodies are also
encompassed within the scope of the present invention. Derivatives
of the IgG class, however, are desirable. Further, an antibody can
be of human, mouse, rat, goat, sheep, rabbit, chicken, camel, or
donkey origin or other species which may be used to produce native
or human antibodies (i.e., recombinant bacteria, baculovirus or
plants).
[0017] For example, naturally-produced monoclonal antibodies can be
generated using classical cloning and cell fusion techniques or
techniques wherein B-cells are captured and nucleic acids encoding
a specific antibody are amplified (see, e.g., U.S. Patent
Application No. 20060051348). In such methods, a collection of
analytes or an individual analyte (e.g., a peptide or polypeptide)
can be used for the initial immunization and in the context of
antibody production is referred to herein as the antigen. The
antigen of interest is typically administered (e.g.,
intraperitoneal injection) to wild-type or inbred mice (e.g.,
BALB/c) or rats, rabbits, chickens, sheep, goats, or other animal
species which can produce native or human antibodies. The antigen
can be administered alone, or mixed with an adjuvant. After the
animal is boosted, for example, two or more times, the spleen or
large lymph node, such as the popliteal in rat, is removed and
splenocytes or lymphocytes are isolated and fused with myeloma
cells using well-known processes, for example, see Kohler and
Milstein ((1975) Nature 256:495-497) or Harlow and Lane
(Antibodies: A Laboratory Manual (Cold Spring Harbor Laboratory,
New York (1988)). The resulting hybrid cells are then cloned in the
conventional manner, e.g., using limiting dilution, and the
resulting clones, which produce the desired monoclonal antibodies,
are cultured (see Stewart, S. (2001) Monoclonal Antibody
Production. In: Basic Methods in Antibody Production and
Characterization, Howard and Bethell (eds.), CRC Press, Boca Raton,
Fla., pp. 51-67).
[0018] Alternatively, antibodies can be derived by a phage display
method. Methods of producing phage display antibodies are
well-known in the art, e.g., see Huse, et al. ((1989) Science
246(4935):1275-81). Selection of antibodies is based on binding
affinity to an analyte or analytes of interest.
[0019] An antibody fragment encompasses at least a significant
portion of the full-length antibody's specific binding ability.
Examples of antibody fragments include, but are not limited to,
Fab, Fab', F(ab').sub.2, scFv, Fv, dsFv, diabody, Fd fragments or
microbodies (see, e.g., U.S. Patent Application No. 20020012909).
An antibody fragment can contain multiple chains which are linked
together, for instance, by disulfide linkages. A fragment can also
optionally be a multi-molecular complex. A functional antibody
fragment will typically include at least about 50 amino acid
residues and more typically will include at least about 200 amino
acid residues. The antibody fragment can be produced by any means.
For instance, the antibody fragment can be enzymatically or
chemically produced by fragmentation of an intact antibody or it
can be recombinantly-produced from a gene encoding the partial
antibody sequence. Alternatively, the antibody fragment can be
wholly or partially synthetically-produced.
[0020] Peptide aptamers which specifically bind to an analyte are,
in general, rationally designed or screened for in a library of
aptamers (e.g., provided by Aptanomics SA, Lyon, France). In
general, peptide aptamers are synthetic recognition molecules whose
design is based on the structure of antibodies. Peptide aptamers
are composed of a variable peptide loop attached at both ends to a
protein scaffold. This double structural constraint greatly
increases the binding affinity of the peptide aptamer to levels
comparable to that of an antibody (nanomolar range).
[0021] Recombinant production of binding agents for the assay
component can be achieved using conventional molecular biology
techniques and commercially available expression systems.
Furthermore, binding agents can be produced using solid-phase
techniques (see, e.g., Merrifield J. (1963) J. Am. Chem. Soc.
85:2149-2154; Seeberger (2003) Chem. Commun. (Camb) (10):1115-21).
Protein synthesis can be performed using manual techniques or by
automation. Automated synthesis can be achieved, for example, using
Applied Biosystems 431A Peptide Synthesizer (Perkin Elmer, Boston,
Mass.). Various fragments of a binding agent can be
chemically-synthesized separately and combined using chemical
methods to produce a full-length molecule.
[0022] Moreover combinatorial chemistry approaches can be used to
produce binding agents (see, e.g., Lenssen, et al. (2002)
Chembiochem. 3(9):852-8; Khersonsky, et al. (2003) Curr. Top. Med.
Chem. 3(6):617-43; Anthony-Cahill and Magliery (2002) Curr. Pharm.
Biotechnol. 3(4):299-315).
[0023] To detect, quantify and identify distinct analytes in a
sample, the assay component can employ a single or plurality of
binding agents. In particular embodiments, a plurality of binding
agents is attached to or deposited on the membrane of the assay
component in a predetermined pattern. Alternatively stated, the
binding agents are arranged in a two-dimensional spatially-resolved
configuration so that upon binding to one or more analytes, the
presence, quantity, or identity of the one or more analytes can be
readily detected. The binding agents can be deposited in a
predetermined pattern such as an ordered array composed of rows,
columns, spirals, etc. In an alternative embodiment, the plurality
of binding agents are deposited in a disordered array.
[0024] A plurality of binding agents encompasses 2, 3, 4, 5, 6, 7,
8, 9, 10, 15, 20, 25, 30, 35, 40, or 50 binding agents. In
particular embodiments, a plurality of binding agents is 5 or more,
10 or more, 15 or more, 20 or more, 25 or more, or 30 or more
binding agents.
[0025] It is contemplated that the instant apparatus can also be
used in conjunction with an assay component which employs molecular
imprinting to bind analytes present in a sample (see, e.g., U.S.
Pat. No. 5,821,311).
[0026] In the context of the present invention, a membrane is a
porous material to which a binding agent can be non-diffusively
bound or attached. For example, the porous material can be a thin
disk of nitrocellulose, PVDF, or the like. The binding agent can be
covalently or non-covalently affixed in or on the membrane by
direct deposition, including, but not limited to, airbrushing,
ink-jet printing, screen printing, stamping, micropipette spotting,
or nanoliter dispensing. Alternatively, the membrane is impregnated
with binding agents using the apparatus of U.S. Pat. No.
4,748,042.
[0027] An analyte which can be bound by a binding agent includes
any compound that can be involved in an antibody:antigen
interaction. Typically the analyte will be an antigen, e.g., a
protein, a carbohydrate, a cell wall component, lipid, a toxin, a
chemical, or a small molecule hapten. It is also possible that the
analyte is an antibody that reacts with a bound antigen or an
antibody to the antibody.
[0028] For instance, an analyte can be a growth factor, a hormone
(e.g., progesterone, hCG, or LHRH), a neurotransmitter, a
catecholamine, an amino acid (e.g., homocyteine), a cytokine, a
lectin, a drug (e.g., cocaine or morphine), a serpin, a protease, a
kinase, a phosphatase, a hydrolase, a transcription factor, a
heat-shock transcription factor, an inflammatory marker (e.g.,
C-reactive protein), a cancer marker (e.g., PSA), a cardiac marker
(e.g., myoglobin or troponin), a DNA-binding protein, a zinc-finger
protein, a leucine-zipper protein, a homeodomain protein, an
intracellular signal transduction modulator or effector, an
apoptosis-related factor, a DNA synthesis factor, a DNA repair
factor, a DNA recombination factor, a cell-surface antigen (e.g., a
bacterial proteoglycan), a hepatitis C virus (HCV) protease or HIV
protease (e.g., HIV-1 or HIV-2), or a polypeptide isolated from a
specific cell, organ or tissue type. In embodiments pertaining to
the presence of a particular cell type (e.g., T-cell), virus or
microorganism in a sample, the analyte can be associated with the
cell, virus or microorganism or partially or wholly extracted from
the cell, virus or microorganism. In particular embodiments, the
presence or level of an analyte is indicative of a specific
disease, disease state or condition, infection or contaminant.
[0029] As used herein, a disease or disease state or condition
refers to any perturbation of the normal state that results in a
change in analyte levels. Examples of perturbations include, but
are not limited to, exposure to an allergen; immunological
disorders; neoplasms; malignancies; metabolic disorders; all organ
and tissue disorders, such as cardiac, liver, prostate, lung,
pancreas, skin, eye, nervous system, lymphatic system, colon and
breast disorders; aging; dementia; mental disorders; therapeutic
drug treatment; drug disorders; pathogen attack; or medical
interventions such as grafts, transplants, or pharmacological
system treatment.
[0030] Advantageously, the instant apparatus can be used in a
point-of-care of ambulatory setting to rapidly detect and diagnosis
disease, thereby facilitating treatment. For example, medications
to prevent heart damage are effective only within a limited number
of hours. Yet, because of their risk for excessive bleeding, these
medications are given only after a diagnosis of heart attack is
made. There are several cardiac markers in blood whose levels rise
in the hours following a heart attack and are useful in making the
diagnosis of a heart attack. Each cardiac marker raises, peaks, and
returns to a normal level according to its own timeline, or
diagnostic window. For example, creatine kinase (CK or CPK), an
enzyme which is not normally found circulating in the blood, is
indicative of muscle or brain damage when present at elevated
levels in the blood. Thus, this enzyme is useful for detecting a
myocardial infarction (heart attack), muscle disease, or stroke.
Similarly, cardiac troponin, a protein that controls the
interactions of actin and myosin, is present at very low levels in
the blood under normal conditions. However, tropinin levels rise
sharply and quickly in response to a heart muscle injury.
Therefore, this protein is valuable at detecting mild heart attacks
and early detection of other heart problems. Troponin I levels have
also been used to help predict a patient's heart attack risk
because of their sensitivity and the fact that elevated levels are
specific to a heart injury. Myoglobin levels in the blood are also
indicative of a heart attack (myocardial infarction) or other
muscle damage. When muscle is damaged, as in a heart attack, larger
amounts of myoglobin are released and blood levels rise rapidly.
Myoglobin has the earliest diagnostic window. It is the first
marker to rise after chest pain begins. Myoglobin levels rise
within two to three hours, and sometimes as early as 30 minutes.
They peak after six to nine hours and return to normal levels
within 24-36 hours. Myoglobin tests are sometimes repeated every
one to two hours to watch for the rise and peak. C-reactive protein
(CRP) is another marker protein indicative of inflammation,
including inflammation of the blood vessels. Elevated CRP levels
can indicate a risk of future heart attack up to 8 years in
advance, even if cholesterol levels are low. Accordingly, an assay
component of the present apparatus invention can contain a
plurality of binding agents which bind cardiac markers, creatine
kinase, cardiac tropinin 1, myoglobin, and CRP, can be used to
detect and quantify said markers for diagnosing a heart attack.
Advantageously, by using the instant apparatus, data can be
acquired from a plurality of data acquisition components (e.g., an
assay component as disclosed herein, a heart monitor, and blood
pressure monitor) so that a differential diagnosis can be readily
made.
[0031] It is contemplated that the diagnoses of heart disease,
cancer, as well as infectious diseases (e.g., SARS, West Nile
virus, Hantavirus, Hepatitis A, Hepatitis B, Hepatitis C, HPV,
measles, mumps, rotavirus, CMV, VZV, Arbovirus, Toxoplasmosis,
Malaria, Chlamydia, H. pylori, Brucellosis, trichomoniasis,
gonorrhea, herpes simplex virus, Lime Disease, Rocky Mountain
Spotted Fever, Mad cow, and Asian Bird Flu) can be achieved using
the present apparatus. Thus, the instant apparatus finds
application in zoological, veterinary and human diagnostic.
Additional applications include the differential diagnosis of
sexually transmitted disease, wherein the assay component could
contain binding agents which bind analytes specific for Chlamydia,
gonorrhea, and herpes simplex virus. Furthermore, an assay
component can be used to bind a variety of drugs (e.g., cocaine,
heroin, morphine, etc.) for use in drug screening. The concurrent
detection of fruit and vegetable contaminants such as fungal
toxins, pesticides, fungicides, or bacteria; meat contaminants such
as bacteria or BSE; as well as soil and water contaminants such as
pesticides, herbicides, fungicides, toxic pollutants, or bacteria
or fungi are also contemplated herein as are detection of
bioterrorism agents (e.g., anthrax).
[0032] In the use of the instant assay component, a sample is
placed in contact with the membrane. After an optimum,
predetermined incubation period has passed, a piston means is
employed to draw analytes of the sample through the membrane into a
means for absorbing liquid, and the presence and/or quantity of
analytes bound to one or more binding agents on the membrane is
determined.
[0033] Various means for absorbing liquid are known in the art and
can be readily employed including a monolithic solid (e.g.,
cellulose acetate or POREX) or a granular solid desiccant such as
DRIERITE (i.e., anhydrous calcium sulfate) or CELITE (i.e.,
diatomaceous earth).
[0034] Likewise, there are a variety of well-known methods for
determining the presence and/or quantity of an analyte bound to a
binding agent. For example, a second labeled binding agent which
recognizes a distinct epitope on the analyte can be employed. Such
a sandwich assay is well-known to those of skill in the art (see,
e.g., "Methods in Immunodiagnosis", 2nd Edition, Rose and Bigazzi,
eds. John Wiley & Sons, 1980; Campbell et al., "Methods and
Immunology", W. A. Benjamin, Inc., 1964; and U.S. Pat. No.
4,376,110). In such assays, the label can be radiometric,
fluorometric, enzymatic, colorometric, or any of a number of other
labels well-known in the art. It will be appreciated that the
instant assay component is not limited to sandwich assays, but also
embraces other heterogeneous assays known in the art. However, in
the embodiments embracing the binding agents deposited on the
membrane in a disordered array, the skilled artisan can appreciate
that the detection of at least two analytes will require the use of
second labeled binding agents which have distinct labels (e.g., a
different fluorescent emission wavelength or color for each analyte
to be detected).
[0035] In addition to the primary binding agents, and secondary
labeled binding agents, the assay can employ a variety of reagents
for stabilizing the analyte:binding agent interaction, reagents for
increasing the specificity of the analyte:binding agent
interaction, as well as washing solutions for removing unbound
analytes and unbound secondary labeled binding agents. Similarly, a
control binding agent (e.g., anti-horseradish peroxidase) can also
be present on the membrane to test if the reagents are working
properly, that is, it should always be a positive test if the
reagents are added in the correct order. For example, when
colorometrically labeled analyte-specific antibodies and
calorimetrically labeled control antibody are used, the antibodies
can be placed on the membrane to form a pattern. For example, a
minus if the test for a particular analyte is negative, or a plus
if the test is positive.
[0036] To facilitate the quantification of distinct analytes in a
sample, the instant assay component can further employ at least two
standards for each analyte being detected. As used herein, a
standard is a predetermined amount of an analyte being detected,
which is provided on the membrane to allow for the quantification
of the analyte. The standards are analyzed to produce working
curves equating analyte signal with the amount of analyte present
in the sample. The amount of analyte present in each sample can
then be either judged as elevated relative to other samples, or
determined absolutely using the working curve. By way of
illustration, 0.1 .mu.g and 10 .mu.g spots of a purified analyte
are placed on the membrane prior to use. After the sample is
applied and analytes drawn through the membrane, a second, labeled
binding agent is applied which binds both the analyte:binding agent
complex on the membrane as well as the analyte standards. In this
manner, the signals generated by the standards are then used by the
apparatus to determine the relative or absolute quantity of the
analyte in the sample.
[0037] As used herein, the term "sample" includes any biological or
environmental material suspected of containing one or more analytes
of interest. It is realized that a sample can lack the analyte of
interest, or, in other words, the test for that analyte is
negative. Biological samples are, e.g., bodily fluids and organic
food stuffs, wherein an organic food stuff is intended to include
any meat or plant material such as grapes, lettuce, wheat, spinach,
etc. A bodily fluid includes whole blood, plasma, serum, sputum,
cerebrospinal fluid, pleural fluid, urine and the like. A bodily
fluid can also include fecal material. Environmental samples are,
e.g., soil, sludge, water, and the like. The sample can be
processed, e.g., centrifuged, extracted, and/or lysed if cells are
present. Alternatively, the sample can be directly placed in
contact with the membrane.
[0038] Analyte-specific binding to the analyte-specific binding
agent can be detected using any suitable detector. In general, the
detector is composed of an illumination source and detection
electronics. The simplest types of light sources include light
emitting diodes (LEDs), laser, laser diodes, and filament lamps.
These sources can be used in conjunction with optical filters,
diffraction gratings, prisms, and other optical components to
provide a specified spectral component of light. Alternative forms
of radiation such as bioluminescence, fluorescence, and others
could also be employed. Although typical fluorophores require
excitation wavelengths in the visible portion of the spectrum
(300-700 nm wavelength), other wavelengths in the infrared and
ultraviolet portion of the spectrum could also prove useful for
illuminating the binding agents on the membrane. The absorbed,
reflected, or re-emitted light can then be propagated to an optical
apparatus for detection, using photosensitive detectors such as
photodiodes or photomultiplier tubes, in combination with some type
of spectral and/or spatial filtering. Spatial filtering of the
light is possible by either transverse scanning of the membrane or
with two-dimensional detectors such as charge coupling device
cameras (CCDs) and video cameras.
[0039] An example of a suitable detector is a reflectometer which
measures the reflectance of reflecting surfaces. The reflectometer
can use a light source which provides a full or partial spectrum of
electromagnetic radiation. An exemplary light source is composed of
LEDs which provide wavelengths of 430 nm (blue), 565 nm (green),
640 nm (red) and 880 nm (infrared) and is current based to
accommodate manufacturing variations. LEDs of this type are
available from Fairchild Semiconductor (Irving, Tex.). The detector
for the reflectometer can be capable of both broad-spectrum and
narrow spectrum sensitivity (individual RGB colors). The detector
and measurement can be implemented in such a manner as to reduce
sensitivity to power supply and coupled noise. A commercially
available detector of this type is available from Texas Advanced
Optoelectronic Solutions Inc. (Plano, Tex.).
[0040] Alternatively, the detector can be a camera or imaging
device which has adequate lighting and resolution for spatially
resolving individual signals produced by the second, labeled
binding agents. Miniature cameras are commonly found in devices
such as cellular phones and endoscopic tools. In this regard, an
imaging device of the present invention can be any known in the art
that is compatible with the various designs and configurations of
the instant apparatus. For example, the camera can employ any
common solid state image sensor including a charged coupled device
(CCD), charge injection device (CID), photo diode array (PDA), or
complementary metal oxide semiconductor (CMOS), which offers
functionality with simplified system interfacing. For example, a
particularly suitable CMOS imager including active pixel-type
arrays is disclosed in U.S. Pat. No. 5,471,515. This CMOS imager
can incorporate a number of other different electronic controls
that are usually found on multiple circuit boards of much larger
size. For example, timing circuits, and special functions such as
zoom and anti-jitter controls can be placed on the same circuit
board containing the CMOS pixel array without significantly
increasing the overall size of the host circuit board. Furthermore,
this particular CMOS imager requires 100 times less power than a
CCD-type imager. The CMOS imager disclosed in U.S. Pat. No.
5,471,515 has enabled the development of a "camera on a chip." As
such, many CMOS imagers can be manufactured at a fraction of the
cost of other solid state imaging technologies. Suni Microsystems,
Inc. (Mountain View, Calif.) has also developed a CCD/CMOS hybrid
which combines the high quality image processing of CCDs with
standard CMOS circuitry construction. The image sensor can also
employ a lens to focus the optical signals. Furthermore, to
increase depth of field and reduce ambient light noise, an aperture
can be used.
[0041] Data Integration, Analysis, Storage, and Transmission. The
present apparatus also provides a computer, which integrates the
detected analyte-specific binding with the data acquired by any one
of the plurality of data acquisition components. The binding and
data thus integrated (i.e., brought together) can then be analyzed
and stored (either long-term or short-term) by the computer for
subsequent access by the user. Desirably, the on-board computer has
an internal operating system that accesses one or more algorithms
and/or computer software to analyze data from the assay component
to determine the presence and/or quantity of analyte(s) that is
being tested. By "analyze", it is meant that the instant apparatus
can do more than merely display an assay measurement value. For
example, charts, plots and graphs of compiled data (e.g., standard
curves for quantifying analytes) can be generated and additional
factors such as data acquired from peripheral data acquisition
components can be used to process and/or display information
relating to the sample being tested or source of the sample. The
algorithm or algorithms used are developed based upon the
parameters in which the apparatus will be used. Additionally, if a
software element is used, it may be adjusted as needed such that
the apparatus becomes simpler and/or more accurate in determining
the presence and/or quantity of analyte(s) present in the sample.
The type of algorithm used can be based upon a variety of factors,
either alone or in combination and including, but not limited to,
the analyte to be detected, the type of assay component used, the
sample to be tested, the image generated, the size of the features
in the image, the image and/or feature sizes and/or shapes in that
pattern, and the desired level of sensitivity, among others.
[0042] The acquired, integrated and analyzed data can be stored in
computer memory in any form, e.g., EEPROM, RFID, RAM, ROM, EPROM or
other form of static or dynamic memory. Any type of computer chip
including a memory can be affixed to, or otherwise associated with,
the apparatus. For example, removable memory "sticks" or "cards"
(e.g., a SIM card) can be used, providing unlimited data capacity.
SIM cards are particularly suitable as they provide data encryption
in addition to data storage. Moreover, SIM cards provide both an
antenna and a transceiver to send and receive information. As many
conventional hand-held electronic devices employ SIM cards, SIM
cards are readily available from a variety of commercial
sources.
[0043] Raw data and/or integrated and analyzed data are displayed
on a display screen. The display screen can be any commercially
available unit used in conventional cell phones, PDA and the like.
For example, the display screen can be a 128.times.64 bit graphic
LCD display with integral backlight, wherein the backlight is
controlled by the on-board computer. Such LCD displays are
commercially available from sources such as MicroTips Technology,
Inc. (Orlando, Fla.).
[0044] Preferably, a large portion of the display screen is used to
display data. However, as indicated above, the display screen can
also provide touch-responsive areas so that, such as is known in
the art, touching those areas will be recognized by the apparatus
and interpreted to modify what is displayed on the screen.
[0045] Power to the apparatus can be supplied by an external source
(e.g., via a tether), internal batteries, or other power source
including one or more power cells. A battery can be one or more
standard power cells, for example alkaline, lithium,
nickel-cadmium; or a molded polymeric or elastomer battery which
could be shaped to fit within the housing of the apparatus.
Alternatively, magnetic induction is another possible source of
power, as is piezoelectrics. In addition, one of skill in the art
could adapt other power sources such as fluid dynamic, solar or the
like to power the instant apparatus. The apparatus can contain a
battery which is sealed within the apparatus (i.e., not user
replaceable) to provide power to the LCD, backlight and detector.
Rechargeable or user replaceable batters can also be provided as
can a back-up battery (e.g., a primary lithium coin cell) to
maintain time. Charging circuitry can also be integrated into a
docking device.
[0046] Other embodiments of the present apparatus include a timer
for timing the assay, one-point assay calibration, memory stick
compatibility for software upgrades, and an annunciator which
provides light, vibration and/or sound output means for user
feedback. Feedback could be, for example, acknowledging to the user
that an attempted data acquisition was successful. This output
signal may also be used to acknowledge error status, a full memory
and/or a cleared memory on the apparatus. An LED provides an
extremely low power consuming and rugged output means for user
feedback.
[0047] A barcode reader is also provided for automatically entering
information about the assay component. Such a barcode reader could
read codes including ISBN, UPC-E, UPC-A, EAN-8, EAN-13, Code 39,
and/or Code 128. Such barcode readers are well-known and
commercially available. The barcode reader can be combined with a
barcode activation system which identifies the test to be analyzed
and automatically initiates one-point assay calibration of that
particular test, thereby precluding mistakes by the user or
erroneous results by the apparatus. Each individual assay component
would contain a unique barcode which would be read and used to
initialize the apparatus such that the appropriate algorithm(s)
would be employed.
[0048] It is contemplated that a variety of input and outputs can
be provided to and from the apparatus, e.g., via port(s) 36 and
output interface 42. These outputs and inputs may include, for
example, digital inputs, digital outputs, analog inputs, analog
outputs, serial communications (e.g., to a printer, modem or host
computer), and network, such as Ethernet, communications. Such
communications can also include wireless data transfer using such
technologies as BLUETOOTH, HomeRF, IEEE P802.15 or proprietary
protocols in the 900 megahertz, 2.4 gigahertz or other frequency
band.
[0049] The instant apparatus can be configured to attach to a host
computer thereby using the host computer to obtain power, storage,
direct download and software control functionality and updates. The
connection to the host computer can be by any means providing
direct connection to the host computer's bus. For example, an
apparatus can be built into or have a connection via a PCMCIA card,
PC card, flash card, USB or proprietary connection, for example to
a PDA, cell phone or optical mouse. The connection can be a direct
electromechanical connection (cable or contacts, e.g., via port 36)
or a wireless connection such as an optical connection. Transfer of
information between the apparatus and a host computer can also be
achieved using a docking device which can accept the apparatus. The
docking device can be an optical reader which accepts optical
output from a key fob in the form of light or other wavelength
signals (IrDA, infra red, sound, RF, visible light) which transmit
the information contained in the memory of the apparatus. The
docking device would then be capable of transmitting the received
information to a computer device by direct connection, RF, or light
signals (IrDA, visible light, or fiber optic).
[0050] The docking device cable can be connected to the host
computer by any available transmission standard or proprietary I/O
port (serial, parallel, USB, audio input, PCMCIA, IDE, ISA, PCI,
SCSI, FIREWIRE, optical), including the keyboard port. In some
embodiments, the docking device is in the form of a mouse device or
other computer peripheral with a mating cavity which the instant
apparatus fits into. Built into a cell phone or PDA, the docking
means can be an optical emitter/detector, Irda port or RFID
interrogator circuitry.
[0051] In particular embodiments of the present invention, data
being transferred between peripheral components and the instant
apparatus as well as between the apparatus and a host computer is
encrypted, in particular when wireless data transfer is employed.
In this regard, the present also provides for encryption and
decryption modules to encrypt and decrypt information in compliance
with HIPAA.
[0052] An advantage of the present apparatus is that tests can be
run on a wide variety of analytes and a variety of different
samples can be analyzed with results obtained within minutes or
seconds. Moreover, when a plurality of binding agents is employed
in the instant assay component, the apparatus can use this data
along with data from a plurality of data acquisition components to
provide a differential diagnosis of diseases or disease states or
conditions, as well as the identification of specific contaminants
in biological and environmental samples. Thus, in the clinical
setting the present invention can provide a quick and accurate
diagnosis during a patient visit, shortening the decision time to
medical intervention and minimizing the need for additional patient
follow-up, thereby reducing overall health care delivery costs.
Furthermore, the instant apparatus can be employed to monitor
patient compliance. Moreover, given the portability of the present
apparatus, data acquisition, integration, analysis and transmission
can be carried out in remote locations.
* * * * *