EP0574134A2
Expired / Lapsed
EP
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Fluid conducting test strip with transport medium
Assignee: LifeScan Inc
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Filing: 1993-05-11
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Granted: —
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Expires: 2013-05-11
Abstract
Abstract The invention provides a reagent strip for measuring the concentration of an analyte in a liquid test sample, such as glucose or cholesterol in whole blood. The reagent strip includes a testing pad containing a color-forming reagent system specific to the analyte. The testing pad is disposed so that a side with relatively small pores defines a testing surface and an opposite side with relatively larger pores defines a sample-receiving surface. A porous sample transport medium is attached to the sample-receiving surface. A change in coloration caused by the color-forming reagent system at the testing surface is quantitatively related to the concentration of the analyte in the liquid test sample. The reagent strip may optionally include a rigid support member which facilitates evaluation of the change in coloration by mechanical viewing means. The invention also provides a method for determining the concentration of an analyte in a liquid test sample.
Inventors
- 👤 David P. Matzinger
- 👤 Stephen E. Zweig
- 👤 Yeung Yu
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 22:01
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/52; G01N33/525; G01N21/00; G01N21/84; G01N21/8483; Y; Y10; Y10T; Y10T436/00; Y10T436/25; Y10T436/25375; Y10T436/255
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
111 words
A reagent strip for measuring the concentration of an analyte in a test sample, suitable for evaluation by the human eye or by mechanical viewing means, comprising: a testing pad formed from an anisotropic membrane containing a color-forming reagent system specific to an analyte and having a side with relatively small pores which defines a testing surface and an opposite side with relatively larger pores which defines a sample receiving surface; and a porous sample transport medium attached to the sample receiving surface of the testing paid, said transport medium being capable of accepting a whole blood sample and transporting a detectable portion of the sample to the sample receiving surface.
Claim 2
Dependent Claim
111 words
A reagent strip for measuring the concentration of an analyte in a test sample, suitable for evaluation by the human eye or by mechanical viewing means, comprising: a testing pad formed from an anisotropic membrane containing a color-forming reagent system specific to an analyte and having a side with relatively small pores which defines a testing surface and an opposite side with relatively larger pores which defines a sample receiving surface; and a porous sample transport medium attached to the sample receiving surface of the testing paid, said transport medium being capable of accepting a whole blood sample and transporting a detectable portion of the sample to the sample receiving surface.
Claim 3
Dependent Claim
20 words
The reagent strip of claim 1 wherein the sample receiving surface is coated with a film containing a hydrophobic polymer.
Claim 4
Dependent Claim
34 words
The reagent strip of claim 1 or claim 2 wherein the transport medium is capable of holding about 35 microliters of blood and of passing about 3 microliters of blood to said testing paid.
Claim 5
Dependent Claim
30 words
The reagent strip of any one of claims 1 to 3 wherein the transport medium has pores which are in the size range of about 20 to about 200 micrometers.
Claim 6
Dependent Claim
19 words
The reagent strip of any one of claims 1 to 4 wherein the transport medium is composed of polyethylene.
Claim 7
Dependent Claim
50 words
The reagent strip of any one of claims 1 to 5 wherein the testing paid has pores in the size range of about 5 to about 50 micrometers on the side with relatively large pores decreasing to about 0.1 to about 1.0 micrometer on the side with relatively small pores.
Claim 8
Dependent Claim
19 words
The reagent strip of any one of claims 1 to 6 wherein the testing paid is composed of polysulfone.
Claim 9
Dependent Claim
34 words
The reagent strip of any one of claims 1 to 7 wherein an adhesive layer formed along an outer edge of the testing pad is attached to the testing pad and the transport medium.
Claim 10
Dependent Claim
29 words
The reagent strip of any one of claims 1 to 7 wherein a discontinuous adhesive layer is positioned between and attached to the testing pad and the transport medium.
Claim 11
Dependent Claim
35 words
The reagent strip of any one of claims 1 to 9 which further comprises a rigid support member defining an aperture therethrough and having a free surface adapted to contact and engage mechanical viewing means.
Claim 12
Dependent Claim
48 words
The reagent strip of claim 10, wherein the portion of the rigid support member about the aperture is of predetermined thickness whereby the testing surface is maintained at an optimum viewing distance relative to said viewing means when the free surface of the support memberengages said viewing means.
Claim 13
Dependent Claim
32 words
The reagent strip of claim 11 wherein the portion of the support member disposed about the aperture has a thickness in the range of about 0.002 to about 0.050 of an inch.
Claim 14
Independent Claim
160 words
A method for measuring the concentration of an analyte in a test sample containing solid color bodies which comprises: providing a reagent strip which includes a testing pad formed from a porous anisotropic membrane containing a color-forming reagent system specific to an analyte which defines a testing surface and a sample receiving surface, and a porous sample transport medium attached to the sample-receiving surface; contacting a test sample of a biological fluid which contains the analyte and solid color bodies with the transport medium; absorbing the test sample into the transport medium, transporting the test sample to the sample receiving surface, and distributing the test sample across the sample-receiving surface; transporting and filtering the test sample through the testing pad in a direction which exposes the sample to progressively smaller pores, separating at least some of the solid color bodies from the test sample; and chemically reacting the testing reagent with the analyte to vary coloration of the testing surface.
Claim 15
Independent Claim
160 words
A method for measuring the concentration of an analyte in a test sample containing solid color bodies which comprises: providing a reagent strip which includes a testing pad formed from a porous anisotropic membrane containing a color-forming reagent system specific to an analyte which defines a testing surface and a sample receiving surface, and a porous sample transport medium attached to the sample-receiving surface; contacting a test sample of a biological fluid which contains the analyte and solid color bodies with the transport medium; absorbing the test sample into the transport medium, transporting the test sample to the sample receiving surface, and distributing the test sample across the sample-receiving surface; transporting and filtering the test sample through the testing pad in a direction which exposes the sample to progressively smaller pores, separating at least some of the solid color bodies from the test sample; and chemically reacting the testing reagent with the analyte to vary coloration of the testing surface.
Claim 16
Dependent Claim
31 words
The method of claim 13 which further comprises comparing the coloration of the testing surface to a calibrated color standard to determine the concentration of the analyte in the test sample.
Claim 17
Dependent Claim
42 words
The method of claim 13 which further comprises locating the testing surface a reproducible distance from a viewing means by contacting the viewing means with a rigid support member which has a controlled thickness, defines an aperture, and abuts the testing surface.
References Cited (Backward Citations)
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