EP0283285A2
Expired / Lapsed
EP
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Method and apparatus for monitoring analytes in fluids
Assignee: DIAGNOSTIC SYSTEMS Inc
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Filing: 1988-03-17
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Granted: —
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Expires: 2008-03-17
Abstract
Abstract The invention includes a photometer (10) and a photometric test strip (31) for use with the photometer for monitoring the presence and amount of an analyte in a liquid sample. The photometer (10) includes a light source (25) and a photodetector (26) which form an optical path for detecting light transmitted through a test strip (31). The latter has a dry support and an indicator portion, both of which allow light of predetermined frequencies to be transmitted therethrough. The photometer (10) includes an electrical circuit (21) for generating a signal proportional to detected light and for generating an output signal representative of the presence and amount of the analyte in the sample of blood being monitored. In a preferred embodiment, the invention includes the use of a nonbibulous test strip (31) having a nonbibulous indicator portion thereon through which light is transmitted and detected following deposition of a blood sample thereon. The photometer may be calibrated to produce an output reading and resonse to the transmitted light which is representative of the milligram percentage of glucose in the blood being monitored.
Inventors
- 👤 Charles F. Neilson
- 👤 David C. Miller
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 11:44
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/8483; G01N33/00; G01N33/48; G01N33/50; G01N33/52; G01N33/528; G01N21/17; G01N21/59; G01N2201/00; G01N2201/06; G01N2201/062
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
190 words
A monitoring system for determining the presence and amount of an analyte in a liquid sample, the system comprising a photometer having a light source for generating a beam of light and for defining an optical path, a test strip positionable in the photometer, a photodetector for generating an electric signal proportional to incident light, and means for generating an output signal in response to the electric signal, characterized in that: said test strip comprises a light transmissive, nonbibulous solid support and a nonbibulous indicator portion having alterable light transmission characteristics and comprising a solidified homogeneous deposit of a reagent system which changes light transmission characteristics upon deposition of a liquid sample including an analyte thereon; and said photodetector and said light source are so arranged that the indicator portion of said test strip is positioned in said optical path so that light from said source is transmitted through said indicator portion and through said solid support to said detector to produce said electrical signal and said output signal, so that said output signal is representative of the presence and amount of an analyte in the liquid sample being monitored.
Claim 2
Dependent Claim
190 words
A monitoring system for determining the presence and amount of an analyte in a liquid sample, the system comprising a photometer having a light source for generating a beam of light and for defining an optical path, a test strip positionable in the photometer, a photodetector for generating an electric signal proportional to incident light, and means for generating an output signal in response to the electric signal, characterized in that: said test strip comprises a light transmissive, nonbibulous solid support and a nonbibulous indicator portion having alterable light transmission characteristics and comprising a solidified homogeneous deposit of a reagent system which changes light transmission characteristics upon deposition of a liquid sample including an analyte thereon; and said photodetector and said light source are so arranged that the indicator portion of said test strip is positioned in said optical path so that light from said source is transmitted through said indicator portion and through said solid support to said detector to produce said electrical signal and said output signal, so that said output signal is representative of the presence and amount of an analyte in the liquid sample being monitored.
Claim 3
Dependent Claim
100 words
A monitoring system according to Claim 1 wherein said means for positioning said indicator portion of said strip comprises: an optical block having respective upper and lower portions with a test strip receiving and positioning channel therebetween and with said light source being positioned adjacent said channel in one of said respective upper and lower portions and with said photodetector being positioned in said other respective portion and adjacent said channel and opposite from said source; and means for operating said source, said detector and said signal generating means in response to a strip being properly positioned in said channel.
Claim 4
Dependent Claim
67 words
A monitoring system according to Claim 1 or 2 wherein said means for generating an output signal further comprises: an operational amplifier electrically connected to said means for generating an electric signal; a display driver electrically connected to said operational amplifier; and a display responsive to said display driver for producing a visible signal representative of the presence and amount of analyte present in the liquid sample.
Claim 5
Dependent Claim
19 words
A monitoring system according to Claim 3 wherein said display responsive to said display driver comprises a segmented display.
Claim 6
Dependent Claim
19 words
A monitoring system according to Claim 3 wherein said display responsive to said display driver comprises a digital display.
Claim 7
Dependent Claim
27 words
A monitoring system according to any preceding Claim wherein said solidified deposit on said test strip changes color upon deposition of a liquid sample which includes glucose.
Claim 8
Dependent Claim
54 words
A monitoring system according to any preceding claim wherein said reagent system comprises: an enzyme for catalyzing the oxidation of glucose to gluconic acid and hydrogen peroxide; a chromophore which is oxidizable in the presence of hydrogen peroxide; and an enzyme for catalyzing the oxidation of said chromophore in the presence of hydrogen peroxide.
Claim 9
Dependent Claim
24 words
A monitoring system according to Claim 7 wherein said reagent system further comprises an emulsion which includes a vinyl acetate and vinyl ethylene copolymer.
Claim 10
Dependent Claim
40 words
A monitoring system according to Claim 7 or 8 wherein said chromophore is selected from the group consisting of: 3-dimethylaminobenzoic acid, 3-methyl-2-benzothiazolinone hydrozone hydrochloride, tetramethyl benzidine and orthotolidine, and said enzyme for catalyzing the oxidation of glucose comprises horseradish peroxidose.
Claim 11
Dependent Claim
125 words
A diagnostic test strip for determining the presence and amount of an analyte in a liquid sample deposited thereon, said test strip comprising: a light transmissive, nonbibulous solid support; and a nonbibulous indicator portion deposited upon at least a portion of said support, said indicator portion comprising a solidified deposit of a reagent system which changes light transmission characteristics in the presence of the analyte, said indicator portion being transmissive at least to light of selected frequencies following addition of a liquid sample thereon, whereby the presence and amount of the analyte in a liquid sample deposited upon said strip may be determined by measuring the frequency and intensity of light transmitted through the liquid sample through the indicator system and through the solid support.
Claim 12
Dependent Claim
125 words
A diagnostic test strip for determining the presence and amount of an analyte in a liquid sample deposited thereon, said test strip comprising: a light transmissive, nonbibulous solid support; and a nonbibulous indicator portion deposited upon at least a portion of said support, said indicator portion comprising a solidified deposit of a reagent system which changes light transmission characteristics in the presence of the analyte, said indicator portion being transmissive at least to light of selected frequencies following addition of a liquid sample thereon, whereby the presence and amount of the analyte in a liquid sample deposited upon said strip may be determined by measuring the frequency and intensity of light transmitted through the liquid sample through the indicator system and through the solid support.
Claim 13
Dependent Claim
18 words
A diagnostic test strip according to Claim wherein said solidified deposit changes color in the presence of glucose.
Claim 14
Dependent Claim
16 words
A diagnostic test strip according to Claim 10 or 11 wherein said liquid sample comprises blood.
Claim 15
Dependent Claim
21 words
A diagnostic test strip according to Claim 10, 11 or 12 wherein said indicator portion further comprises a single homogeneous layer.
Claim 16
Dependent Claim
58 words
A diagnostic test strip according to any preceding Claim 10 to 13 wherein said reagent system comprises: an enzyme for catalyzing the oxidation of glucose to gluconic acid and hydrogen peroxide; a chromophore which is oxidizable in the presence of hydrogen peroxide; and an enzyme for catalyzing the oxidation of said chromophore in the presence of hydrogen peroxide.
Claim 17
Dependent Claim
27 words
A diagnostic test strip according to Claim 14 wherein said chromophore is selected from the group consisting of 3-dimethylaminobenzoic acid, 3-methyl-2-benzothiazolinone hydrozone hydrochloride, tetramethyl benzidine and orthotolidine.
Claim 18
Dependent Claim
23 words
A diagnostic test strip according to any preceding Claim 10 to 15 wherein said solidified deposit of a reagent system comprises an alginate.
Claim 19
Dependent Claim
182 words
A compact, portable, hand held, battery operated photometer for reading test strips inserted thereinto which test strips are formed from a light transmissive support and a light transmissive indicator portion thereon comprising a reagent system for changing the light transmission characteristics thereof upon deposition of a liquid sample including an analyte thereon and for transmitting light at least after deposition of a liquid sample, said photometer comprising: a light source for generating a beam of light of a selected frequency and intensity and for defining an optical path; a photodetector for generating an electric signal proportional to incident light from said light source; and means for generating an output signal in response to the electric signal; characterized in that said photometer includes means for positioning the indicator portion of the test strip in said optical path so that light from said source passing along said optical path passes through the indicator portion and through the solid support and to the photodetector so that the output signal is representative of the presence and amount of an analyte in the liquid sample being monitored.
Claim 20
Dependent Claim
182 words
A compact, portable, hand held, battery operated photometer for reading test strips inserted thereinto which test strips are formed from a light transmissive support and a light transmissive indicator portion thereon comprising a reagent system for changing the light transmission characteristics thereof upon deposition of a liquid sample including an analyte thereon and for transmitting light at least after deposition of a liquid sample, said photometer comprising: a light source for generating a beam of light of a selected frequency and intensity and for defining an optical path; a photodetector for generating an electric signal proportional to incident light from said light source; and means for generating an output signal in response to the electric signal; characterized in that said photometer includes means for positioning the indicator portion of the test strip in said optical path so that light from said source passing along said optical path passes through the indicator portion and through the solid support and to the photodetector so that the output signal is representative of the presence and amount of an analyte in the liquid sample being monitored.
Claim 21
Dependent Claim
75 words
A compact photometer according to Claim 17 wherein said means for positioning the indicator portion of the strip comprises: an optical block having respective upper and lower portions with a strip receiving and positioning channel therebetween and with said light source being positioned adjacent said channel in one of said respective upper and lower portions and with said photodetector being positioned in said other respective portion and adjacent said channel and opposite from said source.
Claim 22
Dependent Claim
32 words
A compact photometer according to Claim 18 further comprising means for operating said source, said detector and said signal generating means in response to a strip being properly positioned in said channel.
Claim 23
Independent Claim
168 words
A method for monitoring the presence and amount of an analyte in a liquid sample, said method comprising: (a) depositing a drop of liquid sample on a nonbibulous test strip which is transmissive at least to light of selected frequencies, and which test strip includes a light transmissive solid support and an indicator portion carrying a nonbibulous solidified homogeneous deposit of a chromophore reagent system which changes color in the presence of an analyte; (b) placing the strip in a self-contained hand held photometer having a light source and a photodetector which together define an optical path, with the indicator portion of the strip being placed between the source and the photodetector and in the optical path; (c) directing light from the source onto and through the indicator portion and the solid support and to the photodetector; and (d) detecting the light transmitted through the indicator portion and through the solid support and to the photodetector and generating a signal responsive to the characteristics of the detected light.
Claim 24
Independent Claim
168 words
A method for monitoring the presence and amount of an analyte in a liquid sample, said method comprising: (a) depositing a drop of liquid sample on a nonbibulous test strip which is transmissive at least to light of selected frequencies, and which test strip includes a light transmissive solid support and an indicator portion carrying a nonbibulous solidified homogeneous deposit of a chromophore reagent system which changes color in the presence of an analyte; (b) placing the strip in a self-contained hand held photometer having a light source and a photodetector which together define an optical path, with the indicator portion of the strip being placed between the source and the photodetector and in the optical path; (c) directing light from the source onto and through the indicator portion and the solid support and to the photodetector; and (d) detecting the light transmitted through the indicator portion and through the solid support and to the photodetector and generating a signal responsive to the characteristics of the detected light.
Claim 25
Dependent Claim
44 words
A method according to Claim 20 wherein the step of depositing a drop of a liquid sample comprises depositing a drop of blood and removing the red blood cells from the test strip prior to the step of directing light onto the test strip.
Claim 26
Dependent Claim
20 words
A method according to Claim 20 or 21 wherein the chromophore reagent system changes color in the presence of glucose.
Claim 27
Dependent Claim
95 words
A method of preparing a test strip according to Claim 10 for monitoring analytes in small liquid samples, said method comprising: forming a dilute aqueous solution of an emulsifying agent; mixing the solution with an emulsified adhesive; admixing a chromophore system which is sensitive to the presence of the analyte to be monitored with the mixture of adhesive and emulsifying agent; applying a relatively thin layer of the adhesive, emulsifying agent and chromophore mixture to a support; and drying the applied layer to thereby form a solidified, homogeneous layer of monitoring chemicals upon the support.
Claim 28
Dependent Claim
29 words
A method according to Claim 23 wherein the step of mixing the solution with an emulsified adhesive comprises mixing the solution with a vinyl acetate and vinyl ethylene copolymer.
Claim 29
Dependent Claim
60 words
A method according to Claim 24 wherein the step of admixing a chromophore system comprises admixing a reagent system which includes an enzyme for catalyzing the reaction of glucose to gluconic acid and hydrogen peroxide, a chromophore oxidizable in the presence of hydrogen peroxide, and an enzyme for catalyzing the oxidation of the chromophore in the presence of hydrogen peroxide.
Claim 30
Dependent Claim
16 words
A method according to Claim 23, 24 or 25 wherein the emulsifying agent comprises an alginate.
References Cited (Backward Citations)
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