Patent EP0539125A1 successfully refreshed from Google Patents.
US3936357A
Expired / Lapsed
US
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Method and device for determining the concentration of a substance in a fluid
Assignee: Polaroid Corp
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Filing: 1974-08-16
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Granted: 1976-02-03
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Expires: 1994-08-16
Abstract
Abstract A diagnostic test device comprising an absorbent medium adapted to receive and retain a measured amount of fluid containing the substance to be tested and reagents adapted to contact said fluid to provide a visual determination of the presence and/or concentration of the substance, wherein the absorbent medium comprises a substantially non-swellable material of substantially uniform and constant porosity and thickness.
Inventors
- 👤 Terry W. Milligan
- 👤 Richard F. Wright
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:39
CPC Classifications
C; C12; C12Q; C12Q1/00; C12Q1/26; C12Q1/32; C12Q1/48; C12Q1/58
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
134 words
A device for determining concentration of a substance in a fluid which comprises fluid absorbing means carrying a substantially non-swellable, absorbent material of constant porosity and thickness; a first and second sheet which are carrying a predetermined amount of reagents adapted to react with said substance to provide a visual indication of the concentration of said substance; at least one of said first and second sheets is transparent; said fluid absorbing means intermediate and pivotally secured at each end to said first and second sheets adapted to be moved to a first superposed position where said reagents and said substance coact; said fluid absorbing means and said first and second sheets adapted to be moved to a second superposed position to contact means for generating the visual indication of the concentration of said substance.
Claim 2
Independent Claim
134 words
A device for determining concentration of a substance in a fluid which comprises fluid absorbing means carrying a substantially non-swellable, absorbent material of constant porosity and thickness; a first and second sheet which are carrying a predetermined amount of reagents adapted to react with said substance to provide a visual indication of the concentration of said substance; at least one of said first and second sheets is transparent; said fluid absorbing means intermediate and pivotally secured at each end to said first and second sheets adapted to be moved to a first superposed position where said reagents and said substance coact; said fluid absorbing means and said first and second sheets adapted to be moved to a second superposed position to contact means for generating the visual indication of the concentration of said substance.
Claim 3
Dependent Claim
28 words
The device of claim 1 wherein said reagents comprise enzymes, coenzymes and said means for generating the visual indication of the concentration of said substance comprise colorimetric indicators.
Claim 4
Dependent Claim
14 words
The device of claim 1 wherein said absorbent fluid means comprises a microporous filter.
Claim 5
Dependent Claim
10 words
The device of claim 1 wherein said fluid comprises blood.
Claim 6
Dependent Claim
19 words
The device of claim 4 wherein said reactants comprise hexokinase, glucose-6-phosphate dehydrogenase, nicotinamide adenine dinucleotide phosphate and adenosine triphosphate.
Claim 7
Dependent Claim
16 words
The device of claim 2 wherein said colorimetric indicator is incorporated in a precipitation chromatographic sheet.
Claim 8
Dependent Claim
20 words
The device of claim 1 wherein one of said transparent sheets includes a scale indicating concentration standards for said substance.
Claim 9
Dependent Claim
23 words
The device of claim 1 which includes means for removing undesirable components from said fluid prior to contacting said reagents with said fluid.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-02-02 | 1979-08-04 | 1980-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-02-02 | 1983-08-04 | 1984-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-02-02 | 1987-08-04 | 1988-02-03 | $7700.00 | Window Closed / Lapsed |