US3918908A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for prothrombin testing
Assignee: Geomet Inc
•
Filing: 1974-05-17
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Granted: 1975-11-11
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Expires: 1994-05-17
Abstract
Abstract A method, useful for the rapid measurement of coagulation rates, employing a uniform bore reaction tube which may be used to take up the sample and contains the appropriate amounts of lyophilized reagents required to conduct individual tests such as that for prothrombin time. In the example disclosed, calibration marks on the tube have been correlated in terms of prothrombin times. The position at which a liquid sample becomes immobilized as it descends down the tube corresponds to the test time. The rate of descent is controlled by a limiting orifice or by inclining the tube to the vertical axis.
Inventors
- 👤 Rudolph H Moyer
- 👤 Donald J Sibbett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:31
CPC Classifications
G; G01; G01N; G01N11/00; G01N11/02; Y; Y10; Y10S; Y10S128/00; Y10S128/22
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
87 words
METHOD OF REPRODUCIBLY MEASURING CHANGES OF VISCOSITY IN A LIQUID SAMPLE SUBJECT TO AN ENCREASE IN VISCOSITY AFTER COMBINATION WITH AT LEAST ONE REAGENT CAPABLE OF ALTERING SAID SAMPLE VISCOSITY COMPRISING: A. INJECTING SAID SAMPLE INTO A HOLLOW CYLINDER HAVING AN INTERNAL DIAMETER SUFFICIENTLY LARGE SO AS TO SUBSTANTIALLY ELIMINATE EFFECTS OF INITIAL SAMPLE VISCOSITY SAID INJECTING STEP INCLUDING COMBINING SAID SAMPLE WITH AT LEAST ONE SAID REAGENT, B. PASSING SAID SAMPLE AND REAGENT COMBINATION IN SAID CYLINDER BY SUPPORTING SAID CYLINDER IN SUCH A MANNER THAT
Claim 2
Dependent Claim
87 words
METHOD OF REPRODUCIBLY MEASURING CHANGES OF VISCOSITY IN A LIQUID SAMPLE SUBJECT TO AN ENCREASE IN VISCOSITY AFTER COMBINATION WITH AT LEAST ONE REAGENT CAPABLE OF ALTERING SAID SAMPLE VISCOSITY COMPRISING: A. INJECTING SAID SAMPLE INTO A HOLLOW CYLINDER HAVING AN INTERNAL DIAMETER SUFFICIENTLY LARGE SO AS TO SUBSTANTIALLY ELIMINATE EFFECTS OF INITIAL SAMPLE VISCOSITY SAID INJECTING STEP INCLUDING COMBINING SAID SAMPLE WITH AT LEAST ONE SAID REAGENT, B. PASSING SAID SAMPLE AND REAGENT COMBINATION IN SAID CYLINDER BY SUPPORTING SAID CYLINDER IN SUCH A MANNER THAT
Claim 3
Dependent Claim
16 words
The method of claim 1 in which the rate of descent of said sample is controlled.
Claim 4
Dependent Claim
21 words
The method of claim 2 in which said control is accomplished by inclining the cylinder to various angles from the vertical.
Claim 5
Dependent Claim
15 words
The method of claim 2 in which said control is accomplished by a limiting orifice.
Claim 6
Dependent Claim
16 words
The method of claim 2 in which said control is accomplished by a porous solid material.
Claim 7
Dependent Claim
19 words
The method of claim 1 in which the interior surface of the cylinder is uniformly wettable by the sample.
Claim 8
Dependent Claim
26 words
The method of claim 1 wherein said combining step comprises contacting said injected liquid sample with a reagent at a specified position within said hollow cylinder.
Claim 9
Dependent Claim
29 words
The method of claim 7 in which the chemical reagent is immediately below a calibration mark indicating the volume of sample with which the cylinder has been previously injected.
Claim 10
Dependent Claim
12 words
The method of claim 7 in which the chemical reagent is lyophilized.
Claim 11
Dependent Claim
18 words
The method of claim 7 in which the chemical reagent is in the form of a reagent plug.
Claim 12
Dependent Claim
19 words
The method of claim 1 in which said reagent is pre-mixed with said liquid sample in said injecting step.
Claim 13
Dependent Claim
34 words
The method of claim 1 in which the chemical reagent comprises thromboplastin reagents and additives in quantities sufficient to cause a prothrombin reaction when dissolved in a liquid sample of whole Blood or plasma.
Claim 14
Dependent Claim
25 words
The method of claim 1 in which the sample comprises said reagents capable of altering the viscosity of said sample upon placement within the cylinder.
Claim 15
Dependent Claim
102 words
Method of reproducibly measuring coagulation rates of fluid samples comprising: A. injecting said fluid sample into a hollow cylinder of uniform bore of a diameter sufficiently large so as to substantially eliminaate effects of sample viscosity, and containing therein lyophilized reagents reactable with said fluid sample; B. passing said sample in said cylinder by supporting said cylinder in a manner such that gravity causes said sample to move in a downward direction thus contacting said lyophilized reagents; C. gauging the movement of said sample as it descends down from said contact with said reagents until it reaches a position of substantial immobilization.
Claim 16
Dependent Claim
102 words
Method of reproducibly measuring coagulation rates of fluid samples comprising: A. injecting said fluid sample into a hollow cylinder of uniform bore of a diameter sufficiently large so as to substantially eliminaate effects of sample viscosity, and containing therein lyophilized reagents reactable with said fluid sample; B. passing said sample in said cylinder by supporting said cylinder in a manner such that gravity causes said sample to move in a downward direction thus contacting said lyophilized reagents; C. gauging the movement of said sample as it descends down from said contact with said reagents until it reaches a position of substantial immobilization.
Claim 17
Dependent Claim
23 words
The method of claim 14 in which the lyophilized reagents comprise thromboplastin and calcium and the fluid sample comprises whole blood or plasma.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-10 | 1979-05-12 | 1979-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-10 | 1983-05-12 | 1983-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-10 | 1987-05-12 | 1987-11-11 | $7700.00 | Window Closed / Lapsed |