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US3854324A
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US
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Blood clotting time and strength measuring system
Assignee: Individual
•
Filing: 1973-06-11
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Granted: 1974-12-17
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Expires: 1993-06-11
Abstract
Abstract The clotting time for a blood specimen is measured by blowing a train of bubbles from a tube immersed in the specimen and then detecting the time of occurrence of an appreciable change in the bubble formation characteristics. The system detects that change by detecting a change in the bubbles or in the reflected pressure profile in an expansible chamber connected to the tube with a pressure sensing device having inertia.
Inventors
- 👤 T Altshuler
- 👤 J Altshuler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:08
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/483; G01N33/487; G01N33/49; G01N33/4905
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
85 words
The method of detecting the commencement of clotting in a blood specimen comprising the steps of A. bubbling a gas below the surface of the specimen, B. monitoring the pressure required to blow the bubbles in the specimen, C. rejecting the high frequency pressure fluctuations characteristic of bubbles blown in unclotted blood, D. detecting only the relatively low frequency fluctuations of the pressure which are characteristic of bubbles blown in clotting blood, and E. measuring the time of commencement of the low frequency pressure fluctuations.
Claim 2
Independent Claim
85 words
The method of detecting the commencement of clotting in a blood specimen comprising the steps of A. bubbling a gas below the surface of the specimen, B. monitoring the pressure required to blow the bubbles in the specimen, C. rejecting the high frequency pressure fluctuations characteristic of bubbles blown in unclotted blood, D. detecting only the relatively low frequency fluctuations of the pressure which are characteristic of bubbles blown in clotting blood, and E. measuring the time of commencement of the low frequency pressure fluctuations.
Claim 3
Dependent Claim
5 words
a small bore cannula, and
Claim 4
Dependent Claim
5 words
a small bore cannula, and
Claim 5
Dependent Claim
36 words
The method as defined in claim 1 and including the additional step of measuring the magnitude of the low frequency fluctuation peaks so as to obtain an indication of the clotting strength of the blood specimen.
Claim 6
Dependent Claim
35 words
The method defined in claim 1 and including the additional step of interrupting the bubbling of gas periodically so as to facilitate the formation of fibrin in the blood at the site of the bubbles.
Claim 7
Dependent Claim
80 words
a conduit connecting the supply to the cannula, said conduit including means to insure uniform gas flow into the cannula despite pressure fluctuations in the cannula, and C. means for detecting a change in the size of the bubbles blown in the blood begins to coagulate, said detecting means including means communicating with the conduit downstream from the insuring means for sensing the pressure in the conduit, said sensing means responding only to relatively low frequency, high amplitude pressure fluctuations.
Claim 8
Dependent Claim
80 words
a conduit connecting the supply to the cannula, said conduit including means to insure uniform gas flow into the cannula despite pressure fluctuations in the cannula, and C. means for detecting a change in the size of the bubbles blown in the blood begins to coagulate, said detecting means including means communicating with the conduit downstream from the insuring means for sensing the pressure in the conduit, said sensing means responding only to relatively low frequency, high amplitude pressure fluctuations.
Claim 9
Independent Claim
56 words
A system for measuring the clotting time and clotting strength of a blood specimen comprising A. means for supporting a container for a blood specimen, B. means for flowing gas into a blood specimen in the container for generating a train of bubbles in the blood having a relatively uniform first size, said flowing means comprising
Claim 10
Independent Claim
56 words
A system for measuring the clotting time and clotting strength of a blood specimen comprising A. means for supporting a container for a blood specimen, B. means for flowing gas into a blood specimen in the container for generating a train of bubbles in the blood having a relatively uniform first size, said flowing means comprising
Claim 11
Dependent Claim
33 words
The system defined in claim 4 and further including A. a container for the blood specimen, and B. said supporting means positioning the container so that the flowing means projects into the container.
Claim 12
Dependent Claim
37 words
The system defined in claim 5 and further including means for adjusting the flowing means relative to the container so that bubbles can be made to originate at any point in the blood volume in the container.
Claim 13
Dependent Claim
34 words
The system defined in claim 5 wherein the flowing means includes a cannula which projects into the container from below and is attached to the container so that the two constitute a disposable unit.
Claim 14
Dependent Claim
13 words
The system defined in claim 4 wherein the cannula has an oblique tip.
Claim 15
Dependent Claim
19 words
The system defined in claim 4 wherein the uniform flow rate insuring means comprise a restriction in the conduit.
Claim 16
Dependent Claim
14 words
The system defined in claim 4 wherein the pressure sensing means is a manometer.
Claim 17
Dependent Claim
15 words
The system defined in claim 4 wherein the pressure sensing means is a pressure transducer.
Claim 18
Dependent Claim
26 words
The system defined in claim 11 and further including means responsive to the output of the transducer for indicating the pressure as a function of time.
Claim 19
Dependent Claim
35 words
The system defined in claim 4 and further including means for interrupting the flow of gas to the cannula periodically so as to facilitate the formation of fibrin in the blood adjacent the cannula tip.
Claim 20
Dependent Claim
28 words
The system defined in claim 13 wherein the interrupting means comprise a valve in the gas flowing means which is turned on and off in a cyclical manner.
Claim 21
Dependent Claim
33 words
The system defined in claim 13 wherein the interrupting means comprises an expansible chamber communicating with the conduit which can accommodate the gas flow while the fibrin is forming at the cannula tip.
Claim 22
Dependent Claim
15 words
The system defined in claim 4 wherein the sensing means has a relatively high inertia.
Claim 23
Dependent Claim
44 words
The system defined in claim 4 wherein the detecting means comprise A. means for directing radient energy through a container for a blood sample, and B. means for detecting changes in the transmitted or reflected component of the energy when the bubble size changes.
Claim 24
Independent Claim
77 words
The method of determining the clotting time of a blood specimen comprising the steps of A. bubbling a gas below the surface of the specimen, B. detecting the pressure required to blow the bubbles, and C. detecting the time of commencement of relatively low frequency fluctuations in the pressure required to blow the bubbles, and D. measuring the magnitude of the fluctuation peaks so as to obtain an indication of the clotting strength of the blood specimen.
Claim 25
Independent Claim
77 words
The method of determining the clotting time of a blood specimen comprising the steps of A. bubbling a gas below the surface of the specimen, B. detecting the pressure required to blow the bubbles, and C. detecting the time of commencement of relatively low frequency fluctuations in the pressure required to blow the bubbles, and D. measuring the magnitude of the fluctuation peaks so as to obtain an indication of the clotting strength of the blood specimen.
Claim 26
Independent Claim
85 words
The method of determining the clotting time of a blood specimen comprising the steps of A. bubbling a gas below the surface of the specimen, B. detecting the pressure required to blow the bubbles, C. detecting the time of commencement of relatively low frequency fluctuations in the pressure required to blow the bubbles, and D. comparing the time of commencement of the pressure fluctuations for the specimen with the time of commencement of similar fluctuations for a specimen of blood having a normal clotting time.
Claim 27
Independent Claim
85 words
The method of determining the clotting time of a blood specimen comprising the steps of A. bubbling a gas below the surface of the specimen, B. detecting the pressure required to blow the bubbles, C. detecting the time of commencement of relatively low frequency fluctuations in the pressure required to blow the bubbles, and D. comparing the time of commencement of the pressure fluctuations for the specimen with the time of commencement of similar fluctuations for a specimen of blood having a normal clotting time.
References Cited (Backward Citations)
US2473553A
Cited
US3380463A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-16 | 1978-06-17 | 1978-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-16 | 1982-06-17 | 1982-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-16 | 1986-06-17 | 1986-12-17 | $7700.00 | Window Closed / Lapsed |