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US4240441A
Expired / Lapsed
US
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Carotid thermodilution catheter
Assignee: United States Department of the Navy
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Filing: 1978-10-10
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Granted: 1980-12-23
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Expires: 1998-10-10
Abstract
Abstract A thermodilution catheter having a proximal high frequency heating coil of fine wires, heat measuring thermocouples, and a distal resistance thermometer, all wound externally on a catheter for measuring arterial blood flow. The device also incorporates electrodes for electrocardiogram tracing.
Inventors
- 👤 Hassan H. Khalil
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:32
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/02; A61B5/026; A61B5/0275; A61B5/028; A61M; A61M25/00; A61M25/0043; A61M25/005
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
111 words
In a bioelectric measuring apparatus for insertion within an internal carotid artery of a living organism, including in combination, an elongated, flexible body, an electrical heater mounted thereon, and a temperature sensing device also mounted on said catheter body, the improvement comprising: temperature transducing means mounted on said catheter body for sensing the temperature rise of said catheter body produced by said electrical heater; and wherein said temperature sensing device and said electrical heater include wire windings having dimensions to facilitate compact placement within said organism and to achieve a predetermined surface area to blood volume flow ratio of from about 0.08 mm 2 /ml/min. to about 0.42 mm 2 /ml/min.
Claim 2
Dependent Claim
111 words
In a bioelectric measuring apparatus for insertion within an internal carotid artery of a living organism, including in combination, an elongated, flexible body, an electrical heater mounted thereon, and a temperature sensing device also mounted on said catheter body, the improvement comprising: temperature transducing means mounted on said catheter body for sensing the temperature rise of said catheter body produced by said electrical heater; and wherein said temperature sensing device and said electrical heater include wire windings having dimensions to facilitate compact placement within said organism and to achieve a predetermined surface area to blood volume flow ratio of from about 0.08 mm 2 /ml/min. to about 0.42 mm 2 /ml/min.
Claim 3
Dependent Claim
23 words
An improved bioelectric measuring apparatus for insertion within a living organism according to claim 1 wherein said electrical heater wire is bifilarly wound.
Claim 4
Dependent Claim
31 words
An improved bioelectric measuring apparatus for insertion within a living organism according to claim 1 further comprising: conducting means, mounted on said catheter body, for electrical contact with said living organism.
Claim 5
Dependent Claim
24 words
An improved bioelectric measuring apparatus for insertion within a living organism according to claim 3 wherein said conducting means comprises one or more electrodes.
Claim 6
Dependent Claim
23 words
An improved bioelectric measuring apparatus for insertion within a living organism according to claim 4 wherein said electrodes comprise bare platinum wire electrodes.
Claim 7
Dependent Claim
57 words
An improved bioelectric measuring apparatus for insertion within a living organism according to claim 1 wherein said temperature transducing means comprises; a first thermocouple positioned on said catheter body along said electrical heater wire winding; a reference thermocouple positioned on said catheter body in series with said first thermocouple and proximal to said electric heater wire winding.
Claim 8
Dependent Claim
22 words
An improved bioelectric measuring apparatus for insertion within a living organism according to claim 6 wherein said thermocouples are copper constantan thermocouples.
Claim 9
Dependent Claim
26 words
An improved bioelectric measuring apparatus for insertion within a living organism according to claim 1 wherein said temperature sensing wire winding comprises 99.99% pure platinum wires.
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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) | 1983-12-23 | 1984-06-23 | 1984-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-23 | 1988-06-23 | 1988-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-23 | 1992-06-23 | 1992-12-23 | $7700.00 | Window Closed / Lapsed |