US4138998A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Indicating temperature within living tissue
Assignee: RCA Corp
•
Filing: 1976-08-18
•
Granted: 1979-02-13
•
Expires: 1996-08-18
Abstract
Abstract A reflector that reflects a microwave signal as a function of temperature is implanted within living tissue of a human. A microwave signal is transmitted to the reflector via an applicator in contact with the skin of the human. A portion of the signal reflected from the reflector is coupled via the applicator to a meter that provides an indication of the temperature of the reflector.
Inventors
- 👤 Markus Nowogrodzki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:03
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/01; A61B5/05; A61B5/0507; A61B5/07; A61B5/076; A61N; A61N5/00; A61N5/02; G; G01; G01K; G01K1/00; G01K1/02; G01K1/024; G01K7/00; G01K7/36
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
183 words
Apparatus for indicating temperature within living tissue, comprising: impedance varying reflector means responsive to temperature changes for changing its impedance as a function of temperature; said reflector means adapted for implantation within said tissue for positioning to reflect impinging microwave signals; a microwave signal transmitter providing said microwave signal to said reflector at a predetermined frequency; a meter for indicating the level of a reflected microwave signal reflected from said reflector in response to said microwave signal from said transmitter; applicator means, adapted for contact with said tissue, for providing a substantially matched impedance at a given temperature for coupling microwave signals to and from said tissue; and means for coupling said transmitted microwave signal from said transmitter to said applicator means for application to said tissue and said reflector and for coupling to said meter a microwave signal reflected to said applicator means from said reflector; whereby said reflector in response to changes in temperature of said tissue from said given temperature will cause the level of said reflected signal to change as a function of said temperature changes in said tissue.
Claim 2
Dependent Claim
183 words
Apparatus for indicating temperature within living tissue, comprising: impedance varying reflector means responsive to temperature changes for changing its impedance as a function of temperature; said reflector means adapted for implantation within said tissue for positioning to reflect impinging microwave signals; a microwave signal transmitter providing said microwave signal to said reflector at a predetermined frequency; a meter for indicating the level of a reflected microwave signal reflected from said reflector in response to said microwave signal from said transmitter; applicator means, adapted for contact with said tissue, for providing a substantially matched impedance at a given temperature for coupling microwave signals to and from said tissue; and means for coupling said transmitted microwave signal from said transmitter to said applicator means for application to said tissue and said reflector and for coupling to said meter a microwave signal reflected to said applicator means from said reflector; whereby said reflector in response to changes in temperature of said tissue from said given temperature will cause the level of said reflected signal to change as a function of said temperature changes in said tissue.
Claim 3
Dependent Claim
27 words
Apparatus according to claim 1 wherein said reflector means includes a ferrite material that has a Curie temperature in a range of 43° C. to 55° C.
Claim 4
Dependent Claim
15 words
Apparatus according to claim 12 wherein said ferrite material is comprised of a lithium-aluminum ferrite.
Claim 5
Dependent Claim
70 words
In the method of providing an indication of temperature within living tissue, the steps of: transmitting a microwave signal at a predetermined frequency into said tissue; reflecting a microwave signal from an impedance varying reflector positioned within said tissue, said reflected signal from said reflector having a signal level that is a function of said temperature; and indicating said reflected signal level as a representation of temperature within said tissue.
Claim 6
Dependent Claim
70 words
In the method of providing an indication of temperature within living tissue, the steps of: transmitting a microwave signal at a predetermined frequency into said tissue; reflecting a microwave signal from an impedance varying reflector positioned within said tissue, said reflected signal from said reflector having a signal level that is a function of said temperature; and indicating said reflected signal level as a representation of temperature within said tissue.
References Cited (Backward Citations)
US2407690A
Cited
SU149914A1
Cited
DE1284528B
Cited
US3491596A
Cited
US3662140A
Cited
US3653385A
Cited
US3975720A
Cited
US3893111A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-02-12 | 1982-08-14 | 1983-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-12 | 1986-08-14 | 1987-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-12 | 1990-08-14 | 1991-02-13 | $7700.00 | Window Closed / Lapsed |