Patent US3340867A successfully refreshed from Google Patents.
US3340867A
Expired / Lapsed
US
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Impedance plethysmograph
Assignee: University of Minnesota Twin Cities
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Filing: 1964-08-19
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Granted: 1967-09-12
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Expires: 1984-08-19
Abstract
No abstract record available.
Inventors
- 👤 William G Kubicek
- 👤 Kinnen Edwin
- 👤 Robert P Patterson
- 👤 David A Witsoe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:57
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/02; A61B5/026; A61B5/0295
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
157 words
A PLETHYSMOGRAPH FOR MEASURING CARDIAC OUTPUT COMPRISING IN COMBINATION EXCITATION ELECTRODE MEANS ADAPTED TO BE CONNECTED TO A MAMMALIAN SUBJECT AT THE SUPERIOR AND INFERIOR ENDS OF THE THORAX, A CURRENT GENERATOR MEANS COMPRISING AN ELECTRONIC OSCILLATOR CONDUCTIVELY CONNECTED TO THE ELECTRODE MEANS FOR SUPPLYING A FLUCTUATING EXCITATION CURRENT THERETO, SENSOR MEANS ADAPTED TO BE CONDUCTIVELY CONNECTED TO SAID THORAX FOR CARRYING A SENSED ELECTRICAL SIGNAL WHICH VARIES AS THE IMPEDANCE CHANGES IN THE THORAX BETWEEN SAID ELECTRODE MEANS, A CONTROL MEANS CONDUCTIVELY CONNECTED TO THE OSCILLATOR FOR BALANCING THE CURRENT FROM THE OSCILLATOR WITH THE SENSED SIGNAL, A FIRST AMPLIFIED CONDUCTIVELY CONNECTED TO THE CONTROL MEANS, A SECOND AMPLIFIER CONNECTED TO SAID SENSOR MEANS WHEREBY SIGNALS OF APPROXIMATELY EQUAL STRENGTH ARE FED TO SAID FIRST AND SECOND AMPLIFIERS FROM SAID CONTROL AND SAID SENSOR MEANS RESPECTIVELY AND A VOLTAGE SUBSTRACTING MEANS CONDUCTIVELY CONNECTED TO EACH OF THE AMPLIFIERS FOR COMPARING THE OUTPUT OF EACH SAID AMPLIFIER.
Claim 2
Dependent Claim
157 words
A PLETHYSMOGRAPH FOR MEASURING CARDIAC OUTPUT COMPRISING IN COMBINATION EXCITATION ELECTRODE MEANS ADAPTED TO BE CONNECTED TO A MAMMALIAN SUBJECT AT THE SUPERIOR AND INFERIOR ENDS OF THE THORAX, A CURRENT GENERATOR MEANS COMPRISING AN ELECTRONIC OSCILLATOR CONDUCTIVELY CONNECTED TO THE ELECTRODE MEANS FOR SUPPLYING A FLUCTUATING EXCITATION CURRENT THERETO, SENSOR MEANS ADAPTED TO BE CONDUCTIVELY CONNECTED TO SAID THORAX FOR CARRYING A SENSED ELECTRICAL SIGNAL WHICH VARIES AS THE IMPEDANCE CHANGES IN THE THORAX BETWEEN SAID ELECTRODE MEANS, A CONTROL MEANS CONDUCTIVELY CONNECTED TO THE OSCILLATOR FOR BALANCING THE CURRENT FROM THE OSCILLATOR WITH THE SENSED SIGNAL, A FIRST AMPLIFIED CONDUCTIVELY CONNECTED TO THE CONTROL MEANS, A SECOND AMPLIFIER CONNECTED TO SAID SENSOR MEANS WHEREBY SIGNALS OF APPROXIMATELY EQUAL STRENGTH ARE FED TO SAID FIRST AND SECOND AMPLIFIERS FROM SAID CONTROL AND SAID SENSOR MEANS RESPECTIVELY AND A VOLTAGE SUBSTRACTING MEANS CONDUCTIVELY CONNECTED TO EACH OF THE AMPLIFIERS FOR COMPARING THE OUTPUT OF EACH SAID AMPLIFIER.
References Cited (Backward Citations)
US3280817A
Cited
US2184511A
Cited
US3095872A
Cited
US3144019A
Cited
US3149627A
Cited
US3224435A
Cited
US3267933A
Cited
US3267934A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-09-11 | 1971-03-13 | 1971-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-09-11 | 1975-03-13 | 1975-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-09-11 | 1979-03-13 | 1979-09-12 | $7700.00 | Window Closed / Lapsed |