US4245649A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for monitoring biological signals from patients, while an electro-surgical appliance is being simultaneously used
Assignee: Individual
•
Filing: 1978-07-25
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Granted: 1981-01-20
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Expires: 1998-07-25
Abstract
Abstract The present invention relates to a system for use in monitoring a biological signal from a patient while an electro-surgical appliance which applies a high r.f. voltage, is being simultaneously used. The signals from a number of transducers are transmitted to an amplifier preferably an ECG amplifier with an input-filter. The amplifier is situated in a Faraday cage which is connected to one of the transducers. The filter is a screened HF-filter and the filter together with the Faraday cage is enclosed in an earth connected grounded container or screen. As a result radiation from the Faraday cage is substantially eliminated.
Inventors
- 👤 Poul Schmidt-Andersen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:54
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/24; A61B5/30; A61B5/307; A61B5/308; Y; Y10; Y10S; Y10S128/00; Y10S128/901
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
115 words
A device for monitoring a biological function of a patient during use of an electro-surgical appliance which delivers high r.f. voltages to the tissue under consideration, the device comprising a reference electrode and two active electrodes adapted to contact the body of the patient, thereby providing a signal representative of the biological function, a signal amplifier having two input terminals, a shielded conductor and a filter for connecting the electrodes with the amplifier, the reference electrode, and the conductor shield being interconnected, and each of the active electrodes, being connected to an amplifier input terminal, an ungrounded shield surrounding said filter and said amplifier, and a grounded container surrounding and insulated from the ungrounded shield.
Claim 2
Independent Claim
115 words
A device for monitoring a biological function of a patient during use of an electro-surgical appliance which delivers high r.f. voltages to the tissue under consideration, the device comprising a reference electrode and two active electrodes adapted to contact the body of the patient, thereby providing a signal representative of the biological function, a signal amplifier having two input terminals, a shielded conductor and a filter for connecting the electrodes with the amplifier, the reference electrode, and the conductor shield being interconnected, and each of the active electrodes, being connected to an amplifier input terminal, an ungrounded shield surrounding said filter and said amplifier, and a grounded container surrounding and insulated from the ungrounded shield.
Claim 3
Dependent Claim
24 words
A device as claimed in claim 1, wherein the filter incorporates an inductor and in which the inductor is provided with an individual shield.
Claim 4
Dependent Claim
47 words
A device as claimed in claim 1, characterized in that the r.f. voltage has a frequency in the range from 750 kHz to 1.6 MHz and in which the capacitance between the ungrounded shield and the grounded container is in the range of 30 to 60 pF.
References Cited (Backward Citations)
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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) | 1984-01-20 | 1984-07-21 | 1985-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-20 | 1988-07-21 | 1989-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-20 | 1992-07-21 | 1993-01-20 | $7700.00 | Window Closed / Lapsed |