US3905373A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrosurgical device
Assignee: Dentsply Research and Development Corp
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Filing: 1974-04-18
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Granted: 1975-09-16
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Expires: 1994-04-18
Abstract
Abstract A radiofrequency electrosurgical device which includes an active electrode means and a passive electrode coupled to a chassis ground of a radiofrequency generator of the device. If the passive electrode is disconnected from the chassis ground, a potential develops between the chassis ground and a system ground. This potential is used to actuate a relay to disable the radiofrequency generator if the passive electrode becomes disconnected.
Inventors
- 👤 Donald I Gonser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 08:17
CPC Classifications
A; A61; A61B; A61B18/00; A61B18/04; A61B18/12; A61B18/14; A61B18/16
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
112 words
A radio-frequency electrosurgical device which comprises a radio-frequency generator having a chassis ground, an active electrode means connected to the radio-frequency generator, the generator being constructed to power the active electrode means, a passive electrode coupled to the chassis ground, a system ground, a transformer, means including a primary winding of the transformer for connecting the system ground to the chassis ground, a relay connected to a secondary winding of the transformer to be actuated when there is a predetermined radio-frequency potential across said connecting means, and means actuated by the relay for disabling the generator from powering the active electrode when the potential across the connecting means exceeds the predetermined value.
Claim 2
Dependent Claim
112 words
A radio-frequency electrosurgical device which comprises a radio-frequency generator having a chassis ground, an active electrode means connected to the radio-frequency generator, the generator being constructed to power the active electrode means, a passive electrode coupled to the chassis ground, a system ground, a transformer, means including a primary winding of the transformer for connecting the system ground to the chassis ground, a relay connected to a secondary winding of the transformer to be actuated when there is a predetermined radio-frequency potential across said connecting means, and means actuated by the relay for disabling the generator from powering the active electrode when the potential across the connecting means exceeds the predetermined value.
Claim 3
Dependent Claim
34 words
A radio-frequency electrosurgical device in accordance with claim 1 wherein the means for coupling the passive electrode to the chassis ground includes capacitor means in series between the passive electrode and the chassis ground.
Claim 4
Dependent Claim
37 words
A radio-frequency electrosurgical device as in claim 1 which includes a variable resistance connected in parallel with the relay for determining the predetermined value of the potential across the connecting means at which the relay is actuated.
Claim 5
Dependent Claim
27 words
A radio-frequency electrosurgical device as in claim 1 wherein there is means actuated by the relay for producing an audible warning signal when the relay is actuated.
Claim 6
Dependent Claim
139 words
In combination with a radio-frequency electrosurgical device which includes a radio-frequency generator, power source means for supplying power to the radio-frequency generator, circuit means connected to the radio-frequency generator for performing electrosurgery on a patient, said circuit means establishing a first current return path from the patient to the radio-frequency generator when connected to the patient, means for establishing an alternate current return path for at least part of said first current return path from the patient to the radio-frequency generator, a monitoring system means connected to the alternate current return path for sensing radio-frequency current passing in said alternate current return path, and means connected to the monitoring system means for disabling the power source means from powering the radio-frequency generator when the radio-frequency current level in the alternate current return path exceeds a predetermined radio-frequency current level.
Claim 7
Dependent Claim
139 words
In combination with a radio-frequency electrosurgical device which includes a radio-frequency generator, power source means for supplying power to the radio-frequency generator, circuit means connected to the radio-frequency generator for performing electrosurgery on a patient, said circuit means establishing a first current return path from the patient to the radio-frequency generator when connected to the patient, means for establishing an alternate current return path for at least part of said first current return path from the patient to the radio-frequency generator, a monitoring system means connected to the alternate current return path for sensing radio-frequency current passing in said alternate current return path, and means connected to the monitoring system means for disabling the power source means from powering the radio-frequency generator when the radio-frequency current level in the alternate current return path exceeds a predetermined radio-frequency current level.
Claim 8
Dependent Claim
21 words
A combination as in claim 5 wherein the alternate current return path is between a system ground and a chassis ground.
References Cited (Backward Citations)
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US3699967A
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US3766434A
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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) | 1978-09-15 | 1979-03-17 | 1979-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-15 | 1983-03-17 | 1983-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-15 | 1987-03-17 | 1987-09-16 | $7700.00 | Window Closed / Lapsed |