Patent US6258085B1 successfully refreshed from Google Patents.
US6258085B1
Expired / Lapsed
US
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Electrosurgical return electrode monitor
Assignee: Covidien AG
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Filing: 1999-05-11
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Granted: 2001-07-10
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Expires: 2019-05-11
Abstract
Abstract The present disclosure provides a method for determining the probability of a patient burn under a return electrode in a momopolar electrosurgical system comprising calculating a heating factor adjacent the return electrode utilizing a first algorithm, calculating a cooling factor adjacent the return electrode utilizing a second algorithm, subtracting the calculated cooling factor from the calculated heating factor to obtain a difference value, comparing the difference value to a threshold value, and adjusting the power dependent on the relationship of the difference value to the threshold value.
Inventors
- 👤 Jeffrey L. Eggleston
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 21:24
CPC Classifications
A; A61; A61B; A61B18/00; A61B18/04; A61B18/12; A61B18/1206; A61B18/1233; A61B18/14; A61B18/16
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
127 words
An electrosurgical system comprising: an electrosurgical generator having an electrosurgical tool for treating tissue, a return electrode, and an impedance sensor in electrical communication with the return electrode to measure impedance of the return electrode, wherein said electrosurgical generator further comprises: a current sensor for measuring an output current delivered by the electrosurgical generator; a microprocessor electrically connected to the current sensor and the impedance sensor for calculating a heating factor and a cooling factor of the tissue under the return electrode, the calculation of the heating factor being based at least in part on the measured output current; and a controller electrically connected to the microprocessor for adjusting a power supply of the generator in response to a relationship of the calculated heating and cooling factors.
Claim 2
Dependent Claim
127 words
An electrosurgical system comprising: an electrosurgical generator having an electrosurgical tool for treating tissue, a return electrode, and an impedance sensor in electrical communication with the return electrode to measure impedance of the return electrode, wherein said electrosurgical generator further comprises: a current sensor for measuring an output current delivered by the electrosurgical generator; a microprocessor electrically connected to the current sensor and the impedance sensor for calculating a heating factor and a cooling factor of the tissue under the return electrode, the calculation of the heating factor being based at least in part on the measured output current; and a controller electrically connected to the microprocessor for adjusting a power supply of the generator in response to a relationship of the calculated heating and cooling factors.
Claim 3
Dependent Claim
27 words
The generator of claim 1 , wherein the microprocessor includes a first algorithm for calculating the heating factor and a second algorithm for calculating the cooling factor.
Claim 4
Dependent Claim
55 words
The generator of claim 2 , wherein the second algorithm is defined as k c t off wherein K c is a constant representative of the time it takes for the tissue to cool down in degrees per minute and t off is the time in seconds that the output current is not being delivered.
Claim 5
Dependent Claim
62 words
The generator of claim 2 , wherein the first algorithm is defined as k h I 2 t on wherein K h is a constant representative of a measured impedance in Ohms of the return electrode, I 2 is the square of said measured output current in milliamps and t on is the time in seconds that the output current is delivered.
Claim 6
Dependent Claim
24 words
The generator of claim 4 , wherein the measured impedance is indicative of the degree of adherence to the tissue of the return electrode.
Claim 7
Dependent Claim
73 words
The electrosurgical generator of claim 1 , wherein the microprocessor includes an algorithm for subtracting the cooling factor from the heating factor to calculate a difference value, and the generator further comprises a comparator electrically connected to the microprocessor for comparing the difference value to a threshold value, the comparator being electrically connected to the controller to generate a first signal indicative of the relationship of the difference value and the threshold value.
Claim 8
Dependent Claim
33 words
The electrosurgical generator of claim 6 , further comprising an alarm electrically connected to the comparator for generating a warning signal if the difference value exceeds the threshold value by a predetermined amount.
Claim 9
Dependent Claim
35 words
The electrosurgical generator of claim 6 , wherein the controller generates a shut off signal to terminate power if the difference value exceeds a predetermined value, the predetermined value being greater than the threshold value.
Claim 10
Dependent Claim
33 words
The electrosurgical generator of claim 8 , wherein the controller generates a second signal to reduce the power if the difference value exceeds the threshold value but does not exceed the predetermined value.
References Cited (Backward Citations)
US3683923A
Cited
US3913583A
Cited
US4094320A
Cited
US4121590A
Cited
US4303073A
Cited
US4494541A
Cited
US4343308A
Cited
US4416276A
Cited
US4416277A
Cited
US4437464A
Cited
US4657015A
Cited
US4658819A
Cited
US4741334A
Cited
US5480399A
Cited
US5496312A
Cited
US5695494A
Cited
US5766165A
Cited
US5797902A
Cited
US5976128A
Cited
US6053910A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-07-09 | 2005-01-08 | 2005-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-07-09 | 2009-01-08 | 2009-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-07-09 | 2013-01-08 | 2013-07-10 | $7700.00 | Window Closed / Lapsed |