US5558671A
Expired / Lapsed
US
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Impedance feedback monitor for electrosurgical instrument
Assignee: Ethicon Endo Surgery Inc
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Filing: 1994-09-23
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Granted: 1996-09-24
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Expires: 2014-09-23
Abstract
Abstract An impedance monitoring device is provided for monitoring the electrical impedance of tissue as it is treated with electrosurgical energy. Based on a predicted model of tissue impedance and a number of initial impedance readings, the impedance at which tissue treatment is completed is predicted. More particularly, a minimum impedance level is measured and a function of the minimum impedance is used to determine impedance at which coagulation is completed. A control device is provided for bringing the output of the generator within an optimum range based on a system load curve. In one embodiment the impedance monitoring device is used in conjunction with a bipolar electrosurgical instrument. Preferably, the instrument comprises electrically opposite electrodes located on one or more tissue engaging surfaces for engaging tissue to be treated.
Inventors
- 👤 David C. Yates
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:02
CPC Classifications
A; A61; A61B; A61B17/00; A61B17/068; A61B17/072; A61B17/07207; A61B18/00; A61B18/04; A61B18/12; A61B18/1206; A61B18/14; A61B18/1442; A61B18/1445; A61B18/1447; A61B17/11; A61B17/115; A61B17/1155; A61B17/32; A61B18/1402; A61B2017/07214; A61B2018/00315; A61B2018/00345; A61B2018/00404; A61B2018/00571; A61B2018/00601; A61B2018/00636; A61B2018/00642; A61B2018/00666; A61B2018/00672; A61B2018/00678; A61B2018/00684; A61B2018/00696; A61B2018/00702; A61B2018/00708; A61B2018/00761; A61B2018/00773; A61B2018/00875; A61B2018/00886; A61B2018/1273; A61B2018/1452; A61B2018/1455; A61B90/00; A61B90/03; A61B2090/032
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
184 words
An electrosurgical device for treating tissue during a surgical procedure, said device comprising: a surgical instrument having a tissue treating portion including an end effector adapted to engage tissue to be treated; electrically isolated first and second poles comprised of tissue contacting first and second electrodes adapted to receive electrosurgical energy from an energy source connected to said electrodes, said first and second electrodes being capable of conducting electrical energy therebetween, at least one of said first and second electrodes being connected to said tissue treating portion of said instrument; an energy control signal generated by an energy control signal generator for controlling RF energy supplied from said energy source to said electrodes; impedance measurement circuitry coupled to said electrodes for measuring the impedance of tissue engaged by said end effector, wherein said impedance measuring circuitry is adapted to determine a minimum impedance value, to determine a target impedance value as a function of said minimum impedance value and to compare measured impedance values to said target impedance value and alter said control signal when said measured impedance value exceeds said target impedance value.
Claim 2
Dependent Claim
184 words
An electrosurgical device for treating tissue during a surgical procedure, said device comprising: a surgical instrument having a tissue treating portion including an end effector adapted to engage tissue to be treated; electrically isolated first and second poles comprised of tissue contacting first and second electrodes adapted to receive electrosurgical energy from an energy source connected to said electrodes, said first and second electrodes being capable of conducting electrical energy therebetween, at least one of said first and second electrodes being connected to said tissue treating portion of said instrument; an energy control signal generated by an energy control signal generator for controlling RF energy supplied from said energy source to said electrodes; impedance measurement circuitry coupled to said electrodes for measuring the impedance of tissue engaged by said end effector, wherein said impedance measuring circuitry is adapted to determine a minimum impedance value, to determine a target impedance value as a function of said minimum impedance value and to compare measured impedance values to said target impedance value and alter said control signal when said measured impedance value exceeds said target impedance value.
Claim 3
Dependent Claim
36 words
The electrosurgical device of claim 1 further comprising: an energy source arranged to supply electrosurgical energy to said electrodes, wherein said energy source is responsive to said control signal to supply said energy to said electrodes.
Claim 4
Dependent Claim
74 words
The electrosurgical device of claim 1 wherein said impedance measuring circuitry includes: a first device for determining the minimum impedance value; a target determining device coupled to said first device, for determining the target impedance value as a function of said minimum impedance value; and a first comparison device for comparing measured impedance values to said target impedance value and generating a signal indicating whether said measured impedance value exceeds said target impedance value.
Claim 5
Dependent Claim
40 words
The electrosurgical device of claim 1 wherein said end effector includes first and second elements moveable relative to each other for engaging tissue therebetween, wherein said first electrode is located on at least one of said first and second elements.
Claim 6
Dependent Claim
22 words
The electrosurgical device of claim 4 wherein said second electrode is located on at least one of said first and second elements.
Claim 7
Dependent Claim
34 words
The electrosurgical device of claim 5 wherein said impedance measuring circuitry is adapted to measure the impedance of the tissue between said first and second electrodes and engaged by said first and second elements.
Claim 8
Dependent Claim
100 words
The electrosurgical device of claim 4, wherein: said first and second elements comprise first and second interfacing surfaces for engaging tissue to be electrosurgically treated; wherein said first pole is comprised of one or more first electrodes located on at least one of said first and second interfacing surfaces; wherein said second pole is comprised of one or more second electrodes located on at least one of said first and second interfacing surfaces; and wherein each of said one or more first electrodes is offset from each of said one or more second electrodes with respect to said interfacing surfaces.
Claim 9
Dependent Claim
15 words
The electrosurgical device of claim 1 wherein said impedance measurement circuitry comprises a microprocessor controller.
Claim 10
Independent Claim
114 words
A method of operating a device for electrosurgically treating tissue during a surgical procedure, said method comprising the steps of: applying RF energy to tissue to be electrosurgically treated by means of an electrosurgical instrument; measuring the impedance of the tissue treated by said electrosurgical instrument; generating an impedance signal representative of the measured impedance value of said tissue; determining a representative minimum impedance value; determining a representative target impedance value as a function of said minimum impedance value; comparing measured impedance values to said target impedance value; and generating a control signal to control the RF energy to said electrosurgical instrument in response to said measured impedance value exceeding said target impedance value.
Claim 11
Independent Claim
114 words
A method of operating a device for electrosurgically treating tissue during a surgical procedure, said method comprising the steps of: applying RF energy to tissue to be electrosurgically treated by means of an electrosurgical instrument; measuring the impedance of the tissue treated by said electrosurgical instrument; generating an impedance signal representative of the measured impedance value of said tissue; determining a representative minimum impedance value; determining a representative target impedance value as a function of said minimum impedance value; comparing measured impedance values to said target impedance value; and generating a control signal to control the RF energy to said electrosurgical instrument in response to said measured impedance value exceeding said target impedance value.
Claim 12
Dependent Claim
47 words
The method of claim 9 further comprising; providing a tissue engaging instrument for engaging tissue to be electrosurgically treated, wherein said instrument includes electrically opposite tissue contacting electrodes; engaging tissue to be electrosurgically treated between said electrodes; and applying electrical energy to tissue engaged between said electrodes.
Claim 13
Dependent Claim
134 words
An electrosurgical impedance feedback control device, said device comprising: impedance measurement circuitry adapted to be coupled to tissue contacting electrodes connected to a tissue treating portion of a surgical instrument and to an energy source arranged to supply therapeutic electrosurgical energy to said electrodes, wherein said impedance measurement circuitry is adapted to measure the impedance of tissue engaged by the tissue treating portion of the surgical instrument; said impedance measuring circuitry comprising: a first device for determining a minimum impedance value; a target determining device coupled to said first device, for determining the target impedance value as a function of said minimum impedance value; and a first comparison device for comparing measured impedance values to said target impedance value and generating a signal indicating whether said measured impedance value exceeds said target impedance value.
Claim 14
Dependent Claim
134 words
An electrosurgical impedance feedback control device, said device comprising: impedance measurement circuitry adapted to be coupled to tissue contacting electrodes connected to a tissue treating portion of a surgical instrument and to an energy source arranged to supply therapeutic electrosurgical energy to said electrodes, wherein said impedance measurement circuitry is adapted to measure the impedance of tissue engaged by the tissue treating portion of the surgical instrument; said impedance measuring circuitry comprising: a first device for determining a minimum impedance value; a target determining device coupled to said first device, for determining the target impedance value as a function of said minimum impedance value; and a first comparison device for comparing measured impedance values to said target impedance value and generating a signal indicating whether said measured impedance value exceeds said target impedance value.
References Cited (Backward Citations)
US2031682A
Cited
DE2455171A1
Cited
US4171700A
Cited
US4126137A
Cited
US4474179A
Cited
US4416276A
Cited
US4494539A
Cited
US4651280A
Cited
US4658819A
Cited
US4671274A
Cited
US4633874A
Cited
US4608981A
Cited
FR2573301A1
Cited
US4685459A
Cited
US4655216A
Cited
GB2213381A
Cited
US4961047A
Cited
US5057107A
Cited
US4985030A
Cited
US5151102A
Cited
DE3942998A1
Cited
US5104025A
Cited
US5085659A
Cited
US5167658A
Cited
US5190517A
Cited
EP0517244A1
Cited
EP0518230A1
Cited
WO1993008754A1
Cited
US5207691A
Cited
WO1993013718A1
Cited
US5423809A
Cited
US5201900A
Cited
US5300070A
Cited
US5389098A
Cited
WO1994010925A1
Cited
US5342357A
Cited
US5437662A
Cited
US5335668A
Cited
US5417687A
Cited
WO1994024951A1
Cited
WO1994024949A1
Cited
WO1995009576A1
Cited
US5429636A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-09-24 | 2000-03-25 | 2000-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-09-24 | 2004-03-25 | 2004-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-09-24 | 2008-03-25 | 2008-09-24 | $7700.00 | Window Closed / Lapsed |