Patent US2158112A successfully refreshed from Google Patents.
EP0703461A2
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Impedance feedback monitor for electrosurgical instrument
Assignee: Ethicon Endo Surgery Inc
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Filing: 1995-09-22
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Granted: —
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Expires: 2015-09-22
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
EP
Data Source
google_patents
Last Synchronized
2026-10-23 06:57
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: 11
Claim 1
Independent Claim
124 words
A control device comprising: impedance measurement circuitry adapted to be coupled to tissue-contacting electrodes associated with a tissue-treating portion of a surgical instrument and to an energy source adapted to supply therapeutic electrosurgical energy to said electrodes; and an energy control signal adapted to control RF energy supplied from said energy source to said electrodes, wherein said impedance measurement circuitry is adapted: to measure the impedance of tissue engaged by said tissue-treating portion of said surgical instrument; to determine a minimum impedance value; to determine a target impedance value as a function of said minimum impedance value; to compare measured impedance values to said target impedance value; and to alter said energy control signal when said measured impedance value exceeds said target impedance value.
Claim 2
Dependent Claim
73 words
The control device of claim 1, wherein said impedance measuring circuitry includes: a first device for determining the minimum impedance value; a second device coupled to said first device for determining the target impedance value as a function of said minimum impedance value; and a third device for comparing measured impedance values to said target impedance value and for generating a signal indicating whether said measured impedance value exceeds said target impedance value.
Claim 3
Dependent Claim
182 words
A control device adapted to be coupled to an energy source for providing electrosurgical energy to tissue to be treated, the control device comprising: a first input for receiving at least one of a first signal representative of voltage delivered from said energy source to said tissue and a second signal representative of current delivered from said energy source to said tissue; a second input for receiving a third signal representative of a target impedance for said tissue on the energy source, determined from the first and second signals; and a function fitting device for providing a fourth signal representative of desired energy output according to a system load curve, the fourth signal corresponding to desired energy output for the target load impedance represented by the third signal; wherein said control device is adapted to: control energy output by the energy source based on the third signal representative of the load impedance; and control the energy source to bring electrosurgical energy delivered by the energy source to the target within a range of desired energy output based on said system load curve.
Claim 4
Dependent Claim
46 words
The control device of claim 3 which includes a comparison device for comparing said fourth signal, representative of desired energy output, to at least one of said first and second signals, said comparison device being adapted to provide a control signal for controlling said energy source.
Claim 5
Dependent Claim
28 words
The control device of claim 4, wherein said control signal represents a difference between said fourth signal and said at least one of said first and second signals.
Claim 6
Dependent Claim
52 words
A generator for providing electrosurgical energy to an electrosurgical device, said generator comprising: an electrosurgical energy source for providing electrosurgical energy to said electrosurgical device; and a control device according to any one of claims 1 to 5, wherein the control device is arranged to control the output of said energy source.
Claim 7
Dependent Claim
71 words
An electrosurgical device for treating tissue during a surgical procedure, the electrosurgical device comprising: electrically isolated first and second electrodes adapted to contact tissue to be treated and to cause electrosurgical energy to be conducted between said electrodes through said tissue; and a control device according to any one of claims 1 to 5, wherein the control device is adapted to control the output of said electrosurgical energy between said electrodes.
Claim 8
Dependent Claim
84 words
An electrosurgical device for treating tissue during an electrosurgical procedure, the electrosurgical device comprising: electrically isolated first and second electrodes adapted to contract tissue to be treated and to cause electrosurgical energy to be conducted between said electrodes through said tissue; an electrosurgical energy source for providing said electrosurgical energy to said electrodes; and a control device according to any one of claims 1 to 5, wherein said control device is arranged to control the output from said electrosurgical energy source to said electrodes.
Claim 9
Dependent Claim
40 words
The electrosurgical device of claim 7 or 8, wherein said first electrode is located on one of a first and a second element and wherein said first and second elements are movable relative to each other for engaging tissue therebetween.
Claim 10
Dependent Claim
22 words
The electrosurgical device of claim 9, wherein said second electrode is located on the other one of said first and second elements.
Claim 11
Dependent Claim
59 words
The electrosurgical device of claim 9, wherein: said first and second elements each comprises an interfacing surface for engaging tissue to be electrosurgically treated, said first and second electrodes each comprises one or more electrode elements located on said interfacing surfaces; and said first and second electrode elements are offset from one another with respect to said interfacing surfaces.
References Cited (Backward Citations)
No citation records indexed.
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