Electrosurgical instrument
First Claim
1. An electrosurgical instrument for the treatment of tissue in the presence of an electrically-conductive fluid, the instrument comprising an instrument shaft and an electrode assembly at one end of the shaft, the electrode assembly comprising:
- a tissue treatment electrode,a return electrode, andan insulation member which electrically insulates the return electrode from the tissue treatment electrode,the tissue treatment electrode being exposed at the extreme distal end of the instrument, andthe return electrode having a fluid contact surface axially spaced from the exposed end of the tissue treatment electrode by the insulation member so that, in use, the return electrode does not contact the tissue to be treated,wherein the instrument further comprises, a feeder for feeding cool electrically-conductive fluid to the region of the exposed end of the tissue treatment electrode in such a manner as to define, in use, a conductive fluid path that completes an electrical circuit between the tissue treatment electrode and the return electrode, andan extractor for removing heated electrically-conductive fluid from the region of the exposed end of the tissue treatment electrode.
1 Assignment
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Accused Products
Abstract
An electrosurgical instrument, which is used to treat tissue in the presence of an electrically-conductive fluid, comprises an instrument shaft and an electrode assembly at one end of the shaft. The electrode assembly comprises a tissue treatment electrode and a return electrode which is electrically insulated from the tissue treatment electrode by means of an insulation member. The tissue treatment electrode is exposed at the extreme distal end of the instrument, and the return electrode has a fluid contact surface spaced from the exposed end of the tissue treatment electrode by the insulation member. The instrument further comprises feed means for feeding electrically-conductive fluid to the region of the exposed end of the tissue treatment electrode in such a manner as to define, in use, a conductive fluid path that completes an electrical circuit between the tissue treatment and the return electrode.
2117 Citations
37 Claims
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1. An electrosurgical instrument for the treatment of tissue in the presence of an electrically-conductive fluid, the instrument comprising an instrument shaft and an electrode assembly at one end of the shaft, the electrode assembly comprising:
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a tissue treatment electrode, a return electrode, and an insulation member which electrically insulates the return electrode from the tissue treatment electrode, the tissue treatment electrode being exposed at the extreme distal end of the instrument, and the return electrode having a fluid contact surface axially spaced from the exposed end of the tissue treatment electrode by the insulation member so that, in use, the return electrode does not contact the tissue to be treated, wherein the instrument further comprises, a feeder for feeding cool electrically-conductive fluid to the region of the exposed end of the tissue treatment electrode in such a manner as to define, in use, a conductive fluid path that completes an electrical circuit between the tissue treatment electrode and the return electrode, and an extractor for removing heated electrically-conductive fluid from the region of the exposed end of the tissue treatment electrode. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. Electrosurgical apparatus comprising a radio frequency generator and an electrosurgical instrument for the treatment of tissue in the presence of an electrically conductive fluid medium, wherein the electrosurgical instrument comprises an instrument shaft and an electrode assembly at one end of the shaft, the electrode assembly comprising:
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a tissue treatment electrode, a return electrode, and an insulation member which electrically insulates the return electrode from the tissue treatment electrode, the tissue treatment electrode being exposed at the extreme distal end of the instrument, and the return electrode having a fluid contact surface axially spaced from the exposed end of the tissue treatment electrode by the insulation member so that, in use, the return electrode does not contact the tissue to be treated, wherein the instrument further comprises feed means for feeding cool electrically-conductive fluid to the region of the exposed end of the tissue treatment electrode in such a manner as to define, in use, a conductive fluid path that completes an electrical circuit between the tissue treatment electrode and the return electrode, and an extractor for removing heated electrically-conductive fluid from the region of the exposed end of the tissue treatment electrode. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20)
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21. An electrosurgical instrument for the treatment of tissue in the presence of an electrically-conductive fluid, the instrument comprising an instrument shaft and an electrode assembly at one end of the shaft, the electrode assembly comprising
a tissue treatment electrode, a return electrode, and an insulation member which electrically insulates the return electrode from the tissue treatment electrode, the tissue treatment electrode being exposed at the extreme distal end of the instrument, and the return electrode having a fluid contact surface spaced from the exposed end of the tissue treatment electrode by the insulation member, wherein the instrument further comprises, a feeder for feeding cool electrically-conductive fluid to the region of the exposed end of the tissue treatment electrode in such a manner as to define, in use, a conductive fluid path that completes an electrical circuit between the tissue treatment electrode and the return electrode, and an extractor for removing heated electrically-conductive fluid from the region of the exposed end of the tissue treatment electrode, and wherein the return electrode is a tubular member which is coated with an insulating sheath, the coated return electrode constituting the instrument shaft, and further comprising a second return electrode, the second return electrode being constituted by a second tubular member positioned concentrically within the first-mentioned tubular member.
- 24. An electrosurgical instrument for the treatment of tissue in the presence of an electrically-conductive fluid, the instrument comprising an instrument shaft and an electrode assembly at one end of the shaft, the electrode assembly comprising a tissue treatment electrode and a return electrode which is electrically insulated from the tissue treatment electrode by means of an insulation member, the tissue treatment electrode being exposed at the extreme distal end of the instrument, and the return electrode having a fluid contact surface spaced from the exposed end of the tissue treatment electrode by the insulation member, wherein the instrument further comprises, a feeder for feeding cool electrically-conductive fluid to the region of the exposed end of the tissue treatment electrode in such a manner as to define, in use, a conductive fluid path that completes an electrical circuit between the tissue treatment electrode, and the return electrode, and an extractor for removing heated electrically-conductive fluid from the region of the exposed end of the tissue treatment electrode, and wherein the feeder is such that the maximum flow rate of electrically-conductive fluid is 0.32 cc/s per 100 watts of electric power applied to the electrode assembly.
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35. Electrosurgical apparatus comprising a radio frequency generator and an electrosurgical instrument for the treatment of tissue in the presence of an electrically conductive fluid medium, wherein the electrosurgical instrument comprises an instrument shaft and an electrode assembly at one end of the shaft, the electrode assembly comprising a tissue treatment electrode and a return electrode which is electrically insulated from the tissue treatment electrode by means of an insulation member, the tissue treatment electrode being exposed at the extreme distal end of the instrument, and the return electrode having a fluid contact surface spaced from the exposed end of the tissue treatment electrode by the insulation member, wherein the instrument further comprises feed means for feeding cool electrically-conductive fluid to the region of the exposed end of the tissue treatment electrode in such a manner as to define, in use, a conductive fluid path that completes an electrical circuit between the tissue treatment electrode and the return electrode, and an extractor for removing heated electrically-conductive fluid from the region of the exposed end of the tissue treatment electrode, and wherein the extractor comprises a fluid return channel and has sufficient power to remove electrically-conductive fluid from said region at a rate faster than that at which the feeder feeds electrically-conductive fluid thereto, thereby ensuring that heated electrically-conductive fluid can escape from said region only via the fluid return channel, and that smoke and other by-products of tissue vaporization are removed from said region via the fluid return channel.
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36. Electrosurgical apparatus comprising a radio frequency generator and an electrosurgical instrument for the treatment of tissue in the presence of an electrically conductive fluid medium, wherein the electrosurgical instrument comprises an instrument shaft and an electrode assembly at one end of the shaft, the electrode assembly comprising a tissue treatment electrode and a return electrode which is electrically insulated from the tissue treatment electrode by means of an insulation member, the tissue treatment electrode being exposed at the extreme distal end of the instrument, and the return electrode having a fluid contact surface spaced from the exposed end of the tissue treatment electrode by the insulation member, wherein the instrument further comprises feed means for feeding cool electrically-conductive fluid to the region of the exposed end of the tissue treatment electrode in such a manner as to define, in use, a conductive fluid path that completes an electrical circuit between the tissue treatment electrode and the return electrode, and an extractor for removing heated electrically-conductive fluid from the region of the exposed end of the tissue treatment electrode, wherein the feed means comprises a fluid feed channel segmented by a plurality of wings which ensure adherence of the fed cool electrically-conductive fluid to the tissue treatment electrode so as to encourage capillary flow of said fluid along said tissue treatment electrode, thereby ensuring that, even when the electrode assembly is powered so as to vaporize electrically-conductive fluid in the region of the exposed end of the tissue treatment electrode, the tissue treatment electrode is intermittently wetted, thereby ensuring that there is a continual source of vapor and a reduction in the power demand.
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37. Electrosurgical apparatus comprising a radio frequency generator and an electrosurgical instrument for the treatment of tissue in the presence of an electrically conductive fluid medium, wherein the electrosurgical instrument comprises an instrument shaft and an electrode assembly at one end of the shaft, the electrode assembly comprising a tissue treatment electrode and a return electrode which is electrically insulated from the tissue treatment electrode by means of an insulation member, the tissue treatment electrode being exposed at the extreme distal end of the instrument, and the return electrode having a fluid contact surface spaced from the exposed end of the tissue treatment electrode by the insulation member, wherein the instrument further comprises feed means for feeding cool electrically-conductive fluid to the region of the exposed end of the tissue treatment electrode in such a manner as to define, in use, a conductive fluid path that completes an electrical circuit between the tissue treatment electrode and the return electrode, and an extractor for removing heated electrically-conductive fluid from the region of the exposed end of the tissue treatment electrode, and wherein the feeding means is such that the maximum flow rate of electrically-conductive fluid is 0.32 cc/s per 100 watts of electric power applied to the electrode assembly.
Specification