Electrosurgical instrument and method
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Accused Products
Abstract
An electrosurgical instrument and method for treating varicose veins. In one embodiment, an elongate catheter has a distal working end that carries an electrosurgical energy delivery surface comprising at least one electrode with a positive temperature coefficient of resistance (PTCR) surface and/or an electrode with a pressure sensitive variable resistance to provide a smart surface for controlling Rf current flow at the interface of electrosurgical surface and the tissue. The electrode surface then can limit or modulate Rf energy delivery through the surface in response to the temperature of the surface or the engagement pressure of the surface against the engaged tissue. In operation, the smart electrosurgical surface prevents arcing at the electrode-tissue interface, and thus controls ohmic heating to prevent tissue desiccation, charring and emboli formation.
43 Citations
44 Claims
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1-24. -24. (canceled)
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25. A method for delivering energy to endoluminal tissue, comprising the steps of:
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providing a catheter configured for endoluminal navigation, a catheter working end having an electrosurgical surface including a positive temperature coefficient of resistance (PTCR) material carried in the surface;
engaging endoluminal tissue with the electrosurgical surface; and
delivering Rf current to the endoluminal tissue wherein said Rf current flows are limited by changes in temperature in at least portions of the PTCR material to prevent arcing. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32)
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- 33. A catheter comprising an elongate flexible member configured for endoluminal navigation with a working end having an electrosurgical surface including at least one of a material having a positive temperature coefficient of resistance (PTCR) and a material having a pressure sensitive variable resistance, and an electrical source operatively coupled to the electrosurgical surface.
- 43. A catheter comprising an elongate flexible member configured for endoluminal navigation with a working end having an electrosurgical surface comprising an electrode with a coating of a polymeric material having a pressure sensitive variable resistance.
Specification