Electrosurgical instrument and method
First Claim
1. A catheter comprising an elongate flexible member configured for endoluminal navigation with a working end having an electrosurgical surface including a material having a positive temperature coefficient of resistance (PTCR), and an electrical source operatively coupled to the electrosurgical surface;
- wherein the working end of the flexible elongate member comprises a tubular member defining an internal lumen;
wherein the tubular member is moveable between a first, non-expanded, configuration in which the tubular member is generally straight and the internal lumen extends along a longitudinal axis of the catheter, and a second, expanded configuration in which the tubular member forms a helix such that the internal lumen does not extend along the longitudinal axis but is instead coiled around it;
wherein the PTCR material of the electrosurgical surface is configured for direct contact with bodily tissue wherein the PTCR material is adapted to transmit electrical energy directly to bodily tissue.
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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.
400 Citations
29 Claims
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1. A catheter comprising an elongate flexible member configured for endoluminal navigation with a working end having an electrosurgical surface including a material having a positive temperature coefficient of resistance (PTCR), and an electrical source operatively coupled to the electrosurgical surface;
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wherein the working end of the flexible elongate member comprises a tubular member defining an internal lumen; wherein the tubular member is moveable between a first, non-expanded, configuration in which the tubular member is generally straight and the internal lumen extends along a longitudinal axis of the catheter, and a second, expanded configuration in which the tubular member forms a helix such that the internal lumen does not extend along the longitudinal axis but is instead coiled around it; wherein the PTCR material of the electrosurgical surface is configured for direct contact with bodily tissue wherein the PTCR material is adapted to transmit electrical energy directly to bodily tissue. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. 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 positive temperature coefficient of resistance (PTCR);
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wherein the working end of the flexible elongate member comprises a tubular member defining an internal lumen; wherein the tubular member is moveable between a first, non-expanded, configuration in which the tubular member is generally straight and the internal lumen extends along a longitudinal axis of the catheter, and a second, expanded configuration in which the tubular member forms a helix such that the internal lumen does not extend along the longitudinal axis but is instead coiled around it; wherein the PTCR material of the electrosurgical surface is configured for direct contact with bodily tissue wherein the PTCR material is adapted to transmit electrical energy directly to bodily tissue. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
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Specification