Patent ID: 9717551
Date: 2017-08-01
CPC Classifications: A61B

Claim:
1. A tissue ablation needle system, comprising: a rigid elongate guide cannula including an open proximal end, an open distal end, and a guide cannula lumen connecting therebetween; an elongate needle cannula that circumferentially defines a needle lumen; an elongate inner probe disposed through the needle lumen and configured to provide a distal needle tip of the needle cannula, where a probe distal end region includes a first electrode; an electroinsulative layer disposed between the needle cannula and the first electrode; and a second electrode disposed proximal of the first electrode, wherein the needle cannula is formed of a continuous conductive material such that a distal end portion of the needle cannula includes the second electrode, where the needle cannula is retractable in the proximal direction relative to the inner probe to expose the probe distal end region at a location distal a needle cannula end, where the needle cannula is longer than the guide cannula such that the needle cannula distal region can be extended through and beyond a distal guide cannula end, released thereby from guide cannula lumen restraint, and where the distal needle tip comprises an outer diameter at least as large as an outer diameter of the needle cannula.