Patent ID: 7776035

Claim:
An electrode system for use with a high frequency generator to induce coherent high frequency heat ablation volumes within targeted tissue of a patient, which comprises: at least three electrodes, each including: a substantially rigid elongated shaft terminating in a sealed distal end section having an exposed conductive tip portion configured to be inserted into the targeted tissue and adapted at a proximal end section to be coupled to a high frequency generator to simultaneously apply an equal output voltage to each of the exposed conductive tip portions; a closed-loop fluid communication channel pathway which includes an inflow opening adapted for connection to a coolant fluid supply, and a channel portion in fluid communication with the inflow opening, which extends distally inside the conductive tip portion to carry coolant to the inside of the conductive tip portion and further extends proximally back to an outlet opening adapted to carry coolant away from the conductive tip portion; wherein the conductive tip portions of the at least three electrodes are arrayed relative to each other in a predetermined non-linear geometric spatial relationship relative to a longitudinal axis of an instrument such that upon application of an output voltage to the conductive tip portions, a coherent ablation isotherm is generated which encloses a desired target volume of the tissue to induce a large heat ablation volume; a distal introducer and a proximal introducer, wherein the distal introducer and the proximal introducer each include a central hole formed therein for selectively receiving a guide needle therethrough, wherein the central holes function to align the distal and proximal introducers with one another, wherein the proximal introducer is movable relative to the distal introducer and is configured to maintain the electrodes therein during movement to insert the electrodes into the tissue, the distal and proximal introducers each include a plurality of arrays of holes formed therein, each array of holes arranged in a linear row, wherein the rows of holes are equally spaced from one another; and a guide needle disposed in the central hole of at least one of the proximal introducer and the distal introducer.