System and method for tissue ablation

Abstract

A tissue ablation device comprises first and second electrodes of opposite polarities, the first electrode being mounted to a first elongated member for movement relative to the second electrode for separation therefrom by a desired distance. A method of ablating a tissue comprises inserting first and second electrodes to desired initial positions relative to a tissue mass to be ablated and applying electrical energy to the first and second electrodes to ablate a first portion of tissue between the first and second electrodes in combination with the step of applying electrical energy to desired second positions separated from the desired initial positions by a distance selected to transfer electrical energy around the first portion of tissue through a second portion of tissue to be ablated, the second portion of tissue surrounding the first portion of tissue.

1 - 21 . (canceled) 
     
     
         22 . A tissue ablation device comprising:
 a first shaft terminating at a first electrode at a distal end thereof;   a second shaft terminating at a second electrode at a distal end thereof, the first shaft and second shaft being slidable relative to each other;   a RF energy source having first and second poles, wherein a first pole is coupled to the first electrode and the second pole is coupled to the second electrode.   
     
     
         23 . The tissue ablation device of  claim 22 , further comprising a control portion configured to manually slide one of the first shaft and second shaft relative to the other. 
     
     
         24 . The tissue ablation device of  claim 22 , further comprising an actuator configured to slide one of the first shaft and second shaft relative to the other. 
     
     
         25 . The tissue ablation device of  claim 24 , wherein the actuator comprises a piezoelectric actuator. 
     
     
         26 . The tissue ablation device of  claim 24 , wherein the actuator comprises a pneumatic actuator. 
     
     
         27 . The tissue ablation device of  claim 24 , wherein the actuator comprises a hydraulic actuator. 
     
     
         28 . The tissue ablation device of  claim 22 , wherein the first shaft and the second shaft are co-linear. 
     
     
         29 . The tissue ablation device of  claim 22 , wherein the first shaft and the second shaft are coaxial. 
     
     
         30 . The tissue ablation device of  claim 29 , wherein the first shaft and the second shaft are rotationally coupled to one another. 
     
     
         31 . The tissue ablation device of  claim 22 , wherein the first electrode comprises an array of electrode tines. 
     
     
         32 . The tissue ablation device of  claim 22 , wherein the second electrode comprises an array of electrode tines. 
     
     
         33 . The tissue ablation device of  claim 22 , further comprising one or more impedance sensors disposed in at least one of the first shaft and the second shaft. 
     
     
         34 . The tissue ablation device of  claim 22 , further comprising an external impedance sensor. 
     
     
         35 . A tissue ablation device comprising first and second electrodes of opposite polarities, the first electrode being mounted to a first elongated member and the second electrode being mounted to a second elongated member, the first and second elongated members being slidable with respect to one another, wherein the first electrode comprises a first array of tines and the second electrode comprises a second array of tines, wherein each respective array of tines, when in a deployed configuration, extend distally from proximal ends coupled to the respective one of the first and second elongated members, curving radially outward therefrom to distal ends, the distal ends of the tines of the first and second arrays being located along first and second circles, with a diameter of the first circle being substantially equal to that of the second circle. 
     
     
         36 . The tissue ablation device of  claim 35 , further comprising a control portion configured to manually slide one of the first elongated member and second elongated member relative to the other. 
     
     
         37 . The tissue ablation device of  claim 35 , further comprising an actuator configured to slide one of the first elongated member and second elongated member relative to the other. 
     
     
         38 . The tissue ablation device of  claim 37 , wherein the actuator comprises a piezoelectric actuator. 
     
     
         39 . The tissue ablation device of  claim 37 , wherein the actuator comprises a pneumatic actuator. 
     
     
         40 . The tissue ablation device of  claim 37 , wherein the actuator comprises a hydraulic actuator. 
     
     
         41 . The tissue ablation device of  claim 35 , wherein the first elongated member and the second elongated member are co-linear. 
     
     
         42 . The tissue ablation device of  claim 35 , wherein the first elongated member and the second elongated member are coaxial. 
     
     
         43 . The tissue ablation device of  claim 42 , wherein the first shaft and the second shaft are rotationally coupled to one another.