Patent ID: 8348940

Claim:
A tissue ablation instrument, comprising: a probe shaft having a distal end and a proximal end; a handle coupled to a proximal end of the probe shaft; a first circumferentially spaced array of tissue penetrating electrodes mounted on the shaft and configured to be selectively deployed from a retracted configuration, in which the first array of electrodes are disposed within the shaft, to a deployed configuration, in which the first array of electrodes extend radially from the probe shaft to form an everting array of electrodes spaced circumferentially about a first location on the probe shaft; and a second circumferentially spaced array of tissue penetrating electrodes mounted on the shaft and configured to be selectively deployed from a retracted configuration, in which the second array of electrodes are disposed within the shaft, to a deployed configuration, in which the second array of wire electrodes extend radially from the probe shaft to form an everting array of electrodes spaced circumferentially about a second location on the probe shaft spaced-apart proximally from the first location; and an electrode deployment assembly housed in the handle and coupled to the respective probe shaft and first and second electrode arrays, wherein the electrode deployment assembly is configured to simultaneously deploy the respective first and second electrode arrays from their retracted configurations to their deployed configurations, wherein, in their respective deployed configurations, the first and second electrode arrays define a volumetric tissue ablation zone.