Tissue ablation apparatus and method

Abstract

A method and apparatus for carrying our thermal ablation of target tissue is disclosed. The apparatus includes an RF ablation device having a multi-electrode electrode assembly designed to be deployed in target tissue, defining a selected-volume tissue region to be ablated, and having infusion channels for infusing a liquid into the target tissue during the ablation process. A control unit in the apparatus is operably connected to an RF energy source, for controlling the RF power level supplied to the electrodes, and to an infusion device, for controlling the rate of infusion of a liquid through the device into the tissue. During both electrode deployment and tissue ablation, impedance and or temperature measurements made within the tissue are used to control the RF source and infusion device, for optimizing the time and extent of tissue ablation.

1 . An apparatus for tissue ablation, comprising:
 an elongated delivery device;   an energy delivery device operably coupled to an energy source, the energy delivery device comprising a plurality of electrodes, each of the electrodes having a tissue piercing distal portion and being positionable in the elongated delivery device, one or more of the electrodes configured to be curved when deployed to a selected tissue site, two or more of the electrodes being configured for liquid infusion to the selected tissue site and each separately comprising an infusion lumen;   an energy control configured to be operably coupled to the energy delivery device for impedance detection within the selected tissue site, and for energy delivery control in response to the detected impedance; and   a fluid control configured to be operably coupled to the at least two infusion electrodes for infusion control in response to the detected impedance.