Radio-Frequency Generator for Powering an Ablation Device

Abstract

An apparatus and method for use in performing ablation of organs and other tissues includes a radio frequency generator which provides a radio frequency signal to ablation electrodes. The power level of the radio frequency signal is determined based on the subject area of ablation. The radio frequency signal is coupled with the ablation electrodes through a transformation circuit. The transformation circuit includes a high impedance transformation circuit and a low impedance transformation circuit. The high or low impedance transformation circuit is selected based on the impedance of the ablation electrodes in contact with the subject tissue. Vacuum level, impedance level, resistance level, and time are measured during ablation. If these parameters exceed determinable limits the ablation procedure is terminated.

1 . A method of ablating tissue, comprising:
 positioning an RF ablation device into contact with target tissue to be ablated;   entering data, corresponding to dimensions of a target area of the tissue, into an input device of an RF generator system operable to output any of a plurality of RF power levels, the RF generator operable to select an appropriate RF power level output to the RF ablation device based on the dimensions of the target area; and   receiving an RF signal at the selected RF power to the RF ablation device for use in ablating the target area of the tissue.   
     
     
         2 . The method of  claim 1 , wherein the RF generator automatically selects an appropriate RF power level in proportion to the length and width of the target area to be ablated. 
     
     
         3 . The method of  claim 1 , wherein the RF generator automatically selects between a low-impedance transformation circuit and a high-impedance transformation circuit. 
     
     
         4 . The method of  claim 1 , further comprising:
 applying vacuum pressure to the RF ablation device.   
     
     
         5 . The method of  claim 4 , further comprising:
 measuring the vacuum pressure applied to the RF ablation device; and   generating a fault if the vacuum pressure falls outside a predetermined range.   
     
     
         6 . The method of  claim 1 , further comprising:
 measuring a duration of ablation; and   terminating ablation if the measured duration exceeds a predetermined limit.   
     
     
         7 . The method of  claim 1 , wherein the positioning step includes positioning the ablation device into contact with a uterus. 
     
     
         8 . The method of  claim 1 , wherein the method further includes using a