Patent ID: 8486065

Claim:
A method of non-microwave ablation of a tumor having a volume, the method reducing electrical shielding caused by simultaneous activation of electrodes and comprising the steps of: (a) separately placing at least two physically independent electrodes at edges of the tumor; (b) connecting a source of radiofrequency power having a frequency to a first electrode to provide resistive heating of tissue at the first electrode; (c) after a first time, disconnecting the source of radiofrequency power from the first electrode to define a first duty cycle at the first electrode; (d) after step (c) connecting the source of radiofrequency power to a second electrode to provide resistive heating of tissue at the second electrode; (e) after a second time, disconnecting the source of radiofrequency power from the second electrode to define a second duty cycle at the second electrode; (f) repeating steps (b) through (e) while varying the first and second duty cycles to deliver different levels of power to the first and second electrodes dependent on a sensed condition of the tissue while also energizing the first and second electrodes at different, substantially non-overlapping times independent of the sensed condition.