Abstract: An electrosurgical system includes an RF output stage configured to impart RF power between first and second electrodes; measurement circuitry measures current and voltage imparted between the first and second electrodes; a processing circuit calculates power and impedance, based upon the measured current and the measured voltage; the processing circuitry uses a proportional-integral-derivative control loop to control RF power imparted between the electrodes, based upon a selected one of the measured current, the measured voltage, calculated power, and the calculated impedance.

Abstract: A method is provided to seal and cut biological tissue. An alternating current (AC) scaling signal is imparted between a set of sealing electrodes. An AC cutting signal is imparted between a set of cutting electrodes in response to a biological tissue impedance between the sealing electrodes reaching a first impedance threshold value. The AC scaling signal is halted at an end of a time interval, beginning while the AC cutting signal is imparted between the cutting electrodes, in response to impedance of the biological tissue disposed between the set of sealing electrodes reaching a second impedance threshold value.