#$%^&*AU2019232880A120200521.pdf#####ABSTRACT A system includes an indifferent electrode, electrical switching circuitry, and a processor. The indifferent electrode, which is configured for placement on a body of 5 a patient, includes multiple electrically-conducting subelectrodes that are electrically-insulated from one another. The electrical switching circuitry is configured to receive a control signal that specifies a selected subset of the sub-electrodes, and in response to 10 electrically connect the selected subset, so as to close an electrical circuit passing through the body of the patient. The processor is configured to determine a required surface area of the indifferent electrode, select the subset of the sub-electrodes that together have the 15 required surface area, and instruct the electrical switching circuitry to electrically connect the selected subset of the sub-electrodes.50 2/2 40 33 55 RF 302 304 301 RL 306 GENERATOR 307 °55 305 30 00 42 __ 30L r 55 32 FIG. 2 PROCESSOR 36 52,-- DETERMINE OPTIMAL RF IMPEDANCE AT LOCATION OF INDIFFERENT ELECTRODE SELECTAREAOF INDIFFERENT ELECTRODE 56 ADJUSTABLATION PROCEDURE 58 ISSELECTED NO AREASTILLVALID? YES FIG. 3 END
