Patent ID: 8647340

Claim:
An electrosurgical system, comprising: an electrosurgical generator configured to output radio frequency (RF) energy; an electrosurgical instrument coupled to the electrosurgical generator configured to apply the RF energy to an operative site; and a thermocouple measurement circuit configured to determine a temperature at the operative site, the thermocouple measurement circuit including: a thermocouple input configured to sense the temperature at a measuring point of the electrosurgical instrument; a compensation circuit configured to compensate for thermocouple effects at junctions of the thermocouple; an instrumentation amplifier configured to sum an output of the thermocouple and an output of the compensation circuit and output a voltage indicative of the temperature sensed by the thermocouple measurement circuit, wherein the electrosurgical generator controls the output energy based on the sensed temperature; a first switch coupled between the thermocouple input and the instrumentation amplifier configured to supply a thermocouple test voltage to the instrumentation amplifier during a test mode; and a second switch coupled between the compensation circuit and the instrumentation amplifier configured to supply a compensation test voltage to the instrumentation amplifier during the test mode.