Patent ID: 6730079
Filing Date: 2004-05-04
Classification: A61B

Abstract:
A method for calculating impedance in a first circuit coupling a first radio frequency electrode to a radio frequency controller where the first radio frequency electrode is disposed in tissue of a mammalian body in the vicinity of a second radio frequency electrode coupled to a second circuit distinct from the first circuit comprising the steps of measuring the impedance of the first circuit to determine an impedance value IMP when radio frequency energy is being supplied to the first and second radio frequency electrodes, measuring the impedance of the first circuit to determine an impedance value IMP0 when radio frequency energy is being supplied to the first radio frequency electrode but not to the second radio frequency electrode, subtracting the impedance value IMP0 from the impedance value IMP to determine an impedance delta value IMP&Dgr;, remeasuring the impedance of the first circuit to determine an impedance value IMP2 when radio frequency energy is being supplied to the first and second radio frequency electrodes and subtracting the impedance delta value IMP&Dgr; from the impedance value IMP2 to arrive at a calculated impedance value for the first circuit.