Patent ID: 9119623
Filing Date: 2015-09-01
Classification: A61B

Abstract:
1. A method for detecting complex impedance using an electrosurgical generator apparatus that controls a variable output signal to a pair of electrodes, the method comprising: providing a reference signal to a reflectometer bridge of an impedance monitoring circuit; superimposing monitor drive signals onto an output signal applied to leads of the electrodes across which a complex impedance to be measured is present, the monitor drive signals being derived from the reference signal; receiving, at the reflectometer bridge, feedback signals from the pair of leads of the electrodes; applying a conditioned form of the feedback signals to each of an in-phase bridge detector and a quadrature bridge detector of the impedance monitoring circuit; outputting, by the in-phase bridge detector, an in-phase bridge signal corresponding to an overall real component of the measured complex impedance, and outputting, by the quadrature bridge detector, a quadrature bridge signal corresponding to an overall imaginary component of the measured complex impedance; receiving, at a controller, the in-phase and quadrature bridge signals, an in-phase reference signal, and a quadrature reference signal; and determining, by the controller and based on the in-phase and quadrature bridge signals and the in-phase and quadrature reference signals, a magnitude and phase angle of the complex impedance.