#$%^&*AU2014203423B220181108.pdf#####ABSTRACT The electrosurgical systems and methods according to the present disclosure use a multistage power converter for generating electrosurgical energy. The electrosurgical systems include an electrosurgical generator (102) having a power converter (701) coupled to an electrical energy source (610) and configured to generate electrosurgical energy. The power converter (701) includes a boost converter (705) configured to convert a first direct current from the electrical energy source to a second direct current, and a phase-shifted pulse width modulation (PS-PWM) resonant inverter (707) configured to invert the second direct current to an alternating current. The electrosurgical generator (102) also includes a plurality of sensors (235, 240) configured to sense a voltage and a current of the generated electrosurgical energy and a controller (715) coupled to the power converter (701) and the plurality of sensors (235, 240). The controller (715) includes a signal processor configured to determine tissue impedance based on the sensed voltage and current, and an output controller configured to select one of a plurality of output characteristics based on the determined tissue impedance, and to generate control signals to control the boost converter (705) and the PS-PWM resonant inverter (77), according to the selected output characteristic.1/10 1I02 12 0 FIG. 1
