MRF-based Multi-functional Inverter for Safer Electrosurgery

This thesis proposes, design, and simulate a new high frequency inverter topology that can deliver high-frequency sinusoidal outputs required by electrosurgery. After that, the hardware prototype of the proposed high-frequency inverter is designed, fabricated, and tested with the utilization of gallium nitride. The closed-loop control is implemented on the developed hardware prototype for output voltage and power regulations. The control performance is examined with both resistive load and biotissue load. The cutting effect of achieved cutting mode is verified through both ex-vivo and in-vivo trials. This thesis also investigates real-time power adaptation strategies that are on the basis of different sensing/feedback approaches, such that collateral tissue damage during electrocuting is reduced. Besides the cutting mode, pulsating coagulation mode with closed-loop control for power regulation is delivered and tested with resistive load, resistive plus capacitive load, and ex-vivo biotissue load with the presence of electrical arcing. The safety of pulsating coagulation mode is enhanced with reduced output voltage stress and shrunk terminal leakage current through proposed nonfixed duty cycle strategy. The coagulation effects are further verified by in-vivo trials to explore the possibility of concurrent cutting and coagulation effects.