GaN-Based 4-MHz Full-Bridge Electrosurgical Generator Using Zero-Voltage Switching Over Wide Load Impedance Range

Area of Science:

• Electrical Engineering
• Medical Devices
• Materials Science

Background:

• Electrosurgical generators (ESGs) are crucial in modern surgery.
• High-frequency operation and efficiency are key challenges in ESG design.
• Gallium Nitride (GaN) technology offers potential for improved power electronics.

Purpose of the Study:

• To develop a 4-MHz full-bridge inverter for an ESG using GaN technology.
• To achieve zero-voltage switching (ZVS) over a wide load impedance range.
• To enhance power performance and efficiency for electrosurgery.

Main Methods:

• Implementation of a 4-MHz full-bridge inverter using GaN switches.
• Design of a resonant circuit for impedance matching and current limiting.
• Optimization of gate-driver inductance and thermal management for GaN devices.
• Testing on porcine tissue samples to validate performance.

Main Results:

• Achieved ZVS turn-on over a wide load impedance range.
• Maximum output power of 99 W and maximum overall efficiency of 89%.
• Overcurrent limited to <3 A under short-load conditions.
• Demonstrated constant power output modes (20, 50, 70 W).

Conclusions:

• The proposed GaN-based ESG inverter effectively achieves ZVS and high efficiency.
• The system demonstrates robust performance suitable for electrosurgical applications.
• GaN technology provides a viable path for advanced ESG development.