Design and Implementation of Radiofrequency Ablation System Based on Power Closed-Loop Control

As an emerging device used in surgery, Radiofrequency (RF) ablation is widely used in minimally invasive surgeries. In the process of surgery, the system needs to output constant power to ensure the quality of surgery when the tissue location or ambient temperature and humidity change. The hardware of the RF ablation system was designed in this paper, and the power closed-loop control was realized. The system uses a microcontroller STM32F303VCT6 and the dual ADC alternate sampling method to require the RF output signal. The RF output power is obtained by frequency-domain analysis of the sampled signal using the Discrete Fourier Transform (DFT) algorithm, and the power is controlled using a PID controller so that the actual output power quickly tracks the user-set power. The experimental results of power control show that the controller can adjust the power of the RF ablation system to the set value within 500 ms, without overshoot in the control process and within ±1 W of power fluctuation after stabilization. Meanwhile, the controller can realize power tracking of the ablation system when the load changes.