Numerical study of thermal ablation of atherosclerosis plaque based on PID controller

Based on thermal injury to biological tissues, this paper proposes a temperature-adaptive control strategy for heating atherosclerotic plaques in the blood flow field under focused ultrasound (FU). The temperatures in the spatial distribution of the blood vessel walls and their changes over time were obtained by solving a thermal-fluid-solid coupling model using the finite element method. The temperatures in the entire vascular region were automatically tracked using a local search procedure. The maximum temperature of the region is controlled below 42 °C by using a proportional-integral-derivative (PID) controller, which can achieve the stability control on a specified power output of FU transducer. The results showed that, compared to the traditional PID control, the PID control optimized by noise mean method had better tracking control in noisy environments. The model can realize rapid and accurate control according to the target function, and may provide a technique for FU hyperthermia in the treatment of atherosclerosis.