Affiliations: [a] School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai, China | [b] Center for Biomedical Engineering, School of Information Science and Technology, Fudan University, Shanghai, China | [c] National Heart and Lung Institute, Imperial College London, London, United Kingdom of Great Britain and Northern Ireland | [d] School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai, China
Correspondence:
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Corresponding author: Yu Zhou, PhD, Shanghai Institute for Minimally Invasive Therapy, University of Shanghai for Science and Technology, 516 Jungong Road, 200082, Shanghai, China. E-mail: zhouyu_working@163.com
Abstract: BACKGROUND:The clinical outcomes of bipolar radiofrequency (RF) lipolysis, a prevalent non-invasive fat reduction procedure, hinge on the delicate balance between effective lipolysis and patient safety, with skin overheating and subsequent tissue damage as primary concerns. OBJECTIVE:This study aimed to investigate a novel bipolar radiofrequency lipolysis technique, safeguarding the skin through an innovative PID temperature control algorithm. METHODS:Utilizing COMSOL Multiphysics simulation software, a two-dimensional fat and skin tissue model was established, simulating various PID temperature control schemes. The crux of the simulation involved a comparative analysis of different PID temperatures at 45 °C, 50 °C, and 55 °C and constant power strategies, assessing their implications on skin temperature. Concurrently, a custom bipolar radiofrequency lipolysis device was developed, with ex vivo experiments conducted using porcine tissue for empirical validation. RESULTS:The findings indicated that with PID settings of Kp = 7, Ki = 2, and Kd = 0, and skin temperature control at 45 °C or 50 °C, the innovative PID-based epidermal temperature control strategy successfully maintained the epidermal temperature within a safe range. This maintenance was achieved without compromising the effectiveness of RF lipolysis, significantly reducing the risk of thermal damage to the skin layers. CONCLUSION:Our research confirms the substantial practical utility of this advanced PID-based bipolar RF lipolysis technique in clinical aesthetic procedures, enhancing patient safety during adipose tissue ablation therapies.
Keywords: Bipolar radiofrequency lipolysis, PID temperature control algorithm, simulation calculations, skin overheating, thermal damage
