Thermomechanical response of biological tissues to sudden temperature rise induced by laser beam: Insights from three-phase lag theory

Abstract The laser irradiation of living tissues poses a risk of thermal damage, making it a critical factor in medical procedures such as laser surgery and thermal therapies. Effectively predicting and managing this damage, particularly in hyperthermia therapy, is essential for maximizing treatment efficacy while protecting surrounding healthy tissues. In this context, theoretical and computational models of biological heat transfer, especially the enhanced Pennes bioheat transport equation, have attracted significant research interest. This study contributes to the field by providing a novel analytical solution to the refined Pennes bioheat model, incorporating the three-phase lag (TPL) concept. The research examines heat transfer in a one-dimensional region, where the outer surface is exposed to laser heating while the inner surface remains thermally insulated. It explores the mechanical effects of thermal shock induced by laser treatment, focusing on heat generation patterns across different laser intensities in diseased human skin tissues. To validate the model, numerical inverse and Laplace transform techniques were applied, producing results consistent with existing literature. The findings not only advance the theoretical understanding of bioheat transfer but also enhance the safety and effectiveness of laser-based medical therapies.