An Asymptotic Solution for Thermal Response in Biological Tissue Induced by Pulsed Laser Based on Dual-Phase-Lag Model

This study presents an asymptotic solution for predicting the thermal response in biological tissues subjected to pulsed laser irradiation using the dual-phase-lag bio-heat transfer model. By applying the Laplace transform coupled with the initial-value theorem, a simplified time-domain solution is derived that effectively captures non-Fourier thermal behavior and clearly reveals qualitative relationships between key parameters and the thermal response. Results show that the ratio of phase lag times critically influences the thermal profile, with smaller values of the ratio of phase lag times reducing peak temperature and enhancing heat uniformity. Furthermore, for constant total energy input, higher-power and shorter-pulse laser configurations induce greater peak temperatures and more extensive thermal damage near the tissue surface. These findings provide theoretical insight into laser-tissue interactions and offer practical guidance for optimizing clinical laser procedures toward minimally invasive and energy-efficient treatments.