Research on the relationship between temperature field and thermal damage in a multidimensional heat transfer model of multi-layered skin tissue

Laser therapy is widely used in clinical applications such as dermatological treatments and local tumor ablation due to its non-invasiveness, controllable energy deposition, and strong spatial selectivity. Although theoretical models based on bioheat transfer and the Arrhenius damage criterion are well-established, several key issues remain unclear in quantitative prediction and model simplification. These include the relative contributions of temperature-dependent thermophysical parameters, the impact of lateral heat diffusion on damage extent, and the coupling mechanism between temperature dependence and model dimensionality (1D/2D). To address the aforementioned issues, a controlled computing framework is established in which dimensional (1D/2D) configurations and temperature-dependent treatments of thermophysical parameters with three-layered skin tissue as the research object. This framework is employed for systematic analysis of the spatiotemporal evolution of temperature fields and Arrhenius thermal damage, with the two-dimensional lateral damage width used to characterize the damage range. The research results indicate that temperature dependence of thermal conductivity is the dominant factor affecting the accuracy of thermal damage prediction in both 1D and 2D models. Neglecting thermal conductivity can lead to overestimation of lateral damage width by up to 0.2 mm and an advance of critical damage time by approximately 0.1 s in two-dimensional simulations. Besides, lateral heat diffusion in 2D calculations significantly amplifies errors in damage extent and critical time which stem from the assumption of constant thermal conductivity, and which further reveal the coupling between temperature dependence and dimensionality effects. This paper provides a theoretical foundation for parameter sensitivity analysis and uncertainty control in laser therapy damage prediction.