Refining thermal therapy: Temperature distribution modeling with distinct absorption in multi-layered skin tissue during infrared laser exposure

Laser therapies embody cutting-edge advances in non-invasive medical techniques. This study concentrates on enhancing precision thermal therapy via a modeling approach for the investigation of the intricate interplay between laser radiation and the complex layers of human skin. Our method involves a representation the skin as three layers—epidermis, dermis, and subcutaneous tissue—and strategically changing a range of wavelengths. We explore the subtle workings of absorption and extinction coefficients, with a specific focus on unraveling the scattering dynamics between these layers. The purpose of this research is to advance the development of thermal therapies, facilitating precise targeting of tissue depths. To simulate heat distribution in multilayered skin tissue, we use a stepwise Heaviside Function to outline thermal and optical properties. We also incorporate a three-phase lag model to capture the finite speed of heat conduction, delayed response, and heterogeneous characteristics of skin tissue. The solution to the governing equation, obtained via numerical simulation, indicates the possibility of selecting optimal laser wavelengths and characteristics. Based on the results, most types of lasers with different wavelengths are absorbed in the first layer and then in the second layer. There are a few lasers that can pass through the first and second layers of the skin and cause a significant temperature increase in the third layer because some of the components of the skin layers are common.This approach enables us to attain desired temperatures at precise depths within the tissue, advancing our comprehension of customized thermal interventions in medical procedures involving laser technology.