A basic estimation on the light distribution and thermal behavior of the human skin through transfer matrix method coupled with Pennes’ bio-heat equation

Abstract

This work is concerned with the investigation of the photo-thermal response of the human skin tissue. A four-layer, one-dimensional air–skin tissue structure has been considered. The considered structure is irradiated by the different light intensities and wavelengths. Light propagation in the skin tissue has been modeled by using a full electromagnetic method. To solve electromagnetic equations numerically, Transfer Matrix Method (TMM) has been used. Inhomogeneity of the multilayer skin tissue structure has been considered by the wavelength dependence of the Complex Optical Refractive Index (CORI). In order to determine the temporal and spatial temperature distribution inside the skin tissue, the TMM has been coupled with Pennes’ bio-heat transfer equation. The equation has been solved semi-analytically with the adiabatic condition by using the Green’s function method. Based on the preliminary findings of this study, the effect of the light intensity and wavelength on the resultant temperature distribution inside the skin tissue structure has been reported. Obtained results could be helpful for designing and improving the practical protocols through the skin photo-thermal therapy process.