Theoretical investigation on the thermo-mechanical responses of the human skin during thermal therapy

Laser ablation is an efficient technique of thermal treatment for tumor, during which process, temperature of the tumor tissue will be elevated by the laser beam. Irreversible burn and thermal deformation appear in the tissue, which can induce the protein denaturation and cell membrane looseness to kill the cancer cells. In order to investigate the thermo-mechanical responses of the skin during therapy process, a mechanical model consisting of an elastic plate resting on viscoelastic foundation was proposed to describe the irradiated skin tissue which is subjected to a moving laser beam. The DPL bio-heat conduction model, Kirchhoff hypothesis and the Kelvin-Voigt model were employed in the present study. The governing equations were analytically solved with the usage of Green's function method and the closed-form solutions for the temperature, deformation and stress distribution in the tissue were obtained. A numerical example was given to illustrate the analytical solutions and representative results were shown in figures to make it more intuitive. The influences of laser moving speed and the phase lags of heat flux vector and temperature gradient were discussed in detail.