Investigation of thermo-mechanical coupled behavior within irradiated biological tissues with temperature-dependent properties

Abstract

The thermo-mechanical coupled behavior of biological tissues excited by a transient heating has been studied in this paper, in which the temperature-dependent physical properties are considered. A non-linear bio-thermo-mechanical coupled model with variable physical parameters has been proposed firstly in the context of the generalized theory with the dual-phase relaxation mechanism. An effective procedure constructed on an explicit finite difference scheme is then implemented to solve this non-linear model numerically. On this basis the thermo-mechanical coupled response and relative thermal damage within a skin tissue irradiated by a pulse laser has been explored. The temporal and spatial distributions of each physical field resulting from various cases have been obtained and illustrated. The results stated that the thermo-mechanical interaction induced by a laser heating would be inhibited by temperature-dependent physical parameters and this inhibition is more significant on the tissue displacement and normal stresses than tissue temperature. The thermal damage is also inhibited when the temperature dependence is considered and the time that healthy tissues can be tolerated would be a larger extension for its accumulative effect with tissue temperature.