Marek Jasiński

Numerical modelling of bioheat transfer in multi-layer skin tissue domain subjected to a flash fire

Publisher Summary This chapter reviews the numerical analysis of thermal processes proceeding in the multilayer domain of skin tissue subjected to an external heat source. Heat transfer in the skin tissue was assumed to be transient and2D. The bio-heat transfer in the domain considered is described by the system of the Pennes equations.On the assumed part of skin surface the Neumann condition determining the value of external heat flux is given, on the conventionally assumed internal surfaces of the tissue–the no-flux condition is accepted. For time t= 0 the initial distribution of temperature is known. The main subject of the chapter is the sensitivity analysis of temperature field with respect to the skin tissue parameters. On the stage of numerical computations the boundary element method has been used. The skin has been assumed to be the homogeneous domain characterized .by mean parameters of successive layers

Numerical Modelling of Hyperthermia and Hypothermia Processes

In the paper the results of different numerical solutions of bioheat transfer problems are presented. The base of numerical algorithms constitute the models containing the bioheat transfer equation (or equations) and the adequate geometrical, physical, boundary and initial conditions. In the first part of the paper the solutions concerning the transient temperature field in the biological tissue subjected to the strong external heat sources (freezing, burns) are presented. Next, the examples of sensitivity analysis application in the range of bioheat transfer are discussed. In the final part of the paper the inverse problems are formulated and the example concerning the identification of thermal parameters is shown.

Modeling of Laser-Soft Tissue Interactions Using the Dual-Phase Lag Equation: Sensitivity Analysis with Respect to Selected Tissue Parameters

Thermal processes occurring in soft tissues are subjected to laser irradiation are analyzed. The transient bioheat transfer is described by the generalized dual-phase lag model. This model consists of two coupled equations concerning the tissue and blood temperatures supplemented by the appropriate boundary and initial conditions. The efficiency of the internal heat source connected to the laser irradiation results from the solution of the diffusion equation. This approach is acceptable when the scattering dominates over the absorption for wavelengths between 650 and 1300 nm, and just such a situation occurs in the case of soft tissues. Sensitivity analysis with respect to the parameters occurring in the mathematical model is done using the direct approach (differentiation of the basic equations and the boundary-initial conditions with respect to the parameter considered), especially the absorption coefficient and scattering coefficient of the soft tissue are considered. At the stage of numerical modeling the basic problem and additional problems connected with the sensitivity functions are solved using the finite difference method. In the final part the conclusions and examples of computations are presented.