Hybrid finite element/finite difference (FE/FD) model to analyze thermal transients in biological vascularized tissues

Purpose – The aim of the paper is to apply a numerical dosimetry procedure to a biological tissue with an embedded discrete vascularisation in order to evaluate the temperature increase produced by radio-frequency (RF) exposure. Design/methodology/approach – The blood temperature inside thin vessels is analysed by a 1D finite difference procedure to solve the convection-dominated heat problem. The tissue temperature inside the remaining 3D domain governed by the heat diffusion equation is calculated by the finite element method. Then, the two separate numerical methods are coupled by an iterative time domain procedure. Findings – The main advantage of the proposed hybrid method is found to be the considerable reduction of the number of unknowns respect to other traditional numerical techniques. Research limitations/implications – In this paper, only the numerical model of the new hybrid procedure has been proposed. In future work realistic biological regions will be examined and the proposed model will be improved by considering the artery/vein coupled structure. Originality/value – The originality of the proposed method regards the solution of the bio-heat equation by means of a new hybrid finite element/finite difference procedure. This procedure is applied inside a vascularized region considering a discrete blood vessel structure.