A coupled continuum-discrete bioheat transfer model for vascularized tissue

For a living tissue embedded with multiscale and heterogeneous vascular network, the thermal transport process is considerable complicated so that it is hard to establish a credible and feasible bioheat transfer model for many biomedical applications. This paper is aimed at establishing a novel bioheat transfer model to characterize the heat transfer process in the vascularized tissue. The coupled continuum-discrete model denoted by CCD was proposed in this work. CCD model consists of 3D temperature equation for solid tissue and 1D equation for blood vessel, which are coupled through the discrete heat-source terms. The blood vessels are classified as visible vessel with detailed geometry information obtained from medical image or vascular tree generation method, and invisible capillary without configuration information. The discrete terms for different vascular sizes were separately established to represent the multiscale conjugated blood-tissue thermal interaction. The comparison of CCD model and the existing bioheat models was discussed in detailed. An efficient numerical scheme for CCD model was also developed and demonstrated to accurately predict temperature field of the vascularized tissue, which is furthermore applied to investigate the heat transfer in a realistic vascularized liver.