Estimation of Temperature Distribution in Biological Tissue by Using Solutions of Bioheat Transfer Equation

Abstract

A living body has a system to maintain its own temperature. We have investigated the heat transfer characteristic common to each organ and therapy. One-dimensional bioheat transfer equation with bioheat generation was transformed to dimensionless form and solved by Laplace transformation on the assumption that biological tissue is homogeneous. Dimensionless steady state solution and transient solution were derived analytically. These solutions can be represented temperature distribution of organ. It is confirmed that these solutions can be applied to estimate temperature distribution of inhomogeneous biological tissue by comparison with numerical solution. It is proved that the size of region where temperature change occurs, steady state thermal penetration depth, is decided by biological properties. Furthermore reaching time to steady state, or the time that biological tissue becomes steady state, is calculated by using these solutions. Additionally temperature chart was proposed for each organs or tissue. This temperature chart can be guideline for medical doctors in the thermal therapy.