Numeric Analysis of Temperature Distribution in Man using a 3D Human Model

Abstract

Premortem three-dimensional body temperature is the basis on which post-mortem cooling commences. Thermo-numeric analysis of post-mortem cooling for death-time calculation applies pre-mortem three-dimensional body temperature as initial conditions; therefore, an accurate determination of this distribution is important. To date, such prediction is not performed. This paper presents a thermo-numeric analysis method of predicting premortem three-dimensional body temperature in man, to be applied in thermo-numeric analysis of the post-mortem interval using the finite-difference time-domain method. The method applied a Pennes BioHeat Equation modified to linearize organ metabolic and blood flow rates with temperature in a transient thermo-numeric analysis scheme to predict naked three-dimensional temperatures of an MRI-built, 3D human model having 247 segmented organs and 58 categories of material properties under chosen boundary conditions. Organ metabolic heat and blood perfusion rates appropriate for a chosen pre-mortem physical activity, and known organ physical and thermal properties, were assigned to each organ. A steady-state temperature equilibration occurred after 8400 seconds. Predicted organ temperatures were topographically inhomogeneous. Skin temperatures varied between 20.5{degrees}C and 42.5{degrees}C, liver capsule temperatures were lower than parenchymal, and rectal luminal temperature were uniform.