Lumped Parameter Bioheat Equation Formulated for System-Level Body Temperature Prediction

System-level prediction of transient human body core temperature is required to improve cooling strategies employed during cardiopulmonary by-pass and intensive care unit protocols. A lumped parameter thermal modeling approach can be used but there are complications due to the presence of metabolic heat generation and blood flow in biosystems. Therefore, a lumped bio-heat transfer formulation is developed for thermal resistance terms to analyze temperature distribution within basic body parts consisting of different tissues. The results are compared with the corresponding analytical solutions and numerical analysis. Legs and arms are represented as cylindrical systems, whereas head is modeled as a spherical system. All models are developed to include blood perfusion, perspiration, convection and radiation on the boundary, and they are all examined both during rest and exercise. Maximum errors determined during rest are 0.9% and 1.2% for the limbs and head, respectively. Consequently, the lumped parameter method is proven to be an accurate and efficient alternative to numerical and analytical models for modeling human thermoregulation system.