New thermal wave aspects on burn evaluation of skin subjected to instantaneous heating

Comparative studies on the well-known Pennes' equation and the newly develo ped thermal wave model of bioheat transfer (TWMBT) were performed to invest igate the wave like behaviors of bioheat transfer occurred in thermal injur y of biological bodies. The one-dimensional TWMBT in a finite medium was so lved using separation of variables and the analytical solution showed disti nctive wave behaviors of bioheat transfer in skin subjected to instantaneou s heating. The finite difference method was used to simulate and study prac tical problems involved in burn injuries in which skin was stratified as th ree layers with various thermal physical properties. Deviations between the TWMBT and the traditional Pennes' equation imply that, for high flux heati ng with extremely short duration (i.e., flash fire), the TWMBT which accoun ts for finite thermal wave propagation may provide realistic predictions on burn evaluation. A general heat flux criterion has been established to det ermine when the thermal wave propagation dominates the principal heat trans fer process and the TWMBT can be used for tissue temperature prediction and burn evaluation, A preliminary interpretation on the mechanisms of the wav e like behaviors of heat transfer in living tissues was conducted. The appl ication of thermal wave theory can also be possibly extended to other medic al problems which involve instantaneous heating or cooling.