Estimation of blood perfusion using phase shift in temperature response tosinusoidal heating at the skin surface

A closed form analytical solution of the Pennes' bioheat equation was obtai ned for temperature distributions in the skin tissue subject to the sinusoi dal heat flux. Phase shifts in the surface temperature response were reveal ed to be related to local blood perfusion rate and heating frequency. The i nfluence of the thermal contact resistance on the perfusion estimation was investigated. It has been proved that this influence is relatively small be cause of the phase shift based estimation and can be effectively eliminated by application of highly conductive grease. This analysis provides the the oretical foundation for a new noninvasive modality of blood perfusion estim ation based on the surface temperature measurement which can have significa nt applications in future clinical practices.