Simulation of Empirical Correlations Between Temperatures and Blood Perfusion During Heating Using a Temperature-Dependent Blood Perfusion Model

This study applies a recently developed temperature-dependent blood perfusion model (TDBPM) coupled with a modified, one-dimensional Pennes bioheat transfer equation to predict the blood perfusion and temperature responses to step function microwave heating applied in the in vivo experiments performed by Sekins’ et al. [1] on human thigh muscle. The TDBPM model links the perfusion increase to the tissue temperature elevation based on physiological mechanisms underlying this temperature-blood-perfusion change phenomenon, i.e., a pharmacokinetic compartmental model. This physiology-based model avoids using ad hoc time delays between blood perfusion increases and tissue temperature elevations as done in previous efforts. It also includes a mechanism that produces the threshold temperature for blood flow increases that has been observed in vivo. In our recent study [2], the TDBPM model was used to simulate both the constant temperature water bath heating used in the in vivo experiments on rat leg muscle performed by Song et al. [3], and the step function microwave heating applied in the in vivo experiments on canine thigh muscle performed by Roemer et al. [4]. The blood perfusion rates predicted by the model are compared with those in vivo experimental data obtained in rat muscle and human muscle and good agreement was obtained. The TDBPM provides a possible explanation to the biochemical and biophysical origins of the relationships between temperature and blood flow that observed in rat muscle and human muscle. The physiology-based TDBPM is a simple, generic model of muscle blood flow responses of different animals to different heating conditions, which provides the type of fundamental information needed for the design of methods to thermally control blood flow in medical applications.