A Small Artery Heat Transfer Model for Self-Heated Thermistor Measurements of Perfusion in the Kidney Cortex

Abstract

A small artery model (SAM) for self-heated thermistor measurements of perfusion in the canine kidney is developed based on the anatomy of the cortex vasculature. In this model interlobular arteries and veins play a dominant role in the heat transfer due to blood flow. Effective thermal conductivity, kss , is calculated from steady state thermistor measurements of heat transfer in the kidney cortex. This small artery and vein model of perfusion correctly indicates the shape of the measured kss versus perfusion curve. It also correctly predicts that the sinusoidal response of the thermistor can be used to measure intrinsic tissue conductivity, km , in perfused tissue. Although this model is specific for the canine kidney cortex, the modeling approach is applicable for a wide variety of biologic tissues.