Objective To investigate the cooling effect of blood flow on living tissue heating. MethodThe ultrasonic tissue phantom with a U-tube was used to simulate the living tissue with counter-current vessels. The distilled water with constant temperature (37.5 °C) was pumped into the phantom through the U-tube. The phantom was then immersed in another water bath and heated from 37.5 °C to 43.5 °C with a constant heating rate in order to simulate the environment of hyperthermia. Meanwhile, 46 thermocouples were employed to measure the temperatures of liquid flow, tube wall and the phantom. Finally, the experimental results of the temperature distribution were visualized by AVS (Advanced Visual System) software. ResultsWith the increase of flow velocity, the temperature of tissue was reduced, especially in the area surrounded by the U-tube. Moreover, the temperatures in the U tube bounded area reduced more significantly when the Reynolds number varied from 50 to 130. ConclusionsThis perfusion phantom experiment was successful to simulate the influences of the counter-current flow on the characteristics of the heat transfer. It showed that because of the existence of the counter-current vessels, the cooling effect of internal tissue surrounded by U-shaped tube was more evident.