热疗中血液灌注率对皮肤组织温度的影响

Effect of Blood Perfusion Rate on Skin Tissue Temperature During Heating

热刺激可促使皮肤局部血管扩张、促进血液循环,增大血流量.为了确定生物组织血管舒张行为规律,建立了鼠背部皮窗加热实验台,获得了加热过程中的血流速率.同时,通过采用数字图像相关技术,获得了加热过程中,血管直径的变化规律.并计算了不同加热条件下对应的血液灌注率.采用Pennes方程,计算并分析了不同加热条件下,皮肤组织温度的变化规律。经过与实验测定的鼠背部皮窗温度进行对比验证,证实该模拟方法能够较好地实现热疗过程中皮肤组织温度场的预测.最后分析了血液灌注对组织温度的影响.将采用自适应血液灌注率计算的组织温度与恒定血液灌注率计算的温度进行了对比.从计算温差,热平衡时间的角度对温度预测的准确性进行了分析.

Hyperthermia can stimulate local blood vessel expansion of the skin, promote blood circulation, and increase blood flow. In order to determine the relaxation behavior of blood vessel in the skin tissue, a rat skin window heating test system was established. The blood flow rate during heating was obtained. By using digital image correlation technique, the variation of vessel diameter in heating process was obtained. The blood perfusion rate under different heating conditions was calculated. The Pennes equation was used to calculate and analyze the temperature variation of the skin tissue under different heating conditions. Compared with the skin temperature of the dorsal skin measured by the experiment, it is proved that the simulation method can better predict the temperature field of the skin tissue in the process of hyperthermia. Finally, the influence of blood perfusion on tissue temperature was analyzed. The tissue temperature calculated by different blood perfusion rates and the constant blood perfusion rate were compared.The accuracy of the predicted temperature is analyzed from the point of view of calculating temperature difference and heat balance time.