沙疗温度及血液灌注对膝关节温度场和应力场的影响

Effects of Sand Therapy Temperature and Blood Perfusion on Temperature and Stress Field of Knee Joint

为探究沙疗过程中沙体温度及血液灌注率对于人体膝关节部位温度场分布以及骨骼热应力的影响,在生物传热学以及经典力学的理论基础上,通过运用将膝关节部位的计算机断层扫描(computed tomography,CT)影像数据导入3D逆向建模软件Mimics建立三维模型,并将模型导入COMSOL软件并进行传热数值模拟的方法来研究了沙疗过程中膝关节温度场以及热应力的变化规律。结果表明:在45℃沙体环境下沙疗30 min,膝关节骨骼的温度和热应力主要集中在髌骨和胫骨上,而在胫骨的长骨部位尤为集中。由骨骼热应力变化曲线可以知道骨骼平均热应力在沙疗20 min时达到顶峰,在20~30 min出现下降趋势,然后在30 min以后随着时间增加开始逐渐减退。可见合适的沙疗时间在20 min左右为最佳,但不超过30 min为宜。在整个沙疗过程中,血液灌注率对于人体的温度场以及应力场起着至关重要的调节作用。

The research aimed to explore the influence of sand temperature and blood perfusion rate on the temperature field distribution and bone thermal stress of human knee joint during sand therapy.Based on the theory of biological heat transfer and classical mechanics,the variation of temperature field and thermal stress of knee joint during sand therapy was studied.The computed tomography(CT)image data of knee joint was put into 3D reverse modeling software Mimics to establish a 3D model.And the model was imported into Comsol software to conduct numerical simulation of heat transfer.The results show that the temperature and thermal stress of the knee bones are mainly concentrated on the patella and the tibia,especially on the long bone of the tibia under the sand treatment at 45℃ for 30 minutes.According to the curve of bone thermal stress change,the average bone thermal stress reaches its peak at 20 min of sand treatment,with a downward trend within 20~30 min,then gradually decreases after 30 min with the increase of time.It can be seen that the best time for sand therapy is about 20 min,and not more than 30 min.The blood perfusion rate plays an important role in regulating the temperature field and stress field of human body during sand therapy.