Study On The Effect Of Thermal Regulation Of Blood Perfusion And The Law Of Temperature Distribution In Knee Joint During The Process Of Sand Therapy

With the quickening pace of life and the improvement of life quality in today’s society,and long periods of sedentary inactivity and irregular eating patterns have become the norm for most people.Over time,due to long-term living indoors and lack of exercise,their own dampness pathogen increases,bone and bone mass will also decline.Among the numerous medical means,the sand therapy with high comfort level and remarkable curative effect is gradually known by people,and has been greatly promoted and applied.The heat brought by sand therapy has a good effect in promoting human blood circulation,removing dampness pathogen,promoting human metabolism and increasing bone mass,and alleviating fatigue and it is particularly effective for knee arthritis.Exploring the biological heat transfer mechanism of the knee joint during sand therapy can better understand the transfer process and distribution of sand temperature inside the knee joint,and it has an important reference significance for the optimization of the knee joint sand therapy scheme and the improvement of the sand therapy equipment.In this paper,a series of studies were conducted on the temperature distribution of human knee joint during sand therapy and the thermal regulation effect of blood perfusion rate during sand therapy.CT(Computed Tomography)scan data of adult male knee joint were extracted and imported into the three-dimensional reverse modeling software Mimics to establish the three-dimensional model.Then mesh division and model assembly were performed in 3-matic,then the numerical simulation of heat transfer was carried out in the three-dimensional simulation software.Through the simulation results,the temperature field distribution of the biological tissue and bone of the knee joint in the process of sand therapy and the distribution law of bone thermal stress caused by heat transfer were analyzed,there is also the regulation effect of blood perfusion rate on the temperature field of tissue and bone and the thermal stress field of bone in the whole sand therapy process.The results of numerical simulation show that the temperature of the outer biological tissue is higher than that of the deep internal position,and the internal temperature field tends to be relatively stable,and the temperature difference between the inner and outer layers gradually decreases with the increase of sand therapy time.During sand therapy,the high bone temperature area is concentrated in the front of patella,the medial and lateral condyle of femur and tibia,and the long bone area in front of tibia.The thermal response of patella to the change of temperature environment is the largest and the thermal response of femur is the smallest under different sand therapy temperature environment.The higher the temperature of biological tissue and bone,the stronger the role of thermal regulation of blood perfusion rate and the blood perfusion rate plays a very important role in maintaining the stability of the temperature field inside the knee joint.As for bone thermal stress,it reached the maximum value at 20 min after sand therapy,showed a downward trend at 20-30 min,and then began to decline continuously after 30 min.Therefore,the most appropriate sand treatment time should be controlled within 20-30 min.In addition,the blood perfusion rate plays a very important role in maintaining the thermal stress stability of the knee joint during sand therapy.