Study On The Effect Of Medical Compression Stockings On Human Calves Based On Biomechanical Mode

Medical compression stockings,referred to as compression stockings,are designed to be effective in preventing varicose veins and aiding post-operative varicose vein treatment through sequential decompression upward along the ankle.The efficacy of compression stockings on the prevention and treatment of varicose veins in the lower extremities has been generally recognized,but the application and promotion of compression stockings are affected by the imperfect design and production methods as well as the mechanism of action of compression stockings on varicose veins,which has yet to be clarified.In this paper,we investigate the effect of medical compression stockings on human calves by constructing a biomechanical model of human calves,and lay the foundation for the scientific production of compression stockings and the elucidation of their mechanism of action on calves.Firstly,two grades of compression socks were custom-made and purchased,and their clothing pressure was tested separately;the results showed that the compression socks made in this study had a good pressure gradient and met the standard requirements,while the pressure gradient of the purchased compression socks was more different from the relevant standards.Secondly,based on MRI medical image data,a three-dimensional biological model containing the tibiofibula,soft tissue and saphenous vein vessels of the lower leg was constructed,which provided a more accurate human lower leg model for finite element analysis.Again,a finite element model of the calf wearing a compression stocking was established,and the magnitude and distribution of the pressure on the surface of the calf,as well as the magnitude and distribution of the stress on the bones,soft tissues and saphenous vessels were obtained.The simulation results show that the lower leg is subjected to higher pressure at the ankle and below the anterior knee,and the stress on the bones is much higher than that on the soft tissues and blood vessels,and the stress distribution on the wall of the saphenous blood vessels decreases from the ankle upwards.The simulated values of the compression sock with the garment pressure on the calf surface showed the same trend as the experimental values with less deviation.Finally,a flow-solid coupling model of the saphenous vein vasculature at the ankle was constructed to study the effect of compression stockings on the venous blood flow in the lower leg.The simulation results showed that wearing compression stockings reduced the caliber of the vessel at the ankle and increased the blood return velocity,and the blood flow velocity increased with the increase of the stress on the vessel wall.The experimental results also showed that wearing compression stockings promoted venous blood return and increased blood flow rate,and the higher the external pressure on the calf,the higher the blood flow rate in the calf veins;the difference between the experimental and simulated values was small,which confirmed the validity of the simulated results.