Abstract:

Varicose veins of the lower extremities are a common and frequentlyoccurring disease in clinical practice. Lower extremity venous diseases affect 25%－40% of women and 10%－20% of men worldwide. With the improvement of medical theory and application technology, the treatment methods and techniques of lower extremity venous diseases have been continuously improved. Compression therapy has a long history in the treatment of varicose veins. Pressure socks are widely used in the treatment of varicose veins. The pressure socks are designed in a progressive segmented manner, and the pressure applied to the leg is gradually reduced from the ankle to the thigh. Due to the different shapes and sizes of human legs, the pressure distribution of different individuals is different. Therefore, it is particularly important to detect the pressure distribution of the actual human body wearing medical socks. At present, the finite element analysis method is widely used in pressure analysis. However, the existing pressure simulation models are mostly fixed single models, which cannot accurately change the thickness according to the circumference of the tester's test site, and cannot easily simulate multiple sets of pressure values under different circumferences according to the leg size.

In orderto simulate the exact pressure distribution exerted by compression stockings on ankles with different girths, an anklecompression stocking simulation model based on finite element software was proposed to simulate the pressure exerted by compression stockings on human ankles with different girths. Firstly, the initial shape and size of ankle were obtained by threedimensional human body scanning, and the geometric model of anklepressure sock was established. Then, the material density, elastic modulus and Poisson's ratio of fabrics at ankle were tested and calculated, and the material models of grade I, grade II and grade III compression stockings and ankle were established. On this basis, the finite element software was used to mesh and establish the contact force simulation model of medical socks and legs. From the simulation results, the simulated pressure values of the anterior and posterior two points of the ankle were obtained, and the contact pressure of the human body after wearing the pressure socks was tested. The results show that the pressure value of the anterior part of the ankle is always greater than that of the posterior part. When people wear different grades of compression stockings, the pressure increases with the increase of the grade of compression stockings. When people wear the same grade of compression stockings, the pressure value of the ankle increases with the increase of the circumference of the ankle, which is linearly distributed. The finite element model is reasonable and effective.

While establishing an effective finite element pressure simulation model, this study provides a new idea for the research of compression stockings from the perspective of the physical and mechanical properties of knitted fabrics.Giving play to the potential of finite element analysis technology in the gradient compression stockings research and application can greatly save product development time and reduce development costs. In practical applications, this study can be used for personal customization of pressure socks, so that the pressure value of each test product conforms to the comfort range of human body, and provides reference for the development and testing of pressure socks products and sportswear protection products, which is conducive to better measurement of clothing pressure.

Key words: compression stockings, ankles, pressure distribution, finite element model, pressure test

摘要： 为了模拟压力袜对不同围度脚踝所施加的确切压力分布，提出一种基于有限元软件构建的脚踝-压力袜仿真模型，模拟压力袜在穿着时对不同围度的人体脚踝施加的压力值。通过三维人体扫描获取脚踝初始形态尺寸，建立脚踝-压力袜几何模型。通过材料密度、弹性模量和泊松比建立Ⅰ级、Ⅱ级、Ⅲ级压力袜及脚踝的材料模型。运用有限元软件进行网格划分，建立医疗袜与腿部接触受力仿真模型。由仿真结果得到脚踝正前、后两点模拟压力值。结果表明：脚踝前部处所受压力值始终大于后部；穿着不同等级压力袜时，压力随压力袜等级的增加而增加；穿着相同等级压力袜时，脚踝所受的压力值随脚踝周长增长而增加，呈线性规律分布；经实测对比，实验验证所建立的有限元模型是合理且有效的。

关键词: 压力袜, 脚踝, 压力分布, 有限元模型, 压力测试