摘要
目的研究大腿截肢患者在行走过程中站立中期时相下残肢的受力情况,为建立完整的大腿接受腔测量与评估系统提供基础。方法首先根据计算机断层扫描图像三维重建大腿截肢患者的骨骼、肌肉软组织和接受腔的三维模型,考虑步行中关节角度变化进行组装。然后,建立模拟步态周期中站立中期时相受力的有限元模型,对模型进行预应力影响下非线性大变形有限元分析。结果当考虑了步行中关节角度变化和预应力的影响以后,计算所得的接触法向界面压力值最大值均位于残肢的末端部位,为257.66 kPa,与实际测量患者步行中站立中期时相下最大应力258.90 kPa符合较好。结论考虑关节角度变化、预应力和摩擦的三维模型能够更为有效地模拟患者在步行中的受力情况。
Objective To investigate the interface pressure on above-knee residual limb at mid stance during walking,so as to provide basis for the establishment of measurement and evaluation system for the above-knee socket.Methods Based on CT images of the femur,soft tissue and above-knee socket of the patient with residual limb,the three-dimensional model was first built,and then to assemble them according to changes of the hip joint in a gait cycle.The finite element model was then established to simulate the loading conditions at mid stance during a gait cycle,and the effect of pre-stress was investigated by nonlinear large deformation analysis.Results If considering the effects such as joint changes and pre-stress,the maximum value by calculation for normal interface pressure distributed on the terminal of stump was 257.66 kPa,which could better match the maximum stress actually measured by the Mflex Sensor Distributing System as 258.9 kPa.Conclusions The three-dimensional finite element model with considering the factors such as hip joint change,pre-stress and friction could effectively simulate the stress condition of patient with residual limb during walking.
出处
《医用生物力学》
EI
CAS
CSCD
2011年第4期321-324,共4页
Journal of Medical Biomechanics
