Biomechanical design framework for prosthetic feet: Experimentally validated non-linear finite element procedure
Biomechanical design framework for prosthetic feet: Experimentally validated non-linear finite element procedure
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DOI：
10.1016/j.medengphy.2021.04.006
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发表时间：
2021-05-24
影响因子：
2.2
通讯作者：
Sujatha, S.
中科院分区：
文献类型：
--
作者：
Balaramakrishnan, T. M.;Natarajan, S.;Sujatha, S.
假肢设计期间的性能评估通常是通过实验进行的，这可能是时间和成本密集型的。这项工作首次应用数值方法来先验确定假脚的各种站立相生物力学参数，如其翻滚特性、压力轨迹中心、踝关节屈曲力矩臂和踝关节活动范围，以辅助其设计。计算过程基于有限元分析，包括几何、材料和接触非线性。采用模拟摇杆倒立摆模型的边界条件计算生物力学参数。以结构复杂的奥托贝克固体踝垫足(SACH)假足为测试装置，采用倒立摆装置对有限元模型进行了验证，数值计算结果与实验结果的比较表明误差较小。例如，翻转形状的曲率半径的百分比误差类似于0.1%。发现的差异在临床上似乎并不显著，这证实了该模型的可靠性。该数值模型可以对影响假肢步态特征的生物力学参数进行详细的先验分析，从而更好地为假肢的设计、分析和处方提供依据。(C)2021年IPEM。爱思唯尔有限公司出版。保留所有权利。
Performance evaluation of prosthetic feet during their design is typically performed experimentally, which may be time and cost intensive. This work presents a first-of-its-kind application of a numerical procedure for the a priori determination of various stance phase biomechanical parameters of a prosthetic foot, such as its roll-over characteristics, centre of pressure trajectory, ankle flexion moment arm and ankle range of motion, to aid in its design. The numerical procedure is based on finite element analysis, which includes geometric, material and contact non-linearity. Boundary conditions emulating the rocker-based inverted pendulum model were employed to evaluate the biomechanical parameters. The finite element model was validated by employing an inverted pendulum-based apparatus using the structurally complex Ottobock Solid Ankle Cushioned Heel (SACH) prosthetic foot as the test device.A comparison of the numerical and experimental results showed low magnitude of errors. For example, the percentage error of the radius of curvature of the roll-over shape was similar to 0.1%. The differences found appear to be clinically insignificant, which substantiates the reliability of the model. The proposed numerical model can be employed to obtain detailed a priori insights into the biomechanical parameters influencing a prosthetic foot's characteristics during gait, which can better inform the design, analysis and prescription of prosthetic feet. (C) 2021 IPEM. Published by Elsevier Ltd. All rights reserved.