【作者】 刘展；

【导师】 樊瑜波； 张明；

【作者基本信息】 四川大学 ， 生物医学工程， 2003， 硕士

【摘要】 一体化假肢是以高分子聚合物为材料从接受腔到假腿一体成型的新型下肢假肢，比传统型假肢更经济、美观、轻便，具有较大的研究价值。但目前一体化假肢还只是一个概念，尚未批量应用于临床。最近，一些学者和机构开始致力于一体化假肢的研发，主要是针对制造和材料方面，尚未涉及对一体化假肢的应力分析。由于一体化假肢与传统型假肢在结构上的差异，因此有必要对其进行应力分析。 本文建立了一系列一体化小腿假肢的三维模型，通过有限元计算得到这些模型的应力分布，并进行了参数分析。具体研究包括： 基于一实验用一体化小腿假肢的真实几何构形，建立了均匀壁面厚度3mm的三维有限元模型，并考虑残端软组织和骨，施加与Heel Off步态时相对应的载荷，通过有限元计算得到其应力分布，作为参数分析的根据。 在以上模型的基础上，加大壁面厚度建立了三个不同壁面厚度的一体化小腿假肢的三维有限元模型，这些模型的材料属性、软组织形状、骨的定位和载荷都与以上模型相同，通过有限元计算分析壁面厚度对模型应力分布的影响。 给模型赋予不同的材料特性，如聚丙烯均聚物、20％玻璃纤维加固的聚丙烯、丙烯酸树脂、聚丙烯和聚乙烯的共聚物，在其它条件不变的情况下，通过有限元计算比较各材料假肢的应力分布。 为模型分别施加与Heel Strike、Foot Flat、Mid-Stance、Heel Off和Toe Off五个典型步态时相相对应的载荷，通过有限元计算分析一体化假肢在各时相应 摘要力分布的特点。 计算了以上各模型的转动惯量，分析质量分布对转动惯量的影响，从而从运动控制方面反馈一体化假肢设计的合理性。 基于一体化假肢接受腔的形状建立传统型假肢的模型，分析接受腔和残端的应力分布，并与一体化假肢的计算结果进行比较，讨沦一体化假肢在应力缓冲方面的作用。 本文的研究工作是首次对一体化假肢进行的三维有限元应力分析，为一体化假肢设计的CAE系统提供了理论依据。本文首次对一体化假肢设计的重要指标—壁面厚度进行了参数分析，并首次将转动惯量引入假肢领域，作为一体化假肢优化设计的参数，具有一定的学术意义和应用价值。更多还原

【Abstract】 Monolimb is a new type of lower-limb prostheses, which is made of macromolecule polymer. The socket and prosthetic shank of monolimb are integrative. Compared with traditional prosthesis, monolimb is more economical, good-looking and portable, so it is worth researching. But monolimb is only an idea now, and it has not been largely applied to clinic. Recently some scholars and institutions started to apply themselves to researching monolimbs, but their researches aimed at manufacture and materials, and have not involved stress analysis of monolimbs. Because of the difference in structure between monolimbs and traditional prostheses, it is necessary to execute stress analysis of monolimbs.The purpose of this research was to establish a series of 3D models of trans-tibial monolimbs. By use of finite element analysis on these models, the stress analysis and parameter analysis ware obtained. This research include:The uniform wall thickness of the model based on real geometry shape of a trans-tibial monolimb for experiments is three millimeters. The soft tissue and bone of stump were considered. The model was applied to the load corresponding to the subphase of the stance of Heel Off. Using a finite element solver, the quasi-static stress distribution within the model was obtained.Using thicker wall thickness, three 3D finite element models with different wall thickness were established. The material properties, stump shape, bone orientationand load were same. Through finite element analysis, the influence of wall thickness to the stress distribution within the models was gained.Various material properties were given to the model, such as polypropylene homopolymer, polypropylene with 20% glass fiber, acrylics, and polypropylene and polyethylene copolymer. Without change of other conditions, through finite element analysis, the stress distributions with various materials were obtained.The model was applied to the loads corresponding to the subphase of the stance of Heel Strike, Foot Flat, Mid-Stance, Heel Off and Toe Off. Using a finite element solver, the characteristics of the stress distribution corresponding to each subphase of stance were analyzed.The moment of inertia of each model was computed. The influence of mass distribution to moment of inertia was analyzed, thus the rationality of monolimb design was fed back in sport control.A model of traditional prosthesis with the same socket shape of the monolimb was established. The stress distributions within socket and stump were analyzed. Compared with the results of the monolimb model, stress damping of monolimb was discussed.This research is the first finite element stress analysis to monolimbs, which provide the basis for CAE of monolimb. And it’s also the first time to analyze wall thickness which is an important parameter in designing monolimb, and to introduce moment of inertia as a parameter in designing monolimb. So it will be valuable in both academic research and clinical practice.更多还原