Basic Research for Artificial Ankle Joint using Statistical

应用统计设计支持系统对人工踝关节进行优化设计。人工关节的设计和材料质量是外科医生可以控制的因素。股骨-胫骨角（股骨轴和胫骨轴之间的外侧角）、骨的几何形状和关节的其他条件是外科医生无法控制的因素。换句话说，如前所述，下肢对线对人工关节周围的应力分布的影响相对较大。这是一个不容忽视的因素。不可控因素的变化导致评估特征值的波动。这种影响必须加以考虑。因此，有必要考虑鲁棒性。稳健性被定义为即使存在变化的因素，所得特征值的变化也很小的条件。以获得稳定特性为目标的设计称为鲁棒设计。也就是说， ...更多信息 是为设计人工踝关节而制作的，术后结果不应受到个体患者下肢对线或外科医生技术差异的影响。在考虑鲁棒性的基础上，对人工踝关节进行了优化设计。因此，我们获得了这些值：宽度应为7.8 mm，高度为4.5 mm，宽度应向胫骨侧部件外侧移动7 mm，插入到突和胫骨之间的材料特性应为7200 Mpa。分析了采用优化设计和稳健性设计的胫骨假体进行全踝关节置换术后的应力分布。由此分析，该类型部件可被认为是FTA的临界指示在182度以下。毫无保留地接受通过将生物力学方法应用于活体中发生的现象而得出的结果是危险的。但是，我们可以把它作为一个指标。我们打算提高分析的准确性，并进一步研究的分析因素，我们的最终目标：三维分析。人体具有非常复杂的三维结构，尤其是脚的关节复杂，由于靠近人工踝关节，因此不能忽视其影响。研究了踝关节周围的应力状态与踝关节的细微关节和足弓的关系。在最初的验证中，作者提出了考虑细微关节三维行为的人工踝关节优化设计。少

The design of artificial ankle joint was optimized by statistical design support system. The design and quality of material of the artificial joint are factors that can be controlled by surgeons. Femoro-tibial angle (lateral angle between the femoral axis and tibial axis), geometry of the bone and other conditions of joints are factors that cannot be controlled by surgeons. In other words, the influence of lower limb alignment on the stress distribution around the artificial joint is relatively large as mentioned earlier. It is a factor that cannot be disregarded. Variations in uncontrollable factors result in fluctuations in the characteristic values of assessment. This influence needs to be considered. So it is necessary to consider robustness. Robustness is defined as a condition in which variations in the resultant characteristic value are small even in the presence of varied factors. A design aiming at obtaining stable characteristics is called a robust design. That is, a proposal … More is made for the design of an artificial ankle joint, and postoperative results should not be influenced by the lower limb alignment of an individual patient or differences in the technical skill of the surgeon. We optimized the design of artificial ankle joints in consideration of robustness. As a result, we obtained these values: the width should be 7.8mm, height 4.5 mm, the width should be shifted 7 mm laterally of the component on the tibial side and the characteristics of the material to be inserted in between the process and tibia should be 7200 Mpa. We analyzed the stress distribution after total ankle arthroplasty using the tibial component designed by optimization and robustness. From this analysis, the critical indication of this type component may thought to be FTA is under 182 degrees. Accepting the results derived by applying a biomechanical method to the phenomenon occurring in the living body without reserve is dangerous. However, we can take them as an indicator. We intend to improve the accuracy of the analysis and make further studies on the analytical factors for out final target: a 3-dimensional analysis. The human body has the very complicated three-dimensional structures, especially, the joints of the foot are complicated, and it is not possible to disregard the influences, because it is near the artificial ankle joint. It was examined that the affect of subtler joint and of the arch in the foot on the stress condition around the artificial ankle joint. In the original this verification, authors proposed the optimization design of artificial ankle joint considering three-dimensional behavior of subtler joint. Less