Dynamic Movement Analysis and Optimal Design for Stabilizer Type Artificial Knee Joint

为了考虑动态条件下稳定器部件的接触条件，对日常生活中最常见的运动--步行进行了三维运动测量，并利用逆动力学和非线性优化方法对人工膝关节的运动进行了动态数值模拟。然后，通过对股骨稳定器安装位置的平移，研究了人工膝关节股骨稳定器的接触条件和最佳安装位置。因此，可以明确，在动态条件下，稳定器对膝关节的稳定做出了显着贡献，即，当膝关节角度变大时股骨的向后运动（后滚运动），稳定器位置的轻微平移在接触条件上产生大的问题，并且当前的安装位置处于不发生这些问题的状态。另外，通过膝关节运动与活体的一致性、接触点运动的平滑性、膝关节接触面的磨损、稳定器接触部的磨损等磨损参数的评价，同时阐明了存在比目前安装位置更优的安装位置，由于存在差异，优化设计需要综合考虑最佳位置取决于参数。此外，考虑到人工膝关节部件在关节手术中的安装误差对关节运动的影响，建议为了延长人工膝关节的寿命，必须提高安装精度和更全面的设计，以吸收手术中的安装误差。

In order to consider the contact condition of the stabilizer part under dynamic conditions, three-dimensional movement measurement for walking, which is considered to be the most general movement in daily life, was performed and the dynamic numerical simulation of the movement of artificial knee joint was performed using the reverse dynamics and the nonlinear optimization method. And then, the contact condition and the optimal installation position of a femur stabilizer of an artificial knee joint were investigated using translation of the installation position of the femur stabilizer. Consequently, it is clarified that, in dynamic conditions, the stabilizer has contributed significantly to the stabilization of knee joint, i.e., posterior movement of a femur (rollback movement) when knee angle becomes large, slight translation of the stabilizer position makes big problem on contact condition, and the present installation position is in the state where these problems do not occur. Moreover, by the evaluation with wear parameters, which are the identity of the knee joint movement with living body, smoothness of the contacting point movement, wear of the contact surface of knee joint, and wear of a stabilizer contact part, it is also clarified that the more optimal position than the present installation position is exist and that comprehensive point of view is required for the optimal design because of the difference of optimal position depending on the parameters. Furthermore, by consideration of the effect of the installation error of the artificial knee joint component at an joint operation on the joint movement, it is suggested that the necessity of installation accuracy and more comprehensive design which could absorb the installation error in the operation, for a longer life artificial knee joint.