仿生人工膝关节机构的运动学分析

Kinematic analysis of simulated knee prosthesis

膝关节是人体最大最复杂的关节,而膝关节装置作为下肢假肢的核心部件,对仿生特性有较高的要求,文章基于仿生学原理,深入分析了本仿生膝关节的运动学特性,如滚动和滑动比例以及瞬心位置曲线等,进一步研究接近正常运动规律的仿生膝关节。以人体膝关节运动规律为原型进行简化,提出了膝关节生物力学模型,分析了仿生膝关节的滑动比率和滚动比率以及瞬心位置的求法,对膝关节的瞬心曲线进行了探讨和计算公式的推导,以及滚动滑动比率的计算,并将其结果与人体膝关节参数进行比较,两者吻合程度较高。这对仿生人工膝关节的运动稳定性分析以及进一步研究其结构和功能具有理论指导意义,从而为深入研制仿生人工腿奠定基础。

Knee joint is the largest and most complex joint of human body. Knee prosthesis, as the core component of lower limb has a great expectation on simulated properties. Based on bionics, this study was designed to analyze kinematic characteristics of simulated knee joint, such as the sliding and rolling ratio of the knee as well as the instantaneous center curve, in order to further investigate an ideal simulated knee joint which was highly similar to normal knee joint. Movement regularity of human knee joint was simplified to introduce biomechanical model of knee joint so as to analyze and deduce formula of sliding ratio, rolling ratio, and instantaneous center curve. The calculation results were compared with parameters of human knee joint, suggesting a high coincidence between simulated and human knee joint. This provides an evidence for analyzing stability of motion and further studying structure and function of simulated knee joint, and this also provides basis for further research artificial simulated leg.