人工寰齿关节结构优化设计及仿真分析

Optimization design and simulation analysis of artificial atlanto-odontoid joint structure

背景:有研究表明传统的各种寰枢关节模型具有良好的生物力学特性,然而不能完全满足人体的要求。基于前人研究的基础,拟通过对寰枢椎关节的要求进行分析,探讨出一种不仅能预防寰枢关节不稳,而且能使枢椎部件具有一定的灵活性的结构,使之更满足人体的需要。目的:利用有限元法分析颅颈交界处寰枢椎外侧关节受扭矩后变化,利用静力学分析探讨寰齿关节模型的三维运动力学性能和疲劳寿命以及安全系数。方法:利用三维造型和有限元软件建立寰齿关节三维有限元模型,对优化后的结构在静力学分析里面进行疲劳分析,围绕模型中心轴施加0.5 N·m的转矩,通过对仿真分析的结果进行分析,从而评估优化后的寰齿关节模型的性能和寿命。结果与结论:传统的寰齿关节模型是通过销钉固定在体内,枢椎不能转动且外形有缺陷,优化后的结构不仅能使寰齿关节保持良好的稳定性又能使其具有关节运动功能,限位块的添加使其有一定的转动角度且不至于超出限制的旋转角度。由于实际要求,应考虑到操作方便、安置牢固、较少甚至消除副损伤,寰齿关节应选用钛合金材质,各部分零件尺寸的选取都需要达到实际要求。结果说明,优化后的寰齿关节模型实现了创新性和实用性的要求,通过实验证明在机械学上是可行的,优化后的结构各项指数均达到要求。

BACKGROUND： Studies have shown that traditional models of atlanto-axial joints have good biomechanical properties, but they cannot completely meet the requirements of the human body. Based on the basis of predecessors＇ research, this article will explore a kind of atlanto-axial joint which can not only prevent its instability but also make the structure of axis parts a certain flexibility to make it meet the needs of the human body through the analysis of the requirement of atlanto-axial vertebral joints. OBJECTIVE： To analyze the torque change at the junction of cranial cervical vertebra lateral atlanto-axial joint by using finite element analysis, and discuss three-dimensional motion mechanical properties and fatigue life and safety factor of the atlanto-axial vertebral models using statics analysis. METHODS： Fatigue analysis was conducted in the static analysis for the optimized structure in the three-dimensional atlanto-axial vertebral models using finite element analysis. Torque of 0.5 N·m was put on the fixed plate. The performance and life span of the optimized model were evaluated by analyzing the results of simulation analysis. RESULTS AND CONCLUSION： The traditional model of the atlanto-odontoid joint is fixed by a pin in the body. The axis cannot rotate and the appearance is defective. The optimized artificial atlanto-odontoid joint can rebuild the good stability of atlanto-axial joints and can retain its movement function. The improved structure not only has a certain rotating angle, but also can limit the rotating angle of the model in a certain torque by the limit block. Because of the actual requirements, in order to lay solid, easy to operate, keep the motor functioning and avoid injury, atlanto-odontoid joint should use titanium alloy material. The selection of parameters has certain requirements. These results suggested that the optimized artificial atlanto-odontoid joint has met the commands of creativity and utility, which has feasibility in mechanics. All the parameters meet the requirements in the optimized structure.