基于梯形槽结构的连续体手术器械弹性关节建模、仿真和实验验证

Modeling,Simulation,and Experimental Verification of a Continuum Elastic Joint of Surgical Instruments Using a Trapezoidal Cutting Groove

面向经自然腔道内镜手术(natural orifice transluminal endoscopic surgery,NOTES),根据手术器械的弯曲性和刚度需求,设计了具有梯形槽结构的连续体手术器械弹性关节,并提出了连续体弹性关节的结构特征参数.为消除结构参数原始单位及其数值数量级的影响,便于确定参数的取值区间,以特征长度为单位将连续体弹性关节的结构特征抽象为4个无量纲的结构参数.由于连续体弹性关节的结构沿轴线方向是循环重复的,切槽部分的变形相同,所以首先提取一节弹性关节进行静力学分析,然后通过叠加获得连续体弹性关节考虑其形状特征的静力学模型.为验证连续体弹性关节力学性能,基于有限元分析软件ABAQUS进行仿真.一方面,基于正交实验设计方法,验证各结构参数对力学性能影响的变化趋势以及显著性,不涉及对具体数值的验证;另一方面,基于控制变量法,验证结构参数对力学性能的影响,并根据仿真结果校正了静力学模型.同时,基于控制变量法,通过实验验证结构参数对刚度系数的影响.结果表明该模型可以有效描述弹性关节的弯曲性能和抗压性能,为弹性关节设计提供指导.

For natural orifice transluminal endoscopic surgery(NOTES),a continuum surgical instrument elastic joint with a trapezoidal groove structure was designed according to the flexural and stiffness requirements of the surgical instrument.The structural characteristic parameters of continuum elastic joints are proposed.To eliminate the influence of the original units and their numerical orders of magnitude on the structural parameters and facilitate the determination of the parameter value range,the structural characteristics of the continuum elastic joints were abstracted into four dimensionless structural parameters based on the characteristic length unit.As the structure of the continuum elastic joint is cyclic and repeated along the axis and the deformation of the groove part is the same,one elastic joint was extracted first for statics analysis and then the statics model of the continuum elastic joint,considering that its shape characteristics were obtained by superposition.To verify the mechanical properties of continuum elastic joints,finite element analysis software ABAQUS was used for simulation.On the one hand,based on the orthogonal experimental design method,the variation trend and significance of the influence of various structural parameters on mechanical properties were verified.This process did not involve the verification of specific values.On the other hand,based on the control variable method,the influence of structural parameters on mechanical properties was verified,and the static model was corrected according to the simulation results.The influence of structural parameters on the stiffness coefficient was verified by the experiments based on the control variable method.The results show that the model can effectively describe the flexural and compressive properties of elastic joints and provide guidance for designing elastic joints.