1.Shanghai Institute for Minimally Invasive Therapy,School of Medical Instrument and Food Engineering,University of Shanghai for Science and Technology;2.University of Shanghai for Science and Technology
目的 设计一种应用于电动吻合器的切口式柔性转弯结构，并研究其转弯性能。方法 切口式柔性转弯结构的设计与建模；建立了转弯结构的运动学和静力学模型并进行仿真计算；采用有限元仿真研究了三组结构在对称切口等刚度和变刚度下的应力、偏转角度、顶部位移及驱动力；搭建了转弯结构性能测试实验平台对仿真结果和模型进行了验证。结果 弯曲过程中转弯结构理论模型与实验结果基本吻合；随着对称切口刚度的优化，变刚度转弯结构的最大应力分别下降了20.64%和39.20% ；变刚度结构（S3）弯曲时所需拉力最小，相较于等刚度结构下降了33.41%，且顶端沿弯曲平面的位移量最小，其值为30.8mm；三组转弯结构最大偏转角度均可达到90°。 结论 转弯结构运动学和静力学模型可用于其拉力和位置变化的计算；采用对称切口变刚度的结构转弯性能优于等刚度结构；切口式柔性转弯结构符合设计要求，满足电动吻合器的转弯需求。
Objective Design a notch flexible turning structure applied to electric stapler and study its turning performance. Methods Design and model the notched flexible turning structure. Established the kinematics and statics models of the turning structure and performed simulation calculations. Using finite element simulation, the stress, deflection angle, top displacement and driving force of three groups of structures under equal and variable stiffness of symmetrical notches are studied. An experimental platform for the performance test of the turning structure was built to verify the simulation results and model. Results The theoretical model of the turning structure in the bending process is basically consistent with the experimental results. With the optimization of the stiffness of the symmetrical notch, the maximum stress of the variable stiffness turning structure has been reduced by 20.64% and 39.20% respectively. The variable stiffness structure (S3) requires the smallest tensile force during bending, which is 33.41% lower than that of an equal stiffness structure, and the tip displacement along the bending plane is the smallest, with a value of 30.8mm. The maximum deflection angle of the three turning structures can reach 90°. Conclusion The kinematics and statics model of the turning structure can be used for the calculation of its tension and position changes. The turning performance of the structure with variable stiffness using symmetrical notch is better than that of equal stiffness structure. The notched flexible turning structure meets the design requirements and meets the turning needs of the electric stapler.