角膜移植手术中打结作业的力学建模与分析

Mechanical modeling and analysis of the knot-tying in cornea grafting microsurgery

根据拍摄的外科医生临床手术缝合影像,将手术打结动作分解为4个基本步骤。以此为依据,建立了结点形成的力学模型并将其简化为对称张紧的受力形式。根据临界滑动条件,缝线间摩擦力和点接触形式作用的张力,建立了结点运动的力平衡方程并求解出合理的拉力角度范围。在此基础上,进一步推导出了缝线末端的运动轨迹方程,并对其进行分析和仿真。通过对比不同拉力条件下的仿真结果,规划出角膜移植手术机器人打结机构末端的最佳运动路径。

According to the images of surgeons＇ clinic operations, the movements of knot-tying in clinic surgery were decomposed into 4 main procedures. The mechanical model of knot performing was constructed and simplified into a symmetrical form of tensed force. Considering critical slip condition, friction between sutures as well as node-to-node contact for the effect of tensile force, the static equilibrium equations for knot＇ s movements were constructed and the feasible rang of force exerting on it was obtained. Based on it, a motion equation was constructed to represent the tracks of sutures＇ end and its simulation was performed. By comparing simulations under different tensile force conditions, the optimal path of end-operator was planned on cornea grafting microsurgery robot for tying knot.