医疗机器人穿刺针避障可达作业空间边界解析描述

Analytic Description of Medical Robot Needles' Collision-free Reachable Workspace Boundary

提出了适用于机器人辅助腹腔介入治疗系统的手术规划方案,通过分析机器人手术流程。提出将穿刺针简化为球铰单关节操作臂的物理模型,基于机器人学中对操作臂避障可达作业空间边界解析描述的研究,利用含参数的非线性方程组对穿刺针的工作空间进行了解析描述,用3阶连续可导超二次曲面方程对腹腔内的肋骨及血管进行了描述,用数值迭代连续法求解出了穿刺针避障可达工作空间边界的1维解流形,并用Matlab进行了3维显示,成功求解出了腹腔内存在肋骨及血管等障碍物情况下穿刺针的工作空间边界,通过仿真实验可知,在穿刺针工作空间边界包括的范围内选取进针点,可保证穿刺针路径不与血管、肋骨等障碍物相碰。本文为医生规划手术方案提供了有效依据,解决了目前系统需要医生凭借自身手术经验来确定针点问题,提高了手术的效率和成功率。

A surgical planning scheme for robot-assisted celiac interventional therapy system is proposed.Through analyzing the surgical procedure,a physical model is presented to simplify the needle into an operation arm with a single globe hinge joint.The nonlinear equations with parameter are adopted to obtain the analytic description of the needle＇s workspace based on the study on the analytic description of the arm＇s collision-free reachable workspace boundary in robotics.The ribs and blood vessels in the abdominal cavity are described with third-order continuous differentiable super quadric surface equation.With numerical iterative continuation method,the unidimensional manifold of needle＇s collision-free reachable workspace boundary is solved,and the three-dimensional models are displayed with the Matlab toolbox.For the case that ribs and vessels exist in the abdominal cavity,the workspace boundary of the needle is successfully obtained.According to simulation results,the needle-insertion path will not collide with fraises such as ribs and vessels if the entry point is selected within the needle＇s workspace boundary.This paper provides an effective means for doctors to make successful surgery operation planning,solves the problem that the current system determines the entry point by doctors＇ own surgical experiences, and improves the efficiency and success rate of surgery.