胸腹部微创手术机器人设计和运动精度分析

摘要

为提高胸腹部微创放疗手术的精度,提出一种新型的CT引导的7自由度穿刺机器人系统.根据临床需求,采用丝传动方式解决了空间限制和CT引导下的驱动兼容性问题,进而设计了一种全新的机器人构型;通过运动学分析,得到了穿刺针工作空间形状,根据空间尺寸要求优化了机器人结构参数;基于拉格朗日方程建立机器人系统动力学模型,得到了调姿过程中各关节力/力矩与关节运动参数的关系.最终,通过定位误差修正实验,提高了机器人定位精度,并在此基础上完成了机器人穿刺精度实验,穿刺平均误差为1.09 mm,证明了机器人系统满足手术精度要求.%This paper presents a novel CT-guided puncture robotic system with 7 degrees of freedom (DOF),which can improve the accuracy of the brachytherapy for thoracoabdominal cancer.According to the design requirements,the space constraints and CT compatibility of the drive mode was solved with remote tendon-sheath transmission,and a new structure of the robot was developed.Using kinematical analysis,the structure parameters of the robot were optimized according to the space dimension.Dynamics model for robot was established to acquire the relationship between the joint force/torque and the motion parameters of the joint based on the Lagrangian equation.Finally,the experiment of positioning error correction was made to improve the positioning accuracy of the robot.And the measurement experiment of robot puncture accuracy was completed,in which the error is 1.09 mm.It proved the robot system can meet the requirements of surgical accuracy.