基于虚拟夹具的微创外科手术机器人运动约束研究  

Motion Constraint Study of a Minimally Invasive Surgical Robot Based on Virtual Fixtures

作　　者：梁科 王树新[1,2] 李建民[1,2] 苏赫[1,2] 卜逸凡 牛顺康[1,2] Liang Ke;Wang Shuxin;Li Jianmin;Su He;Bu Yifan;Niu Shunkang(School of Mechanical Engineering,Tianjin University,Tianjin 300350,China;Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education,Tianjin University,Tianjin 300350,China)

机构地区：[1]天津大学机械工程学院,天津300350 [2]天津大学机构理论与装备设计教育部重点实验室,天津300350

出　　处：《天津大学学报（自然科学与工程技术版）》2020年第4期331-340,共10页Journal of Tianjin University：Science and Technology

基　　金：国家重点研发计划资助项目(2017YFC0110401);国家自然科学基金资助项目(51875390);国家自然科学基金国际(地区)合作与交流资助项目(51520105006).

摘　　要：机器人辅助微创外科手术(RMIS)技术能够显著提高外科医生对手术的执行能力.然而,现有的机器人主从遥操作模式下所存在的不足之处(如手眼协调性差、可视空间狭窄、力反馈信息的缺失等)容易导致医生产生过度操作而引起机器人执行机构的碰撞干涉(包括机械臂之间的碰撞干涉及内窥镜杆与手术器械杆的碰撞干涉)和手术器械末端脱离手术视野,由此带来的安全性问题不容忽视.本文提出了一种基于虚拟夹具的微创外科手术机器人空间运动约束方法,以"MicroHand S"机器人系统作为应用平台,在进行机械臂构型及运动学分析的基础上,针对上述问题展开研究,通过构建碰撞干涉检测模型实时监测机器人执行机构之间及机器人与环境物体之间的相对距离,并设置相应的安全预警区域,采用人工势场与虚拟代理点相结合的方式对机器人执行机构的运动空间加以限制,从而达到对医生的操作动作进行合理的引导与约束,提高手术效率与操作安全性的目的.该方法无需构建复杂的几何模型,虚拟夹具的定义方便快捷,对于其他主从操作模式下的微创外科手术机器人系统及类似的人机交互环境具有普适意义.最终的虚拟仿真实验结果表明,在有、无虚拟夹具两种操作环境下,实验参与人员的表现有着明显的差异,从而验证了所提出方法的有效性.Robot-assisted minimally invasive surgery(RMIS)can significantly improve surgeons’ ability to perform surgical procedures.However,shortcomings in the robotic master-slave teleoperation mode(such as poor hand-eye coordination,narrow visual space,and lack of force feedback)can lead to misoperation by the surgeon.This,in turn,can lead to collision interference(including collision interference between robotic arms and the arm between the endoscopic and instrumental rods)and deviation of the surgical instrument tip from the visual field.The resulting safety problems cannot be underestimated.To address these problems,based on an analysis of manipulator configurations and kinematics,this study proposes a motion constraint method for a minimally invasive surgical robot based on virtual fixtures,using the "MicroHand S" system as a research platform.The relative distances between robotic manipulators and between a manipulator and environmental objects were monitored in real time using the proposed collision interference detection model.A safety warning area was set up,and the motion space of the manipulator was restricted using an artificial potential field and Proxy.This allowed the surgeon’s motions to be guided and constrained reasonably and improved surgical efficiency and operational safety.The method did not require a complicated geometric model,and the definition of "virtual fixture" was convenient and efficient.This can be applied to other minimally invasive surgical robots with master-slave teleoperation modes and similar human-machine interactions.In conclusion,the results of a virtual simulation experiment showed a significant difference in surgical performance between participants with and without the virtual fixture,thereby verifying the effectiveness of the proposed method.

关 键 词：机器人辅助微创外科手术 碰撞干涉检测 虚拟夹具 人工势场 代理点 

分 类 号：TP242.3[自动化与计算机技术—检测技术与自动化装置]