【作者】 丁杰男；

【导师】 王树新；

【作者基本信息】 天津大学 ， 机械电子工程， 2008， 博士

【摘要】 喉部微创手术是医生借助手术工具,通过喉镜狭小腔道实施的喉部手术。受到喉镜狭小空间的限制,该类手术仍无法进行复杂的手术操作。针对喉部狭小空间特点,本论文设计开发了一套具有七自由度的冗余手术机器人系统。该机器人采用主从控制模式,其末端工具的冗余自由度可有效解决喉镜空间限制,在狭小空间内实现手术缝合操作。本文以喉部微创手术机器人系统为研究对象,在以下几方面取得创新性成果:1)喉部微创手术机器人机械系统设计。针对喉部微创手术特点,将机器人分为末端工具、主动支架和被动支架三部分进行模块化设计。将末端工具的弯曲自由度与开合动作合成,简化了机构;采用“类曲柄滑块机构”保证工具具有较大的挟持力。主动支架采用远端回转中心机构保证微创口的安全;将内窥镜固定在主动支架上,提高了机器人在图像下的配准精度。被动支架设计具有重力补偿功能,方便医生对机器人手动定位。2)针对具有冗余特性的喉部微创手术机器人系统,提出了一套适用于实时操作的冗余机器人逆运动算法。该算法通过对末端工具的弯曲关节加入扰动的办法获得冗余逆运动学的解空间。再利用多优化指标融合的办法对冗余逆运动学解排序,从而得到最优逆解。针对喉镜约束特点设计的优化指标,可以充分利用末端工具弯曲自由度避免末端工具与喉镜之间的碰撞,实现狭小空间内的手术缝合操作。3)喉部微创手术机器人狭小空间内缝合动作的验证。基于开源机器人仿真软件包,构建了喉部微创手术机器人仿真开发平台,进行了逆运动学算法进行调试和狭小空间内缝合操作的验证。并将逆运动学算法在喉部微创手术机器人样机上实现,在真实环境下验证了机器人的缝合功能。4)设计并实现了基于PC机的主从“异构”型机器人控制系统。采用分层结构的实时控制算法,通过微小扰动建立主从操作手之间的对应关系,减小了计算量;通过增加反馈环节,减小近似计算误差;采用样条插值方法减轻人手抖动。并最终实现了主从“异构”机器人精确的位置控制。设计了一系列实验对喉部微创手术机器人系统的各项性能指标进行测量。实验表明该机器人具备了临床手术对精度及灵活度的要求,可进行临床试验。更多还原

【Abstract】 In laryngeal minimally invasive surgery (LMIS), the surgeon employed the long laryngeal tools through constrained air-path to implement the whole therapy. Due to the restriction of the suspended Laryngeal’s space, the current therapy can not implement complex operation. This dissertation designed a novel 7dof LMIS robot system. The LMIS robot worked in tele-operation mode and controlled by the surgeon through a remote master manipulator device. With the dexterous end effectors, the LMIS robot can implement suturing assignment under constrained space. The paper focused on the LMIS robot system design and implementation and made the following contributions.1. A novel mechanism was designed for LMIS robot. The LMIS robot was separated as end-effectors, active platform and passive arm three parts. In order to simplify its mechanism, the end-effectors’redundant joint coincided with open-close joint; the“Similar Crank-Slider”mechanism allowed the end-effectors possessed enough gripping force. The active platform employed a remote center mechanism to guarantee the safety of the trocar; meanwhile it can increase the register precision between robot and image by attaching them together. The passive arm designed with gravity compensation feature, which allowed surgeon easily position the robot in space.2. An online algorithm was presented to solve the redundant LMIS robot inverse kinematics problem. By perturbing end-effectors yaw joint with small displacement, the algorithm firstly generated multi redundant inverse kinematics solutions. And then ranked all the solutions followed by multiple redundant optimization criteria (ROC). Except for employing the existing ROC, one novel ROC followed the suspended Laryngeal’s space restriction characteristic was introduced. The novel ROC can make use of the end-effectors redundant joint to avoid the collision between tools and suspended larynscopy, which guarantied the robot implement the suturing assignment in constrained space.3. The verification of the LMIS robot’s capability of suturing in constrained space. Based on an open source toolkit, a virtual environment with LMIS robot and suspended laryngeal’s model was built in computer. The virtual environment allowed debugging LMIS robot inverse kinematics algorithm and can verify the LMIS robot’s capability of suturing in constrain space. Based on simulation result, LMIS robot inverse kinematics algorithm was implemented on LMIS robot prototype. Finally the LMIS robot’s capability of suturing in constrain space was verified in reality.4. Design and implementation of a PC based the tele-controller for isomeric master and slave (m/s) manipulator. The controller designed with multi-level structure. The high-level algorithm employed the robot kinematics relative calculation and run on PC software level with low speed. In order to satisfy the robot control real time requirement, this algorithm maped the small variation instead of homogeneous transform between m/s to reduce calculation. The low-level algorithm computed robot trajectory planning and implemented by motion controller with high speed.At last, serial experiments have been done to evaluate the robot performance. After the experiment result complies with the design requirement, the LMIS robot implemented the suturing experiment in tele-operation mode. The experiment result showed the LMIS robot possessed the ability to apply in clinic environment.更多还原