Simple noninterference mechanism between the pitch and yaw axes for a wrist mechanism to be employed in robot-assisted laparoscopic surgery
Simple noninterference mechanism between the pitch and yaw axes for a wrist mechanism to be employed in robot-assisted laparoscopic surgery
复制标题
俯仰轴和偏航轴之间的简单无干扰机构，用于机器人辅助腹腔镜手术中采用的腕机构
作者：
M. Jinno
腹腔镜手术，也被称为微创手术，是一种与加速术后恢复相关的手术技术。然而，它只能由拥有先进手术技能的外科医生进行。腹腔镜手术中的主要挑战之一是由于套管针施加的有限自由度而限制钳子的自由运动。近年来，为了克服这一问题，许多带关节钳的主从机械手已被用于腹腔镜手术。铰接钳的腕部机构影响从操纵器在患者腹腔中的可控性和运动范围。因此，关节钳腕部机构的改进对于机器人辅助腹腔镜手术具有重要意义。本研究提出一种新的手腕机构，用于腹腔镜手术中使用关节钳。所提出的设计的自由度由采用各种线和滑轮（俯仰、偏航和夹持器轴）的电机驱动或手动驱动轴提供。该机构的运动学模型是通过一个非常简单的机构，使用弧形导轨和导线孔之间的俯仰轴和偏航轴解耦。弧形导轨可最大限度地减小俯仰轴运动导致的偏航和夹持器轴线的线路径长度误差。弧形导轨的最佳位置由最小的金属丝路径长度误差的均方根值决定。与先前开发的用于临床使用的机器人镊子相比，所提出的腕部机构仅具有一半数量的部件。此外，在最大外径为7.5 mm的原型模型上证明了所提出机制的有效性。相反，所提出的机构的缺点在于传动机构的效率和空载输入扭矩。
Laparoscopic surgery, which is also called minimally invasive surgery, is a surgical technique that is associated with accelerated post-operative recovery. However, it can only be performed by surgeons possessing advanced surgical skills. One of the main challenges in laparoscopic surgery is the restriction of the free motion of forceps because of the limited degrees of freedom imposed by the trocar. Recently, to overcome this problem, many master–slave manipulators with articulated forceps have been used in laparoscopic surgery. The wrist mechanism of the articulated forceps affects the controllability and range of motion of the slave manipulator in the abdominal cavity of a patient. Therefore, improvement of the wrist mechanism of the articulated forceps is important for robot-assisted laparoscopic surgery. This study proposes a new wrist mechanism for using articulated forceps in laparoscopic surgery. The degrees of freedom of the proposed design are provided by motor-driven or manually driven axes employing various wires and pulleys (pitch, yaw, and gripper axes). The kinematic model of this mechanism is decoupled between the pitch axis and yaw axis by a very simple mechanism using arc-shaped guides and wire guide holes. The arc-shaped guides minimize the wire path length error of the yaw and gripper axis wire resulting from the motion of the pitch axis. The optimized position of the arc-shaped guides is decided by the minimal root-mean-square value of the wire path length error. The proposed wrist mechanism has only half the number of parts as compared to the previously developed robotic forceps for clinical use. Furthermore, the effectiveness of the proposed mechanism was demonstrated on a prototype model with a maximum outer diameter of 7.5 mm. Conversely, the disadvantages of the proposed mechanism lie in the transmission mechanism efficiency and no-load input torque.