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.

中文翻译：

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用于机器人辅助腹腔镜手术的腕部机构，在俯仰和偏航轴之间具有简单的无干扰机制

腹腔镜手术，也称为微创手术，是与加速术后恢复相关的手术技术。但是，只能由具有高级手术技能的外科医生执行。腹腔镜手术的主要挑战之一是由于套管针施加的自由度有限，限制了钳子的自由运动。最近，为了克服这个问题，许多带有铰接钳的主从操纵器已被用于腹腔镜手术。铰接钳的腕部机构影响患者腹部中从机械手的可控性和运动范围。因此，改善关节钳的腕部机构对于机器人辅助的腹腔镜手术很重要。这项研究提出了一种新的腕关节机制，用于在腹腔镜手术中使用铰接式钳子。所提出设计的自由度由采用各种金属丝和皮带轮（俯仰，偏航和抓取器轴）的电机驱动轴或手动驱动轴提供。该机构的运动学模型通过非常简单的机构使用弧形导向器和导线导向孔在俯仰轴和偏航轴之间解耦。弧形的导向装置使俯仰轴的运动引起的偏航和夹持器轴导线的导线路径长度误差最小。弧形导轨的最佳位置取决于导线路径长度误差的最小均方根值。与先前开发的临床用机械钳相比，拟议的腕部机械装置仅具有一半的零件数量。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。