Invasiveness of laparoscopic surgery can be further reduced by using needlescopic instruments which diameter approaches that of a hypodermic needle. However, such needlescopic instruments are limited by the lack of wrist mechanisms with precise and sharp articulating motion. In this article, we present a two-degree-of-freedom wrist mechanism with articulating motion and enhanced kinematic tractability for micro laparoscopic surgery. The mechanism consists of two highly curved nitinol tubes serially connected by rotary joints whose axes intersect at a remote center of motion (RCM). Its elasticity is only utilized for introducing through a trocar. Once introduced, the rigid body motions of each tube by the rotary joints generate pivoting motion of the attached end-effector about the RCM point. This allows large reorientation of the end-effector's direction with minimal displacement. The serial link structure of the mechanism leads to analytic solutions for tractable kinematics. The design, manufacturing, and the validation of the kinematics of the mechanism are presented, and the feasibility of the mechanism is demonstrated through the peg transfer test using a teleoperated robot system.

中文翻译：

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具有关节运动和运动学可运动性的显微腹腔镜手术针镜腕机构

腹腔镜手术的侵袭性可以通过使用直径接近皮下注射针的直径的针镜仪器来进一步降低。然而，由于缺乏具有精确和尖锐的关节运动的腕部机构，这种针镜仪器受到限制。在本文中，我们为微型腹腔镜手术提供了具有关节运动和增强的运动学可牵引性的两自由度腕部机制。该机构由两个高度弯曲的镍钛合金管组成，这些镍钛合金管通过旋转接头串行连接，其轴线在远程运动中心（RCM）处相交。它的弹性仅用于通过套管针引入。一旦引入，通过旋转接头的每根管的刚体运动都会产生连接的末端执行器绕RCM点的枢转运动。这样可以对末端执行器进行较大的重新定向 s方向，位移最小。该机构的串行链接结构导致可解决运动学的解析解。介绍了该机构的运动学设计，制造和验证，并通过使用遥控机器人系统的销钉传递试验证明了该机构的可行性。