Purpose

The development of surgery is to be minimally invasive and collaborative with robot systems, which has caught increasing attention in recent years. However, the narrow access routes and confined working spaces in vivo usually make distal end-effectors of surgical systems not easy to operate. To overcome this problem, a novel cable-driven distal end-effector mechanism designed for single-port robotic surgery was proposed.

Methods

A cable-driven joint structure and the corresponding methods of threading cables were proposed which can maintain the length and even the tension force of cables constant during operation. Based on the proposed joint structure, the cable-driven distal end-effector mechanism consists of a parallelogram mechanism and a snake mechanism. The parallelogram mechanism is used to enlarge its reachable workspace through establishing the triangulation of operation. The snake mechanism is used to achieve the expected pose through providing sufficient bending degrees of freedom. All of the degrees of freedom can be decoupled at the expense of a slightly more tedious process of threading cables.

Results

The primary prototype and its miniature assembled and threaded manually performed as expected regardless of bend, translation and their combination. But the inadequate tension force of cables and assembly errors affect the load capacity and accuracy, which need to be improved by automatic assembly.

Conclusion

A cable-driven distal end-effector mechanism composed of a parallelogram mechanism, and a snake mechanism used for single-port robotic surgery was proposed. The mechanism adopts a novel cable-driven joint structure and corresponding methods of threading cables to keep the length and even the tension force of cables constant during surgery.

中文翻译：

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用于单端口机器人手术的电缆驱动远端执行器机构

目的

外科手术的发展将是微创的并与机器人系统协作，近年来，机器人系统已引起越来越多的关注。然而，体内狭窄的进入路径和狭窄的工作空间通常使外科手术系统的远端执行器不易于操作。为了克服这个问题，提出了一种为单端口机器人手术设计的新型电缆驱动的远端执行器机构。

方法

提出了一种电缆驱动的接头结构和相应的穿线电缆方法，该结构可以在操作过程中保持电缆的长度甚至张力恒定。基于提出的关节结构，电缆驱动的远端执行器机构由平行四边形机构和蛇形机构组成。平行四边形机制用于通过建立操作的三角测量来扩大其可到达的工作空间。蛇形机构用于通过提供足够的弯曲自由度来实现预期的姿势。所有的自由度都可以解耦，但要花费略微繁琐的电缆穿入过程。

结果

无论弯曲，平移及其组合如何，主要的原型及其微型组件均按预期方式手动组装和穿线。但是电缆的拉力不足和装配误差会影响负载能力和精度，这需要通过自动装配加以改进。

结论

提出了一种由平行四边形机构和用于单端口机器人手术的蛇形机构组成的电缆驱动的远端执行器机构。该机构采用新颖的电缆驱动接头结构和相应的电缆穿线方法，以在手术过程中保持电缆的长度甚至张力恒定。