Minimally invasive surgery (MIS) has recently seen a surge in clinical applications due to its potential benefits over open surgery. In MIS, a long manipulator is placed through a tortuous human orifice to create a channel for surgical tools and provide support when they are operated. Currently the relative large profile and low stiffness of the manipulators limit the effectiveness and accuracy of MIS. Here we propose a new foldable manipulator with tunable stiffness. The manipulator takes a braided skeleton to enable radial folding, whereas membrane is used to seal the skeleton so as to adjust stiffness through creating negative pressure. We demonstrated experimentally, numerically, and analytically that, a flexible and a rigid state were obtained, and the ratio of bending stiffness in the rigid state to that in the flexible state reached 6.85. In addition, the manipulator achieved a radial folding ratio of 1.95. The proposed manipulator shows great potential in the design of surgical robots for MIS. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B, 2019.

中文翻译：

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一种基于编织结构的刚度可调的可折叠机械手。

微创手术 (MIS) 由于其优于开放手术的潜在优势，最近在临床应用中出现了激增。在 MIS 中，一个长的机械手穿过一个曲折的人体孔道，为手术工具创建一个通道，并在操作时提供支持。目前，机械手相对较大的轮廓和低刚度限制了 MIS 的有效性和准确性。在这里，我们提出了一种具有可调刚度的新型可折叠机械手。机械手采用编织骨架实现径向折叠，而膜用于密封骨架，通过产生负压来调节刚度。我们通过实验、数值和分析证明，获得了柔性和刚性状态，刚性状态下的弯曲刚度与柔性状态下的弯曲刚度之比达到了 6.85。此外，机械手实现了1.95的径向折叠比。所提出的机械手在 MIS 手术机器人的设计中显示出巨大的潜力。© 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B，2019。