Novel Design of Mechanically Etched Concentric Tube Robot with Advanced Stability and Workspace

外科手术机器人为外科医生提供了额外的灵活性、精确度和控制能力，从而更准确、更有效地执行手术。然而，最小的商业手术机器人在5毫米到8毫米之间，这对于神经外科手术和通过单个切口或钻孔进行经口修复来说太大了。工业和研究团体已经尝试构建更小直径的电缆驱动的离散连接系统，但在机制和材料方面存在基本挑战，这是限制因素。一种新颖的方法是使用“连续”机器人机械手，其中机械手是一种连续的材料，可以驱动尖端控制。对于毫米尺寸的工具，我们提出了一种使用镍钛（Nitinol）形状记忆合金的方法，这种合金是在同心管机器人（CTR）中组装的。通过旋转和平移每个管子，人们可以在笛卡尔空间中控制尖端。CTRs为手术任务提供了足够的灵活性和刚度，但由于“扭转发条”，其工作空间受到限制。“扭转缠绕”是由内外管之间的摩擦引起的，其中远端尖端旋转可能与近端尖端输入不匹配。随着“发条”的增加，它会导致一个不稳定点，并导致不必要的咔嚓运动。为了克服扭转不稳定性，我们的研究将研究和优化在镍钛诺管上机械蚀刻各种图案的技术，以提高镍钛诺管的扭转线性响应。初步结果表明，简单的刻蚀模式可以提高线性度，消除“咔嗒”运动。这个假设有3个要点：1。蚀刻将产生具有增加扭转稳定性的蜂窝管。优化后的管子将减少手术工具的长度和曲率。蚀刻管可用于CTR进行神经外科和经口手术。在这项工作中，该项目将涉及2名博士研究生，临床研究员和一名研究工程师，他们将被培训为连续体机械手，机械优化和手术工具开发领域的专家。这项研究将在病童医院的图像引导创新和治疗干预中心（CIGITI）进行。CIGITI是领先的图像引导研究中心，其员工和学生在手术机器人研究领域获得了许多国际，国家和省级奖项。

Surgical robotics have provided surgeons with additional dexterity, precision and control to perform procedures more accurately and efficiently. However, the smallest commercial surgical robots range between 5mm and 8mm where they are too large for procedures in neurosurgery and trans-oral repairs through a single incision or burr hole. Industry and research groups have attempted to build smaller diameter cable driven discrete jointed systems but there are fundamental challenges in the mechanisms and materials which are limiting factors. A novel approach is use a "continuum" robotic manipulator where the manipulator is a continuous material that can be actuated for tip control. For millimetre-sized tools, we have proposed an approach to use Nickel Titanium (Nitinol) shape memory alloys that are thermally shape set where they are assembled in a concentric tube robot (CTR). By rotating and translating each tube, one is able to control the tip in Cartesian space. CTRs provide sufficient dexterity and stiffness for surgical tasks but there are limitations in their workspace due to "torsional wind-up". The "torsional wind-up" is caused by friction between the inner and outer tubes where the distal tip rotation may not match the proximal tip input. As this "wind-up" increases, it causes a point of instability and leads to unwanted snapping motion. To overcome the torsional instability, our research will study and optimize techniques to mechanically etch various patterns on Nitinol tubes to increase the linear response of the torsion of Nitinol tubes. Preliminary results have shown the simple etching patterns can increase the linearity and remove the "snapping" motion. There are 3 main points to the hypothesis: 1. Etching will create cellular tubes with increased torsional stability, 2. Optimized tubes will have reduced wind-up at lengths and curvatures for surgical tool and 3. Etched tubes can be implemented for a CTR to perform neurosurgery and trans-oral procedures. For this work, this project will involve 2 PhD level graduate students, clinical fellows and a research engineer who will be trained to be experts in the area of continuum manipulators, mechanical optimization and surgical tool development. This research will be conducted at the Centre for Image Guided Innovation and Therapeutic Intervention (CIGITI) at the Hospital for Sick Children. CIGITI is leading image guided research centre where its staff and students have received numerous international, national and provincial awards in the area of surgical robotics research.