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

手术机器人技术为外科医生提供了额外的灵活性，精确性和控制，以更准确和有效地执行手术。然而，最小的商业手术机器人范围在5 mm和8 mm之间，它们对于神经外科手术和通过单个切口或钻孔的经口腔修复手术来说太大了。工业和研究团体已经尝试构建更小直径的线缆驱动的离散连接系统，但是在作为限制因素的机构和材料方面存在根本性的挑战。一种新颖的方法是使用“连续体”机器人操纵器，其中操纵器是可以被致动用于尖端控制的连续材料。对于毫米大小的工具，我们已经提出了一种方法，使用镍钛（镍钛诺）形状记忆合金，热形状设置，它们组装在一个同心管机器人（CTR）。通过旋转和平移每个管，能够在笛卡尔空间中控制尖端。CTR为手术任务提供了足够的灵活性和刚度，但由于“扭转缠绕”，其工作空间存在限制。“扭转缠绕”是由内管和外管之间的摩擦引起的，其中远端头端旋转可能与近端头端输入不匹配。随着这种“上紧”的增加，它会导致一个不稳定点，并导致不必要的快速运动。为了克服扭转不稳定性，我们的研究将研究和优化技术，在镍钛合金管上机械蚀刻各种图案，以增加镍钛合金管扭转的线性响应。初步结果表明，简单的蚀刻图案可以增加线性度，消除“抢购”运动。这个假设有三个要点：1。蚀刻将产生具有增加的扭转稳定性的蜂窝管，2。优化的管将减少手术工具的长度和曲率的缠绕，3.蚀刻管可用于CTR以执行神经外科手术和经口腔手术。对于这项工作，该项目将涉及2名博士水平的研究生，临床研究员和一名研究工程师，他们将接受培训，成为连续操作器，机械优化和手术工具开发领域的专家。这项研究将在患病儿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，其工作人员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.