Robotics Research Center, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, Singapore.
The Photonics Institute, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, Singapore.
Ann Biomed Eng. 2020 Jan;48(1):342-356. doi: 10.1007/s10439-019-02352-8. Epub 2019 Sep 4.
Haptic feedback for flexible endoscopic surgical robots is challenging due to space constraints for sensors and shape-dependent force hysteresis of tendon-sheath mechanisms (TSMs). This paper proposes (1) a single-axis fiber Bragg grating (FBG)-based force sensor for a TSM of a robotic arm and (2) an integrated sensor-model approach to estimate forces on other TSMs of that arm. With a robust and simple structure, a temperature-compensated sensor can be mounted on the distal sheath to measure forces applied by the TSM. This proposed sensor was integrated with a Ø4.2 mm articulated robotic arm driven by six TSMs, with a measurement error of 0.37 N in this work. The measurement from the single sensor was used to identify parameters in the force-transmission models of all other TSMs in the robot, realizing a one-sensor-for-all-distal-forces measurement method. The sensor-model approach could accurately estimate the distal force with an RMSE of 0.65 N. An animal study was carried out to demonstrate the sensor's feasibility in real-life surgery. The sensor-model approach presented a robust, space-saving, and cost-effective solution for haptic feedback of endoscopic robots without any assumption on the shapes of the robot.
由于传感器的空间限制和肌腱鞘机构（TSM）的形状相关力滞后，用于柔性内窥镜手术机器人的触觉反馈具有挑战性。本文提出了 (1) 一种用于机器人臂 TSM 的单轴光纤布拉格光栅（FBG）力传感器，以及 (2) 一种用于估计该臂其他 TSM 上力的集成传感器-模型方法。具有坚固且简单的结构，温度补偿传感器可以安装在远端护套上，以测量 TSM 施加的力。在这项工作中，该传感器与一个 Ø4.2 毫米的铰接机器人臂集成在一起，该机器人臂由六个 TSM 驱动，测量误差为 0.37 N。从单个传感器的测量结果用于识别机器人中所有其他 TSM 的力传递模型中的参数，实现了一种用于所有远端力测量的单传感器方法。传感器-模型方法可以准确估计远端力，均方根误差为 0.65 N。进行了动物研究以证明传感器在实际手术中的可行性。传感器-模型方法为内窥镜机器人的触觉反馈提供了一种稳健、节省空间和具有成本效益的解决方案，而无需对机器人的形状做出任何假设。
