Qi Ronghuai, Nayar Namrata U, Desai Jaydev P
Medical Robotics and Automation (RoboMed) Laboratory, Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA.
IEEE Trans Med Robot Bionics. 2023 Nov;5(4):867-878. doi: 10.1109/TMRB.2023.3310039. Epub 2023 Aug 30.
Mitral regurgitation (MR) is one of the most common valvular abnormalities, and the gold-standard for treatment is surgical mitral valve repair/replacement. Most patients with severe MR are over the age of 75, which makes open-heart surgery challenging. Thus, minimally invasive surgeries using transcatheter approaches are gaining popularity. This paper proposes the next generation of a robotic transcatheter delivery system for the mitral valve implant that focuses on the design of the actuation system, modeling, and task space control. The proposed actuation system is compact while still enabling bidirectional torsion, bending, and prismatic joint motion. A pulley structure is employed to actuate the torsion and bending joints using only one motor per joint in conjunction with an antagonistic passive spring to reduce tendon slack. The robotic transcatheter is also optimized to increase its stability and reduce bending deflection. An inverse kinematics model (with an optimization algorithm), singularity analysis method, and joint hysteresis and compensation model are developed and verified. Finally, a task space controller is also proposed. Experiments, including trajectory tracking and demonstrations of the robot motion in an porcine heart and a phantom heart through a tortuous path are presented.
二尖瓣反流（MR）是最常见的瓣膜异常之一，治疗的金标准是外科二尖瓣修复/置换术。大多数重度MR患者年龄超过75岁，这使得心脏直视手术具有挑战性。因此，使用经导管方法的微创手术越来越受欢迎。本文提出了一种用于二尖瓣植入的下一代机器人经导管输送系统，重点在于驱动系统的设计、建模和任务空间控制。所提出的驱动系统结构紧凑，同时仍能实现双向扭转、弯曲和棱柱关节运动。采用滑轮结构，每个关节仅使用一个电机来驱动扭转和弯曲关节，并结合一个对抗性被动弹簧以减少肌腱松弛。该机器人经导管也进行了优化，以提高其稳定性并减少弯曲挠度。开发并验证了逆运动学模型（带有优化算法）、奇异性分析方法以及关节滞后和补偿模型。最后，还提出了一个任务空间控制器。展示了包括轨迹跟踪以及机器人在猪心脏和模拟心脏中通过曲折路径的运动演示等实验。
