Constrained haptic-guided shared control for collaborative human–robot percutaneous nephrolithotomy training. (May 2021) - Wilz, Olivia
Abstract: Percutaneous nephrolithotomy is a procedure used to treat patients with large or irregularly shaped kidney stones. Surgical instruments are inserted through a small incision to access the kidney and remove the calculi. Surgeons who have less experience with the procedure manifest significantly higher rates of complications due to the procedure's steep learning curve. This issue is further exacerbated by a lack of training opportunities in clinical settings. This paper introduces a teleoperative framework that can provide training to surgeons as well as assistance during procedures, based on two main components. Firstly, a type of constrained inverse kinematics that decouples the tooltip position from its orientation using a remote centre of motion, and incorporates the joint limits analytically. This reduces the workload of the procedure by having the surgeon control only the tooltip position rather than the position and the orientation while preventing the inverse kinematics from returning joint angles outside of the robot's abilities. This kinematic framework also allows a three-degrees-of-freedom haptic device to control a six-degrees-of-freedom manipulator. Secondly, haptic feedback is provided to help guide and teach the surgeon during the procedure. Haptic feedback allows the surgeon to remain in full control during the procedure while still receiving haptic cues and assistance. Experimental results indicate that the haptic cues improved user's accuracy, and they had shorter and smoother paths. This leads to a shorter procedure time overall. The results also indicate that the haptic assistance helped teach users the ideal trajectory of the procedure and that users who were taught with haptic feedback performed better than those who never experienced any haptic feedback.