Trajectory Generation of CPM Device for Upper Limbs Considering Constraint Caused by Joint Disorder

Continuous Passive Motion (CPM) is a postoperative orthopedic treatment or physiotherapy. After surgery in Ulna Collateral Ligament (UCL) injury to the elbow, excessive UCL extension aggravates the injury. Postoperative large stiffness increases reaction force at hand of patient excessively near the end of the range of motion. Controlling pro/supination effectively suppresses the reaction force, but the UCL may be extended excessively by the pro/supination. In this paper, focusing on postoperative UCL treatment, we propose the trajectory generation method for controlling the pro/supination to suppress both the reaction force and the UCL extension based on a skeleton model. Finally, experimental results with simulated patient show the effectiveness of our proposal. 1