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

Abstract

Continuous Passive Motion (CPM) is a postoperative orthopedic treatment or physiotherapy. After surgery in Ulna Collateral Ligament (UCL) injury to the el-bow, 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 sup-presses the reaction force, but the UCL may be ex-tended excessively by the pro/supination. In this pa-per, focusing on postoperative UCL treatment, we pro-pose 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.