Design and experiment of an ankle rehabilitation robot after fracture surgery

In order to address the problem of functional rehabilitation after ankle fracture surgery. This paper presented a novel ankle fracture rehabilitation robot. The robot adopted R-3RRS-P hybrid structure, which was simple in structure and had two working modes: rehabilitation training and motion axis switching. Comparing with existing ankle rehabilitation robot, the proposed robot could simulate more realistic kinematics of ankle joint complex. Additionally, different body types of patients could be adapted. The kinematic and static models were established in detail using geometric method and screw theory. The coverage of the healthy ankle motion ability was formulated as an optimization problem to improve the robot performance. Multi-objective optimal design was carried out to determine the dimensional parameters. The interference-free working space was calculated by numerical method. A prototype of the proposed robot was developed, and a series of experiments were performed to evaluate the function and feasibility of the proposed robot.