Cable-Conduit-Driven Parallel Hip Exoskeleton and Its Implementation in Rehabilitation Training

Rehabilitation training of patients who received total hip arthroplasty (THA) operation is necessary for their rebuilding of motor function. However, most existing exoskeleton devices for hip rehabilitation have an anthropomorphic structure. Misalignment between the mechanical and planted prothesis center is a problem that can cause additional stress in the hip for anthropomorphic exoskeletons, which are thus not applicable to THA rehabilitation training process. Also, the parasitic force due to the cable pulling of soft exoskeletons is also regarded as a shortcoming for users. To address these limitations and to provide training assistance for THA patients for better recovery, a novel hip exoskeleton with parallel structure is presented in this paper. The proposed exoskeleton has a remote actuation and Cable-conduit transmissions and is hence light in weight and can provide bidirectional assistive/resistive torque in the hip without generating stress in the hip, which is significant for THA patients having weak and sensitive planted hip joints. A controller is presented for a stable and safe human-machine interfacing during training with desired assistance delivered. Experiment results based on a benchmark platform verify the performance of the proposed exoskeletons system.