Development of a closed-loop hand function rehabilitation system with high-density electromyogram-based motion decoding and electrical stimulation-based motion induction

Combining nerve electrical stimulation-based motion induction and electromyogram (EMG)-based motion decoding enables active rehabilitation and can potentially improve fine motor function in stroke patients. However, current commercial electrical stimulators lack the ability to switch between different stimulation sites, resulting in typically a single type of motion that cannot meet the needs of training for multiple hand motions. In addition, the stimulation current causes the EMG signals to contain stimulation artifacts, which directly affects the accuracy of motion decoding. In this study, we developed a closed-loop hand function rehabilitation training system based on peripheral nerve electrical stimulation and synchronous motion decoding. It consists of a high-density EMG acquisition module with real-time stimulation artifact removal and a multi-channel electrical stimulation module with a switching matrix. Its performance was experimentally tested and the results showed that the system can function faultlessly on healthy subjects. With this rehabilitation system, stroke patients can achieve active rehabilitation training with the unaffected hand driving the affected side, which can potentially help to change the neuroplasticity of brain and promote the recovery of motor function.