Continuous decoding of movement onset and offset of sustained movements from cortical activities

Detection of movement intention from neural signals combined with assistant device provides an effective tool for neurorehabilitation. Since sustained movements are often required in motor rehabilitation therapies, it is important to monitor the onset and offset of the movement to ensure the participation of patients. In this study, we compared the movement-related cortical potentials (MRCPs) and event-related (de)synchronization (ERD/ERS) between different duration sustained movements. For mid and long duration movements, there are obvious MRCP and ERD around movement offset and the amplitude of MRCP increases as the duration increases. Besides, we built a pseudo-online detection system to detect the onset and offset of the movement. The average true positive rate (TPR) of onset detection is 85.2%. Compared to the onset, the offset is more difficult to detect, whose average TPR is 65.3%. This study could help us further understand the neural mechanism during sustained movements and provide guidance to build brain computer interface (BCI) for close-loop rehabilitation.