BCI protocol
shoulder abduction
SECONDARY
The design of the BCI-controlled functional electrical stimulator is shown in Fig. 
Flow chart of BCI training. (1–2) EEG amplifiers collect EEG signals generated during motor imagery. (2) Emotive Epoc + and 14 channels and two reference electrode placement positions. (3) A computer (OS Windows7): data processing and instruction conversion are performed, and motion intention is classified and decoded. (4) The computer side screen provides visual assistance and visual feedback during motor imagery. (5) The functional electrical stimulator stimulates the muscles to complete motor execution, giving sensory and perceptual feedbackBCI system comprised two monitor screens (one displayed the principal computer interface for the operation of the researchers, and the other performed prompt and feedback messages), a mainframe computer to record and process brainwave activity, and a FES equipment. The treatment was carried out in an independent and quiet room and included the following treatment steps: (1) patients comfortably sat at the secondary monitor screens of the BCI system; (2) they wore the electrode caps, which were used to collect electroencephalogram (EEG) signals through the 10–20 method of international standard electroencephalogram measurement, and conductive fluid was applied to the electrodes to ensure that each electrode is in good contact according to the screen prompts. (3) The appropriate treatment action was selected according to the patient’s specific situation. Silicone electrode pads were placed on the muscles for stimulation, and the current level was slowly adjusted so that it could be tolerated by the patients [The movements imagined by the exercise were: shoulder abduction, upper arm adduction, flexion of the forearm with the palm facing upward, wrist dorsiflexion, fist clenching, and wrist inversion. The selection was individualized according to the patient’s functional status and timely adjusted according to the patient’s different stages. The stimulation parameters were empirically determined to achieve the required motion without causing discomfort to the patient.