Development and feasibility of a motor imagery-based brain-computer interface-controlled closed-loop functional...

Objective.Conventional swallowing functional electrical stimulation (FES) is usually delivered in open loop or triggered by peripheral signals, which may not align precisely with voluntary swallowing intention. We developed a motor imagery-based brain-computer interface (MI-BCI)-controlled closed-loop swallowing FES system for post-stroke dysphagia (PSD) and investigated its neurophysiological basis, decoding performance, and short-term feasibility.Approach.Two experiments were conducted. In experiment 1, swallowing MI (SMI)-related electroencephalography (EEG) features were identified in healthy controls (HC,n= 15), patients with PSD (n= 15), and post-stroke patients without dysphagia (PSND,n= 15). A threshold-based decoder based on Fp1 spectral power ratios was then validated in an independent HC cohort (n= 10). In experiment 2, 10 patients with PSD received 10 sessions of MI-BCI-controlled closed-loop swallowing FES over 2 weeks, and feasibility, usability, and safety were assessed.Main results.During SMI, Fp1 spectral power ratios decreased relative to rest. Theδ/αratio decreased significantly in all three groups, whereas theδ/(α + β)ratio and the(δ + θ)/(α + β)ratio decreased significantly in HC and PSND and showed the same downward trend in PSD. Patients with PSD also showed higherθ-band power at T3 than HC and PSND (P= 0.0382). The decoder achieved a mean classification accuracy of 71.5% in the independent validation cohort. In experiment 2, adherence was 100%, with 29.8 ± 6.2 successful closed-loop triggers per session, a mean system usability scale score of 72.8 ± 4.2, and no serious adverse events.Significance.These findings support the technical feasibility of the proposed system, indicate acceptable short-term usability, and show no major safety concerns during the intervention period.Trial Registration.ChiCTR2400079388.