During my bachelor’s thesis I examined if EEG markers could serve as a real-time index of consciousness for patients undergoing propofol-sedated endoscopy.
- Two-channel scalp EEG was bandpass-filtered into α (8–13 Hz), low-β (13–20 Hz), high-β (20–31 Hz), and γ (31–49 Hz) bands. Instantaneous amplitude, phase, and frequency were extracted via Hilbert transforms and resampled to 1 Hz.
- These features were compared with clinician annotations (including RASS) using ROC/AUC analysis to identify the most discriminative markers.
- Band-limited amplitudes—especially within the β range, with α supporting transitions between relaxed wakefulness and light sedation—proved most informative, whereas phase-synchronisation metrics generalised poorly across subjects.
- Variability in signal quality, occasional amplifier saturation, sampling-rate jitter, and metadata granularity prevented a single universal metric, motivating subject-specific modelling and richer datasets.
The results support multi-feature, personalised approaches for closed-loop sedation monitoring and highlight the need for larger, standardised corpora.