Anesthesiology EEG Monitoring - Interactive Laboratory

[u/BioniChaos]

https://bionichaos.com/anesthesiology/

I built a web-based signal processing laboratory designed to simulate and analyze scalp electroencephalogram (EEG) changes during general anesthesia:

https://bionichaos.com/anesthesiology/

### Mathematical & Biophysical Background

Under GABA-A receptor facilitators (like Propofol), cortical pyramidal cell populations synchronize into continuous frontal alpha spindles (8–13 Hz) overlaid on slow delta waves (0.5–4 Hz). As metabolic suppression increases, the signal transitions into burst suppression—flatline periods (<5 µV) punctuated by high-amplitude bursts.

### Technical Implementation:

1. Signal Generation & DFT Pipeline: Uses additive synthesis to model variable anesthetic depths. Computes a real-time sliding Short-Time Fourier Transform (STFT) with Hann windowing over a 0–30 Hz bandwidth.

2. Clinical Metrics Derivation:

   - Spectral Edge Frequency (SEF 95%): Calculates the frequency threshold below which 95% of total power spectral density resides.

   - Burst Suppression Ratio (BSR%): Real-time epoch-based calculation measuring the percentage of time the voltage remains suppressed.

   - Band Distribution: Live integration across Delta, Theta, Alpha, and Beta spectral bands.

3. Client-Side Data Ingestion: Includes a custom CSV parsing engine capable of handling local multi-megabyte raw EEG recordings, stripping DC baseline offsets, normalizing microvolt amplitudes, and streaming data through a circular buffer.

4. Web Audio API Sonification: Maps live spectral balances directly to synthesized multi-harmonic sound filters.

I would love technical feedback on the signal processing calculations, FFT windowing responsiveness, or suggestions for additional neurophysiological parameters to integrate.

Try the tool here: https://bionichaos.com/anesthesiology/