Signal Processing

import { initEegWasm, band_powers } from "@elata-biosciences/eeg-web";

await initEegWasm();

const powers = band_powers(samples, sampleRateHz);
// powers.delta  0.5-4 Hz
// powers.theta  4-8 Hz
// powers.alpha  8-13 Hz
// powers.beta   13-30 Hz
// powers.gamma  30-100 Hz

import {
  alpha_power,
  beta_power,
  theta_power,
  delta_power,
  gamma_power,
  custom_band_power,
} from "@elata-biosciences/eeg-web";

const alpha = alpha_power(samples, sampleRateHz);
const beta = beta_power(samples, sampleRateHz);
const theta = theta_power(samples, sampleRateHz);
const delta = delta_power(samples, sampleRateHz);
const gamma = gamma_power(samples, sampleRateHz);

// Custom frequency range
const mu = custom_band_power(samples, sampleRateHz, 8.0, 12.0);

import { compute_power_spectrum, get_fft_frequencies } from "@elata-biosciences/eeg-web";

const spectrum = compute_power_spectrum(samples, sampleRateHz);
const frequencies = get_fft_frequencies(samples.length, sampleRateHz);

// spectrum[i] is the power at frequencies[i] Hz

const frame: HeadbandFrameV1 = /* ... from transport ... */;
const channelIndex = 0; // TP9

const channelSamples = frame.eeg.samples.map(row => row[channelIndex]);
const powers = band_powers(new Float64Array(channelSamples), frame.eeg.sampleRateHz);