systole.hrv.frequency_domain#

systole.hrv.frequency_domain(rr: List | ndarray, sfreq: int = 5, method: str = 'welch', fbands: Dict[str, Tuple[str, Tuple[float, float], str]] | None = None, input_type: str = 'rr_ms') → DataFrame[source]#

Extract the frequency domain features of heart rate variability.

Parameters:

rr: R-R interval time-series, peaks or peaks index vectors. The default expected vector is R-R intervals in milliseconds. Other data format can be provided by specifying the “input_type” (can be “rr_s”, “peaks” or “peaks_idx”).
sfreq: The sampling frequency (Hz) used to interpolate the instantaneous heart rate for PSD computation.
method: The method used to extract the power of the different frequency bands. Default is 'welch' (only one method is implemented for now).
fbands: Dictionary containing the names of the frequency bands of interest (str), their range (tuples) and their color in the PSD plot. Default is >>> {‘vlf’: (‘Very low frequency’, (0.003, 0.04), ‘b’), >>> ‘lf’: (‘Low frequency’, (0.04, 0.15), ‘g’), >>> ‘hf’: (‘High frequency’, (0.15, 0.4), ‘r’)}
input_type: The type of input provided. Can be “peaks”, “peaks_idx”, “rr_ms” or “rr_s”. Defaults to “rr_ms”.

Returns:

stats: Frequency domain summary statistics. * ‘vlf_peak’ : Very low frequency peak (HZ). * ‘vlf_power’ : Very low frequency power (ms²). * ‘lf_peak’ : Low frquency peak (Hz). * ‘lf_power’ : Low frequency power (ms²). * ‘hf_peak’ : High frequency peak (Hz). * ‘hf_power’ : High frequency power (ms²). * ‘vlf_power_per’ : Very low frequency power (%). * ‘lf_power_per’ : Low frequency power (%). * ‘hf_power_per’ : High frequency power (%). * ‘lf_power_nu’ : Low frequency power (normalized units). * ‘hf_power_nu’ : High frequency power (normalized units). * ‘total_power’ : Total frequency power (ms²). * ‘lf_hf_ratio’ : Low / high frequency ratio (normalized units).