tests_hrv.py

import numpy as np

import neurokit2 as nk


def test_hrv_time():
    ecg_slow = nk.ecg_simulate(duration=60, sampling_rate=1000, heart_rate=70, random_state=42)
    ecg_fast = nk.ecg_simulate(duration=60, sampling_rate=1000, heart_rate=110, random_state=42)

    _, peaks_slow = nk.ecg_process(ecg_slow, sampling_rate=1000)
    _, peaks_fast = nk.ecg_process(ecg_fast, sampling_rate=1000)

    hrv_slow = nk.hrv_time(peaks_slow, sampling_rate=1000)
    hrv_fast = nk.hrv_time(peaks_fast, sampling_rate=1000)

    assert np.all(hrv_fast["HRV_RMSSD"] < hrv_slow["HRV_RMSSD"])
    assert np.all(hrv_fast["HRV_MeanNN"] < hrv_slow["HRV_MeanNN"])
    assert np.all(hrv_fast["HRV_SDNN"] < hrv_slow["HRV_SDNN"])
    assert np.all(hrv_fast["HRV_CVNN"] < hrv_slow["HRV_CVNN"])
    assert np.all(hrv_fast["HRV_CVSD"] < hrv_slow["HRV_CVSD"])
    assert np.all(hrv_fast["HRV_MedianNN"] < hrv_slow["HRV_MedianNN"])
    assert np.all(hrv_fast["HRV_MadNN"] < hrv_slow["HRV_MadNN"])
    assert np.all(hrv_fast["HRV_MCVNN"] < hrv_slow["HRV_MCVNN"])
    assert np.all(hrv_fast["HRV_pNN50"] == hrv_slow["HRV_pNN50"])
    assert np.all(hrv_fast["HRV_pNN20"] < hrv_slow["HRV_pNN20"])
    assert np.all(hrv_fast["HRV_TINN"] < hrv_slow["HRV_TINN"])
    assert np.all(hrv_fast["HRV_HTI"] > hrv_slow["HRV_HTI"])


def test_hrv_frequency():
    # Test frequency domain
    ecg1 = nk.ecg_simulate(duration=60, sampling_rate=2000, heart_rate=70, random_state=42)
    _, peaks1 = nk.ecg_process(ecg1, sampling_rate=2000)
    hrv1 = nk.hrv_frequency(peaks1, sampling_rate=2000)

    ecg2 = nk.signal_resample(ecg1, sampling_rate=2000, desired_sampling_rate=500)
    _, peaks2 = nk.ecg_process(ecg2, sampling_rate=500)
    hrv2 = nk.hrv_frequency(peaks2, sampling_rate=500)

    assert np.allclose(hrv1["HRV_HF"] - hrv2["HRV_HF"], 0, atol=1.5)
    assert np.isnan(hrv1["HRV_LF"][0])
    assert np.isnan(hrv2["HRV_LF"][0])
    assert np.isnan(hrv1["HRV_VLF"][0])
    assert np.isnan(hrv2["HRV_LF"][0])


def test_hrv():

    ecg = nk.ecg_simulate(duration=60, sampling_rate=1000, heart_rate=110, random_state=42)

    _, peaks = nk.ecg_process(ecg, sampling_rate=1000)

    ecg_hrv = nk.hrv(peaks, sampling_rate=1000)

    assert all(elem in ['HRV_RMSSD', 'HRV_MeanNN', 'HRV_SDNN', 'HRV_SDSD', 'HRV_CVNN',
                        'HRV_CVSD', 'HRV_MedianNN', 'HRV_MadNN', 'HRV_MCVNN',
                        'HRV_pNN50', 'HRV_pNN20', 'HRV_TINN', 'HRV_HTI', 'HRV_ULF',
                        'HRV_VLF', 'HRV_LF', 'HRV_HF', 'HRV_VHF', 'HRV_LFHF',
                        'HRV_LFn', 'HRV_HFn', 'HRV_LnHF',
                        'HRV_SD1', 'HRV_SD2', 'HRV_SD2SD1', 'HRV_CSI', 'HRV_CVI',
                        'HRV_CSI_Modified', 'HRV_SampEn']
               for elem in np.array(ecg_hrv.columns.values, dtype=str))