pecg package

• pecg.ecg package
  • pecg.ecg.FiducialPoints
    • FiducialPoints
      • FiducialPoints.wavedet()
      • FiducialPoints.epltd()
      • FiducialPoints.xqrs()
      • FiducialPoints.jqrs()
  • pecg.ecg.Biomarkers
    • Biomarkers
      • Biomarkers.intervals()
      • Biomarkers.waves()
  • Module contents

pecg.Preprocessing

class pecg.Preprocessing.Preprocessing(signal: array, fs: int)

Bases: object

The Preprocessing class provides some routines for pre-filtering the ECG signal as well as estimating the signal quality. :param signal: the ECG signal as a ndarray, with shape (L, N) when L is the number of channels or leads and N i the number of samples. :param fs: The sampling frequency of the signal [Hz].

import pecg
from pecg import Preprocessing as Pre
pre = Pre.Preprocessing(signal, fs)

notch(n_freq: int)

The notch function applies a notch filter in order to remove the power line artefacts. :param n_freq: The expected center frequency of the power line interference. Typically, 50Hz (e.g. Europe) or 60Hz (e.g. US) :return: The filtered ECG signal, with shape (L, N) when L is the number of channels or leads and N is the number of samples.

filtered_ecg_rec = pre.notch()

bpfilt()

The bpfilt function applies a bandpass filter between [0.67, 100] Hz, this function uses a zero-phase Butterworth filter with 75 coefficients. :return: The filtered ECG signal, with shape (L, N) when L is the number of channels or leads and N is the number of samples.

filtered_ecg_rec = pre.bpfilt()

bsqi(peaks: array = array([], dtype=float64), test_peaks: array = array([], dtype=float64))

bSQI is an automated algorithm to detect poor-quality electrocardiograms. This function is based on the following paper:[1]. The implementation itself is based on: [2].

[1]

Li, Qiao, Roger G. Mark, and Gari D. Clifford. “Robust heart rate estimation from multiple asynchronous noisy sources using signal quality indices and a Kalman filter.” Physiological measurement 29.1 (2007): 15.

[2]

Behar, J., Oster, J., Li, Q., & Clifford, G. D. (2013). ECG signal quality during arrhythmia and its application to false alarm reduction. IEEE transactions on biomedical engineering, 60(6), 1660-1666.

Parameters:

• peaks – Optional input- Annotation of the reference peak detector (Indices of the peaks), as an ndarray of shape (L,N), when L is the number of channels or leads and N is the number of peaks. If peaks are not given, the peaks are calculated with jqrs detector.

• test_peaks – Optional input - Annotation of the anther reference peak detector (Indices of the peaks), as an ndarray of shape (L,N), when N is the number of peaks. If test peaks are not given, the test peaks are calculated with xqrs detector.

Returns:

The ‘bsqi’ score, a flout between 0 and 1.

bsqi_score = pre.bsqi()
if bsqi_score < 0.8:
    print('It's a bad quality ECG recording!')

Module contents