Brno University of Technology ECG Quality Database (BUT QDB)

BUT QDB is a database created by the cardiology team at the Department ofBiomedical Engineering, Brno University of Technology, for the purpose ofevaluating ECG quality. The data comprises 18 long-term recordings of single-lead ECGs and associated 3-axis accelerometer data, collected from 15 subjects(9 female, 6 male) aged between 21 to 83 years. Recordings were carried outbetween August 2018 and October 2019 while the subjects were undertakingordinary everyday activities ("free-living conditions"). Data was collectedusing a mobile ECG and accelerometer (Bittium Faros 180) with a samplingfrequency of 1,000 Hz for ECG signals and 100 Hz for accelerometer signals.The minimum length of recording is 24 hours.Three signals were fully annotated in terms of ECG signal quality. Theremaining 15 signals were annotated in two selected segments, each of 20minutes in duration. Furthermore, five additional segments of poor signalquality were also annotated. Signal quality was classified as follows: Class 1indicates that all ECG significant waveforms (P wave, T wave and QRS complex)are clearly visible and their onsets and offsets can be detected reliably;Class 2 indicates that the noise level is increased and ECG significant pointscannot be reliably detected, but the signal enables reliable QRS detection;Class 3 indicates that QRS complexes cannot be detected reliably and thesignal is unsuitable for any further analysis.