Real-time QRS detector using Stationary Wavelet Transform for Automated ECG Analysis

In this paper, we propose an online QRS detector algorithm using Stationary Wavelet Transforms (SWT) for real time beat detection from single-lead electrocardiogram (ECG) signals. Daubechies 3 (‘db3’) wavelet is chosen as the mother wavelet for SWT analysis. The information from the first ten seconds of the ECG signal is used as a learning template by the algorithm to initialize thresholds for beat detection. These thresholds are then modified every three seconds, thereby quickly adapting to changes in heart rate and signal quality. Hence false beat detections are vastly suppressed in this approach, while identifying true beats with a high degree of accuracy. Our algorithm yields a sensitivity (SE) of 99.88% and a positive predictive value (PPV) of 99.84% on the MIT-BIH Arrhythmia Database, SE of 99.80% and PPV of 99.91% on the AHA database and an SE of 99.97% and PPV of 99.90% on the QT database.