Slope analysis based methods for detection of ventricular fibrillation and ventricular tachycardia

Ventricular fibrillation (VF) and ventricular tachycardia (VT) are among the life-threatening cardiac arrhythmias and their in-time and accurate detection are very significant. In this paper, the capability of slope to detect cardiac shockable arrhythmias as a feasible time-domain feature of the electro-cardiogram signal (ECG) is discussed. Several slope analysis methods were investigated and an innovative algorithm which works in real-time is introduced. Furthermore, slope analysis is employed in one of the genuine methods of VT and VF detection as a pre-processing step instead of the conventional amplitude thresholding and it is shown that it can better reflect the shockable cardiac arrhythmias irregularities. Finally, the validity of all the methods were assessed by 231 records collected from CCU of the Royal Infirmary of Edinburgh, MIT-BIH arrhythmia database, CU ventricular tachy-arrhythmia database (including 91 normal rhythm, 82 VT and 58 VF), all annotated and verified by expert cardiologists. The classification accuracy results showed a reliable performance in discrimination between normal, VT and VF rhythms.