Influence of analysis duration on the accuracy of a shock advisory system

This study evaluates the influence of analysis duration on the accuracy of AED shock advisory system (SAS), which is adapted to provide `Shock´/`No Shock´ decision in real time at every second from 2s to 10s. MIT-BIH Malignant Ventricular Arrhythmia database is used for validation of the SAS accuracy on a computer. Four basic ECG criteria used in the presented SAS are evaluated: heart rate, slope uniformity of positive vs. negative peaks, deflections from signal extrema and signal mean in a narrow frequency band for enhancement of the QRS complexes. They show significant differences forshockable and non-shockable rhythms, considering all analysis durations. The presented SAS with analysis duration from 2s to 10s is fully compliant with the AHA performance goal for AEDs. Short ECG episodes, however, require verification for consistency of the rhythm over time.