A flexible arrhythmia discrimination method based on fuzzy logic

A simple method to detect atrial fibrillation (AF) is added to the fuzzy logic-based arrhythmia discrimination method. Electrocadiogram(ECG) is analyzed as follows: (1)the degree of normalcy(DN) of ECG is evaluated by fuzzy logic and the average number of p waves is calculated, (2)if DN is less than 20%, the arrhythmia is judged as VF, (3)if DN is larger than 20%, AF is checked based on the number of p waves; if the number of p waves is two or less, ECG is judged as either NSR or VT based on the heart rate and its morphological features, and if the number of p wave is larger than two and the p-wave rate is less than 350bpm., ECG is judged as AF. Ten ECG charts(3 NSR, 5 AF, 2 VF) are evaluated using this algorithm. NSR and VF were successfully discriminated Four out of dye AFs could be detected as AF, while one case was judged as VT. Though the results obtained here are not perfect yet, since the program can be optimized for an individual patient very easily, we believe this is one of the promising methods which will be employed in the future cardiac devices.