Applying Analysis Tools of Heart Rate Variability Upon Determining P-Wave Interval of ECG

One aspect in analysis of soundness of the heart is to monitor the variation of p-p interval in ECG the electrocardiogram. This paper reports an efficient hardware method of identifying the p-wave in the ECG and counting the time interval between successive p-waves. The hardware unit named as PWLL (p-wave locked loop) gets locked to the p-wave of the given ECG automatically and provides the p-p interval count in both analog and digital form. This count is read to PC for further analysis. Alternatively, in a software method an algorithm is used to identify the p-wave from the samples of ECG and the time interval is counted and presented. Graphical presentation of the current p-p time interval is made on the monitor screen. Also, important analysis tasks such as autocorrelation of p-p interval and its power spectral density are estimated and presented instantaneously. The visual presentation of these information enables the cardiologists to diagnose the functioning of the heart more effectively.