Analog implementation of the single fiducial point alignment technique for real-time high resolution ECG analysis in the P-R interval

A real-time, signal averaging system for high-resolution ECG, which implements an analog version of the Single Fiducial Point (SFP) alignment technique was implemented and tested. The output pulse from the analog SFP detector was used as the trigger signal channel in a digital averaging oscilloscope with a moving average function. The performance of this ECG averaging system was evaluated in the spectral range between 100 and 300 Hz. The results of the system performance trials indicated the recovery of cardiac micropotential events, as short as 2 ms of duration, in the P-R interval, which reflected a relatively low trigger jitter (about /spl plusmn/0.5 ms), when compared with the one obtained using computer based methods, such as the maximum coherence matching (MCM) technique. The jitter error of this SFP averaging system was related to a bandwidth limitation of about 260 Hz.