Yuichiro Watanabe

Zero Method in Wagnere's Procedure for the Measurement of Phase Characteristics of ECG systems

In the conventional Wagners procedure for the measurement of phase characteristics, it is necessary to maintain the amplitude ratio of the fundamental frequency component to the third harmonic component in the output waveforms as 3 to 1. Otherwise, it is necessary to follow a tedious procedure of computation. The accuracy of the conventional Wagners procedure is poor because the phase delay is computed from the height of the peaks in the output waveforms. In this paper wepropose to enrol a zeromethod into Wagners procedure in order to improve the accuracy of the measurement of the phase delay. In the proposed procedure it is only necessary to make the height of the peaks equal to each other, and this can more accurately be done than the measurement of the height of the peaks. Consequently, zero method improves the accuracy of the measurement of the phase delay.