Waveform phase shift study to compute the relationship between the mason-likar and the standard limb lead electrode placements

Variations due to electrode positions are particularly pronounced in the R-wave amplitudes in limb leads between resting ECG and stress ECG records as they are recorded with wrist or shoulder placed electrodes. Since the human torso is not electrically homogenous, the alteration in the morphology due to electrode position also causes a rotation in the phase angle of the waveform. The purpose of the present study is to analyze ECG waveforms, recorded simultaneously at different electrode positions and derive a transformation function that can project the waveform recorded in any electrode position to another shifted position. The computed transformation function provided an almost perfect ECG, visually indistinguishable from actual limb lead systems. A subject-specific transformation is available for interpolating ECG signals corresponding to any intermediate electrode location.