NOISE COHERENCE IN CLOSELY-SPACED ELECTRODES - THE IMPLICATIONS FOR SPATIAL AVERAGED ECG RECORDINGS

Ensemble signal averaging is conventionally used to reduce the noire c ontent of ECG recordings. One shortcoming of this technique is that it removes the possibility of registering transient signals. As a conseq uence the simultaneous averaging of spatially related lead; has been u sed. This relies on the recording electrodes receiving correlated sign al components for reinforcement together with uncorrelated noise. We h ave developed a methodology for studying EMG noise reduction by spatia l averaging and present results for different electrode spacings which suggest minimum separations for noise rejection.