On two weighted signal averaging methods and their application to the surface detection of cardiac micropotentials

In this paper, the variance normalized averaging (VNA) and the optimal weighted averaging (OWA) are derived and their application to the surface detection of cardiac micropotentials is discussed. Theoretical analysis and computer simulation showed that VNA and OWA are superior to the conventional signal averaging (CSA) in reducing random noise with changing variance and the larger the change of noise variance the better the improvements of VNA and OWA relative to CSA. Clinical application of VNA and OWA using a proposed noise variance estimation technique indicated that residual noise on the PR and ST segments can be further reduced in most of the cases. This manifests that the new techniques have a potential advantage for improving the effectiveness of signal averaging as a fundamental method for surface detection of cardiac micropotentials.