Fetal source extraction from magnetocardiographic recordings by dependent component analysis

Phys Med Biol. 2005 Oct 7;50(19):4457-64. doi: 10.1088/0031-9155/50/19/002. Epub 2005 Sep 13.

Abstract

Fetal magnetocardiography (fMCG) has been extensively reported in the literature as a non-invasive, prenatal technique that can be used to monitor various functions of the fetal heart. However, fMCG signals often have low signal-to-noise ratio (SNR) and are contaminated by strong interference from the mother's magnetocardiogram signal. A promising, efficient tool for extracting signals, even under low SNR conditions, is blind source separation (BSS), or independent component analysis (ICA). Herein we propose an algorithm based on a variation of ICA, where the signal of interest is extracted using a time delay obtained from an autocorrelation analysis. We model the system using autoregression, and identify the signal component of interest from the poles of the autocorrelation function. We show that the method is effective in removing the maternal signal, and is computationally efficient. We also compare our results to more established ICA methods, such as FastICA.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms*
  • Electrocardiography
  • Female
  • Fetal Monitoring*
  • Heart Rate, Fetal / physiology*
  • Humans
  • Magnetics*
  • Pregnancy
  • Signal Processing, Computer-Assisted