title: Fetal source extraction from magnetocardiographic recordings by dependent component analysis.
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.
authors.affiliation: Department of Physics and Mathematics, FFCLRP, University of Sao Paulo, Ribeirao Preto, SP, Brazil.
authors.forename: Draulio B
authors.initials: DB
authors.lastname: de Araujo
authors.forename: Allan Kardec
authors.initials: AK
authors.lastname: Barros
authors.forename: Carlos
authors.initials: C
authors.lastname: Estombelo-Montesco
authors.forename: Hui
authors.initials: H
authors.lastname: Zhao
authors.forename: A C Roque
authors.initials: AC
authors.lastname: da Silva Filho
authors.forename: Oswaldo
authors.initials: O
authors.lastname: Baffa
authors.forename: Ronald
authors.initials: R
authors.lastname: Wakai
authors.forename: Noboru
authors.initials: N
authors.lastname: Ohnishi
mesh_terms: D000465:Algorithms; D004562:Electrocardiography; D005260:Female; D005323:Fetal Monitoring; D006340:Heart Rate, Fetal / Q000502:physiology*; D006801:Humans; D008280:Magnetics; D011247:Pregnancy; D012815:Signal Processing, Computer-Assisted