Affiliations: Department of Automation, Northwestern Polytechnical University, Xi'an, Shaanxi, China
Correspondence:
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Corresponding author: Pengju He, Department of Automation, Northwestern Polytechnical University, Xi'an 710129, Shaanxi, China. E-mail:hepengju@nwpu.edu.cn
Abstract: Nowadays, detecting fetal ECG using abdominal signal is a
commonly used method, but fetal ECG signal will be affected by maternal ECG.
Current FECG extraction algorithms are mainly aiming at multiple channels
signal. They often assume there is only one fetus and did not consider
multiple births. This paper proposed a single channel blind source
separation algorithm to process single abdominal acquired signal. This
algorithm decomposed single abdominal signal into multiple intrinsic mode
function (IMF) utilizing empirical mode decomposition (EMD). Correlation
matrix of IMF was calculated and independent ECG signal number was estimated
using eigenvalue method. Nonnegative matrix was constructed according to
determined number and decomposed IMF. Separation of MECG and FECG was
achieved utilizing nonnegative matrix factorization (NMF). Experiments
selected four channels man-made signal and two channels ECG to verify
correctness and feasibility of proposed algorithm. Results showed that the
proposed algorithm could determine number of independent signal in single
acquired signal. FECG could be extracted from single channel observed signal
and the algorithm can be used to solve separation of MECG and FECG.
