The BSSR method extracted fetal ECG signals with a significantly higher correlation to directly recorded scalp ECGs compared to nonholonomic ICA (r=0.88 vs 0.74, p<0.01).
Does a novel extraction method using maternal ECG cancellation and BSSR accurately extract fetal ECG from abdominal composite signals compared to direct recording?
A novel signal processing method combining maternal ECG cancellation and blind source separation accurately extracts fetal ECG components from abdominal signals.
Absolute Event Rate: 0.88% vs 0.74%
p-value: p=<0.01
In contrast to the ultrasonic measurement of fetal heart motion, the fetal electrocardiogram (ECG) provides clinically significant information concerning the electrophysiological state of a fetus. In this paper, a novel method for extracting the fetal ECG from abdominal composite signals is proposed. This method consists of the cancellation of the mother's ECG and blind source separation with the reference signal (BSSR). The cancellation of the mother's ECG component was performed by subtracting the linear combination of mutually orthogonal projections of the heart vector. The BSSR is a fixed-point algorithm, the Lagrange function of which includes the higher order cross-correlation between the extracted signal and the reference signal as the cost term rather than a constraint. This realizes the convexity of the Lagrange function in a simple form, which guarantees the convergence of the algorithm. By practical application, the proposed method has been shown to be able to extract the P and T waves in addition to the R wave. The reliability and accuracy of the proposed method was confirmed by comparing the extracted signals with the directly recorded ECG at the second stage of labor. The gestational age-dependency of the physiological parameters of the extracted fetal ECG also coincided well with that of the magnetocardiogram, which proves the clinical applicability of the proposed method
Sato et al. (Tue,) conducted a other in Pregnancy (fetal ECG monitoring) (n=37). Blind source separation with reference signal (BSSR) vs. Nonholonomic independent component analysis (ICA) was evaluated on Correlation coefficient with directly recorded fetal scalp ECG (p=<0.01). The BSSR method extracted fetal ECG signals with a significantly higher correlation to directly recorded scalp ECGs compared to nonholonomic ICA (r=0.88 vs 0.74, p<0.01).