A Combined Independent Source Separation and Quality Index Optimization Method for Fetal ECG Extraction from Abdominal Maternal Leads

Abstract

The non-invasive fetal electrocardiogram (fECG) technique has recently received considerable interest in monitoring fetal health. The aim of our paper is to propose a novel fECG algorithm based on the combination of the criteria of independent source separation and of a quality index optimization (ICAQIO-based). The algorithm was compared with two methods applying the two different criteria independently—the ICA-based and the QIO-based methods—which were previously developed by our group. All three methods were tested on the recently implemented Fetal ECG Synthetic Database (FECGSYNDB). Moreover, the performance of the algorithm was tested on real data from the PhysioNet fetal ECG Challenge 2013 Database. The proposed combined method outperformed the other two algorithms on the FECGSYNDB (ICAQIO-based: 98.78%, QIO-based: 97.77%, ICA-based: 97.61%). Significant differences were obtained in particular in the conditions when uterine contractions and maternal and fetal ectopic beats occurred. On the real data, all three methods obtained very high performances, with the QIO-based method proving slightly better than the other two (ICAQIO-based: 99.38%, QIO-based: 99.76%, ICA-based: 99.37%). The findings from this study suggest that the proposed method could potentially be applied as a novel algorithm for accurate extraction of fECG, especially in critical recording conditions.

Advanced Bioelectrical Signal Processing Methods: Past, Present and Future Approach—Part I: Cardiac Signals

“…Billeci and Varanini et al in 2017 [ 172 ] proposed a novel fECG algorithm based on the ICA and the quality index optimization (QIO), which made a new hybrid method (the ICAQIO-based method). They compared this hybrid method with the ICA and the QIO by way of synthetic data from the fECG synthetic database (FECGSYNDB) and the real data from the Physionet Challenge 2013 database [ 161 , 162 ].…”

Novel Hybrid Extraction Systems for Fetal Heart Rate Variability Monitoring Based on Non-Invasive Fetal Electrocardiogram

“…The TP determination interval was 50 ms left and 50 ms right of the reference annotations. This interval was determined based on a study by Billeci and Varanini in 2017 [125]. This interval then serves to determine the number of FNs.…”

“…By means of the TP, FP and FN values obtained, ACC can be calculated using equation 28, which is an estimate of the probability of correct detection of the R-peak (TP) by the hybrid method used relative to the reference. Parameter SE can be calculated using equation (29), PPV can be calculated using equation (30) and F1 can be calculated using equation (31) [58], [125].…”

“…The statistical evaluation of the fECG signal extraction quality relative to the reference can then be seen in Fig. 8, which illustrates a block scheme for plotting fHR variable curves over time, for plotting Bland-Altman graphs and for determining TP, FP, FN, µ, 1.96σ , ACC, SE, PPV and F1, see [58], [125], [128]. In the first step, the detection of R-peaks locations using a CWT-based detector is performed on the signals extracted, see [133]- [135].…”

Comparative Effectiveness of ICA and PCA in Extraction of Fetal ECG From Abdominal Signals: Toward Non-invasive Fetal Monitoring

“…The multi-source methods are based on Subspace Denoising Fatemi and Sameni ( 2017 ) or Blind Source Separation (BSS), namely: Independent Component Analysis (ICA), Martín-Clemente et al ( 2011 ), Vrins et al ( 2004 ), Najafabadi et al ( 2006 ), Mochimaru et al ( 2004 ), Sameni et al ( 2007 ), De Lathauwer et al ( 2000 ), Marossero et al ( 2003 ), Gurve et al ( 2017 ), Billeci and Maurizio ( 2017 ); Principal Component Analysis (PCA), Gurve et al ( 2017 ), Kahankova et al ( 2017b ), and so on. BSS is a frequently used method for fECG signal filtering.…”