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Licensed Unlicensed Requires Authentication Published by De Gruyter February 22, 2007

Fetal ECG extraction during labor using an adaptive maternal beat subtraction technique

Mihaela Ungureanu, Johannes W.M. Bergmans, Swan Guid Oei and Rodica Strungaru
From the journal


Fetal ECG (FECG) monitoring using abdominal maternal signals is a non-invasive technique that allows early detection of changes in fetal wellbeing. Several other signal components have stronger energy than the FECG, the most important being maternal ECG (MECG) and, especially during labor, uterine EMG. This study proposes a new method to subtract MECG after detecting and removing abdominal signal segments with high-amplitude variations due to uterine contractions. The method removes MECG from abdominal signals using an approximation of the current MECG segment based on a linear combination of previous MECG segments aligned on the R-peak. The coefficients of the linear model are computed so that the squared error of the approximation over the whole current segment is minimized. Abdominal signal segments strongly affected by uterine contractions are detected by applying median filtering. The methods proposed are tested on real abdominal data recorded during labor, with FECG recorded using scalp electrodes synchronously recorded for comparison.

Corresponding author: Mihaela Ungureanu, Applied Electronics and Information Engineering Department, Politehnica University of Bucharest, 061071, Romania Phone: +40-21-4114429 Fax: +40-21-2243654


[1] Ungureanu M, Bergmans JWM, Oei SG, Strungaru R, Mischi M. Improved method for fetal heart rate monitoring. In: Proceedings of the 27th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, China 2005: 5916–5919.10.1109/IEMBS.2005.1615837Search in Google Scholar

[2] Van Bemmel JH. Detection and processing of foetal electrocardiograms. PhD dissertation. Utrecht: Frafisch Bedrijf Schotanus & Jens NV 1969.Search in Google Scholar

[3] Akselrod S, Karin J, Hirsch M. Computerized detection of fetal ECG from maternal abdominal signal. Proc IEEE Conf Comput Cardiol1987; 14: 261–264.Search in Google Scholar

[4] Devedeux D, Marque C, Mansour S, Germain G, Duchene J. Uterine electromyography: a critical review. Am J Obstet Gynecol1993; 169: 1636–1653.10.1016/0002-9378(93)90456-SSearch in Google Scholar

[5] Outram NJ, Ifeachor EC, van Eetvelt PWJ, Curnow JSH. Techniques for optimal enhancement and feature extraction of fetal electrocardiogram. IEEE Proc Sci Meas Technol1995; 142: 482–489.10.1049/ip-smt:19952074Search in Google Scholar

[6] Widrow B, Glover JR, McCool JM, et al. Adaptive noise cancelling: principles and applications. Proc IEEE1975; 63: 1692–1716.10.1109/PROC.1975.10036Search in Google Scholar

[7] Richter M, Schreiber T, Kaplan DT. Fetal ECG extraction with nonlinear state-space projections. IEEE Trans Biomed Eng1998; 45: 133–137.10.1109/10.650369Search in Google Scholar

[8] De Lathauwer L, De Moor B, Vandewalle J. Fetal electrocardiogram extraction by blind source subspace separation. IEEE Trans Biomed Eng2000; 47: 567–572.10.1109/10.841326Search in Google Scholar

[9] Deng Y, Wolf W, Schnell R, Appel U. New aspects to event-synchronous cancellation of the ECG interference: an application of the method in diaphragmatic EMG signals. IEEE Trans Biomed Eng2000; 47: 1177–1184.10.1109/10.867924Search in Google Scholar

[10] Ungureanu M, Kroworsch B, Wolf W. Diaphragmatic EMG monitoring: some aspects on specific signal processing requirements. In: Pandalai SG, editor. Recent research developments in biomedical engineering. Trivandrum, India: Transworld Research Network 2002: 49–66.Search in Google Scholar

[11] Comani S, Mantini D, Lagatta A, Esposito F, Di Luzion S, Romani GL. Time course reconstruction of the fetal cardiac signals from fMCG: independent component analysis versus adaptive maternal beat subtraction. Phys Meas2004; 25: 1305–1321.10.1088/0967-3334/25/5/019Search in Google Scholar

[12] Astola J, Kuosmanen P. Fundamentals of nonlinear digital filtering. Boca Raton, FL: CRC Press 1997: Chapter 1.Search in Google Scholar

[13] Rangayyan RM. Biomedical signal analysis. New York: John Wiley & Sons 2002: 85–90.10.1109/9780470544204Search in Google Scholar

[14] Rompelman O, Ros HH. Coherent averaging techniques: a tutorial review. Part 1: noise reduction and the equivalent filter. J Biomed Eng1986; 8: 24–29.10.1016/0141-5425(86)90026-9Search in Google Scholar

[15] Reichert TA, Longini RL, Crowley JS, Yu JM. A noninvasive extraction of the fetal electrocardiogram. Comput Biomed Res1977; 10: 1–7.10.1016/0010-4809(77)90046-5Search in Google Scholar

[16] Bergveld P, Meijer WJH. A new technique for the suppression of the MECG. IEEE Trans Biomed Eng1981; 28: 348–353.10.1109/TBME.1981.324803Search in Google Scholar PubMed

[17] Azevedo S, Longini R. Abdominal-lead fetal electrocardiographic R-wave enhancement for heart rate determination. IEEE Trans Biomed Eng1980; 27: 255–260.10.1109/TBME.1980.326631Search in Google Scholar PubMed

[18] Geue D, van Leeuwen P, Lange S, Gronemeyer D. Simulation of coupling behavior of heart rhythms for study of phase synchronization. Biomed Tech2002; 47: 229–232.10.1515/bmte.2002.47.s1a.229Search in Google Scholar PubMed

Published Online: 2007-02-22
Published in Print: 2007-02-01

©2007 by Walter de Gruyter Berlin New York

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