ABSTRACT Extraction of foetal heartbeat rate from a single passive sound sensor on the mother’s abdomen is demonstrated. The extraction is based on the assumption that a disjoint band of frequencies exist and foetal signal is concentrated in this band, and further that it can be represented conveniently as a set of wavelet coefficients. The algorithm has been applied to each stream of data obtained from six different channels and the detection performance is elaborated. The algorithm has also been tested on signals from non-pregnant abdomens to show successful rejection of adult heartbeat. The extraction of the desired signal is done in two stages so as to eliminate components from the maternal heart-beat.
Cite this paper
nullAcharyya, R. , Scott, N. and Teal, P. (2009) Non-invasive foetal heartbeat rate extraction from an underdetermined single signal. Health, 1, 111-116. doi: 10.4236/health.2009.12018.
 Varady,, P., Wildt, L., Benyó, Z., and Hein, A. (2003) An advanced method in fetal phonocardiography, Computer Methods and Programs in Biomedicine, 71, 283-296.
Kovacs, F., Torok, M., Habermajer, I. (2000) A rule- based phonocar-diographic method for long-term fetal heart rate monitoring. IEEE Trans. on Biomed. Eng., 47(1).
Haykin, S. (2000) Unsupervised adaptive filtering, Vol 1: Blind source separation, Wiley.
Makino, S., Lee, T., and Sawada, H. (2007) Blind speech separation, Springer.
Yilmaz,O. and Rickard,S. (2004) Blind separation of speech mixtures via time frequency masking,” IEEE Transaction on Signal Processing, 52(7), 1830-1847.
Kieler, H., Cnattingius,S., Haglund, B., Palmgren, J., and Axelsson, O. (2002) Ultrasound and adverse effects, Ul-trasound in Obstetrics and Gynaecology, 20(1), 102-103.
Hyvarinen, A., Karhunen, J. and Oja, E. (2001) Inde-pendent component analysis, John Wiley & Sons.
Acharyya, R., Scott, N.L., Teal, P., Deuss, E., and Flierl, J. (2008) Signal separation for non-invasive monitoring of foetal heartbeat, BioMedical Engineering and Infor-matics.
Acharyya, R. and Flierl, J. (2008) Blind source separa-tion by time frequency masking of an underdetermined system, International Conference on Bioinformatics and Biomedical Engineering.
Jimenez-Gonzalez, A. and James, C.J. (2008) Blind source separation to extract foetal heart sounds from noisy abdominal phonograms: A single channel method, 4th IET International Conference on Advances in Medi-cal, Signal and Information Processing, MEDSIP’08.
Jiménez-González, A., James, C.J. (2009) Extracting sources from noisy abdominal phonograms: A sin-gle-channel blind source separation method, Medical and Biological Engineering and Computing, 47(6), 655-64.
Strang G. and Nguyen, T. (1997) Wavelet and filter banks, Wellesley-Cambridge Press.