Comparison of SVD methods to extract the foetal electrocardiogram from cutaneous electrode signals

  • D. Callaerts
  • B. De Moor
  • J. Vandewalle
  • W. Sansen
  • G. Vantrappen
  • J. Janssens
Physiological Measurement

Abstract

The paper presents and compares three methods making use of the singular value decomposition (SVD) of a matrix to extract the foetal electrocardiogram (FECG) from cutaneously recorded electrode signals. The first method constructs a set of orthogonal foetal signals (the so-called principal foetal signals) from the recordings, but needs electrode positions far from the foetal heart, in addition to the abdominal electrodes that pick up a mixture of maternal and foetal electrocardiogram. An online adaptive algorithm has been developed such that a real-time implementation becomes feasible. The second method is a new online approach to a technique presented by van Oosterom. Although this method has some important drawbacks and is suboptimal as far as foetal signal-to-noise ratio is concerned. it is still very useful when only a foetal trigger is required, as the signal obtained is not a complete FECG, Finally, a third method is proposed, based on the generalised SVD and interpreted with the new concept of oriented signal-to-signal ratio. An online version is also presented for this method and some results are shown.

Keywords

Abdominal foetal electrocardiogram Foetal principal signals GSVD Oriented energy Oriented signal-to-signal, SVD 

References

  1. Bergveld, P. andMeijer, J. H. (1981) A new technique for the suppression of the MECG.IEEE Trans.,BME-28, 348–354.Google Scholar
  2. Callaerts, D., Vanderschoot, J., Vandewalle, J., Sansen, W., Vantrappen, G. andJanssens, J. (1986a) An adaptive on-line method for the extraction of the complete foetal electrocardiogram from cutaneous multilead recordings.J. Perinat. Med.,14 (6), 421–433.Google Scholar
  3. Callaerts, D., Vanderschoot, J., Vandewalle, J. andSansen, W. (1986b). An on-line adaptive algorithm for signal processing using SVD. InSignal Processing III, Elsevier Science/North Holland/, Amsterdam, The Netherlands, EURASIP 86, The Hague, 953–956.Google Scholar
  4. Callaerts, D., Vanderschoot, J., Vandewalle, J., Sansen, W., Vantrappen, G. andJanssens, J. (1987) Fetal electrocardiogram measuring method and equipment (FEMME).J. Perinat. Med.,15, Suppl. 1, World Symposium on Computers in the Care of Mother, Fetus and Newborn, Vienna, 33.Google Scholar
  5. De Moor, B., Vandewalle, J. andStaar, J. (1987) Oriented energy and oriented signal-to-signal ratio concepts in the analysis of vector sequences and time series. InSVD and signal processing: algorithms, applications and architectures.Deprettere, E., (Ed.), North Holland, 209–232.Google Scholar
  6. de Moor, B. (1988) Mathematical concepts and techniques for modelling of static and dynamic systems. Ph.D. thesis, Department of Electrical Engineering, Katholieke Universiteit Leuven, Belgium, June 1988.Google Scholar
  7. Ferrara, E. R. andWidrow, B. (1982) Fetal electrocardiogram enhancement by time sequenced adaptive filtering.IEEE Trans.,BME-29, 458–460.Google Scholar
  8. Golub, G. H. andvan Loan, C. F. (1983)Matrix computations. North Oxford Academy, Oxford, UK.MATHGoogle Scholar
  9. Longini, R. L., Reichert, T. A., Yu, J. M. andCrowley, J. S. (1977) Near-orthogonal basis functions: a real time fetal ECG technique.IEEE Trans.,BME-24, 39–43.Google Scholar
  10. Ostendorp, T., van Oosterom, A., Jongsma, H. andvan Dongen, P. (1986) The potential distribution generated by the fetal heart at the maternal abdomen,J. Perinat. Med.,14, (6), 435–444.CrossRefGoogle Scholar
  11. Oostendorp, T. (1989) Modelling the fetal ECG. Ph.D. Thesis, Katholieke Universiteit Nijmegen, The Netherlands, Jan 1989.Google Scholar
  12. Parlett, B. N. (1980)The symmetric eigenvalue problem. Prentice Hall, Englewood Cliffs, New Jersey.MATHGoogle Scholar
  13. Plonsey, R. (1969)Bioelectric phenomena. McGraw-Hill, New York.Google Scholar
  14. Staar, J. (1982) Concepts for reliable modelling of linear systems with application to on-line identification of multivariable state space descriptions. Ph.D. thesis, Department of Electrical Engineering, Katholieke Universiteit Leuven, Belgium, June 1982.Google Scholar
  15. Sureau, C. andTrocellier, R. (1961) Etude de quelques problémes techniques en électrocardiographie foetale.Med. Electron. & Biol. Eng.,1, 181–188.Google Scholar
  16. van Bemmel, J. H. (1968) Detection of weak electrocardiograms by autocorrelation and crosscorrelation of envelopes.IEEE Trans.,BME-15, 17–23.Google Scholar
  17. van Oosterom, A. andAlsters, J. (1984) Removing the maternal component in the fetal ECG using singular value decomposition. InElectrocardiography '83.Ruttkay-Nedecky, I. andMacFarlane, P. (Eds.), Excerpta Medicine, Amsterdam, The Netherlands, 171–176.Google Scholar
  18. van Oosterom, A. (1986) Spatial filtering of the fetal electrocardiogram.J. Perinat. Med.,14, (6), 411–419.Google Scholar
  19. Vanderschoot, J., Vandewalle, J., Sansen, W., Vantrappen, G. andJanssens, J. (1983) An application of SVD to the extraction of weak bioelectrical signals.Revue HF,XII, 253–258.Google Scholar
  20. Vanderschoot, J., Vandewalle, J., Janssens, J., Sansen, W. andVantrappen, G. (1984) Extraction of weak bioelectrical signals by means of singular value decomposition. InAnalysis and optimization of systems.Bensoussan, A. andLions, J. L., (Eds.), Lecture Notes in Control and Information Sciences 63, Springer Verlag, Berlin, 434–448.Google Scholar
  21. Vanderschoot, J., Callaerts, D., Sansen, W., Vandewalle, J., Vantrappen, G. andJanssens, J. (1987) Two methods for optimal MECG elimination and FECG detection from skin electrode signals.IEEE Trans.,BME-34, 233–243.Google Scholar
  22. Vandewalle, J. andCallaerts, D. (1988) Singular value decomposition: a powerful concept and tool in signal processing. Proc. Conf. on Mathematics in Signal Processing, Warwick, Dec. 1988.Google Scholar
  23. Wheeler, T., Murrills, A. andShelley, T. (1978) Measurement of the fetal heart rate during pregnancy by a new electrocardiographic technique.Br. J. Obstet. Gynecol.,85, 12–17.Google Scholar
  24. Widrow, B., Glover, J. R., McCool, J. M., Kannitz, J., Williams, C. H. S., Hearn, R. M., Zeidler, J. R., Dong, E. andGoodlin, R. C. (1975) Adaptive noise cancelling: principles and applications.Proc. IEEE,63, 1692–1716.CrossRefGoogle Scholar

Copyright information

© IFMBE 1990

Authors and Affiliations

  • D. Callaerts
    • 1
  • B. De Moor
    • 1
  • J. Vandewalle
    • 1
  • W. Sansen
    • 1
  • G. Vantrappen
    • 2
  • J. Janssens
    • 2
  1. 1.Department of Electrical Engineering, ESAT LaboratoryKatholieke Universiteit LeuvenHeverleeBelgium
  2. 2.Department of Computer ScienceStanford UniversityStanfordUSA

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