Comparison of SVD methods to extract the foetal electrocardiogram from cutaneous electrode signals.
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.
Callaerts
D
D
Katholieke Universiteit Leuven, Department of Electrical Engineering, Heverlee, Belgium.
De Moor
B
B
Vandewalle
J
J
Sansen
W
W
Vantrappen
G
G
Janssens
J
J
D004562:Electrocardiography / Q000379:methods*; D004566:Electrodes; D005333:Fetus / Q000502:physiology*; D006801:Humans; D008433:Mathematics; D012867:Skin