Joachim Behar, DPhil candidate, Dept. Eng. Sci.University of Oxfordhttp://joachim.behar.perso.neuf.fr/Joachim

Current issues in healthcare5. Foetal Electrocardiography

Centre for Doctoral Training in Healthcare Innovation

Goal: assessing the foetus well being. Early detection of cardiac abnormalities might help medications and precaution at delivery

Doppler ultrasound routinely used

Why using ECG? Study of the morphology and temporal parameters of the FECG could provide valuable information to assess the foetus well-being.

History Observed by M Cremer (1906)

Two methods for FECG Scalp ECG Abdominal ECG

The non invasive ECG is constituted by Foetal brain activity Myography (muscle signal) Movement artefacts Mixture of FECG and MECG (Multiple pregnancy)

Working in... Time domain? Frequency domain?

Working in the time domain ?

Fig: 3 seconds of FECG and MECG mixtures obtained using abdominal electrodes.

Working in the frequency domain ?

Fig: Power spectral density distribution using the burg method (order 20) and for 5min of scalp electrode ECG and 5min adult ECG.

Many attempt at separating the FECG from the MECG using various methods based on filtering, blind source separation, event synchronous canceller.

But “the analysis of foetal ECGs is still in its infancy…” (Sameni et al 2010)

The main problem is to extract t the FECG waveform…

… and prove that this is what you are actually looking for!

… and prove that the method is working on a sufficiently large database (by opposition to one subject).

Separation of the foetus ECG waveform from the mixture

And how do we scientifically prove that what we are extracting is the actual FECG waveform? (gold standard?)

…

A Review of Fetal ECG Signal Processing; Issues and Promising Directions. Reza Sameni1and Gari D. Cliord. The Open Pacing, Electrophysiology & Therapy Journal (TOPETJ), vol. 3, pp. 4-20, November 2010.

Martens, S.M.M., Rabotti, C., Mischi, M., and Sluijter, R.J. (2007). A robust fetal ECG detection method for abdominal recordings. Physiol. Meas., 28:373–388.

Noninvasive Fetal Electrocardiogram Extraction: Blind Separation Versus Adaptive Noise Cancellation Vicente Zarzoso, Associate Member, IEEE and Asoke K. Nandi*, Senior Member, IEEE

etc.