Traitement de l'électromyogramme utérin pour la caractérisation des contractions pendant la grossesse

abstract The uterine electrohysterogram (EWG) has been recorded on the abdomen of pregnant women, from 19 to 37 weeks of gestation (WG), and processed in order to detect preterm delivery. The EHG being corrupted by different electromagnetic noises, we have developed specific algorithms, based on wavelet decomposition, for the denoising of the EHG. Classical parameters, extracted from the spectral and temporal representations and from the instantaneous frequency of the EHG, have permitted us to follow the solution of the signals during pregnancy, Furthermore, a discriminant analysis permitted us to evidence a difference between contractions leading to term or preterm deliveries, as soon as 30 WG Non-stationary parameters have then been computed from EHG signals, in order to follow the two electrical waves that are known on animal recordings to be related to contraction efficiency. The extraction and characterization of these waves are made by extracting the ridges of the scalogram, computed from the continuous wavelet transform. The instrumental part development has started with the analysis of maternal movement artifacts, and with the comparison of different kinds of electrodes, suitable for 24 hours recording. A first portable recorder prototype is presently under development.