title: Separating sets of term and pre-term uterine EMG records.
abstract: The analysis of uterine EMG (electrohysterogram-EHG) records may help solve the problem of predicting pre-term labor. We investigated the adaptive autoregressive (AAR) method to estimate the EHG signal spectrograms and sample entropy, to separate and classify sets of term and pre-term delivery records, using the Term-Preterm EHG Database. The database contains four sets of records divided according to the time of delivery (term or pre-term: ⩾37 or < 37 weeks of gestation, respectively) and according to the time of recording (early or later: before or after the 26th week of gestation, respectively). Using the AAR method the term and pre-term delivery records recorded early can be separated (p = 0.002), as well as all term and pre-term delivery records (p < 0.001). Using the sample entropy, the results showed that all term and pre-term delivery records can be separated (p = 0.022). The spectra of the signals for term delivery records have the tendency of moving to lower frequencies as the time of pregnancy increases. We investigated a few classifiers to classify records between term and pre-term delivery sets. Using median frequency measurements and additional clinical information with the synthetic minority over-sampling technique, the quadratic discriminant analysis classifier achieved a 97% classification accuracy for the records recorded early, and 86% for all records regardless of the time of recording; while for the sample entropy measurements, for the same sets of records, using the support vector machine classifier, the classification accuracies were 80% and 87%, respectively.
authors.affiliation: Faculty of Computer and Information Science, University of Ljubljana, Večna pot 113, 1000 Ljubljana, Slovenia.
authors.forename: A
authors.initials: A
authors.lastname: Smrdel
authors.forename: F
authors.initials: F
authors.lastname: Jager
mesh_terms: D000465:Algorithms; D036861:Delivery, Obstetric; D004576:Electromyography / Q000379:methods*; D019277:Entropy; D005260:Female; D006801:Humans; D011247:Pregnancy; D047928:Premature Birth / Q000503:physiopathology*; D012815:Signal Processing, Computer-Assisted; D047929:Term Birth / Q000502:physiology*; D014599:Uterus / Q000502:physiology*