Extraction of Morphological, Time domain and Non-linear Features of FHR Signals

Electronic fetal heart rate monitoring is routinely performed by obstetricians in clinical settings to assess fetal health during labor. The Cardiotocograph (CTG) is an instrument used for the continuous recording of instantaneous fetal heart rate and uterine contractions. Various algorithms and software have been developed to extract and analyze several features from the recorded fetal heart rate signal. CTG-OAS is one such software that provides the user with the necessary tools to preprocess, extract, analyze, and classify the fetal heart rate variability. CTG-OAS was used to acquire various morphological, linear, and non-linear features from the CTG records of 57 patients. In the present study, FHR tracings were analyzed to extract the features of baseline fetal heart rate and its variability along with the number of accelerations and decelerations. The time domain features that define different types of fetal heart rate variability were also acquired along with the non-linear entropy parameters.