New Indices Extracted from Fetal Heart Rate Signal for the Assessment of Fetal Well-Being

Abstract

In this paper, new parameters based on the Phase Rectified Signal Average (PRSA) of the Fetal Heart Rate (FHR) signal are introduced to assess fetal wellbeing. They are defined as the positive and negative slopes of the PRSA curve, namely Acceleration Phase Rectified Slope (APRS) and Deceleration Phase Rectified Slope (DPRS), depending on the sign of the slope. The parameters were computed on FHR time series recorded from 59 healthy and 61 Intra Uterine Growth Restricted (IUGR) fetuses, during CTG non-stress tests. The performance of APRS and DPRS was compared with the performance of other parameters extracted from the PRSA curve already existing in literature, and with other clinical indices that are provided by computerized cardiotocographic systems. The APRS and DPRS performed better than any other parameter considered in this study to distinguish between healthy and IUGR fetuses. We believe that these new indices might provide useful improvements of the quality of fetus early diagnosis.KeywordsCardiotocographyFetal MonitoringHeart Rate VariabilityPhase Rectified Signal Average