Recovery of missing samples in fetal heart rate recordings with Gaussian processes

Missing samples are very common in fetal heart rate (FHR) recordings due to various reasons including fetal or maternal movements and misplaced electrodes. They introduce distortions and cause difficulties in their analysis. In this paper, we propose a Gaussian process-based method that can utilize other intrapartum signals (e.g., uterine activity and maternal heart rate) to recover the missing samples in FHR recordings. The proposed approach was tested on a short real FHR recording segment and its performance was compared with that of cubic spline interpolation which is widely used in pre-processing of FHR recordings. Our results show that the proposed approach, with utilization of UA signals, achieves 2.35 dB to 14.85 dB better recovery performance. Furthermore, even when the percentage of missing samples is more than 50%, the mean square error of this approach is still below one beat per minute.