Determination of fetal heart rate from abdominal signals: evaluation of beat-to-beat accuracy in relation to the direct fetal electrocardiogram

Abstract

The main aim of our work was to assess the reliability of indirect abdominal electrocardiography as an alternative to the commonly used Doppler ultrasound monitoring technique. As a reference method, we used direct fetal electrocardiography. Direct and abdominal signals were acquired simultaneously, using dedicated instrumentation. The developed method of maternal signal suppression as well as fetal QRS complexes detection was presented. Recordings were collected during established labors, each consisted of four signals from the maternal abdomen and the reference signal acquired directly from the fetal head. After assessing the performance of the QRS detector, the accuracy of fetal heart rate measurement was evaluated. Additionally, to reduce the influence of inaccurately detected R-waves, some validation rules were proposed. The obtained results revealed that the indirect method is able to provide an accuracy sufficient for a reliable assessment of fetal heart rate variability. However, the method is very sensitive to recording conditions, influencing the quality of signals. Our investigations confirmed that abdominal electrocardiography, even in its current stage of development, offers an accuracy equal to or higher than an ultrasound method, at the same time providing some additional features.

Fetal Heart Rate Monitoring Using Maternal Abdominal Surface Electrodes in Third Trimester: Can We Obtain Additional Information Other than CTG Trace?

“…A transabdominal ECG can be performed with the Monica AN24 Monitor (Monica Healthcare, Nottingham, UK), MindChild Medical (North Andover, MA) and KOMPOREL (ITAM, Zabrze, Poland) [5]. The new system of spatiotemporal filtering used in the KOMPOREL allows for a decrease in the number of detection errors which significantly increases the detection performance for signals of very different quality [6,7].…”

Quantification of Fetal ST-Segment Deviations

“…Moreover, unfortunately no clinical report relative to the fetus conditions were available in the used "Abdominal and Direct Fetal Electrocardiogram Database" [10], so that not possible to link the obtained results to acid-base status of the fetuses in order to evaluate the metabolic acidosis birth.…”

“…Specifically, during labor, when the membranes were ruptured and the uterine cervix was dilated, a scalp electrode was applied to the fetal head and FECG was recorded [5]. All acquisitions (sampling frequency: 1000 Hz) were performed at the Department of Obstetrics at the Medical University of Silesia, and are part of "Abdominal and Direct Fetal Electrocardiogram Database" [10] of PhysioNet (www.physionet.org) [11], freely accessible on the web under the ODC Public Domain Dedication and License v1.0. The database has been fully anonymized and may be used without further Institutional Review Boards approval.…”

Quantification of Feto-Maternal Heart Rate from Abdominal ECG Signal Using Empirical Mode Decomposition for Heart Rate Variability Analysis

“…The first dataset was collected from the PhysioNet [49] website entitled "Abdominal and Direct Fetal Electrocardiogram Database" (adfecgdb), which contains multichannel fECG recordings obtained from 5 different women in labor, between 38 and 41 weeks of gestation [50][51][52]. Each recording consists of a reference direct fECG signal registered directly from the fetal scalp and four differential signals acquired by placing Ag-AgCl electrodes around the navel region of the maternal abdomen surface.…”