Refinement of the OBMedical LaborView System

Overview

Despite its limitations, fetal heart rate (FHR) tracing analysis is the best monitor of fetal well-being during labor or preparation for cesarean delivery. Current monitoring methods: transabdominal ultrasound (CTG: cardiotocograph) and fetal scalp electrodes (FSE) have limitations (tracing loss during fetal movement, potential to confuse maternal for fetal heart rate, inability to monitor during cesarean section or abdominal surgery) and, in the latter case, risks (infection, hematoma). A reliable, non-invasive monitor of the fetal heart rate that can be used during labor, non-obstetric and obstetric surgery during pregnancy is needed. Recent developments in use of maternal abdominal electrodes for extraction of the FHR and contraction information inform this study. LaborView®, developed by researchers at University of Florida (UF) College of Medicine and OBMedical, is an FDA-approved non-invasive labor monitoring device. Refinement of the extraction algorithms continues, and that work is most effectively performed at UF, where the primary researchers and OBMedical are located. LaborView monitoring will be recorded from up to150 subjects admitted to Labor and Delivery at UFHealth. Data will be simultaneously obtained from the standard labor monitor. These signals will then be analyzed off-line for comparison and refinement of algorithms.

Despite its limitations, fetal heart rate (FHR) tracing analysis is the best monitor of fetal well being during labor. Typically, continuous electronic fetal monitoring is via transabdominal ultrasound (CTG: cardiotocograph). A transducer is strapped to the maternal abdomen and positioned in such a way to detect fetal rather than maternal heart rate. There are occasional periods of signal loss as the patient or her fetus moves, as well as times when the monitor incorrectly records the maternal signal. Maternal obesity presents particular challenges to non-invasive monitoring. When there is particular concern regarding the fetal heart rate tracing the obstetrician may opt for a fetal scalp electrode (FSE). This is screwed into the fetus' presenting part through the opening in the cervix (requires ruptured membranes and adequate dilation). This signal is usually more reliable, but entails risks of chorioamnionitis, fetal scalp infection, scalp hematoma, and potential vertical transmission of maternal viruses including HIV and hepatitis. Recently, devices have come to market that extract the FHR and uterine electromyograph (EMG) from maternal abdominal electrodes. The proposed study will provide data for refinement of the LaborView device produced by OBMedical. Specific Aims: The goal of this research is to evaluate the LaborView device under various settings and fetal heart rate accuracy as compared to a traditional CTG monitor. Research Plan: All patients admitted to the Labor \& Delivery Suite at UF Health, will be eligible for inclusion in the study except minors and those unable to consent for themselves. Following written informed consent, the external monitors (tocodynamometer and ultrasound) may not be removed. Per LaborView directions, electrode application sites will be prepared to reduce skin impedance, electrodes will be applied to the maternal abdomen and data acquired for comparison with CTG data obtained through the traditional monitoring system. FHR, ECG (electrocardiography), and uterine activity data from the existing fetal monitors will be collected via a laptop PC connected to the systems for comparison. The comparison will be performed off-line. Evaluation of the data obtained will include (1) comparison of the calculated FHR with that of the CTG and/or fetal scalp electrode. Nothing is required of the subjects. They will be non-invasively monitored for one to several hours. The information obtained will not be used for medical decision-making and there is no significant risk to the patient or her fetus. No longitudinal follow-up is planned or indicated.