Detecting Critical Patterns in Maternal-Fetal Heart Rate Signals

Abstract

The present study examined how individuals detect critical patterns in maternal-fetal heart rate (MFHR) signals. Twenty-eight undergraduate students monitored simulated maternal-fetal heart rate signals for decelerations lasting either 30 or 44 seconds. They completed four 10-min sessions representing four different signal-to-noise S/N ratios (10, 4, 2, and 1), in which the S/N ratio represented the magnitude of the deceleration to background heart rate variability. The results showed that the introduction of any variability reduced the ability to detect signals and increased false alarms. Further, with S/N ratios of 2 and 1 participants made equivalent numbers of hits and false alarms. These results show that as the S/N ratio decreases, observers struggle to distinguish critical patterns from the background fetal heart activity. These findings highlight the source of one problem often observed when interpreting MFHR signals in clinical settings and underscore the need for auxiliary aids.