Automated Software Analysis of Fetal Movement Recorded during a Pregnant Woman’s Sleep at Home

Abstract

Fetal movement is an important biological index of fetal well-being. Since 2008, we have been developing an original capacitive acceleration sensor and device that a pregnant woman can easily use to record fetal movement by herself at home during sleep. In this study, we report a newly developed automated software system for analyzing recorded fetal movement. This study will introduce the system and compare its results to those of a manual analysis of the same fetal movement signals (Experiment I). We will also demonstrate an appropriate way to use the system (Experiment II). In Experiment I, fetal movement data reported previously for six pregnant women at 28-38 gestational weeks were used. We evaluated the agreement of the manual and automated analyses for the same 10-sec epochs using prevalence-adjusted bias-adjusted kappa (PABAK) including quantitative indicators for prevalence and bias. The mean PABAK value was 0.83, which can be considered almost perfect. In Experiment II, twelve pregnant women at 24-36 gestational weeks recorded fetal movement at night once every four weeks. Overall, mean fetal movement counts per hour during maternal sleep significantly decreased along with gestational weeks, though individual differences in fetal development were noted. This newly developed automated analysis system can provide important data throughout late pregnancy.

Reference values for a fetal movement acceleration measurement recorder to count fetal movements

“…Furthermore, an original computer software system for the FMAM recorder has been developed to automatically analyze and count fetal movements. We found a high agreement between manual and automated signal analysis, meaning the new software can be used to accurately count fetal movements and successfully minimize the number of artifacts (7). The FMAM recorder has made it possible for mothers to count gross fetal movements for many hours at home.…”

“…All data transferred to the computer were first analyzed using the newly developed software system (version 1.04A), and some revisions were made using its manual functions. These procedures have been explained in detail elsewhere (7). We will introduce them briefly here:…”

“…However, a minimum threshold amplitude level can be set at various levels and is helpful to reduce manual work. In a previous study (7), the default values were maternal level 20 and fetal level 15. In this study, we also set Articles | Ryo et al the fetal level at 20.…”

Correlation between umbilical cord length and gross fetal movement as counted by a fetal movement acceleration measurement recorder

“…An epoch with any fetal movements was judged to be one positive epoch. The decision was made using a custom-made software system (Version 1.04 A, NoruPro Light Systems, Inc. Tokyo Japan), which was developed for the FMAM recorder [12,14]. The ratio of positive epochs to all epochs during one night was calculated as the movement index.…”

A Wearable System for In-Home and Long-Term Assessment of Fetal Movement

“…In recent years, with the advancement of microelectronic technology as well as the development in signal processing, automatic detection of fetal movements by using accelerometers and advanced signal processing technologies has gained a lot of attention [9,10,11,12,13,14,15,16,17,18,19]. When contacted with the maternal abdominal wall, a movement of fetal body parts with sufficient force generates vibrations that could be detected by one or a set of accelerometers placed on the surface of the abdomen.…”