(199) Fetal Heart Rate Measurement Using the Oxitone 1000M Wrist Device Compared to Standard Doppler Monitoring

The Oxitone 1000M is a wearable medical device designed for remote monitoring of heart rate using trans-illumination photoplethysmography technology from peripheral sites, specifically the maternal  wrist

This study aimed to evaluate the accuracy of fetal heart rate (FHR) measurement using the Oxitone 1000M device in comparison with the standard Doppler fetal heart rate monitor.

Study Design:

A prospective observational study comparing two methods of FHR assessment simultaneously. The Oxitone 1000M device and the hospital’s external Doppler monitor, the Philips Avalon FM30,as the reference.

Patients were recruited  in the second half of a low-risk, singleton pregnancy. Monitoring was conducted as part of routine prenatal follow-up.

The Oxitone algorithm’s performance was assessed using statistical methods, including correlation analysis and Bland-Altman plots, to evaluate agreement with the reference device.

Results:

We enrolled 20 participants who underwent NST. For each participant, FHR measurements obtained using the Oxitone algorithm and compared to those acquired from the reference device

The average gestational week was 34.6 ( 25.5-40.6 weeks) with an average BMI of 29.3 (18.1-39). Eight patients (40%) were primiparous, and 4 (20%) had contractions.

The average recording duration was 58 minutes (40- 100 minutes). In an average one-hour recording for each patient, signal data were obtained continuously for 54.9% of the time.

The majority of the averaged measurements obtained using the Oxitone algorithm fell within a ±10% error margin relative to the reference device.

We evaluated the agreement and differences between the fetal heart rate measurements derived from the Oxitone device and the reference device for all participants. A total of 89.9% of the calculated data points were within a ±10% error range. Among the remaining values, 8.57% exceeded the upper limit, while 1.53% fell below the lower limit, with an average error of 6.8767 bpm (4.31%) .

Conclusion:

The Oxitone 1000M is a pioneering wearable device that enables non-invasive, passive remote FHR monitoring from the maternal wrist.