New Method for Beat-to-Beat Fetal Heart Rate Measurement Using Doppler Ultrasound Signal

Area of Science:

• Biomedical Engineering
• Signal Processing
• Obstetrics

Background:

• Current fetal monitoring relies on Doppler ultrasound for fetal heart rate (FHR) analysis.
• Existing autocorrelation methods for FHR determination introduce errors in beat-to-beat variability assessment.
• Need for improved accuracy in FHR determination and representation as a time series of events.

Purpose of the Study:

• To develop novel analysis methods for enhancing FHR determination accuracy.
• To represent FHR as a time series of events for improved clinical interpretation.
• To reduce measurement errors in beat-to-beat FHR variability.

Main Methods:

• Simultaneous recording of Doppler ultrasound and direct fetal electrocardiogram during labor.
• Separation of Doppler bandwidths for heart wall and valve motion analysis.
• Autocorrelation method with trapezoidal prediction function, followed by event time series generation via duplicate correction or periodicity segmentation.

Main Results:

• Achieved a mean heart interval measurement error of only 1.35 ms.
• Beat-to-beat variability assessment errors ranged from -1.9% to -10.1%.
• New methods demonstrated higher accuracy in interval measurement and improved reliability in FHR variability estimation compared to published results.

Conclusions:

• The developed methods significantly improve the accuracy of fetal heart rate determination.
• Enhanced reliability of fetal heart rate variability estimation is achieved.
• These advancements offer a more precise tool for computer-aided fetal monitoring.