Multi-Detector Heart Rate Extraction Method for Transabdominal Fetal Pulse Oximetry

Area of Science:

• Biomedical Engineering
• Obstetrics
• Fetal Monitoring

Background:

• Intrapartum fetal well-being assessment relies on fetal heart rate (FHR) monitoring.
• Current FHR monitoring has a high false-positive rate for detecting fetal hypoxia.
• Non-invasive fetal pulse oximetry offers potential for improved hypoxia detection accuracy.

Purpose of the Study:

• To develop and evaluate a multi-detector fetal signal extraction method for non-invasive fetal oxygen saturation monitoring.
• To improve the accuracy of fetal heart rate (FHR) calculation from transabdominal signals.
• To reduce errors in FHR measurement compared to single-detector methods.

Main Methods:

• A multi-detector fetal signal extraction technique using adaptive noise cancellation on signals from four photodetectors.
• Extraction of four separate FHRs via peak detection after adaptive noise cancellation.
• Application of weighting, outlier rejection, and averaging to obtain a mean FHR.

Main Results:

• The multi-detector method demonstrated up to 18.56% lower root-mean-square FHR error.
• The technique achieved up to 57.87% lower maximum absolute FHR error compared to single-detector methods.
• Evaluation was performed in a hypoxic lamb model with hemodynamic ground truth.

Conclusions:

• The multi-detector fetal signal extraction method significantly enhances FHR accuracy.
• This approach improves the reliability of non-invasive fetal monitoring during labor.
• The findings support the potential of this method for more accurate fetal hypoxia detection.