Fetal ECG extraction during labor using an adaptive maternal beat subtraction technique

Area of Science:

• Biomedical Engineering
• Signal Processing
• Obstetrics

Background:

• Non-invasive fetal ECG (FECG) monitoring via maternal abdominal signals is crucial for fetal well-being assessment.
• Maternal ECG (MECG) and uterine EMG are significant noise sources obscuring FECG signals, especially during labor.

Purpose of the Study:

• To develop and validate a new method for subtracting MECG from abdominal FECG signals.
• To improve the accuracy of non-invasive FECG analysis by mitigating noise from maternal sources and uterine contractions.

Main Methods:

• A novel MECG subtraction technique is proposed, approximating MECG using linearly combined, R-peak aligned previous segments.
• Median filtering identifies and excludes abdominal signal segments contaminated by high-amplitude uterine contractions.
• The method was validated using real abdominal data recorded during labor, with simultaneous scalp FECG for comparison.

Main Results:

• The proposed method effectively subtracts MECG from abdominal signals.
• Detection and removal of uterine contraction-affected segments enhance signal quality.
• Validation against invasive FECG confirms the efficacy of the non-invasive approach.

Conclusions:

• The developed method offers a promising approach for accurate non-invasive FECG monitoring.
• This technique can aid in the early detection of fetal distress during labor.
• Improved FECG signal quality facilitates better clinical decision-making.