Fetal Movement Assessment Using Optically Pumped Magnetometers from Multisensor Magnetocardiographic Recordings

Area of Science:

• Biomedical Engineering
• Medical Physics
• Obstetrics

Background:

• Fetal movement (FM) is a critical indicator of fetal well-being.
• Fetal magnetocardiography (fMCG) assesses FM via fetal heart rate (FHR) analysis.
• Optically pumped magnetometers (OPMs) offer a cryogenic-free alternative to SQUIDs for biomagnetic measurements.

Purpose of the Study:

• To evaluate the efficacy of a bed-based, stand-alone optically pumped magnetometer (OPM) array for fetal magnetocardiography (fMCG).
• To assess the capability of OPM sensors in quantifying fetal heart rate (FHR) and fetal movement (FM).

Main Methods:

• Utilized a 14-sensor, dual-axis OPM array in a shielded environment to acquire fMCG signals.
• Employed a projection operator algorithm for signal isolation and an OPM-based algorithm for FM computation.
• Collected data from four pregnant women between 28 and 36 weeks gestation.

Main Results:

• Successfully obtained fMCG signals using the stand-alone OPM system.
• Quantified FHR and FM metrics comparable to those from previous SQUID-based studies.
• Demonstrated the feasibility of OPM technology for real-time fetal monitoring.

Conclusions:

• Preliminary data confirm the potential of OPM sensors for non-cryogenic, bed-based fMCG.
• OPM technology shows promise for advancing fetal health monitoring and research applications.
• This approach may lead to more accessible and cost-effective prenatal diagnostics.