Abstract With the advancements in biomagnetic technology and signal extraction methods it has been possible to non- invasively record simultaneously an array of fetal parameters with a single device, such as fetal magnetoencephalography (MEG) and magnetocardiography (MCG) along with fetal movement, state, and breathing and uterine smooth muscle magnetomyography. Fetal biomagnetic studies have shown that this technology can provide new relevant clinical parameters and supplement the existing ones for assessment of fetal and maternal well-being, which can be made available to physicians starting in the antepartum period until delivery. The magnetic signals acquired from the entire maternal abdomen consist of the superposition of biological signals from all electrically active sources. For any pregnant mother, the signals with the largest amplitude are generated by the maternal and fetal heart. The study of the fetal heart, and in particular, the developing cardiac conduction system, has been significantly aided in the last two decades by the introduction of FMCG. Currently, we can record non-invasive fetal magnetocardiographic (FMCG) signals with a magnetic sensor-based system called SARA (SQUID Array for Reproductive Assessment) installed at University of Arkansas for Medical Sciences. Despite all these benefits in prenatal assessment, the major hurdles facing SQUID technology include system and maintenance cost, cryogenic helium cooling, a rigid one-size-fits-all array, and a single position option for the mother. In order to overcome some of these problems, we plan to test the feasibility of using uncooled biomagnetometer for potential prenatal assessments based on microfabricated optically-pumped magnetometers (OPM). The OPMs have many features similar to cryogenic SQUID-based systems as they measure the same field components, and are compatible with standard magnetically-shielded rooms. We believe that OPM-based system could provide an inexpensive alternative thus increasing the availability of fetal biomagnetometers. Since fetal heart is a relatively large signal, we will primarily focus on its extraction and validation from the biomagnetic signals recorded by OPMs for this exploratory R21 grant proposal. The specific aims include - Aim 1: Evaluate OPM sensors on low-risk pregnant women by validating the signals with simultaneous recording using the current SQUID based SARA system. Aim 2: (A) Configure a stand-alone array of the OPMs that conforms to the shape of the maternal abdomen to obtain signals with sufficient signal- to-noise ratio for fetal applications (B) Extract and quantify the FMCG waveform components, fetal movement and breathing by performing serial recordings in low-risk fetuses.

R21HD091744

2017-08-01

2021-07-31