Room Temperature Fetal Magnetocardiography using Optically Pumped Magnetometers

Graduate #93
Discipline: Physics
Subcategory: Physics (not Nanoscience)

Margo A. Batie - University of Wisconsin-Madison
Co-Author(s): Sarah Bitant, University of Wisconsin Madison, WI

Fetal magnetocardiography (fMCG), the magnetic analog of ECG, is a technique used to detect fetal arrhythmias and monitor fetal well-being. The current standard for fMCG, is a cryogenically cooled device called a superconducting quantum interference device (SQUID). Recent advancements in quantum sensing have led to the development of optically pumped magnetometers (OPMs), magnetic field sensors that operate at room temperature with comparable sensitive to that of SQUIDs. OPMs offer decreased sensor size, increased flexibility of sensor placement, and lower cost. The purpose of this study was to evaluate the performance of an OPM-based fMCG system versus a SQUID-based system. Fetal MCG signals were recorded using each system individually, in a magnetically shielded room, then performance was compared based on various performance parameters such as signal-to-noise ratios. The signal measured by the OPMs was on average a factor of 2 lower than the fetal heart signal measured by the SQUID. This likely due to the OPMs being configured as magnetometers, as opposed to gradiometers, making them more susceptible to environmental interference than the SQUID. With further research into more effective noise suppression and crosstalk reduction techniques, OPMs have the potential to be a cheaper alternative to current instrumentation without compromising sensitivity.
References: Boto E, Bowtell R, Krüger P, Fromhold TM, Morris PG, Meyer SS, et al. (2016) On the Potential of a New Generation of Magnetometers for MEG: A Beamformer Simulation Study. PLoS ONE 11(8): e0157655. doi:10.1371/journal.pone.0157655 Yu SH, Wakai RT. Maternal mcg interference cancellation using splined independent component subtraction. IEEE Transactions on Biomedical Engineering. 2011;vol. 58(no. 10):2835–2843.

Funder Acknowledgement(s): This study is funded through NIH grant R01 HL063174 and R44 HL114182.

Faculty Advisor: Ronald Wakai, rtwakai@wisc.edu

Role: -data acquisition -data processing