Ultrasensitive Quantum Magnetic Detector Digs for Fetal Arrhythmias

Researchers at the University of Wisconsin-Madison are using ultrasensitive magnetic detectors to screen fetuses for heart rhythm problems. The vernix, also known as vernix caseosa, a waxy white substance found coating the skin of babies, prevents electrical signals of the tiny beating heart of the fetus from being conducted to the surface of the expectant mother’s body, making it impossible for standard EKG techniques to detect the rhythm. However the heart also generates weak magnetic signals. The only detector sensitive enough to measure these is a superconducting quantum interference device, or SQUID, which has been used for submarine detection and oil exploration in addition to its medical usage. Until recently SQUIDs were almost exclusively for adult brain mapping studies.
The passive detector, in this case from 4D Neuroimaging that recently went out of business, is positioned over the pregnant woman’s belly, where it picks up the faintest magnetic signals and sends the information back to a computer in an adjacent room. The detector makes hour-long, continuous recordings, in contrast with ultrasound which captures only a small window of activity. The team has used the detector to analyze heartbeat irregularities in more than 300 patients so far and a mobile detector is under construction.
Press release: Ultrasensitive Detector Pinpoints Big Problems in Tiny Fetal Hearts…
Related: Magnetocardiography for Fetal Arrhythmias Heart Rhythm. 2008 July; 5(7): 1073-1076