Open AccessAtomic magnetometer for human magnetoencephalograpy.
Author(s) -
Peter Schwindt,
Cort Johnson
Publication year - 2010
Language(s) - English
Resource type - Reports
DOI - 10.2172/1011666
Subject(s) - magnetometer , magnetoencephalography , miniaturization , squid , laser , magnetic field , rubidium , optoelectronics , physics , sensitivity (control systems) , interference (communication) , materials science , optics , electrical engineering , computer science , telecommunications , electronic engineering , nanotechnology , engineering , medicine , ecology , channel (broadcasting) , potassium , electroencephalography , quantum mechanics , psychiatry , metallurgy , biology
We have developed a high sensitivity (<5 fTesla/{radical}Hz), fiber-optically coupled magnetometer to detect magnetic fields produced by the human brain. This is the first demonstration of a noncryogenic sensor that could replace cryogenic superconducting quantum interference device (SQUID) magnetometers in magnetoencephalography (MEG) and is an important advance in realizing cost-effective MEG. Within the sensor, a rubidium vapor is optically pumped with 795 laser light while field-induced optical rotations are measured with 780 nm laser light. Both beams share a single optical axis to maximize simplicity and compactness. In collaboration with neuroscientists at The Mind Research Network in Albuquerque, NM, the evoked responses resulting from median nerve and auditory stimulation were recorded with the atomic magnetometer and a commercial SQUID-based MEG system with signals comparing favorably. Multi-sensor operation has been demonstrated with two AMs placed on opposite sides of the head. Straightforward miniaturization would enable high-density sensor arrays for whole-head magnetoencephalography