Magnetoencephalography with High-sensitivity 16-channel Single-module Optically Pumped Magnetometer

The understanding of the human brain function and behavior is critical for many applications including developing diagnostic methods and treatments of various neurological disorders, such as epilepsy. One powerful method of imaging neuronal activity is magnetoencephalography (MEG), a non-invasive brain imaging tool that sensitively measures the biomagnetic fields produced by the brain’s electrical activity. MEG can accurately evaluate spike activity of brain disorders and study the brain response to specific external stimuli. The leading high-sensitivity multichannel MEG systems are based on arrays of a low-temperature superconducting quantum interference device (SQUID) magnetometer; however, the need for cryogenic infrastructure is a serious drawback. We aim to develop an alternative, more practical, portable MEG module based on high-sensitivity 16-channel optically pumped magnetometers (OPMs). OPMs based on lasers and alkali-metal vapor cells are currently the most sensitive non-cryogenic magnetic-field sensors. The 16-channel operation is originally based on a single alkali-metal vapor cell and two broad laser beams, substantially reducing the cost of sensors and allowing the compact size. In this talk, we will describe the concept of our MEG module and present our recent progress on MEG measurements using the MEG module.