Researchers present an ultra-precise brain imaging tool
A joint team from the Russian Quantum Center, Skoltech, and the Higher School of Economics has presented a novel supersensitive solid-state magnetometer operating at room temperature. The researchers for the first time used it to detect and record brain electrical activity with a technique called magnetoencephalography, which could become dozens of times cheaper with the new device. The paper was published in Human Brain Mapping.

High accuracy is a key advantage of magnetoencephalography (MEG) over other similar techniques used for studying the electrical activity of the brain. Biological tissues are transparent for magnetic fields. However, only a very limited number of laboratories around the world have MEG equipment, which uses either extremely cold liquid helium or high-temperature gas and is very expensive and difficult to manufacture.

A team from the Russian Quantum Center (RQC) developed a new sensor using yttrium-iron garnet films. This is the first solid-state supersensitive room-temperature magnetometer in the world. It is based on a quantum sensor and is capable of registering very weak or deep electrical sources in the brain. Owing to its wide dynamic range, the device requires less magnetic shielding, which means a lower cost for both the hardware and the entire research infrastructure.

To test the new type of sensor in action, Skoltech and Higher School of Economics researchers performed an experimental study, measuring a simple brain-induced field—the alpha rhythm—which constitutes sinusoidal electric currents in the back of the brain. The new sensor successfully detected the onset of the alpha rhythm, and the result was validated by other methods.

In the future, the team plans to study various sensor configurations, including a flexible band-type device placed around a patient's head to ensure the utmost efficiency and accuracy in detecting the exact location of electrical activity in the cerebral cortex. The current findings call for further exploration of the technology and step-by-step development of an MEG device based on solid-state sensors, which will mark an important step forward in noninvasive neuroimaging and neurointerfaces.