Wearable Brain Scanner Prototype Can Scan Entire Brain During Movement

The OPM-MEG system. A) Schematic diagram of the whole system. B) Magnetically shielded room. C) Flexible (EEG style) cap. D) Rigid additively manufactured helmet. Both helmets contain push-fit clips to house the 2nd generation QuSpin OPMs (shown inset in C) and D)). Courtesy: NeuroImage

A newly designed, lightweight helmet can be used as a brain scanner, potentially tracking the electrophysiological processes that are believed to contribute to a variety of mental health disorders.

Researchers from the University of Nottingham published details of their brain scanner in the journal NeuroImage. In the paper, they detailed the specifics of their prototype, a 49-channel device that can scan the entire brain even while the patient moves. This design, the team said, makes the hat-like scanner perfect for children or other patients who have difficulty staying still during the image-gathering process.

“Understanding mental illness remains one of the greatest challenges facing 21st century science. From childhood illnesses, such as autism, to neurodegenerative diseases, such as Alzheimer’s, human brain health affects millions of people throughout the lifespan,” said Matt Brookes, senior research fellow in physiology, pharmacology, and neuroscience from the University of Nottingham. “In many cases, even highly detailed brain images showing what the brain looks like fail to tell us about underlying pathology, and consequently, there is an urgent need for new technologies to measure what the brain actually does in health and disease.”

To get a more comprehensive picture of the electrical currents in the brain and the brain’s activity, the investigators built upon an existing – though new – technology, called OPM-MEG (optically-pumped magnetometer magnetoencephalography), that non-invasively captures a millisecond-by-millisecond image of the brain’s electrophysiology during different tasks. Currently, however, OPM-MEG offers a small number of sensors, approximately 13, that target specific brain regions.

By working with an engineering company Added Scientific from Nottingham, the team designed and printed the 3D helmet with a higher channel count that can pinpoint – down to the millimeter – the areas of the brain that control hand movements and vision. The team designed and compared two whole-head scanners: a flexible, EEG-like cap and a rigid helmet.

According to the team, both designs enabled the capture of high-quality data, but the rigid helmet offered better reconstruction of field data into 3D images of changes in neuronal current. By repeatedly measuring two participants, the investigators determined the signal detection for the device was highly robust, they said. The system is also comparable to the performance of existing cryogenic MEG devices.

Based on these findings, the team said, the new whole-head scanner could make it easier to scan children, as well as epileptic patients during seizures. Doing so could unlock a greater understanding of the abnormal brain activity that prompts seizures.

Still, warns lead author Ryan Hill from the University of Nottingham, further study is needed to determine both the capabilities and limitations of the OPM-MEG.

“Although there is exciting potential, OPM-MEG is a nascent technology with significant development still required,” he explained. “Whilst multi-channel systems are available, most demonstrations still employ small numbers of sensors sited over specific brain regions and the introduction of a whole-head array is an important step forward in moving this technology towards effective commercial application.”