A type of wearable brain scanner is revealing new possibilities for understanding and diagnosing mental illness now that the technology has been expanded to scan the whole brain with millimeter accuracy.

Scientists from the University of Nottingham developed the initial prototype of the brain scanner in 2018 – a lightweight device worn like a hat that scans the brain even while a patient is moving. Their latest research has expanded to a fully functional 49-channel device that can be used to scan the whole brain and track electrophysiological processes that are implicated in a number of mental health problems.

Understanding mental illness is one of the greatest challenges facing science. “From childhood illnesses such as autism to neurodegenerative diseases such as Alzheimer’s, human brain health affects millions of people,” explained Professor Matt Brookes at 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.”

Brain cells operate and communicate by producing electrical currents. These currents generate tiny magnetic fields that can be detected outside the head. Researchers use MEG to map brain function by measuring these magnetic fields. This allows for a millisecond-by-millisecond picture of which parts of the brain are engaged when we undertake different tasks, such as speaking or moving.

Unlike large, cumbersome scanners that require patients to remain very still, the wearable scanner allows the patient to move freely. The early prototype of the system had just 13 sensors and could only scan limited sections of the brain. The team worked with Added Scientific in Nottingham to develop a novel type of 3D printed helmet, which is key to the function of the 49-channel device. The higher channel count means that the system can be used to scan the whole brain. It can show areas in the brain that control hand movement and vision with millimeter accuracy.

The new scanner unlocks a lot of possibilities, such as scanning children who find it hard to keep still or scanning epileptic patients during seizures to understand the abnormal brain activity that generates those seizures.