Brain activity recorder could help disabled people control remote devices

The research, collated by the Francis Crick Institute, University College London (UCL) and Stanford University in the US, was conducted on mice.

The team developed an accurate and scalable method to record brain activity across large areas, including on the surface of the brain and in deeper regions simultaneously. 

Using the latest in electronics and engineering techniques, the new device combines silicon chip technology with super-slim microwires that are up to 15-times thinner than human hair.

The wires are so thin they can be placed deep inside the brain without causing significant damage. Alongside its ability to accurately monitor brain activity, the device could also be used to inject electrical signals into precise areas of the brain, the team said.

“This technology provides the basis for lots of exciting future developments beyond neuroscience research,” said Andreas Schaefer, group leader in the neurophysiology of behaviour laboratory at the Crick and professor of neuroscience at UCL.

“It could lead to tech that can pass a signal from the brain to a machine, for example, helping those with amputations to control a prosthetic limb to shake a hand or stand up,” he continued. “It could also be used to create electrical signals in the brain when neurons are damaged and aren’t firing themselves, such as in motor neurone disease.”

When the device is connected to a brain, electrical signals from active neurons travel up the nearby microwires to a silicon chip, where the data is processed and analysed showing which areas of the brain are active.

The researchers said the design of the device allows it to be easily scaled up depending on the size of the animal, with a few hundred wires for a mouse to over 100,000 for larger mammals or eventually, humans.

“One of the great challenges in recording brain activity, especially in deeper regions, is how to get the wires, called electrodes, in position without causing a lot of tissue damage or bleeding,” said Mihaly Kollo, a postdoc at the Crick’s neurophysiology of behaviour laboratory and senior research associate at UCL. “Our method overcomes this by using electrodes that are sufficiently thin.”

One of the major challenges faced by the team was recording the activity of so many neurons distributed in layers in complex, three-dimensional shapes. “Again, our method provides a solution as the wires can be readily arranged into any 3D shape,” he clarified.

The technology described in the study is also the basis for a fully integrated brain-computer interface system that is currently being developed by Paradromics, a company founded by one of the authors of this research.

The Texas-based firm is working to develop a medical device platform that will improve the lives of people with critical diseases, including paralysis, sensory impairment and drug-resistant neuropsychiatric diseases.