Scientists in Switzerland have developed a brain-monitoring electrode that can be fitted through a small hole in the skull and then be fanned out to cover a larger area of the cortex.
Cortical electrodes are used to monitor and stimulate electrical activity in the brain for patients with conditions like epilepsy, which causes seizures.
The new system, developed by bio-electronics experts at the Swiss Federal Institute of Technology (EPFL), is designed to record information from the surface of the brain.
EPFL researchers started the project when a neurosurgeon asked them to find ways to implant electrodes on the surface of the brain in a minimally invasive manner.
The electrodes are so soft that they can sit right between the surface of the brain and the skull, according to researchers, who say these could provide minimally invasive solutions for epilepsy patients.
"We came up with this idea of doing a deployable electrode array, which means that you need to make the array out of materials that are compliant enough so that they can be inserted into a small container and then pushed and deployed at the surface of the brain," said Stephanie Lacour, a neuro-technologist at EPFL.
How does it work?
The device looks like a flower.
It can be inserted through a small hole in the skull as a bud, with its six “petals” folded up inside to the loader, and once placed on the surface of the brain, a fluid is poured to gently spread out the petals.
When the petals are open like on a fully bloomed flower, the loader can be detached.
The whole system can pass through a small incision of about 2 cm in diameter when folded up and then fans out up to 4cm in diameter.
The team described the device as "somewhat like a spiralled butterfly intricately squeezed inside its cocoon before metamorphosis".
To make the device so flexible, the team combined soft bioelectronics and soft robotics, and used metallic electrodes that can be stretched and deformed.
More trials needed
The electrode array has been successfully tested in a mini-pig and will now be developed by Neurosoft Bioelectronics, an EPFL spin-off.
The researchers behind the technology believe that it could be deployed widely in the clinic due to its minimally invasive nature.
"So now what we hope to achieve is to scale the technology to fit it to humans, and increase the number of electrodes so that we can have a larger, richer information from the brain," said Lacour.