Monitoring the brain get downright medieval. In the most invasive type of procedure, surgeons saw into the skull, remove a sizeable chunk of bone, and place a grid of electrodes directly on the brain, where it can carry out tasks ranging from data collection to neurostimulation.
We now have a glimpse of how that messy procedure could one day be relegated to the history books, after scientists in Switzerland built a device that can be deployed through a smaller two-centimeter hole in the cranium and unfold like a flower inside the whisper-thin space between bone and brain. The procedure, first carried out on the brain of a miniature pig, could lead to new frontiers in the monitoring and treatment of epilepsy and other neurological disorders in humans — or even, perhaps, in commercial brain-computer interfaces like at Elon Musk's struggling Neuralink.
"This is to answer a specific request from neurosurgeons who are hoping to have minimally invasive devices," said Stéphanie Lacour, the lead researcher on the project and professor at the École Polytechnique Fédérale de Lausanne (EPFL), in a video.
Lacour’s research focus is on soft bioelectronics designed to elegantly connect with parts of the human nervous system, such as the brain and spine.
For this particular challenge, her team reconsidered the current shape of brain electrode arrays, which generally have electrodes embedded on a flat, flexible surface. In contrast, her team devised an electrode array with six spiral-shaped arms, each embedded with flexible gold electrodes. The array is first folded within a cylinder-shaped loader, then deployed by surgeons who bore a small hole into the skull and place the cylindrical loader over it. A mechanism then pushes the array through the hole and causes it to unfold its six arms in the one-millimeter space between bone and cortex, like a particularly gory flower.
The scientists were inspired by soft robotics research, and particularly "eversion," which is when an object is turned inside out. It’s an action that many soft robotic engineers have focused on in order to deploy robots in complex environments, such as coral reefs. For the electrode array prototype, pushing liquid into each arm causes it to turn itself inside out and gently unfold over the cortex like a petal or tentacle.
"Minimally invasive neurotechnologies are essential approaches to offer efficient, patient-tailored therapies,” said Lacour in a statement. “We needed to design a miniaturized electrode array capable of folding, passing through a small hole in the skull and then deploying in a flat surface resting over the cortex.”
The researchers published a paper about the project in the journal Science Robotics. Next, the researchers are planning to bring this device to brains everywhere in a spinoff company that recently nabbed a bucket of Swiss francs equal to $2.8 million in funding.
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