For people with brain and spinal cord injuries, these systems can eventually restore communication and movement, allowing them to live more independently.But currently, they Not so practicalMost require cumbersome settings and cannot be used outside the research laboratory. People equipped with brain implants are also limited in the types of actions they can perform because the number of neurons that the implant can record at the same time is relatively small. The most commonly used brain chip Utah array is a bed composed of 100 silicon needles, each with an electrode at the tip that can be inserted into the brain tissue. One of the arrays is about the size of Abraham Lincoln’s face on a penny and can record the activity of hundreds of peripheral neurons.
But many of the brain functions that researchers are interested in — such as memory, language, and decision-making — involve networks of neurons that are widely distributed throughout the brain. “To understand how these functions really work, you need to study them at the system level,” said Chantel Pratt, an associate professor of psychology at the University of Washington, who is not involved in the neuroparticle project. Her work involves non-invasive brain-computer interfaces that are worn on the head rather than implanted.
The ability to record from more neurons can achieve finer motor control and expand the current possibilities of brain control devices. Researchers can also use them in animals to understand how different brain regions communicate with each other. “When it comes to the way the brain works, the whole is really more important than the sum of the parts,” she said.
Florian Solzbacher, co-founder and president of Blackrock Neurotech, a company that makes the Utah array, said that distributed neural implant systems may not be necessary for many near-term uses, such as enabling basic exercise functions or using computers. However, more futuristic applications, such as restoring memory or cognition, will almost certainly require more complex settings. “Obviously, the Holy Grail will be a technology that can record as many neurons as possible across the entire brain, surface and depth,” he said. “Do you need the entire complexity of it now? Probably not. But in terms of understanding the brain and looking forward to future applications, the more information we have, the better.”
He went on to say that smaller sensors could also mean less damage to the brain. Current arrays, even if they are already small, can cause inflammation and scars around the implant site. “Usually, the smaller something you make, the less likely it is to be detected as a foreign body by the immune system,” said Solzbacher, who was not involved in Brown’s research. When the body detects a foreign body like a fragment, it will try to dissolve and destroy it, or wrap it with scar tissue.
Solzbacher warned that although small may be better, it is not necessarily foolproof. Even tiny implants may trigger an immune response, so nerve particles need to be made of biocompatible materials. One of the main obstacles to the development of brain implants is to minimize damage while constructing durable implants to avoid the risk of replacement surgery. Current arrays can last for about six years, but many arrays will soon stop working due to scar tissue.
If nerve particles are the answer, then how to get them into the brain is still a question. In their rodent experiments, Brown’s researchers removed most of the mouse skull, which is not ideal for humans for obvious reasons. Current implanted arrays require drilling holes in the patient’s head, but Brown’s team hopes to avoid invasive brain surgery altogether. To this end, they are developing a technique to insert nerve particles involving fine needles that will be penetrated into the skull through a special device. (Neural Networks Looking for a “sewing machine”-like robot to deliver its coin shape Brain implant.)