Wouldn’t it be great if you could control your PC with your brain? Well, this sort of thing may be closer than you think.
Brain-computer interfaces that can translate thoughts into actions will change how stroke patients, paraplegics and other people with limited mobility interact with their surroundings. But so far, these devices have involved bulky corded equipment inside research labs, requiring patients to be tethered to a computer. Now researchers at Brown University have built the first wireless version. Like a cellphone embedded in the brain, their new implantable brain sensor can relay broadband signals in real time from up to 100 neurons
X-rays of brain-computer-interface implants in Yorkshire pigs and rhesus macaque monkeys several months after surgery. Photo: David A Borton et al.
Researchers at Brown University have built the first wirelessly rechargeable brain implant that could be used to control wheelchairs, robotic arms, or computer interfaces like cursors and keyboards, as detailed in a paper published in the Journal of Neural Engineering.
Brown and a commercial spin-off called BrainGate have been testing a wired version of the system for years. But being tethered to a computer limits a patient’s range of motion — and it leaves an incision in your head that’s susceptible to infection, says Juan Aceros, a researcher on the project who is now an engineering professor at North Florida University.
So far, the wireless version has only been tested in two Yorkshire pigs and four rhesus macaque monkeys, but Aceros says they plan to test the system on human subjects. This requires approval from the FDA, which may take a couple years. The good news is the devices have been implanted in the animal subjects for over a year without significant complications.
Implantable Brain Interface Engineers Arto Nurmikko and Ming Yin examine their prototype wireless, broadband neural sensing device. Fred Field for Brown University
If you’re an able-bodied person, don’t expect your doctor to implant this device in your head anytime soon. For now, the team’s primary aim is to help disabled humans, as was detailed in a paper published last May on BrainGate’s efforts to help stroke patients control a robotic arm. One patient was able to use the arm to serve herself coffee — the most complex action that had been achieved through neuroprosthetics at the time — simply by imagining herself using her own arm to maneuver the cup.
The wireless implant is contained in a 56 by 42 by 9 mm hermetically sealed titanium case. The bulk of the device sits on top of the skull under the skin. Only a tiny sensor is inserted about one millimeter into either the motor cortex or primary somatosensory cortex region of the cerebral cortex of the subject’s brain. But depending on what sort of neural signals researchers want to pick-up, they may need to implant deeper into another part of the brain.
The team at Brown implanted the device into the motor cortex because they’re interested in motor activity. “We’re targeting the cortex because it lets us work with neuroprosthetics,” Aceros says.
Image courtesy of Huntington’s Outreach Project for Education at Stanford
Just like many cell phones and personal electronics, the implant can be inductively recharged — i.e., recharged wirelessly. It consumes only about 100 milliwatts of power and can last for up to seven hours. “Just a few years ago, this device would have been impossible to manufacture,” says Aceros. “We worked with companies to push the state of the art in this design.”
The transmitter’s range is between two and three meters, says Aceros. The team has already developed a more advanced next generation system that uses less power, has more range, and can actually receive input. The current version can only record neural activity, but the next version’s stimulation function would enable patients to be able to feel the weight of something lifted with a robotic arm, says Aceros. “Being able to feel weight gives people more control,” he says.
But it wouldn’t be possible to check your Facebook updates through the implant, so don’t count on these devices replacing your laptop or smartphone.
Which raises the question of what happens when a patient wants to upgrade to a newer model. Aceros says that they have successfully tested replacing implants in animal subjects. “It is brain surgery,” he says. “However, it’s not something where you have to kill the subject, you can just come and take it out.”
One of the few problems the team has run into was the heating of the device, which required them to spray cold water on the test animals’ heads to keep them comfortable. But they were able to work that issue out and can now charge wirelessly without the device getting too hot. The team has planned for every contingency they could think of, which is part of why the process has been so smooth thus far. But there are potential problems looming on the horizon.
Given that researchers have demonstrated the ability to remotely hack certain types of insulin pumps and defibrillators, it seems like it’s only a matter of time before someone figures out how to exploit brain implants. But we’re still a long way from that.
“At the current state of neuroscientific research, simply interpreting the data we collect is an enormous challenge and is being tackled by neuroscientists around the world,” says Dave Borton, one of the primary authors of the paper. “However, one day our understanding of the brain will be much greater, and privacy will play an increasingly large role in technological development.”
“Without a doubt, at that time security and privacy measures will need to be implemented, just like we do now with personal data,” he says. “For now, we focus our energy (and a lot, at that) on solving the fundamental challenges in extracting the information out of the brain for use in basic neuroscience studies, and potential therapies for neuromotor disease.”
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