Wireless Brain Implant Represents a Small Step for Human-Computer Interfaces

By Wesley Fenlon

While previous brain interfaces requires a wire running between hardware and human tissue, this implant fits under the skin and can transmit thoughts wirelessly.

Brain-computer interfaces have long seemed like technology's answer to debilitating physical problems. If you're quadriplegic, a brain interface with a computer could give you access to the Internet and new forms of communication. An interface with a robotic arm could give you back some movement. These technologies have come a long way in the past few years, and successful tests with human patients and monkeys point to a bright future. There's a big limitation with many of those implants, though--according to Technology Review, current interfaces plug into the the user's head through a hole in the skin, which can lead to infection and requires assistance to set up. Enter the field's latest prototype: a wireless interface.

The wireless brain-computer implant, developed at Brown University, has been successfully tested on two macaques and two pigs, recording dozens of neurons of activity and sending that information to a receiver. Human subjects are next. The implant, which measures about two inches long, contains a battery, a copper charging coil, custom signal processors, and radio and infrared transmitters. That's all packed into a titanium case designed to rest under the skin but above the skull. Tiny wires connect the implant to a neuron-reading chip that's embedded in the brain.

The implant uses inductive charging to fill up its battery, so it can stay embedded in the skin--the charger just has to be close enough to the patient's head to convey a charge. According to Technology Review, the implant can transmit tens of megabytes of data per second, which is impressive. Other body implants we've seen, which are even smaller than this one, are too weak to send a realistically useful amount of information from a human body to an outside receiver.

Image Credit: Journal of Neural Engineering

They've also found the implant to be safe and operational after more than a year, though the performance of the electrodes in the embedded brain chip has degraded since its installation. That's something that will have to change for the chip to be useful to humans long-term. And two inches sounds huge for a head implant, but it's still a major step forward from wired technologies. The first step is making the implant; the next is making it work well, giving quadriplegic subjects the ability to control computers or wheelchairs or phones or robotic devices with their thoughts.