#computer-brain interface

Goal: restore function for disabled people

He says the goal of his team’s work is to develop technology to help disabled people complete tasks they would otherwise be unable to do. “The ability to interact with the environment through exploration of the three-dimensional world is an important component of the autonomy that is lost when one suffers a paralyzing neurodegenerative disorder, and is one that can have a dramatic impact on quality of life,” they write in their paper published June 4 in the Journal of Neural Engineering.

They hope their work will one day lead to paralyzed patients being able to control artificial limbs, wheelchairs or other devices with their thoughts.

Five test subjects put on the EEG cap, which allowed 64 electrodes to make contact with their scalps. They were trained to imagine they were making different movements, each of which was translated by a computer connected to the cap into a flight instruction that was sent to the quadcopter through a wireless connection. If a person imagined he was making a fist with his right hand, for instance, his brain’s motor cortex generated a specific electrical signal. The cap picked up this tiny impulse, which is millions of times smaller than a volt, and the computer interpreted this into an instruction for the helicopter to turn right. Imagining he was clenching both fists meant a signal for the helicopter to go up, and so on.

After going through a few rounds of training, the testers piloted the quadrotor through an obstacle course of suspended lightweight foam rings whose internal diameter was 7.5 feet. While the highest achieving volunteer successfully maneuvered 90.5 percent of challenges, the five together averaged more than 80 percent success, a rate that He called “quite reasonable.”

“The subjects needed to move around a three-dimensional space and to pilot through these suspended rings without crashing,” He says. “It required lots of complex movements.”

In their report, the team wrote that they found subjects performed better because maneuvering through the course required them to focus on both target acquisition and obstacle avoidance. “By a balance of positive and negative motivators, higher performance in the task, and the real risk of crash, subjects were compelled to higher levels of performance and remained engaged in the experimental task,” they wrote. “Such a balance will be crucial in determining the limits of brain-computer interfaces.”

More to come

While their experimental cap captured brain impulses through 64 sensors to gather an abundance of data, He says the contacts with the head will eventually number just a couple of electrodes. One day, the entire interface may even run through one or more temporary electronic tattoos worn by the user.

Now that they have demonstrated the interface’s potential, He says his research group will focus on creating specific applications to control robotic arms and prosthetics with thought.