Brain-sensing tech allows users to type at rate of 12 words per minute

Tweleve words per minute may not seem like a huge feat to you, but if you suffer from a movement disorder, or happen to be a monkey, this a big deal.

A team of electrical engineers led by Krishna Shenoy at Stanford University Bio-X lab has developed a technology that detects brain signals to move a cursor.


The engineers tested the technology on animals, training them to to copy text and type at a rate of up to 12 words per minute.

The technology is capable of directly reading brain signals, allowing for the movement of cursor to a keyboard. In their experiment conducted with monkeys, the researchers discovered that the animals could transcribe passages from the New York Times and Hamlet at a rate of up to 12 words per minute.

Earlier versions of the technology have been tested successfully in people with paralysis, but the typing was much slower and imprecise. The new research speeds up the technology, while making it more accurate.

“Our results demonstrate that this interface may have great promise for use in people,” said Paul Nuyujukian, postdoctoral fellow who will join Stanford faculty as an assistant professor of bioengineering in 2017. “It enables a typing rate sufficient for a meaningful conversation.”

When it comes to assisting those with movement disabilities in communication, other approaches include tracking eye movements or even tracking movements of individual muscles in the face. These technologies have limitations, though, and require a degree of muscle control that might be difficult for some people.

For example, some people may not be able to use eye-tracking software due to drooping eyelids and other people find eye-tracking technology tiring.

Directly reading brain signals could overcome some of these challenges and provide a way for people to communicate their thoughts and emotions.

The Stanford team’s technology involves the use of a multi-electrode array that’s implanted in the brain and directly reads signals from a region that ordinarily directs hand and arm movements used to move a computer mouse.

The team members have been improving the algorithms for translating those signals and making letter selections. They tested individual components of the updated technology in prior monkey studies but never demonstrated the combined improvements in typing speed and accuracy.

“The interface we tested is exactly what a human would use,” said Nuyujukian. “What we had never quantified before was the typing rate that could be achieved.” Using these high-performing algorithms developed by Nuyujukian and his colleagues, the animals could type more than three times faster than with earlier approaches.

Though the monkeys typed at a rate of 12 words per minute, people using this system may type more slowly since they think about what they want to communicate or how to spell words. People could also be in distracting environments or possess additional impairments that slow the ultimate communication rate.

“What we cannot quantify is the cognitive load of figuring out what words you are trying to say,” said Nuyujukian.

Despite those challenges, the researchers say that even a rate lower than the 12 words per minute achieved by monkeys would be a significant advance for people who aren’t otherwise able to communicate effectively or reliably.

“Also understand that we’re not using auto completion here like your smartphone does where it guesses your words for you,” said Nuyujukian. Eventually the technology could be paired with the kinds of word completion technology used by smartphones or tablets to improve typing speeds.

This study also demonstrated that the implanted sensor could be stable for several years. The animals had the implants used to test this and previous iterations of the technology for up to four years prior to this experiment, with no loss of performance or side effects in the animals.

The team is running a clinical trial now, in conjunction with Jaimie Henderson, professor of neurosurgery, to test this latest interface in people. If successful, these kinds of communication technologies that directly interpreting brain signals could create a new way of life for people with paralysis and their interaction with loved ones.

Story via Stanford University.

Comments are closed, but trackbacks and pingbacks are open.