The system was tested on a 58-year-old woman in the late stages of amyotrophic lateral sclerosis, or ALS. Unable to speak or move her muscles, she had to identify the letters by imagining that she was moving her right hand. Previously, her only method to communicate was through eye movements and blinks.
Vikash Gilja, a professor of electrical and computer engineering at the University of California San Diego, who was not connected with the research, said the system used by the Ramsey team “does not push the envelope of performance, but that was not the purpose of the study. The news here is they have developed a system they fitted to one individual over a long time period and that individual was able to use it on their own without a lot of technical support.”
The hope is that such systems could eventually help others who can’t move but whose brains are still capable of thought and communication, such as some people who’ve had strokes.
When it came time to spell words, letters would be highlighted on a computer screen and the woman would try to “click” on the one she wanted.
It took the researchers several months to refine their algorithms to inhibit unintended brain clicks. Results from eye tracking were used to confirm what the volunteer typed.
Initially, the woman needed 52 seconds to identify one letter.
“The time required dropped to 33 seconds per letter when word prediction was used,” the researchers reported. At times, she can do up to four letters per minute.
She can spell words directly without help and it gives her the ability to alert her caregiver that she needs assistance without relying on the caregiver noticing her eye movements.
“This is a significant advance in our field,” Jonathan Brumberg, an assistant professor of speech-language-hearing at the University of Kansas, who was not connected with the work, told Reuters Health in an email. “It has significant advantages because the patient could use the device outdoors and with minimal dependency on others for setting up the device.”
“By using/modifying existing hardware, the cost of future devices may be lower than those with completely custom hardware,” said Brumberg. “Also, using existing commercial solutions means that surgeons will likely be familiar with the components and already have developed appropriate procedures for their use.”
“I think of it as an achievement that puts implants for [brain-computer interface] on the map and it allows us develop more sophisticated devices,” he said.
Article source: http://www.cbc.ca/news/health/locked-in-1.3850636?cmp=rss