Brain-Computer Interface Reads Brainwaves

by Amy Madsen on Wed, 2010-06-30 10:57

A communication system that reads brainwaves helps people with ALS speak their minds

Article Highlights:
  • Cathy Wolf of Katonah, N.Y., is helping researchers test an alternative communication system that lets users communicate using brain signals instead of muscles.
  • The Brain-Computer Interface system reads electric currents created by cellular activity in the brain, allowing users to control a computer and communicate through e-mail, other computer-based communication systems, or synthetic speech.
  • A multisite clinical trial for BCI is planned to begin by the end of this summer. 
  • It's hoped that BCI will be made widely available for in-home use by people unable to communicate by other means as a result of disease or injury.

Note: This article was titled "The Thinking Cap" in the print edition of the July-August 2010 MDA/ALS Newsmagazine.

Cathy Wolf of Katonah, N.Y., is able to manage only a small amount of muscle movement in her face and neck. Still, she’s helping test an alternative communication system that, it’s hoped, will help her and others with ALS compensate for this loss of voluntary muscle control.

Wolf currently uses the WiViK onscreen keyboard, E-triloquist speech program software and a switch she can operate with her eyebrow. When the time comes, she says, she will use BCI full time.

Brain-Computer Interface (BCI) is under development by researchers at the Wadsworth Center, an arm of the New York State Department of Health, in Albany, N.Y. The BCI system — comprising a small laptop computer, an amplifier, a 20-inch monitor and a cap fitted with electrodes — “reads” the electric currents created by cellular activity in the brain, allowing the user to control a computer and communicate through e-mail, other computer-based communication systems or synthetic speech.

Brain signals instead of muscles

The Wadsworth team’s BCI communication system has been in use since 2006. Although it has potential for use by people affected by spinal cord injuries, stroke or other diseases, Wolf and the four other people currently testing the system all have ALS.

The BCI system is calibrated to the individual, and its use in anyone with advanced ALS requires a caregiver or someone else who can first put the cap containing the electrodes on the user’s head, and then start the system. From there, the user can control everything using brain signals instead of muscles, up to and including shutting down the computer.

ALS to BCI

Wolf, 63, earned a doctorate in psychology from Brown University in Providence, R.I., after which she began work in the field of human-computer interaction. At the IBM Thomas J. Watson Research Center in Yorktown Heights, N.Y., she worked on speech and handwriting recognition and natural conversational interfaces, registering nearly a dozen patents and publishing in a number of scientific journal articles along the way.

In fall 1997, Wolf learned she has ALS. Since then, management of the disease has included a tracheostomy and ventilator, and a feeding tube. Unable to speak, Wolf communicates with her husband Joel and the rest of the world using a WiViK onscreen keyboard; E-triloquist speech program software; and a SCATIR switch that works through detection of a reflected beam of light and which she operates with her eyebrows.

In addition to writing for the American Academy of Neurology’s magazine Neurology Now, Wolf is an amateur poet and has published two poems in peer-reviewed journals. She was profiled in the January 2007 issue of the MDA/ALS Newsmagazine.

At the Helen Hayes Center for Rehabilitative Technology in West Haverstraw, N.Y., where she sought help when her speech began to fail, Wolf worked with center director Debra Zeitlin. Zeitlin reached out to Theresa Vaughan, a clinical coordinator and research scientist at the Wadsworth Center, and Vaughan introduced Wolf to BCI.

Cathy’s nurse places the electrode cap on Cathy’s head, then injects conductive gel into the electrode spaces. With everything in place and the system turned on, Cathy operates her computer by paying attention to single characters or function shortcuts on the “matrix.”

’Natural fit’

Wolf has been working with researchers on the BCI project for two and a half years now, and Vaughan, who directs the BCI clinical project, says she was a “natural fit” when it came to testing the system.

“Cathy’s been able to help with a number of technical issues,” Vaughan explains, “because she happens to be a psychologist with a degree and a great deal of experience in computer-human factors and computer-human interface.”

Wolf has observed and contributed to advances in the BCI system and its usability during the time she’s been involved in its testing.

“Some were technical progress for which I take no credit,” she says, adding, “I think I have influenced the arrangement of the matrix and some features of the e-mail client. For example, after losing my work several times in the e-mail application, I suggested that the system should always get confirmation from the user before exiting the mode in which one composes e-mails. This naturally comes from human-computer interaction principle: The user is always in charge.”

In-home use

For now, Wolf uses the BCI system at home on a part-time basis, but notes, “When I am no longer able to move, I will use BCI full time.”

Once she’s fitted with the cap and the system is turned on, Wolf selects characters that flash on an 8-inch by 9-inch matrix on the monitor by “attending to” (paying attention to) the one she wants.

“As your brain operates, the neurons are firing and when they’re firing they’re creating fields,” Vaughan explains. A measurement of those fields, the electrical activity of the brain, is called an electroencephalogram, or EEG.

The BCI system reads an individual’s EEGs through electrodes that rest on or near the scalp. Once the system is calibrated to an individual, it knows what that person’s EEGs look like when he or she is paying attention to a particular target, and so calls up the characters or keystrokes the user is focusing on.

“The computer recognizes what they intend to select,” Vaughan says, “and that appears on the screen.”

From there users can compose, often character by character, synthesized voice output or written communication.

“Composing is not always letter by letter,” Wolf notes, as predictive spelling capabilities built into the program provide a number of alternative selections based on the first and subsequent letters she chooses. “For example, if I select T, five alternatives, such as ‘the,’ ‘to’ and ‘they,’ will be presented in a box below the e-mail. I would select one of the alternatives or continue typing if my word is not there.” The feature “makes a big difference” in the time it takes to compose, Wolf says.

Challenges

Although it’s still in the testing phase (a multisite clinical trial is planned to begin by the end of this summer), the Wadsworth group ultimately hopes to make BCI widely available for in-home use by people unable to communicate by other means as a result of disease or injury.

Several challenges remain.

“The cap is a gatekeeper because good signals are necessary for the system,” Vaughan says. “But we would like to make it easier to doff and don, more cosmetically appealing, and we’d love to improve the fit and make it more comfortable for long-term use.”

The researchers also are continually working to reduce the complexity of the system while refining the functionality.

The next step is to get it “to people who actually need the technology and who could use it in their daily lives,” Vaughan says, but at this point, “it’s still essentially a research system that we’re putting into peoples’ homes.”

Crossing communication off the list of losses

It brings Wolf satisfaction to know that her help in testing the BCI communication system may prove beneficial for others with ALS.

Her hope for the future of BCI is that it will give people with ALS the comfort of knowing that even if they become completely paralyzed, they will never need to give up communication.

“Nothing is more human than the ability to communicate,” Wolf says. “To have that taken away is a tragedy. BCI gives you some of that back.”

Amy Madsen
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