Researchers at SpeakYourMind Foundation, a nonprofit organisation in the US, with help from BrainGate lab at Brown University in Providence, Rhode Island, has developed this low-cost brain-computer interface to brain-injured patients.

“We have also developed a prototype eye-tracking tool called 'SYMeyes' - consisting of a webcam - that allows brain stem stroke patients to answer yes or no questions by moving their eyes,” informed Dan Bacher, founder and executive director of the SpeakYourMind Foundation, in a press release.

The eye-tracker system costs about USD 30.

Comparable systems in the market cost about USD 10,000 to USD 15,000, Bacher said.

Bacher has also developed a system that allowed people to spell words by controlling a computer cursor on a virtual keyboard - using signals from the BrainGate implant.

The virtual keyboard also suggests word completions to speed up typing.

Bacher, with a team of volunteers and students, develops low-cost, personalised eye-tracking and head-tracking technologies - using basic components available at most electronics stores, a laptop and custom software.

“We are helping restore communication to people who lack the ability due to stroke, amyotrophic lateral sclerosis (ALS), brain injury or other problems,” Bacher was quoted as saying.