In recent years, a brain-computer interface (BCI) developed by the US BrainGate consortium has allowed people to control a robotic arm and to type, using only their thoughts. Now, a group of paralyzed volunteers has utilized the technology to perform various functions on a tablet.
At the heart of the BrainGate system is a silicon chip that's about the size of a baby aspirin, which is implanted in the motor cortex of the user's brain. Utilizing 100 integrated electrodes, that chip detects the electrical activity of individual nerve cells. Those electrical signals are sent to a computer, which uses previously-"trained" algorithms to identify specific patterns of activity which are associated with thoughts of performing specific tasks. The computer then accordingly sends commands to the device that's being controlled.
In the latest study, which is part of an ongoing clinical trial, the BrainGate BCI was implanted in three test subjects with little or no use of their arms and legs. Their decoded neural signals were sent to a Bluetooth interface configured to work like a wireless mouse, which in turn transmitted commands to an unmodified Google Nexus 9 tablet. All preloaded accessibility software on the tablet was turned off.
Utilizing this setup, the volunteers were able to perform activities such as shopping online, searching for videos on YouTube, scrolling through a news aggregator, browsing music selections on a streaming service, plus composing emails and chats – all by thinking about pointing and clicking a mouse. One woman even played part of Beethoven's Ode to Joy on a digital piano interface.
As far as actual performance goes, the participants managed to make up to 22 point-and-click selections per minute via various apps, and could type up to 30 effective characters per minute within standard text and email interfaces. All three people found the system to be fun and easy to use.
"This has great potential for restoring reliable, rapid and rich communication for somebody with locked-in syndrome who is unable to speak," says Jose Albites Sanabria, who took part in the research while he was a grad student at Rhode Island's Brown University. "That not only could provide increased interaction with their family and friends, but can provide a conduit for more thoroughly describing ongoing health issues with caregivers."
A paper on the study – which also included scientists and physicians from the Providence Veterans Affairs Medical Center, Massachusetts General Hospital and Stanford University – was recently published in the journal PLOS ONE.
Source: Brown University
