Invention gives new hope for those trapped without a voice

Donoghue's groundbreaking technology allows patients to control a robot arm with their thoughts. Photo / Thinkstock

The robotic arm clutched a glass and swung it over a series of coloured dots that resembled a Twister gameboard. Behind it, a woman sat immobile in a wheelchair. Slowly, the arm put the glass down, narrowly missing one of the dots.

"She's doing that!" exclaims Professor John Donoghue, watching a video of the scene on his office computer - though the woman onscreen had not moved at all.

"She has the arm under her control," he says, beaming with pride. "We told her to put the glass down on that dot."

The woman, who is almost completely paralysed, was using Donoghue's groundbreaking technology to control the robot arm with only her thoughts.

Called BrainGate, the device is implanted into her brain and hooked to a computer to which she sends mental commands.

The video played on, giving Donoghue, 62, even more reason to feel pleased. The patient was not satisfied with her near miss and the robot arm lifted the glass again. After a brief hover, the arm positioned the glass on the dot.

This is the remarkable world of the brain-computer interface, or BCI, of which BrainGate is one of the leading devices and Donoghue one of its most successful pioneers.

It sounds like science fiction, but it is motivated by a desire to help chronically injured people. They include those who have lost limbs, have motor-neurone disease or are paralysed by spinal cord injuries.

But the people it might help the most are those whom medicine assumed were beyond all hope, those with "locked-in syndrome".

These are often stroke victims whose healthy minds are trapped inside bodies that can no longer move.

The most famous example was French magazine editor Jean-Dominique Bauby who managed to dictate a memoir, The Diving Bell and the Butterfly, by blinking one eye.

In the book, Bauby, who died in 1997 shortly after the book was published, described the prison his body had become for a mind that still worked normally.

Donoghue believes BrainGate would have opened Bauby's prison door, even if just a little.

He and his team have devoted years of research to BrainGate, first testing the technology on monkeys and then moving to clinical trials using human subjects.

Now the project is involved with a second set of human trials, pushing the technology to see how far it goes and trying to miniaturise it and make it wireless for a better fit in the brain.

BrainGate's concept is simple. It plugs into the brain, picks up neural signals and beams them into a computer where they are translated into moving a cursor or controlling a computer keyboard.

With it, paralysed people can move a robot arm or drive their own wheelchair, just by thinking about it.

In his book, Bauby called his immobilised body a diving bell and his mind a butterfly trapped inside. He described his sadness at being unable to talk back when his loved ones spoke to him on the phone.

"How dearly I would love to be able to respond with something other than silence to those tender calls," he wrote.

The woman on the video that Donoghue just played has almost the exact same condition Bauby had. Now she can talk to Donoghue over the internet, moving a cursor over a keyboard with her mind.

Donoghue works in a rambling old mansion perched on top of a hill, part of Brown University in the college town of Providence, Rhode Island.

It is here that he and his team are decoding the language of the brain.

This language is made up of electronic signals fired by billions of neurons, and it controls everything from our ability to move, think and remember to consciousness itself.

Donoghue's genius was to develop a small device that can tap directly into the brain and pick up those signals so a computer can translate them.

Gold wires are implanted into the brain's motor cortex, which controls movement. Those wires feed back to a tiny information storage device attached to a "pedestal" in the skull. Another wire feeds from the device into a computer.

Test subjects with BrainGate looks like they have a large plug in the top of their heads.

BrainGate's computer programs are able to decode the neuron signals picked up by the wires and translate them into the subject's desired movement.

It is a form of mind-reading based on the idea that thinking about moving a cursor to the right will generate different brain signals to thinking about moving it to the left.

After the first BrainGate patient was plugged into a computer in 2004, the technology has developed rapidly, and last month BrainGate passed a milestone when one paralysed patient went past 1000 days with the implant still in her brain and enabling her to move a computer cursor with her thoughts.

Donoghue talks enthusiastically of one day hooking up BrainGate to a system of electronic stimulators plugged into the muscles of the arm or legs.

That would open up the prospect of patients moving not just a cursor or their wheelchair, but their own bodies.

Donoghue comes across as a pragmatic and careful scientist. Perhaps that comes from his humble background as the son of a working-class Boston Irish bricklayer father and a housewife mother. Or from an academic career spent almost entirely in the same institution.

But he does allow himself to dream, just a little, of where BrainGate's technology might go one day. His team is working on a miniaturised and wireless version.

Although it has not yet been implanted in a human, that version will remove the need for a "plug" in the skull and could enable patients to be permanently connected.

"One hundred years from now, when people are walking around with an artificial nervous system made of wires and chips, people will say, 'I bet they didn't imagine this'," Donoghue says.

One person who did think about it was Bauby. At the end of The Diving Bell and the Butterfly he dreams of one day being let out of his prison.

"Does the cosmos contain keys for opening up my diving bell? A subway line with no terminus? A currency strong enough to buy my freedom back? We must keep looking."

Bauby died before there was much hope for that.

Others similarly stricken in the future may be luckier.

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