Mind-controlled hand offers hope for the paralysed

Credit: The Lancet

Pentagon-backed scientists on Monday announced they had created a robot hand that was the most advanced brain-controlled prosthetic limb ever made.

The mind-powered prosthesis is a breakthrough, the team of neurologists and bio-engineers reported in The Lancet.

With further development "individuals with long-term paralysis could recover the natural and intuitive command signals for hand placement, orientation and reaching, allowing them to perform activities of daily living," they said.

Researchers have long been interested in the brain-machine interface, whereby implants pick up in associated with movement.

These signals are then transcribed into computer code, which orders the to move.

The new work vastly improves the code, or algorithm, by which the first signal is transcribed into the second, the investigators said.

"One of the biggest challenges has always been how to translate that indicate limb movement into computer signals that can reliably and accurately control a robotic prosthesis," said Andrew Schwartz, a professor of neurobiology at the university.

"Most mind-controlled prosthetics have achieved this by an algorithm which involves working through a complex 'library' of computer-," he said.

"However, we've taken a completely different approach here, by using a model-based which closely mimics the way that an unimpaired brain controls . The result is a prosthetic hand which can be moved far more accurately and naturalistically than previous efforts."

The team, based at the University of Pittsburgh in Pennsylvania, implanted two microelectrode arrays into the left of a 52-year-old woman.

She had been left paralysed from the neck down, unable to move her arms and legs due to a condition called spinocerebellar degeneration.

Two weeks after the operation, the prosthesis was connected and the woman embarked on 14 weeks of training—but on only the second day, she was able to move the limb through mind power.

The training aimed at achieving skills in nine tasks, such as gripping and moving small objects, stacking cones and bumping a ball so that it rolled outside a loose coil of wire.

At the end, the volunteer completed the tasks with a success rate of up to 91.6%, and more than 30 seconds faster than at the start of the trial.

The researchers said they were sure this is a success as they used an exhaustive benchmark test designed to identify genuine changes and root out flukes or anecdotal evidence.

The next steps are likely to see a robot limb incorporate sensors to tell the patient whether a surface is hot or cold or rough or smooth, and to use wifi, rather than a wire, to connect the patient's skull and the prosthesis.

In October 2011, a team at Duke University in North Carolina reported that they had implanted brain electrodes in monkeys that enabled the animals to sense the texture of a virtual object.

One of the funders of the latest study is the Defence Advanced Research Projects Agency (DARPA), a branch of the US Department of Defence that looks into futuristic technology with a potential military use, including by wounded veterans.

More information: Paper: www.sciencedirect.com/science/… ii/S0140673612621643

add to favorites email to friend print save as pdf

Related Stories

Mind-moved bionic arm goes on display in US

Feb 17, 2011

A bionic prosthetic arm that is controlled by its operator's thoughts and feels like the amputee's lost limb went on display Thursday at a major US science conference.

Robotic Hand That Senses Touch (w/ Video)

Oct 21, 2009

(PhysOrg.com) -- Developed by researchers at Lund University in Sweden and Scuola Superiore Sant'Anna in Italy, the Smart Hand project has given patient, Robin af Ekenstam (see video) the sense of touch in ...

Smartphone technology improves prosthetic limbs

Dec 13, 2010

Losing a limb can be a devastating experience, and while electrically powered prostheses can serve as a replacement for a lost arm, they are notoriously difficult to operate, and will never fully replace normal hand function. ...

Recommended for you

Damage to brain networks affects stroke recovery

Nov 21, 2014

(Medical Xpress)—Initial results of an innovative study may significantly change how some patients are evaluated after a stroke, according to researchers at Washington University School of Medicine in St. ...

Dopamine leaves its mark in brain scans

Nov 21, 2014

Researchers use functional magnetic resonance imaging (fMRI) to identify which areas of the brain are active during specific tasks. The method reveals areas of the brain, in which energy use and hence oxygen ...

User comments

Adjust slider to filter visible comments by rank

Display comments: newest first

wealthychef
5 / 5 (1) Dec 17, 2012
Will this take 10 years to come to market? I'm so impatient for the wave of medical breakthroughs to really start making the huge difference we all know they will.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.