Wednesday, June 11, 2008

Monkeys and Robots... A Powerful Pairing!!!

Mind over matter: monkeys control robots with brain power

PARIS (AFP) — Scientists have trained monkeys to manipulate a robotic arm solely with brain power, and could soon help amputees and paralysed stroke victims do the same, according to a study released Wednesday.

Immobilised monkeys with electrode filaments inserted into their cerebral cortext learned in only days to reach out with the free-standing prosthesis, pluck a tasty morsel with a pincer-like claw, and pop it in their mouths. When the path of the arm -- positioned next to the shoulder -- was deliberately blocked, the animals simply willed it around the obstacle with their minds, says the study, published in Nature.

"The entire task is now performed with brain control," Andrew Schwartz, the lead researcher and a professor at the University of Pittsburgh, told AFP.

In preliminary experiments, also with Macaca mulatta monkeys, computers assisted with various parts of the task, he explained. The study's findings are the first reported use of a so-called "brain-machine interface" (BMI) to perform a practical action in three dimensions -- in this case feeding oneself -- purely via brain control of a computerized arm, noted John Kalaska, an expert on the central nervous system at the University of Montreal.

Strokes, spinal cord injuries and degenerative neuromuscular diseases cripple tens of thousands of people every year, rendering the simplest of actions -- opening a door, scratching an itch, drinking a glass of water -- frustratingly difficult or impossible.

Those afflicted with the most severe form of paralysis, known as locked-in syndrome, are fully-conscious prisoners inside a body that no longer responds to the most basic of commands.
"These patients are still able to produce the brain activity that would normally result in voluntary movements," explained Kalaska.

"But their condition prevents those signals from either getting to the muscles or activating them," he said in a commentary, also in Nature.
Schwartz's experiments provide the most tantalising hope to date that paralysis victims can one day short-circuit their own nervous system by hardwiring their brains directly to a computerized robot.

"Hopefully we will be implanting microelectrode arrays [in humans] in the next two years," Schwartz told AFP.

"At that point it should be relatively easy to perform this kind of task," he said.
In the meantime, Schwartz and his team are making improvements on the robotic arm, adding points of articulation in the wrist and hand to the five already built in -- three at the shoulder, one at the elbow, and one at the hand.

This does not mean that "neuroprosthetic robots will soon be available at the local rehabilitation clinic," cautions Kalakska, who says several barriers remain before such devices can be easily deployed.

The long-term reliability of the electrodes -- about the breadth of a human hair -- must be vastly improved.

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