Wednesday, July 25, 2007

Bionic hand can peel a banana

Touch Bionics, a Scotland-based company, will formally unveil the i-LIMB in Vancouver on July 29

William Lin, CanWest News ServicePublished: Monday, July 23, 2007

OTTAWA -- At an age when many bodies begin to slow down, John German is rediscovering the simple pleasures of using his hands to peel a banana and operate a manual can opener.
After losing part of his left arm two decades ago, he has avoided such simple joys as using his previous prosthetic to grasp the fingers of a baby for fear he could hurt the child.

About a month ago, the 40-year-old clinical technician from Altoona, Penn., switched to the remarkably human-like i-LIMB, a new bionic hand that its company hails as a "generational step" in prosthetics.

Touch Bionics, a Scotland-based company, will formally unveil the bionic hand in Vancouver on July 29 at the World Congress of the International Society for Prosthetics and Orthotics.
"The current products that are in the market only have one grip position, which is effectively the index and middle finger closing down to meet the thumb," said Phil Newman, the company's head of sales and marketing.

The i-LIMB provides patients with new grips that weren't possible for amputees before, allowing them to insert a key into a hole, put on a tie and, in German's case, peel a banana.
The hand uses a rotating thumb and individually powered fingers to form various grips. Also, the skin covering is convincingly life-like, with knuckles and fingernails.
For German, it looks like the real thing.

The hand's movements are not directly generated by brain signals, said Newman, as some science fiction fans might believe.

In each of the fingers, a sensor recognizes the level of resistance on an object and tells them to stop grasping. Each finger also has its own motor.
The five individually powered fingers grips around objects and locks when enough force has been used.

German said his last hand was "no better than a wireless mechanical hook."
"In the past month, I'm rediscovering some tasks," German said, "and really rediscovering what it's like to have a hand that is not just shaped like an original hand, but one that functions like an original."

But the prosthetic hand's functions are still limited.

"There are going to be some functions that you cannot perform like playing the piano," Newman said.

The i-LIMB hand costs $18,000 U.S.

Powered by batteries that last a day located inside the patient's socket, the arm must be recharged overnight.

So far, the bionic hand has been fitted on 14 patients.

© The Vancouver Sun 2007

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