# Amputees put Power Knee to test



## Boondocksaint375 (Oct 23, 2007)

*Amputees put Power Knee to test*


BY  ELISABETH DYER
ST. PETERSBURG TIMES

     TAMPA - One man was an Army Ranger chasing after  Manuel Noriega in Panama when he was shot five times and lost his right  leg.

Another lost his left leg to bone cancer. A third had his leg  amputated above the knee after he got stuck on a conveyor belt at a chicken feed  plant.

The amputees have different stories, but this in common: They are  among a few dozen people in the world who use a cutting-edge, electric-powered  artificial limb that employs Bluetooth technology to help the leg mimic natural  movement.

And they were all recently at the University of South Florida,  helping researchers try to determine if the artificial knee mimics real leg  movement well enough to warrant broader use.

The Ossur Power Knee,  manufactured in Iceland, propels users forward when walking and lifts them out  of chairs and up stairs.

University of South Florida assistant professor  Jason Highsmith is studying how well the knee synchronizes movement with the  remaining leg.

Backed by a $1 million grant from the Department of  Education, he'll see if the knee mimics the shortening action of the quadriceps  muscles that typically lift a sound leg. Ease of movement for above-the-knee  amputees could lead to mass production of the high-powered prosthetic, which is  now used by just 40 people worldwide.

Usually, amputees shift to their  able-bodied sides when rising. Over time those muscles compensate, becoming more  developed while the side not being used atrophies, Highsmith said.

"They  are muscularly imbalanced," he said. "The idea is that by adding some of that  power back into the prosthesis, we can balance the muscles and spare the  joints."

It works like this: Pressure sensors in the shoe of the  able-bodied side send signals to the prosthetic knee by Bluetooth technology  that is strapped to the ankle.

Jim Beeson, 57, has been wearing the knee  for a year. He lost his leg in a work accident at a steel company in 1985. But  he couldn't get comfortable with prosthetics, so he used a wheelchair for 12  years.

A year ago, he told his doctor he wanted to walk again.

She  told him about the Power Knee. Now a police officer, he couldn't be  happier.

"I go fishing with my grandchildren, shopping with the wife,  whereas before, I just stayed home," he said.

At USF last week , the  amputees stood on scales to measure pressure as they stood while attached to  sensors monitoring muscle contraction and joint motion. They sat and stood,  again and again.

The artificial knees need some adjustment to get them to  move naturally.

Sometimes the knee propelled the foot too far, causing it  to kick out when a user sat down. Other times, it has been known to lift too  forcefully as the person tries to stand.

Once finished, Simon Bouchard  detached his artificial foot with a tool he doesn't leave home without, and set  it at a sharper angle. Bouchard, 30, lost his leg to cancer in  2002.

Bouchard, who lives in Quebec, says he was the first person to use  the knee in 2004.

"Other legs in the market use your energy, but this one  has its own power. It's important to show what it can do because one day  insurance will pay for this."

It's not perfect yet, said Bill Dunham, 39,  from Arkansas.

At 10 pounds, it's heavier than the 3.5-pound C-leg he  prefers to wear. Also, the Power Knee's battery doesn't last all day, Dunham  said.

He spun his leg upside down to show the stamp: human bionic, which  Webster defines as performance enhanced by electronic or electromechanical  devices.

Experts say technology to improve life for amputees is growing  as improved medical care brings more people back from Iraq without  limbs.

The Power Knee costs about $120,000, compared with $20,000 for  standard prostheses, said Highsmith, who also designed and built a prosthetic  hand for kayakers from a steel pipe last year.

He plans to publish the  results of the knee study early in 2008 in a scientific  journal.

"Unfortunately these people often become sedentary," Highsmith  said. "This may keep them up and moving longer."


http://www.ocala.com/article/20071023/NEWS/210230322/1002/NEWS&source=RSS


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## Gypsy (Oct 23, 2007)

That's really awesome stuff right there.


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## The91Bravo (Oct 23, 2007)

Damn...  great efforts


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## Typhoon (Oct 23, 2007)

That is incredible to hear about. I am certain that when the manufacturing capacity for such devices is improved that the cost will come down along with it.


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## pardus (Oct 23, 2007)

Typhoon said:


> That is incredible to hear about. I am certain that when the manufacturing capacity for such devices is improved that the cost will come down along with it.



I hope so, that is bloody expensive.
Great product though!


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## tova (Oct 23, 2007)

This is one instance when technology is truly a good thing :)


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