[tt] CBC on advances in prosthetics

[Hughes, James J.]

http://www.cbc.ca/cp/health/070924/x092404A.html

No bionic people yet, but war fuelling new advancements in prosthetics

Published: Monday, September 24, 2007 | 12:52 PM ET

Canadian Press: Chris Morris, THE CANADIAN PRESS

FREDERICTON - As she grew up, Adele Fifield was keenly aware that her
artificial leg was more than a few steps behind the bionic marvels
portrayed in popular science fiction shows.

The old hydraulic version she used in earlier years worked fine at a
slow, steady stroll, but got balky if she changed her speed.

    Adele Fifield shows off her hightech prosthetic leg and foot. THE
CANADIAN PRESS/Jonathan HaywardAdele Fifield shows off her hightech
prosthetic leg and foot. THE CANADIAN PRESS/Jonathan Hayward 

"The knee had pistons or cylinders, like the pistons in a car," says
Fifield, 41, head of the National Amputee Centre for The War Amps in
Ottawa.

"They would compress and help swing the leg forward. But . . . anytime I
would change my speed, I would have to wait for the leg to catch up to
me."

Fifield lost most of her left leg when she was 13 years old to the same
kind of bone cancer that claimed the life of Canadian hero, Terry Fox.

She has spent the past 28 years as an advocate for Canada's amputees and
she has experienced first-hand the technological revolution that is
making the loss of a limb, or limbs, much less difficult for an
individual to bear.
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Fifield was one of the first amputees in Canada to be fitted with a
so-called C-leg, referring to the computerized microprocessor in the
knee which makes the leg much more responsive and natural.

"The microprocessor has a sensor down into the shin and at the knee and
50 times a second it is sending messages back to the hydraulic unit to
open and close the valves instantly to reflect whether I'm speeding up
or slowing down," Fifield says.

"It's a significant change. You don't have to think about how you're
walking."

Welcome to the brave new world of cybernetics.

The technology of artificial limbs has come a long way from the peg leg
and the hook and, thanks to the cruel reality of modern warfare, there's
growing impetus for even more advancements.

In the United States and Canada, government interest in developing
better prosthetic limbs has grown as a result of the wars in Iraq and
Afghanistan.

Improvements in body armour and in battlefield medical practices have
helped lower the number of casualties from those conflicts, but the side
effect has been a significant increase in the number of amputees.

Prosthetic advancements range from complex, thought-controlled devices
to the simple, yet elegant design that has allowed sprinter Oscar
Pistorius of South Africa to become famous as the fastest man on no
legs.

The carbon-fibre blades that Pistorius uses to run on have forced
Olympic officials to consider his qualification for the games, and they
worry the technology of his prosthetics may give him an unfair advantage
over sprinters using their natural legs.

"It's a very exciting time," says Fifield, adding that The War Amps has
about 18,000 Canadians registered for its services.

"In my job here, I speak to hundreds of amputees every year. It is very
encouraging to be able to say to the parents of a child born without a
limb . . . 'the sky is the limit."'

Fuelling that optimism are scientists like Kevin Englehart and Peter
Kyberd at the University of New Brunswick in Fredericton, home to one of
North America's most advanced prosthetic research facilities.

UNB's Institute of Biomedical Engineering has been awarded contracts on
two major initiatives sponsored by the Defense Advanced Research
Projects Agency, the U.S. military's research and development wing.

One of the areas of research Englehart is involved in is developing ways
to extract information not only from a person's remaining muscles, but
also from the nerves and the brain itself.

The science is being applied to thought-controlled prosthetic arms in
which nerves are surgically relocated from a missing limb to muscles
that are seldom used by an amputee, such as those in the chest.

When an amputee wishes to close the prosthetic hand, signals from the
brain travel down the nerves but, instead of reaching a dead end at the
missing limb, are re-routed to the chest muscles, causing them to
contract.

Electrodes sense this activity, and send a signal to a tiny computer
embedded in the artificial limb. The prosthetic hand then closes,
allowing the individual to hold a glass or tie a shoe.

Thinking "lift" will contract another part of the muscle, allowing the
person to raise the prosthetic arm.

Englehart says he knew his research was valuable when one of the people
being tested with the arm praised the ease of movement it offered.

"He said, 'I don't have to learn how to use this. This thing learns how
to use me,"' Englehart says.

"It validated the 15 years of research we've been doing."

Kyberd, whose research is focused on creating a more dexterous
prosthetic hand, says the main hurdle to significant advances in
artificial limbs is funding.

He says it is difficult to imagine that any of the latest high-tech
designs will be rendered cheap enough for the average Canadian amputee
to afford.

Fifield's C-leg, for instance, costs in excess of $50,000 and funding
for such products is not always available from insurance companies or
public health care programs.

"That's what we're interested in - developing prosthetic devices that
will be affordable for Canadians," Kyberd says.

Whatever advances the future holds for amputees, researchers are not
promising to create bionic men and women.

In fact, it's more likely the world would see human limb cloning before
it would see the perfect mechanical replication of lost limbs.

"The means by which you control an intact limb is unbelievably complex
both in the sense of the number of motor neurons that descend into the
arm but also the number of sensory neurons that go back and regulate how
you control that limb," Englehart says.

"The next five to 10 years will see some exciting advances in prosthetic
devices, but nowhere in the distant future is there any way that we are
going to approach that level of sophistication artificially. We'll be
able to regrow a limb before we'll be able to reproduce it
technologically."