'Robo-legs' help amputees get around

Blond and buff, Cameron Clapp is a teenage star.

Dressed fashionably in a faded T-shirt, baggy shorts and sneakers, he recently strolled along the crowded pavements of Times Square. He walked confidently, flashing the megawatt smile that brightens his Web site and various photographs in newspapers and magazines that have chronicled his story as he travels the country.

Few, if any, of the onlookers had little idea that he is the poster manchild of a new generation of people who are not only embracing all types of breakthrough technologies, but also incorporating them into their bodies.

For people who see Clapp for the first time, he is an object of wonderment: a young man walking tall on shiny robotic legs.

"I make it look easy," said Clapp, who is 19 and still shows flickers of the cocky skater boy he was before he became what he calls "a severe case".

Clapp lost both his legs above the knee and his right arm just short of his shoulder after falling onto train tracks almost five years ago near his home in California. After years of rehabilitation and trying a series of prosthetics, each more technologically sophisticated than the last, he finally found his legs.

"I do have a lot of motivation and self-esteem," Clapp said, "but I might look at myself differently if technology was not on my side." In the last few years, technology has definitely been on his side, in the form of the C-Leg. Introduced by Otto Bock HealthCare, a German company that makes advanced prosthetics, the C-Leg combines computer technology with hydraulics. It literally does the walking for the walker.

Blazing advancements, including lightweight composite materials, keener sensors and tiny programmable microprocessors are restoring remarkable degrees of mobility to amputees, said William Hanson, president of Liberating Technologies, a company in Massachusetts that specialises in developing and distributing advanced (rather than the more conventional kind) prosthetic arms and hands. Statistics show that more than twice as many men as women are amputees.

But something more subtle, and possibly far-reaching, is also occurring, some technologists say.

The line that has long separated human beings from the machines that assist them is blurring as complex technologies become a visible part of people who depend upon them. Unlike pacemakers and fabricated heart valves that are embedded in the body, these technologies are, so to speak, worn on their users' sleeves.

The cyborg factor
Increasingly, amputees, especially young men like Clapp, and soldiers who have lost limbs in Afghanistan and Iraq, are choosing not to hide their prosthetics under clothing as previous generations did. Instead, many of the estimated 1.2 million amputees in the US proudly polish and decorate their electronic limbs for all to see.

Long an eerie theme in popular science fiction, the integration of humans with machines has often been presented as a harbinger of a soulless future populated with flesh-and-metal cyborgs, RoboCops and Terminators. But major universities such as Carnegie Mellon and the University of California at Berkeley, as well as companies and the US military, are exploring ways in which people can be enhanced by strapping themselves into wearable robotics, or exoskeletons.

"There is a kind of cyborg consciousness, a fluidity at the boundaries of what is flesh and what is machine, that has happened behind our backs," said Sherry Turkle, the director of the Initiative on Technology and Self at the Massachusetts Institute of Technology, who is writing a book on robots and culture. "The notion that your leg is a machine part and it is exposed, that it is an enhancement, is becoming comfortable in the sense that it can be made a part of you."

Research at MIT in the 1970s led to the development of the Boston Digital Arm, one of the most realistic-looking modern arm prosthetics in the world, manufactured by Liberating Technologies.

Over the years, prosthetics like the C-Leg and the Boston Digital Arm have benefited from the explosion of improving technologies for personal computers and mobile phones. For example, Hanson of Liberating Technologies said that smaller and more powerful microprocessors and rechargeable batteries have helped his company make electronic limbs more reliable.

Statistics on how many amputees use artificial limbs are not available, but figures from the US National Center for Health Statistics show that in 1994 (the latest numbers available), about 200,000 people in the US used a prosthetic limb.

While some users are eager to display their prosthetic marvels, many of which are paid for by private and public health insurance, others like to have them modelled to appear more human. Besides selling prosthetics, Liberating Technologies, for one, offers 19 kinds of silicon sleeves for artificial limbs to make them seem more natural.

"There are two things that are important: one is functionality and the other is cosmetic," Hanson said. "Various people weigh those differences differently. There are trade-offs."

He said that a 16-year-old girl, for instance, might want to wear a more natural-looking prosthetic limb. But at 35 and maybe a working mother, she may choose a more functional limb.