Bionic animals: learn how high-tech prosthetics fop animals are helping humans

Science World, Sept 1, 2008 by Emily Costello

A Dolphin named Winter lost her tail in a crab trap. Motala the elephant stepped on a landmine. Beauty the eagle had her beak shot off. In the wild, this dolphin, elephant, and eagle would probably die. But in each of these cases, kind people stepped in. They managed not only to save the animals, but also to fit each one with a prosthetic tail, foot, or beak. The artificial parts help the animals have healthier, more natural lives. People benefit too. Each one of these animals has an inspirational story that has given hope to countless human amputees. More surprising, the team of specialists working with Winter the dolphin are using what they've learned to improve human prosthetics.

It couldn't happen at a better time. More Americans than ever are living with prosthetics. The United States is currently home to about 1.9 million amputees. That figure is expected to skyrocket to 2.7 million by 2020. Injured veterans returning from combat in Iraq and Afghanistan account for some of the increase in amputees, but most people lose limbs to the complications of diabetes and other diseases. Luckily, technological advances have allowed scientists to make prosthetics lighter, smarter, and more comfortable than ever, says Kevin Carroll, vice president of prosthetics for Hanger Prosthetics and Orthotics in Maryland.

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He should know. Carroll has designed prosthetic feet that mimic crampons for mountain climbers, and legs for elite runners--in addition to a new tail for Winter the dolphin.

A STORY OF SURVIVAL

Winter was discovered in a crab trap off the coast of Florida in 2005. Rescuers rushed the baby bottlenose dolphin to the Clearwater Marine Aquarium. "When she first got here, we really didn't think she would make it," remembers Dana Zucker, chief operating officer at the aquarium. A rope had gotten tangled around the marine mammal's tail, cutting off blood flow to the muscles there. Eventually, her tail fell off. But the dolphin was a fighter, and she began to recover. She grew and gained weight, and began to swim using her flippers and a side-to-side motion. Although pleased by her recovery, Winter's keepers were worried by her strange swimming style. Dolphins usually swim by moving their bodies up and down. The keepers knew that over time, Winter's weird way of swimming would harm her spine.

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Carroll heard the story of Winter's plight on the radio and offered to help. He put his knack for developing prosthetics for people to work, and in a little more than a year he had designed a flexible artificial tail made from silicon for Winter. But Carroll had a bigger challenge ahead; he had to figure out how to attach the tail to Winter. "We spoke to everyone we could think of--innovative thinkers," Carroll says. He and his team considered using a vacuum system to hold the tail in place, but eventually they settled on a gel sleeve. The sleeve was designed to mimic blubber; it protected Winter's sensitive skin while keeping the tail in place. Carroll expected the gel sleeve to be the only one of its kind; but he soon realized that his team's invention had applications beyond helping Winter.

HUMANS BENEFIT TOO

Not long after fitting Winter with the sleeve, Carroll was visiting with Brian Kolfage, a veteran who lost both legs and his right hand in a mortar attack in the Iraq war.

Kolfage's prosthetic legs were getting little use because daggerlike growths of bone at the amputation site made them too painful to wear. Then the men hit on the idea of trying a gel sleeve like Winter's on the veteran. "It was perfect," Kolfage says. The cushioning gel eased Kolfage's pain and allowed him to walk. "I really didn't think it would work, but it was like the difference between night and day," says Kolfage.

Carroll's work with Winter has turned up other surprising applications for people in need of prosthetics. Doctors usually rely on human patients to tell them where a prosthetic is rubbing. Since dolphins can't talk, Carroll had to come up with another way to discover how well Winter's prosthetic tall fit. He ended up using thermography, a procedure in which a heat-sensing infrared camera is used to record the surface temperature of different parts of the body. "Hotspots" on the image show where the prosthetic is rubbing and likely causing pain for the wearer. With humans, thermography could help pinpoint painful areas with greater precision.

WHERE ARE THEY NOW?

Thanks to her prosthetic tall, Winter has thrived at the aquarium in Florida. She has grown into a healthy 82 kilogram (180 pound) dolphin with thousands of human friends who come to the aquarium each year to see her.

What about Motala, the elephant, and Beauty, the eagle? Today, Motala is a star in Thailand. And Beauty's new beak allows her to drink unassisted--a feat that was impossible after the shooting incident. Although she will never be able to return to the wild, the 7-year-old eagle explores the world in her own way: She spends her days visiting schools so kids can learn about wildlife.