Prosthetics That Can Feel?

April 14, 2010 3:27:32 PM PDT
One-point-two million Americans are living with a lost limb. That's about one out of every 200 people in the United States, and 200,000 rely on a prosthetic. Now, for the first time, a new arm may give amputees more control and even the ability to feel. It could be medicine's next big thing. "I've climbed mountains in Alaska," Michael Moran said. "I built this house."

Until one day, when this professional painter's ladder connected with a power line.

"It blew five holes out of my head and 42 holes out of my back," Moran said. "It melted off 40 percent of my skin."

After 25 surgeries, Moran is back outside. He's doing it all with one hand. Moran lost his left arm in the accident. He uses a hook to help him keep on target, but it's the small things he misses.

"I can drive a bulldozer, but I can't tie my shoes," Moran said. "It's the finite details."

Doctors at the University of Michigan are developing a prosthesis that can feel hot and cold and detect pressure. They do it by using the nerves that remain in the arm.

"The nerves are all that remain connected to the brain," Paul S. Cederna, M.D., FACS, plastic surgeon at the University of Michigan, said. "So the brain forever will continue to send signals down those nerves, trying to tell the hand what to do, even if the hand isn't there."

It's called Artificial Neuromuscular Junction.

"We're trying to harness those nerves which are already carrying the signals it takes to control the hand, and have those nerves give their signals through an electrical device that can communicate to the prosthesis and get the prosthesis to work like a normal hand,"said Dr. Cederna.

Doctors harvest muscle cells from a patient's thigh, grow the cells on a scaffold and coat it with a polymer that conducts electricity. The bioengineering scaffold is placed over the served nerve endings like a cup.

It could give amputees something they thought they had lost forever.

"The first thing I would do if I got my arm back would be to hug my kids with two hands so I could feel it," Moran said.

Right now the new prosthesis is being tested in animals. Dr. Cederna hopes to test it in people in the next three years.