A Better Hand

Health Contributor Dr. Dave Hnida of CBS Station KCNC in Denver points to the future of bionic hands as CBS This Morning continues "Body Shop," its series on new medical technology.

Until now, prosthetic hands have been able to do only one thing, open and close. But in a little lab in New Jersey that is changing, and the change is starting with an 11-year-old girl named Melissa.

Melissa Del Pozzo is a happy child who likes to play basketball after school or maybe ride her bike. But when Melissa gets home she does one thing her friends don't do. After taking off her shoes, she takes off her prosthetic arm.

"I can do a lot of stuff without using my fake arm," Melissa says.

Melissa was born without a left arm below the elbow. She got her first prosthesis when she was just nine months old. But there are a few things Melissa's prosthetic hand isn't capable of doing that her mother thinks she might like to try. "She would be able to play the piano, and play a horn if she wanted to. Tie her shoes a little better, maybe," says Linda Del Pozzo.

Melissa might soon get the chance thanks to Dr. William Craelius of Rutgers University. He is developing the first prosthetic hand with fingers that move independently.

Dr. Craelius notes that human beings who lose a limb can experience a so-called "phantom finger" syndrome, a sensation of movement in a limb that no longer exists. "We have such a sense of our entire body that is imprinted in the brain and so the fascinating thing about it is questions like, 'How long does it last? Is it still present in those who let's say never had a limb'?" Dr. Craelius says.

Melissa feels that "phantom finger" sensation, too, in her missing left hand, allowing her to manipulate its artificial replacement. "I think of my fingers moving and they move the fingers," she says.

In fact, the tendons and muscles in Melissa's upper arm that would have moved her fingers still function, they just end with her arm at the elbow. The motion of those tendons controls the fingers in the artificial hand.

Dr. Craelius explains: "When I want to move and flex my index finger, I have a tendon that I can feel in my arm here. The basic principle of this device is that the socket is instrumented with sensors that detect a motion of a tendon or muscle that would normally be tied to a specific finger motion."

These sensors are hooked up to a computer that directs the movement of the artificial fingers. The prosthetic hand is a prototype. Melissa is still learning to use it.

Eventually she will have five working fingers on her new hand and Melissa will get to explore a little bit more of the world. "For like, typing and stuff on the computer, and that's cool, I like to type," she says.

The hand Melissa tried is still under construction by Alernative Prosthesis Services. Eventually it will have a cover that will make it look more like a limb. It will be made of silicone from a mold of an actual hand and then painted to match Melissa's skin tone.

Click here for Part Two of this series.

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