After two years, project leaders at the Applied Physics Laboratory will decide which approach or approaches work best and deserve another two years of funding. The Utah team is focusing on implanting electrode arrays in nerves in the residual limb.
"The nerve is potentially an excellent site for communicating with the nervous system," Clark says. "It's like a private hotline to the muscle."
He says a prototype of the bionic arm should be ready for testing in four years. It is not yet known if any Utah residents who lost arms will participate in clinical trials.
Existing prosthetic arms differ from the arm the university will help develop. Current models have limited movements, such as bending the elbow and wrist and opening and closing the hand, while the new arm will be capable of about 20 different movements, including moving fingers independently, says Clark.
Existing prosthetic arms typically are controlled by signals from an intact muscle, such as a shoulder shrug, so only one movement can occur at a time, he adds. "The new arm will take the signals that go to all the different arm muscles at once, and all the person has to do is think about natural movement and the arm will respond in a natural way. We're basically listening in on what the nervous system would be telling the natural arm, and translating that into signals that will move the artificial arm in the same way."
Finally, says Clark, "this new arm will provide sensory feedback to make the arm feel like a person's own arm. Existing prosthetic arms are so hard to use, and feel so unnatural, that sometimes people just don't use them. They put them on the closet shelf."
How the Funding Will Work
The initial two-year phase of the University of Utah's work will bring in up to $4.8 million. The second two-year phase could bring
Source:Alcoholism: Clinical & Experimental Research