It sounds like an idea from the 22nd century: A robotic hand for amputees, with its own nervous system grown from mouse cells.
But engineers are developing these computerized prostheses right now in a lab in .
“We are working on how to convey an improved sense of touch,” said Erik Engeberg, the FAU researcher leading the project. “The goal is to give back to amputees fine movements and dexterity and convey to them different kinds of temperature and touch sensations, such as a light touch, a fast touch and a vibrational touch.”
The research project, fueled by a $1.3-million grant from the National Institutes of Health, is also working to restore the sensation of pressure, the firmness of a grip, the feel of the weight of an object, and its quality of fragility or density.
Or as Engeberg says: “feeling the difference between holding a ball and holding an egg.”
Engeberg and his team see the path to that restored sense of touch and grip through a robotic hand with its own nervous system consisting of dorsal root ganglia, or clusters of nerve cells, grown from mice. They plan to electrically stimulate the ganglia with sensors from the robotic hand and see how the nerves rebuild, hoping the same will happen in the prostheses of hand amputees.
Engeberg said it’s a unique approach to the problem of loss of touch sensation.
Those who have lost a hand, about 690,000 people in the United States, face limited options as they search for a prosthesis. Only a small number of manufacturers have entered the market; and the $25,000 cost is often not covered by insurance, said Karen Lundquist, spokeswoman for the non-profit Amputee Coalition, based in Virginia.
Joshua Marcus, of Boca Raton, has experienced the grueling quest for a properly fitting prosthesis.
Marcus, 31, an attorney who lost his left arm above the elbow in a boating accident in 2008, said his five-pound prosthesis is too heavy to wear for his daily activities. He also can’t get it to fit properly in its socket.
He said he hasn’t worn it in three months, even though it cost about $100,000.
“A hand that could sense touch and heat is really good, but it’s not my first priority,” Marcus said. “My number one concern is fit and making it comfortable.”
Engeberg, who has been working on similar mechanical engineering problems since 2006, said he looks forward to learning more about the issues faced by amputees such as Marcus, as well as the interaction of the mind and the body and how behavior collaborates with nerve regeneration to reestablish one of our most important senses.
He expects the project— being done by researchers, engineers, a brain scientist and an orthopedic surgeon — to take about four years, which is also the duration of the grant.
“This is such an engaging topic,” Engeberg said. “It’s what gets me out of bed every morning.”