by
Olga Deshchenko, DOTmed News Reporter | April 15, 2011
From the April 2011 issue of HealthCare Business News magazine
Unlike Johns Hopkins’ Modular Prosthetic Limb, Goldfarb’s team isn’t relying on implanted microchips. It’s using surface electrodes. “The reason we don’t do implants is because right now, there are many challenges with the implementation of implants and we want people to be able to use the prosthesis in the near term,” says Goldfarb.
“Implants are probably 20 years away,” he says. “We’re working on things that hopefully will be useable within the next decade by amputee populations.”
In Goldfarb’s design, the controller takes over some functions of the brain. “We imbue the hand with a lot of its own low-level intelligence, its own coordination, so that it requires a lot less attention from the user,” he explains.
For example, if a healthy person picks up an apple off a table, there isn’t any conscious thought about what each of the joints is doing because it’s taken care of by low-level coordination centers, located in the medulla oblongata and the cerebellum parts of the brain. Goldfarb’s prosthesis mimics that capability. “We have low-level coordination centers that are run off little micro-controller chips on the hand and then the person just gives [the prosthesis] higher level information,” says Goldfarb.
Goldfarb’s work is being funded by the National Institutes of Health, and this year, his team plans to test the prosthesis on five amputees. The researchers will compare their ability to do activities of daily living using Goldfarb’s invention to a standard myoelectric prosthesis.
The controller of the device, says Goldfarb, is unlike anything else on the market. “But what we believe isn’t really that important, that’s why we want to do these tests,” he says.
“We think what we have will really advance this field and provide more functionality and improve quality of life for upper-extremity amputees,” Goldfarb says.
Ongoing research: sense & control
While some researchers are working on improving the dexterity of current prostheses, others continue to explore ways to make amputees feel like their prostheses are a natural part of their bodies. But for prosthetic limbs to truly feel like biological arms or legs, researchers must overcome a significant challenge: establishing a two-way connection with the peripheral nervous system.
Such a system should be able to not only sense the activity of the nerves and direct the motion to the prosthesis but also stimulate sensory nerves to offer feedback to the amputee’s brain to control the device.
Thanks to a $5.6 million DARPA grant, a number of facilities are currently collaborating on a two-year effort to develop a system that will do just that. The project is split in two parts – nerve stimulation and sensing.
