Many of us take shaking hands for granted without realizing that a simple gesture actually involves a complicated coordination of muscles and nerve impulses. But shaking hands, and a host of other capabilities, are now possible for amputees thanks to advancements made to the LUKE prosthetic arm that uses sensors to decode natural muscle signals, essentially translating the amputee’s thoughts into movement.
The modular prosthetic LUKE arm developed by DEKA Research and Development in Manchester was demonstrated at an event at the end of February. It is the result of a multi-year, $40-million contract from DARPA (Defense Advanced Research Projects Agency), a funding arm of the Department of Defense.
Next Step Bionics and Prosthetics, also in Manchester, designed the socket interface, which connects the prosthesis to the patient’s arm. Mobius Bionics in Manchester manufactures the LUKE arm. Matt Albuquerque, president and founder of Next Step, was first asked to give insight to the DEKA engineers and talk about the type of improvements that would help.
“They also asked for access to people who had upper extremity injuries that could help them make something that was useful and practical,” Albuquerque says. “Chuck Hildreth and Ron Currier came to mind.” As a certified prosthetist, Albuquerque had worked with both men for years. Currier is an Air Force veteran and a retired chief of prosthetics at the Manchester Department of Veterans Affairs. He is also a bilateral transradial (below the elbow) amputee and the first person to use two LUKE arms.
“The level of intuitive control is remarkable,” Albuquerque says. “He is using the muscles that he used to use [when he had hands]. He told me once that when he dreams, he dreams of himself with hands. This taps into that natural movement…. I’ve been doing this for 30 years, and it was the first time I’ve ever been speechless. It really was the first time it felt like we were truly recreating human motion with an artificial limb.”
From left: Matt Albuquerque, Chuck Hildreth, Ron Currier and Dean Kamen. Courtesy of Next Step Bionics and Prosthetics.
For Currier, who has undergone multiple surgeries to repair his shoulders from deterioration caused by a lifetime of wearing prosthetics, the LUKE arms open up a world of possibilities. He says scuba diving is one of his passions, but with the body-powered prosthetics, the amount of bands he had to wear to give him the power to swim is what ultimately destroyed his shoulders.
“These are going to give me back my independence,” Currier says. “Once I get these perfected, I am going to celebrate by doing two things: I’m going to jump out of a perfectly good airplane, and I want to go ice climbing on (Cathedral Ledge) and repel down.”
Hildreth, also a bilateral amputee, lost his right arm and shoulder. The LUKE arm allows him to use both arms together. “The system adjusts to you, and that is nice,” Hildreth says, “Amputees have always had to put up with things and adjust. It is nice to have it adjust to me.”
At the demonstration in February, Hildreth picked up grapes and easily popped them into his mouth. “The fine control that he has is just remarkable,” Albuquerque says. “Never mind that he is not crushing the grape. To be missing your whole arm from the shoulder down and to able to pick something up like a grape, without smashing it and put it in your mouth—that is truly remarkable.”
Another piece of breakthrough technology is the LUKE arm’s wrist motion that combines deviation with flexion and extension, a feature no other prosthetic hand has. “Why is that such a big deal?” Albuquerque asks. “Try picking something up off a high shelf and not spilling it without changing the position of your wrist.”
The custom-made arms cost about $200,000, though the price can vary. The VA paid for Currier’s LUKE arms, and Hildreth’s were covered by grants and donations. Albuquerque says the VA has done a good job of getting new products out on the market with the hope that, as more are manufactured, the cost will come down to make them more accessible to people in the non-veteran community.
Albuquerque says he believes the potential is immense and that the technology will be used in lower limb prostheses. “It just makes sense to use the muscles on your legs to drive a knee or a foot,” he says. “This is just the beginning of opening up a whole new world for people who have had amputations by tapping into what naturally goes on.”
Dean Kamen, president of DEKA, did not balk when DARPA approached his company for the project even though it involves a high-cost item for a limited market. “They said, ‘look, these people have literally, literally given their arms for this country, we can’t keep giving them the same 150-year-old technology that the military gave soldiers in the Civil War.’ Back then they gave them a wooden stick with a hook on it, today they give them a plastic stick with a hook on it.”