David Dorrance invented the split hook in 1912, a prosthetic device allowing people missing an arm to pick up things. For more than a century, the split hook was the go-to for those hoping to be functional with the limb they lost. But this week, the Food and Drug Administration gave the thumbs up to the Defense Advance Research Projects Agency-funded DEKA Arm System, an electromechanical prosthetic limb that replicates the natural movement, shape and strength of an adult human’s hand and arm.
Just eight years ago, DARPA formed the Revolutionizing Prosthetics program “to deliver near-natural upper extremity control to people who have lost their limbs in service to the country,” said the program’s manager, Justin Sanchez, in an interview with FedScoop. Backing DEKA, a research and development corporation in New Hampshire, DARPA accelerated the revolution of the prosthetic limb — a system unchanged for 100 years — in less than a decade.
Whereas amputees with split hooks might struggle tempering their strength when handling small, frail objects, Sanchez said the DEKA Arm can hold the likes of an egg or a grape without crushing or dropping them. Conversely, it can also handle something intense like a power tool.
“If you talk to somebody that’s living with an amputation,” Sanchez said, “what’s most important to them is that they become independent and that they can do all the things that they did before they lost their arm.”
Most commonly, users control the device with a sensor attached to their foot. Because it’s re-programmed with different hand grips and movements, amputees can make simple gestures like bending the DEKA Arm’s wrist upward by simply lifting their toes, or rotating it by rolling on the ball of their foot. The FDA approval also supports muscle activity to control the limb.
While the proper operation of the prosthetic was of great concern during development, DARPA also sought to help as many amputee service members as possible. To do this, DARPA and DEKA focused on two major elements of the prosthetic: its modularity and fully integrated functionality.
Of course, amputees have no say in what part of how much of their limb(s) they lose. So, a one-size-fits-all prosthetic wouldn’t cut it. The DEKA Arm’s modularity takes that into account.
“If you need three-quarters of your arm, we give you three-quarters of your arm,” Sanchez said. “If you need a full arm, we can give you a full arm.”
Likewise, the integration of the control components makes the prosthetic more adaptable to the wearer.
“All of the motors and actuation and control systems are integrated in such a way that we can break this arm apart into different pieces, depending on the needs of the individual,” Sanchez said.
DARPA winning FDA approval for the DEKA Arm this week was reason for celebration. But Sanchez said the agency wouldn’t have gotten there so quickly if it weren’t for the help of some other federal agencies along the way. The Department of Veterans Affairs provided participants for and funded the study that would lead to FDA approval. The Army also helped with funding and contact management that helped with meeting FDA requirements, according to a release.
Sanchez said this project is a good example of “how government organization and agencies can work together to produce something truly spectacular and revolutionary in terms of helping our military. That’s what this is all about.”
While DARPA doesn’t have control over taking the prosthetic to market, it looks forward to seeing the technology go toward bettering the lives of injured service members. Tom Doyon, DEKA’s project manager for the prosthetic, said his organization has a very similar vision for the prosthetic, which it calls the “Luke,” based on the “Star Wars” character Luke Skywalker, who lost an arm and received a similar device.
“We are proud and excited that the FDA has approved the DEKA Arm System for commercialization,” he said in an email. “This approval allows us to now focus on manufacturing and bringing to market the arm system so that we can deliver it to those in most need of this amazing technology – in particular our wounded veterans.”
The DEKA Arm is one of several prosthetic projects DARPA has initiated. In April, the agency announced its more-ambitious HAPTIX program, seeking to deliver natural sensations to amputees through the use of a prosthetic.
