“But it wasn’t until recent times that DARPA [the Defense Advanced Research Projects Agency] began driving interest in developing upper limb prosthetics – funding the robotic arm that private industry probably would not have because there still weren’t that many who needed it. It’s not being callous, it’s just practical. You can’t manufacture something that doesn’t sell enough to cover its costs – or price it out of reach. You also need software engineers who can do a lot of programming, then repair and maintenance – all hard core business issues that have to be addressed.”

Neuroprosthetics, linking the brain to a robotic prosthetic – hard-wired or wireless – has been in development for several years and has been showing remarkable success in lab tests since the beginning of this decade. The technology has advanced to the point where the Federal Drug Administration (FDA) held a meeting in November 2014 with researchers from DARPA, industry, and academia to discuss the regulations governing bringing a neuroprosthetic to market and the steps that must be taken to achieve that.

While welcoming the agency’s willingness to consider the future of such devices as an approved way to assist amputees and those with spinal dysfunctions, some also have voiced concern about the FDA’s tough regulations and paperwork requirements moving forward. They are perhaps the most stringent in the world, affecting not only American researchers and development companies, but foreign manufacturers whose own regulatory agencies are less demanding – but still must meet FDA requirements to market their products in the United States.

Even with FDA approval, doctors prescribing the devices still will have to deal with insurance companies, which tend to be slow to approve new procedures and technologies and make extensive demands for proof they are needed and will work for each individual patient.

Military personnel – active duty and veterans – have an advantage there because both the Department of Defense (DOD) and the VA have committed to providing the latest technology to those qualified to receive it, unlike civilian insurers, who are more likely to delay or even deny approval for the newest advanced prosthetics.

Another “double-edged sword” issue is the speed with which technology is advancing. While initially that would appear to be a good thing, it actually can stifle R&D because by the time a company gets FDA and insurance approval – spending millions of dollars in the process – one or more new generations of technology may have made the initial device obsolete before the first patient, outside the lab, has a chance to use it.

Some military surgeons have reported being asked, by wounded warriors whose legs were saved by improved technologies and far-forward efforts of combat medics, nurses, and doctors, to amputate those limbs, anyway. One surgeon said a young soldier who could expect his injured leg to have about 85 percent of its former capability demanded it be amputated and replaced with a cutting-edge prosthetic some have rated at 120 percent of normal human ability.

“Most people see people in the news with lower extremity prosthetics who are running and playing basketball, but that’s because they’re on level surfaces,” Tyler said. “But if they start walking in a dark room or uncertain terrain, they have a hard time. We believe that by giving them a sense of touch and, hopefully, position in the foot, they will be able to do a lot better.”

Although more lower limb amputees from the last 15 years of war in Southwest Asia are walking on advanced prosthetic legs and feet, another device most people don’t think of as a prosthetic is far from museum status.

“There has been so much press about [prosthetics] in the past few years, but as the war fades into memory, so will the money and congressional interest in pursuing more advances. And there will be fewer numbers of new amputees and it won’t be big news anymore.”

“There have been advances in wheelchairs to help make veterans mobile and independent – lightweight, better materials, more sophisticated electronic controls, hubs that use battery energy to propel a manual wheelchair forward, which helps a quadriplegic maintain the cardiovascular system,” Downs said. “The iBot, which was invented by DEKA, can stand up on two wheels, but it didn’t generate enough customers to stay in production, an example of what might be called an orphan product, which is a danger with a lot of expensive, high-tech stuff.

“Experiments also are underway on implants into muscles above the break. Signals come down the nervous system, but when they hit the injury, they stop. So researchers are looking at hooking the nerves above the break to viable muscles below the break. Bypassing the break would be a great advance because the individual, perhaps, would be capable of greater mobility.”

The real cutting edge in prosthetic research development test and evalution (RDT&E) is neurological, from invasive brain implants to non-invasive skullcaps. At the University of Pittsburgh, a female quadriplegic with brain implants was able to move a robotic arm by consciously thinking about how she would have done so with her own arm. And for the first time in three decades, she was able to pick up a piece of chocolate and feed it to herself.

Downs himself, who lost an arm in Vietnam, is taking part in a one-year Army evaluation of a robotic arm with 10 internal computers. Funded by DARPA and built by DEKA Research & Development Corp. (Manchester, New Hampshire), the arm’s movements are controlled by the user’s feet – tilting the foot forward creates electrical signals in the brain that are translated, resulting in the robotic hand grasping. Other foot movements enable different arm movements and hand actions.

“The future is the neural interface, being able to wear a skullcap that is not invasive and move arms by just thinking about it,” Downs said, but added that is only the first step toward user-controlled, multi-function robotic hands. “When I first got the robotic arm, touching something caused a buzzer to go off, just to let me know I was touching something. I didn’t particularly like it because it buzzed too often, but it was a step toward developing a sense of feel. Now they are looking at sensing cold and heat.”

The current generation of neural interface technology, while showing remarkable potential, is largely a one-way street – signals can be sent from the brain to a prosthetic’s robotic controller, but there is no sense of touch going back to the brain. That is the latest focus for far edge research – installing nano-sensors, even sensor-optimized artificial skin, on robotic hands.

“There has been some work in the past with residual limbs. We implant a small device on the nerves that once led to the hand, then stimulate that nerve. The person feels as though they have touched something with their finger, so when we connect that to the prosthetic and they touch something, it feels to them as though it is their hand touching something,” Tyler explained.

“While sensory is the most important goal, the other side is placing electrodes within the remaining muscles in the forearm that once made fingers move. So when you think about moving your finger, that implant stimulates those muscles. We also are working on processes called pattern recognition and targeted muscle reinnervation.”