Supporting Our Troops Means Needing and Improving Prosthetic Limbs

Veterans Day marks an occasion to give a little more consideration to the complicated relationship between the United State and its armed services.

The US military exists to compel or deter behavior through the use or threat of force. As a hierarchical organization governed by a massive central-planning bureaucracy, it can seem inherently at odds with the capitalist, representative democracy that it protects. The civilians of wealthy democracies, meanwhile, can feel conflicted, or even downright hostile, about the actions of their national armed forces.

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In every war, casualties abroad can be used as political ammunition at home. The 1991 Gulf War was the gold standard for setting high expectations regarding a minimal loss of life. Anti-war activists also learned from the lessons of Vietnam that opposition to a war — such as the 2003 Iraq War — should not become opposition to the troops themselves. These days, the call to "support our troops" has become one basis for bipartisan agreement in an otherwise dysfunctional Washington.

Within the armed forces, this has created a steady push to reduce casualties. Body armor, counter-IED armor for vehicles, and medical treatment all improved dramatically in the decade after 9/11. But one of the unanticipated consequences of getting better at saving the lives of young soldiers and marines has been a sharp increase in the number of wounded.

A lot of people who would have died from their wounds in previous wars are less likely to do so today. In most historical conflicts, roughly two to four people were wounded for every person killed. For US forces in Iraq, about 7.3 people were wounded in action for every death.

This is a great advance in lifesaving, but it has put a lot of strain on the medical system. For instance, the Veterans Health Administration — whose delays in delivering treatment throughout its system has been the focus of recent scandal — is struggling to cope with veterans who generally are physically much more beaten up, broken down, and busted than were veterans of previous wars.

Another area that has changed because of these developments is cutting-edge prosthetics technology. Prosthetic technology, or really any form of human-machine interface involving invasive surgery, has historically not been a big focus of military technology development. There are just too many ethical and political minefields associated with surgically implanting members of the military with chips and metal and wiring them up. Even doing the basic research on some of that hasn't always been a huge winner, because preparing for future maimings or amputations is simply a harder political sell than doing something else, like developing better armor to prevent the injuries in the first place.

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But the wars in Iraq and Afghanistan changed all of that. For several years now, the Defense Advanced Research Projects Agency (DARPA) has been working on creating much better prosthetics, and the technology has since progressed by leaps and bounds. This effort is now yielding some amazing advances in robotics and electronics that interface directly with a wearer's nervous system, which are in turn opening up a host of other possibilities.

This progress is partly due to the fact that losing a limb in combat radically reshapes the ethical and moral issues surrounding experimentation and development. Surgically attaching electrodes to a healthy soldier's nervous system for an experiment might seem invasive and exploitative, while performing the same procedure to help an amputee control a prosthetic limb can be seen as practically a national obligation. This alteration in the ethical landscape has had interesting results.

For instance, amputees often complain of "phantom pain" or "phantom limbs" — a feeling of pain or other sensation in the limb that has been removed. Such sensations are a sign that the peripheral nerves that normally carry such signals to the brain remain alive and well, even if they don't connect to anything.

DARPA's Hand Proprioception and Touch Interfaces (HAPTIX) program — itself a result of another DARPA program, Reliable Neural-Interface Technology (RE-NET) — connects those peripheral nerve endings to electrodes. Not only does this reduce phantom pain, it allows electronics connected to those nerves to transmit sensations. Adaptation of the technology to allow connection with musculoskeletal nerves allows the amputee to control a prosthetic arm.

The technology to allow the brain to control a robot arm has been around for a while now, and has lately become increasingly well known on its own. But it's easy to see how the ability to send sensations back to the user is a major development for prosthetics. Without the signal to tell the brain where the arm is and what it's doing, the person wearing the prosthetic relies on vision alone.

If an attachment point for the prosthesis can be grafted to the bone as well as the nerves, so that the prosthetic limb is mechanically stable, the arm can function pretty convincingly.

What started as a surge in prosthetic technology to largely help veterans may soon take on a life of its own. The military has had an interest in robotics for years, but there's still a ways yet to go beforeit really comes into its own. Nonetheless, there's an enormous amount of potential. Remotely operating a robot arm with the dexterity and sensation of a human arm could be a game changer for explosive ordinance disposal. It might even help future bomb squad techs avoid the situations that cost their predecessors their arms and helped spur the development of advanced prosthetics.

Follow Ryan Faith on Twitter: @Operation_Ryan

Photo via Flickr