U.S soldiers in Afghanistan develop simple prosthetic leg using local resources

While we've covered many developments in the field of prosthetics, such high-tech advances are beyond the reach of those in the developing world where the rates of amputation due to war are highest.

Now U.S. Army soldiers stationed in Afghanistan have developed a simple prototype prosthetic leg that can be constructed using local resources to allow the victims of improvised explosive devices (IEDs) and land mines to get back on their feet quickly and cheaply.

Although he says he could have contacted a charity in the U.S. to get high-quality prosthetic limbs for a handful of victims near Forward Operating Base Pasab, Afghanistan, Dr. (Maj.) Brian Egloff, brigade surgeon, Headquarters and Headquarters Company, 3rd Brigade Combat Team, said it would only have been a temporary solution and so he and his colleagues set about finding an enduring design for a prosthetic leg.

The result was a prototype consisting of a simple cast attached to a metal rod with a flat hooked foot. The cast can be fitted in as little as a day and can be recast to accommodate the growth of the wearer. The metal rod and flat hook can be easily reproduced and allow the patient to walk more naturally.

An eight-year-old boy who lost both legs after stepping on a land mine and needed to be carried around on his father's back received the first prototype leg on June 26, 2011.

"It helped knowing that the leg was for a small 8-year-old boy who was happy all the time - despite his situation," said Warrant Officer Brian Terry, 710th Brigade Support Battalion, 3rd BCT, who constructed the prototype.

"This patient and people like him have no mobility whatsoever," added Egloff. "It's all about increasing mobility and allowing them to live a more productive lives."

Terry said the next step is for the Afghan doctors in this region to make their own prosthetics and to train them how to instruct victims on the use of the leg.

Detecting land mines with sound

Detecting land mines with sound

The researchers built a prototype detector and tested it at the Cold Regions Research and Engineering Laboratory Army Corps of Engineers land-mine facility in New Hampshire. They were able to detect both metal and plastic mines but said that the system will have to get a major boost in acoustic power before minefield searchers can use it safely.

Robert W. Haupt, a technical staff member at Lincoln Lab, explores innovative ways to find and reduce the large number of land mines abandoned in war-torn countries. An estimated 26,000 people are killed or maimed every year by 60 to 70 million undetected land mines in 70 countries. Those casualties include military troops but most are civilians--half of them children under age 16--who step on uncleared minefields after a war.

Many existing prototype mine detection systems can detect only metal, have limited range or are impractical in the field. "Reliable methods that quickly and accurately locate land mines made of metal and plastic, unexploded ordnance and other mine-like targets are desperately needed," Haupt said.

Haupt and fellow Lincoln Lab staff member Ken Rolt developed a high-powered sound transmitter that looks like a stop sign studded with 35mm film canisters or prescription pill containers. This is called a parametric acoustic array, and Haupt and Rolt have built one of the most powerful ones around.

The array is made up of ceramic transducers--devices that emit a powerful narrow acoustic beam at ultrasonic frequencies. One meter away, the ultrasonic pressure level measures 155 decibels--more acoustic power than a jet engine. Immediately outside the beam, the acoustic intensity dies away to almost nothing.

By a process know as self-demodulation, the air in front of the acoustic beam converts the ultrasound to much lower frequency audible tones that sound like extremely loud tuning forks. Unlike ultrasound, the low-frequency sound can penetrate the ground, causing detectable vibrations in the mine's plungers and membranes.

"The use of ultrasound allows us to make a very narrow and highly directional beam, like a sound flashlight," Haupt said. It would take a huge number of conventional loudspeakers to do the same trick, and they would weigh too much, take up too much space and use too much power to be practical, he said. Plus, they would deafen anyone within earshot. "Using a narrow sound beam, we can put sound just where we want it, and we can minimize sound levels outside the beam to avoid harming the operators or people nearby," he said.