The price of a new prosthetic leg can cost anywhere from $5,000 to $50,000, and an upper extremity device can range from $3,000 to $30,000. The high cost keeps a lot of people from these important devices, especially in the developing world.
However, a team of graduate students at University of Massachusetts at Lowell has found a way around the high cost of high tech prosthetics. Using medical grade plastics, they were able to cut the cost down to $20.00 per unit.
The team of students won first place at the 8th annual American Society of Mechanical Engineers this April. Erin Keaney and Jonathan Perez de Alderete, two of the four team members, joined us to talk about their design, their research, and their future plans for getting the limb into use.
"The device that we have actually undercuts the cost of the average prosthetic tenfold," says Keaney. "That actually allows, financially, 80 percent of amputees to have access to our product."
Perez de Alderete says there is a disparity in the prosthetics available to persons in industrialized societies when comparing access to those in developing nations.
"Part of the problem is actually the fact that the cost of these limbs is incredibly, incredibly high," says Perez de Alderete. "A prosthetic leg can range from $15,000 to several hundred thousand dollars depending on the quality of the limb you're looking at. If you're looking at someone like Blade Runner (aka Oscar Pistorius), the cost of his limbs are completely out of the reach of a normal person."
The number one challenge for most prosthetic producers is the cost of materials and the cost of the product's design—in order to have the ability to mass produce prosthetic limbs, those costs must be kept down. In developing nations, additional challenges also present themselves.
"It's really making sure that we can meet the needs of the areas that this will be in, so taking in electricity considerations and cultural considerations has been a big part of this," says Keaney.
The team has been able to develop prosthetics that are multifunctional—one device can function as an arm, an elbow, a leg or knee, for example.
"The forearm, the upper arm, the thigh and the lower part of the leg are pretty much the same components," says Keaney. "We can change the angle with different plates, and that adjusts with the size."
Perez de Alderete adds that the human body has a certain uniformity, which makes it easy to substitute different prosthetics for different body parts. These UMass students are also taking a unique approach when it comes to specific areas of the body, like a human hand.
"When we designed the hand, we designed it as a platform," he says. "Inside the hand there's a hollow space. That space can be wired with motors for people who want and have access to an electric system. For people who can't afford that or don't want that, they can get a cable-driven system—you swap out the motors with a special cartridge. For little kids, the cable system might not quite be what they need, so we have a ratchet system—basically some meshed gears so they can position the hand themselves with their other hand. You get the functionality you want based on either how much you're willing to pay, or what you need in your life."
Both Keaney and Perez de Alderete say that they hope their design can function as a universal device that allows individuals to determine how they would like to use the product. While having such versatility might seem like an obstacle, the students say it actually allows them to reach a broader group of people.
"If we wanted to mass produce, you would need access to an injection molding machine," says Perez de Alderete. "Taking that into consideration, we actually designed the whole thing to pack flat. We could actually ship a kit anywhere in the world to someone who needs it, and it's about a four inch by four inch by six inch package. It's a very small package that holds the entire limb."