Students Design High Tech, Low Cost Artificial Limbs

Wednesday, May 21, 2014

The price of a new prosthetic leg can cost anywhere from $5,000 to $50,000 and an upper extremity device can range from $3,000.00 to $30,000. Limiting the amount of people able to get the devices. 
Utilizing medical grade plastics, a team of graduate students at University of Massachusetts at Lowell created prosthetics that would cut the cost down to  $20 per unit.  
Late last week, I was joined by Erin Keaney and Jonathan Perez de Alderete (al-der-RHET-ay),  two of the four Nonspec team members, who won first place at the American Society for Mechanical Engineers 8th Annual IShow late last month.

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."


Erin Keaney and Jonathan de Alderete

Produced by:

Tim Einenkel and Ellen Frankman


T.J. Raphael

Comments [5]

Daryl from missouri

Very interesting, a picture would be great
i am a relatively new amputee (AKA), the prosthetic leg seems a little heavy, but I need for the weight bearing capacity to be 250 to 300lb.
Is there a material that you are working with that would satisfy the weight capacity but be mnade of lighter material.

Jul. 29 2015 02:30 PM
Brad from Orange County, CA

Can you send me photos of your prosthetic.


Jun. 16 2015 07:35 PM
Rosie Vaughn from Chicago, Illinois

I think that you guys ideas are fantastic, I have a grandson that was missing his hand halfway up to the elbow at birth, he is thirteen years old now and a little vain about it. He recently fell, lost two teeth because he had began to stuff his sleeve into his pocket to make it look like he has an arm. If someone can contact me in Chicago so that I can look into the prosthetics I would really appreciate it.

Mar. 24 2015 09:21 AM
Molly from Seattle

These are very cool ideas. As a prosthetist I know that there are many issues around the device-skin interface and long term care/repair of a prosthesis that require the expertise of a prosthetist or at least training and follow up care availability to make a prosthetic limb work functionally for a patient. Consider getting a prosthetists input on stories like these. Limb replacement is not just an engineering problem, it's a medical-emotional issue as well. There's a reason we have prosthetists in healthcare.

May. 21 2014 12:45 PM
Larry Fisher from Brooklyn, N.Y.

My 7 year old asked me for bionics for his birthday. I asked him why. He said to kick my ass. I told him he has to ask his mother for that present.

We went home and watched videos on new bionics. My son looked at the prosthetic hands that could do anything and raised eyebrows at each other and said,"Wow!" at the same time.

May. 21 2014 12:36 PM

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