Research Highlights / Full Story

Printing Affordable Prosthetic Devices

In the past four years, the emergence of affordable 3D printers and the do-it-yourself Maker movement have sparked a revolution in prosthetic devices. Just as a painter uses layers of paint and specific brush strokes to create art, a 3D printer uses specific digital instructions to lay down layer upon layer of plastic to create a finger or palm.

The customized parts are then assembled using string, nuts, bolts, and Velcro from an everyday hardware store. The total cost is less than $50, nowhere near the thousands of dollars people pay for traditional prosthetic devices. 

“This is an inexpensive process that can be completed by almost anyone, especially now that many schools and libraries have 3D printers for people to use,” said Jon Schull, a research scientist in RIT’s Center for Media, Arts, Games, Interaction and Creativity (MAGIC).

In 2013, Schull created the online community e-NABLE, a group that is advancing the development of these affordable devices by connecting 3D-printing hobbyists and professionals with people in need of prostheses. Today, the popularity of e-NABLE has exploded with more than 5,100 volunteers helping at least 500 people around the world. 

At RIT, more than a dozen students, alumni, and volunteers have joined Schull. Using their design and biomedical engineering skills, they hope in the future to take these assistive devices beyond children with birth abnormalities to help people who have lost limbs due to war and violence, natural disasters, or disease.

In May 2014, RIT students developed a prototype and design for e-NABLE’s first 3D-printed mechanical forearm (the “RIT arm”), which they donated to two recipients in Buffalo. The team is now working to create exoskeleton devices and more effective arms and hands to augment or replace muscles. They also are collaborating with a Johns Hopkins University research lab.

“I think that the technologies and practices that Jon and the students at RIT are helping to create could significantly improve millions of lives worldwide,” said Dr. Albert Chi, a trauma surgeon at Johns Hopkins Hospital and world-renowned researcher on state-of- the-art prostheses. “Now is the time to bring e-NABLE’s collaborative approach to design and democratization of 3D-printed prostheses into mainstream medicine.”

 
Putting e-NABLE on the Map

Born in Shanxi, China, a mining area about 300 miles southwest of Beijing,  Lucas LeMay would wake up every morning to streets covered with inches of coal dust. He was living in a province that saw a rate of birth defects six times higher than the national average.

But in 2008, everything changed. Jim and Kim LeMay traveled to the city in search of a son. They fell in love with the shy, clever 4-year-old boy and decided to adopt him. Lucas was still adjusting to life with a big sister, Lindy, and his dog, Chance, in Walworth, N.Y., when the first 3D-printed hand was created in 2011.

As the story of that first hand goes, after a South African carpenter named Richard Van As sawed off most of the fingers on one hand in an accident, he became determined to get back to work. Because he couldn’t afford a prosthetic device, he turned to the Internet to learn how to make one. 

He connected with Ivan Owen, an American prop maker who had created a mechanical puppet hand, and together the pair from halfway around the world designed and produced a working hand for the carpenter. By flexing his wrist, Van As was able to control the fingers, which were attached to cable “tendons” that would tighten and relax the hand’s grip.

They also created a hand for a 5-year-old in South Africa, who, like Lucas, was born without fingers on his right hand due to a congenital condition called Amniotic Band Syndrome. ABS is the result of fibrous bands that wrap around a hand or a foot in utero and cut off circulation. About one in 1,200 children born every year has underdeveloped fingers and limbs as a result of the condition. 

Although the first hand was designed with aluminum, Owen decided that using plastic parts created by a 3D printer would save time and money. Calling it the Robohand, they posted a crude 3D-printable design and an instructional how-to video online for anyone to use. 

“When I came across that video, I immediately got excited,” said Schull. “Comments on YouTube videos are rarely inspirational, so what I saw amazed me,” said Schull. “People were saying, ‘This is cool, I have a 3D printer and I’d do this.’” 

Schull then had the idea to create a custom Google map and linked it to a comment of his own. He simply said, “If you’re willing to receive inquiries from people who need an assistive device, put yourself on this map. Crowd source the distribution network.” 

Within six weeks, there were 70 pins on the Google map—e-NABLE was created. 

 
Making a Difference

For the LeMays, there was never an urgency to purchase a commercial prosthetic hand. Lucas had visited a doctor when he first came to the United States, but it would have cost thousands of dollars. And he didn’t need one. 

“He’s very clever,” said Kim LeMay. “He’s figured out his own way to play the Xbox and he’s even learning how to play the guitar.”

However, when a friend posted a link to e-NABLE on Kim LeMay’s Facebook wall, she was intrigued. 

As Lucas got older, he did encounter a few activities where more grip would be useful. A second hand could put more power behind his baseball swing and steady his basketball shot.

At this point, the e-NABLE community had grown to almost 1,000 members worldwide, and Schull and RIT students were playing a crucial role in its success.

When 10-year-old Lucas visited RIT for the first time in June 2014, the local group had already created two arms and three hands. 

Jade Myers, a graduate student in RIT’s professional studies program, designed and built Lucas’s new hand. It was a natural fit, even though it was the first 3D-printed hand she had ever built. 

Having always had an interest in prosthetic devices, she came to RIT with plans to tailor her major toward prosthetic design, robotics, and cybernetics.

“I happen to know a lot of veterans who have waited years to get a prosthetic device, and that’s just not right,” said Myers. “If we have the ability to build people an affordable alternative that can help, then we really need to be doing it.”

While building Lucas’ hand, Myers encountered a few complications. They learned that they needed to make the shell level thicker because the plastic was splitting.

 “There is certainly a learning curve for building these devices, and there are always more improvements to make on your design,” she said. 

 The family of 8-year-old Lusie Santangelo of Greece, N.Y., has also learned that with these printable prosthetics comes room for improvement.

Lusie, who was adopted as a baby from Armenia, was born without most of her forearm, also due to Amniotic Band Syndrome. Like Lucas, Lusie had reached an age where a prosthetic arm would help her be more active, said her mother, Kathy Santangelo. Lusie wants to swing on the monkey bars at recess, ride her bike down her driveway, and ring the bell in her bell choir. In the fall of 2014, the RIT team fitted Lusie with an arm, but it provided limited functionality because the elbow-activated string tensioner on her arm did not allow for full arm movement.  

Schull and Skip Meetze, a full-time volunteer on RIT’s team and a retired Xerox engineer, connected with prosthetist Jeff Erenstone, an e-NABLE volunteer based in Lake Placid, N.Y., whose full-time job is making orthotics and prosthetics for amputees out of carbon fiber and titanium. Erenstone got involved with e-NABLE because of the impact he believes it will have on people in developing countries. He developed a design—called the Monette—that utilizes a shoulder harness and a custom-fitted socket that is molded using heat. In April 2015, the Santangelo family returned to RIT to meet with Erenstone, and he fitted Lusie with a new printable arm using the Monette socket design.

“A custom socket is crucial to the proper fit of a prosthesis for a transradial patient,” said Erenstone. “And this was the first time this design has ever been fitted on someone. To be able to print and fit Lusie with a new 3D-printed arm in just a few hours is something that would take me weeks to do at my prosthetist practice,” said Erenstone. 

Erenstone will travel to India soon to fit a little boy with an arm like Lusie’s.

It’s volunteers like Erenstone that Schull believes will help e-NABLE grow in both numbers and impact.

“I see the community working together to create a variety of assistive technologies,” Schull said. “e-NABLE really only works because we have so many professionals, volunteers, and recipients who are willing to collaborate and help each other.”  

Erenstone agrees and says volunteering for the e-NABLE community is addictive.

“It’s the engineering and seeing these designs progress and understanding where the potential is that makes it exciting for me. I really like working with these incredible designers around the world. This is a solution for a big world problem and to be part of that feels pretty good.”