3-D Printing Offers Amputees a Hand
Photo courtesy of Peter Binkley.
Peregrine Hawthorn has an easier time getting multiple coffees at Starbucks these days. He used to have to carry one cup in his right hand while balancing another between his left arm and side, using just the right amount of force so it stayed in place and didn’t spill.
His story may hold promise for injured workers who sustain amputations.
Born with no fingers on his left hand, the 21-year-old generally has not used prosthetics, saying they are awkward and hard to come by for someone with his particular anatomy.
Then he saw a YouTube video about an African carpenter who had lost four fingers in a woodworking accident and ultimately got prosthetic fingers created by a 3-D printer.
“My dad was in the process of getting a 3-D printer,” Hawthorn said. “We didn’t know what to do with it at the time.”
Once they had the printer, father and son downloaded a design and printed a product called Snap-Together Robohand. But the instructions were less than stellar.
“We had to figure out how to mount it to Peregrine,” said Peter Binkley, Peregrine’s father. “It had plastic parts with right angles, but the human body doesn’t really have right angles. We heated up the plastic and bent it to fit Peregrine’s shape better and mounted it to leather that’s like a cuff on his arm.”
VIDEO: e-NABLE volunteers are connected through the Internet, and donate their time and the use of 3D printers to print and assemble the movable plastic hands.
That was in the spring of 2013 when Hawthorn was finishing high school and Binkley was teaching French and English as a second language. Now the two are developing a variety of low-cost prosthetics and working with an organization called e-NABLE, described as a “global network of philanthropic volunteers using 3-D printing to give the world a ‘Helping Hand.’ ”
Essentially, it is a community of volunteers who create open source, publicly available devices and provide easily accessible information for people with upper limb differences who need a 3-D printed prosthetic.
The two work as a team with Binkley doing much of the designing to date and Peregrine serving as the test pilot and developer. Part of the trick is creating devices that serve a variety of needs.
“Usually you have to choose; it either looks great or it is useful,” Binkley said. “We’re trying to do both.”
For example, they have been able to improve the overall grip strength without sacrificing its looks. “It looks cool,” Binkley said. “It’s not your typical prosthetic.”
And it needs to be comfortable for the user. “It almost doesn’t matter how functional it is if it’s not comfortable,” Hawthorn said. “I had some early on that were uncomfortable enough that it would hurt if I did too much. Being uncomfortable impairs the functionality.”
“The beauty of these designs is that the vast majority of the parts you can get pretty much anywhere. If you have a Lowe’s, you can definitely put one of these together.” — Peregrine Hawthorn, test pilot and developer, e-NABLE
Making the most appropriate prosthetic involves the right balance of natural and printed materials. An all-plastic device can be made faster than one with leather, for example.
“There have been attempts to make a prosthetic that is 100 percent 3-D printed, which sounds really cool but plastic is a hard material,” Binkley said. “You can wear some hard material but you don’t really want a device that is completely hard.”
What makes the prosthetics especially appealing is the cost factor. Binkley and Peregrine have designed their devices by starting with downloads of designs that are available free to the public.
They realized that modifying and customizing the devices was key for the user. Binkley, who previously had no experience in engineering or computer-based design, said he started to learn Blender “a free and open source modeling tool.”
The most expensive item needed is the 3-D printer. Binkley spent $800 two years ago and points out the cost of the printers has come down.
The supplies required include nylon filament, stainless steel screws, and leather. “The beauty of these designs is that the vast majority of the parts you can get pretty much anywhere,” Hawthorn said. “If you have a Lowe’s, you can definitely put one of these together.”
The two are making the designs available throughout the world. Their focus has been primarily on congenital amputees. They are doing it voluntarily and make no money on them.
Binkley said developing the prosthetics commercially would require government approval. But it’s something he would be interested to see.
“If there are people in the [workers’ comp] industry who are interested in what this open source prosthetic has to offer, I’d be very excited to share what we can do,” he said. “This does have a tremendous potential to help people, and I think for people who are service providers it provides a possibility to improve a person’s outcomes at very little cost.”
The area of open source 3-D printing is relatively new. Binkley believes it offers tremendous opportunity.
“The explosion of these designs is only two years old. So you can be certain that we will be seeing many more designs with the potential to accommodate a wide variety of limb differences and amputations,” Binkley said.
“It is in the interest of insurance professionals and those working in workers’ compensation to have access to low-cost solutions that significantly improve the lives of amputees, and possibly getting those injured workers back into the workplace. We would be very excited to see the conversation go that direction.”