Texas Tech University

Honors College, Biology Student Creates 3D Printed Child's Prosthetic Hand in Library Makerspace

Glenys Young

May 17, 2018

Prosthetic Hand

SivaTeja Pati says he will continue to refine the design moving forward.

Eight-year-old Toby Carrizales loves Spider-Man.

Spider-Man's true identity, Peter Parker, is more than he seems. He is a man who lives to save others, a man who has great power – and therefore, great responsibility – in his hands.

It's understandable why Toby, who was born without a left hand, idolizes him.

Late Friday afternoon, Toby – in a full-body Spider-Man costume, mask over his head and eyes visible through its slits – became a little more like Spider-Man: part human, part superhuman.

SivaTeja Pati, a biology major at Texas Tech University, presented Toby with a custom-made, Spider-Man-patterned prosthetic hand he designed and 3D printed for the boy, using the Makerspace in the University Library.

The beginning

Pati, who goes by “Teja,” has been on the health care track for a long time. He was involved in Health Occupation Students of America at Seven Lakes High School in his hometown of Katy, Texas, and shadowed physicians at four different medical centers throughout his junior and senior years. The same month he graduated, he joined the community volunteer fire department as an EMT.

After starting at Texas Tech in fall 2016, Pati joined the American Medical Student Association. So it's no surprise that he intends to go to medical school once he graduates – and he's even speeding up that process. Though he's just finishing his second year at Texas Tech, 20-year-old Pati is already a senior by hours.

As an aspiring physician sometimes does, Pati was scrolling the National Institutes of Health (NIH) 3D Print Exchange database one day when he stumbled across a 3D printable file comparing a healthy brain to the brain of a person with Alzheimer's disease.

These brains were some of the earliest items Pati 3D printed, using the Makerspace in the University Library. The red brain is that of a healthy person while the white brain is that of someone with Alzheimer's disease.

“I wanted to see what was being done with 3D printing in medicine, because something like this would be great to have in biology classes or medical school,” Pati said. “In the program, you can actually slice the brain in half and print off two halves and show your students the structures inside. As opposed to a picture, you can say, ‘Here, touch it.'”

The brains were some of his earliest 3D printing endeavors. Also on the NIH database, he found designs for a prosthetic hand from an open source group called e-NABLE, which shares designs for affordable prosthetics. Pati downloaded some of these designs, brought them into the Makerspace and, with the help of Makerspace specialist Sean Scully, 3D printed a hand to show in class for a persuasive speech on the need for an e-NABLE group in Lubbock.

“If you were to look at a map of the state of the closest e-NABLE communities, you have one in Austin, San Antonio, somewhere near Dallas and one in New Mexico. In the middle is Lubbock, about 300 miles away from each other place,” Pati said. “That's a big circle with no one to actually do anything. It's the same thing with University Medical Center – they're the only Level 1 trauma center from here to those major cities. If someone happened to get in a life-threatening incident, they'd need to come here. If someone needed a 3D prosthetic hand, they'd have to go 300 miles the other way.”

This was the first prosthetic hand Pati 3D printed. It uses the same grasp-type mechanism as the hand he made for Toby.

The speech inspired Pati to take action, so he began working to start a 3D printing club through the Makerspace, a branch of which would focus on prosthetics.

Shortly thereafter, in early December, Scully got a call out of the blue from a woman named Anna Carrizales, who said, “I hear you make hands for people – will you 3D print a hand for my grandson?”

Scully told her they could, and if the library could pair her up with a student or a member of the Texas Tech community, it probably could be done for free.

“‘I can at least point you to one student who I know has already printed something similar,'” Scully recalled telling her, “and that was Teja.”

The research project

Although the project would involve far more engineering than the biology major was accustomed to, Pati agreed to take on the project because of its interdisciplinary nature and the role that sort of work has in the field he aspires to enter.

“When I think of medicine, I don't think of just a doctor with a stethoscope giving someone a shot. I think of a person who cares about who they're treating, who they're helping. It's someone who isn't just fluent in medicine, but in everything that can support medicine,” Pati said. “There are projects such as 3D printing a kidney or a heart. Those are fantastic in and of themselves, but as a student, you'd need special 3D printers, special filament, you'd need money to buy all of that stuff. We are using what we have already to improve someone's quality of life.”

While Pati was working on the project, however, the Makerspace had to begin charging a nominal fee to cover materials for personal projects, so Scully urged Pati to turn it into a research project, which would be free. Pati, already a student in the Honors College, connected with John Carrell, an assistant professor of engineering in the college who became Pati's Undergraduate Research Scholars (URS) adviser.

With Carrell's expertise in engineering and Scully's expertise in computer-aided design and drafting, Pati was able to customize the open source design to fit Carrizales' grandson, Toby.

“We used our 3D-scanning capabilities here in the Makerspace to scan Toby's arm, then we were able to 3D print it so he wouldn't have to come in constantly,” Scully said. “Some of the parts need to be form-fitted, so we have to heat them up and mold them. Because we were able to establish it as free, printing a large arm didn't seem to be too expensive.

This is a 3D printed copy of Toby's arm that Pati used as a model when creating the boy's prosthetic hand.

“We have a structure scanner that attaches to the iPad. It's hard to get an 8-year-old to sit still long enough, but we got a really good scan. Then, we were able to print that out so Teja could go and form the pieces around that.”

The actual fabrication of Toby's hand took two to three months, but Pati's process has been much longer, Carrell said.

“He's had to print his first large hand and see how the mechanisms work and how to put it together, and there's all sorts of troubleshooting that go into optimizing the 3D print process,” Carrell explained. “He's done a lot of the initial work, and then the actual work as far as getting Toby's hand put together and the Spider-Man accents.”

The next step

As Toby practiced grabbing dry erase markers, a roll of paper towels and a water bottle, Pati explained Toby's new hand is only the first step in a much longer research process.

“This hand has a grasp-type motion,” Pati said, demonstrating how the angle of the wrist determines whether the plastic hand is open- or close-fisted. “My research focuses on a pinch grip.”

The pinch grip, using the index and middle fingers and the thumb, is still in the design phase, but Pati is confident.

“He'll eventually be able to pick up small, flat things,” Pati said.

Carrell and Pati want to maintain some sort of mechanical method to switch between the grasp and pinch grips. Not only is that a simpler method than an electronics-based solution, but it's also a more reasonable option for Toby's family.

“There are all sorts of things you could put on it, gyroscopes or little Arduino boards that could give more functionality or feedback, but it becomes more cost prohibitive, especially for Toby, who's going to be growing up and will need hands to grow with him,” Carrell said. “Keeping it on the mechanical side, we can print a hand for about $20. For all the electronics, it would be much more expensive.”

It's a consideration many parents can identify with.

“With my kids, we're having to buy them a new pair of shoes every couple months,” Carrell said. “I imagine it would be the same kind of process with a hand. If you don't have the means to buy an expensive prosthetic, there's probably times when you have to make do with what you have, and then you go without sometimes.”

The impact

When Toby was 4 months old, he received his first prosthetic, Carrizales said. In tears, she said the way he studied his new hand reminded her quite forcefully of his initial fascination with the first.

“It was more like a doll hand,” explained Toby's mother, Desiree Lopez. “It didn't serve any purpose, it was more of a cosmetic thing. He didn't like it, so we maybe put it on him twice.

“He hasn't had anything else until now.”

While Toby is still a little in shock, Lopez said, he has big plans for life with his new hand.

“He mentioned throwing a football,” she said. “He's trying to learn to ride his bike without training wheels and he was having trouble balancing while holding on with just one hand. Now he can use this to grip the handlebars.”

Although Toby never let life with only one hand slow him down – he already has been taking piano lessons for years – Lopez said she appreciates how many more possibilities he has now.

“When I saw him pick up a ball on Friday, that's something that's so simple, but he's never been able to do that,” she said. “Seeing that made me really emotional because I never thought I'd see him do that. I can't imagine how he must feel.”

And the fact that his new hand looks like Spider-Man is an added bonus.

“It just makes him feel like a superhero,” Lopez said. “It's like a super power for him.”

Scully said the hand's appearance plays a big role in that.

“There's the stigma that's attached to having a disability and feeling that you're less,” he said. “Dressed up as Spider-Man with a Spider-Man hand really flips that on its head. He goes from someone who has to deal with this thing to someone who can show off. That's a very different dynamic in terms of how you approach learning and your outside community and everything.”

Thanks to Pati and the Makerspace, Toby doesn't have to go without anymore. As he picked up a stress ball, turned to his grandmother and released it into her open hand, a grin began to spread across his face.

“That was rough,” Scully admitted. “It was hard not to cry, especially once he was able to pick things up. He was able to figure out so fast exactly how that works. Right now, it's such an early stage of the prototype, I can't imagine what he'll be able to do as Teja moves forward.

“This is one of the things I wanted to do with this Makerspace: affordable prosthetics for kids, interacting with the community and advancing the technology on a local level. I think that's what makerspaces are all about. And fostering people who are excited about it and giving them the resources to follow through. I think that's how most big innovations happen.”

Watching his young friend, Pati said the results were well worth the effort he put in.

“I was just elated; I was so happy he got the motion,” he said. “These things might take one to two weeks to get the full motion. When we grab something, we pull and our wrist pops back. His hand requires him to push forward. Because his other hand is fully developed, the motion opposes what comes naturally to him. But the fact that he was able to pick up a ball almost immediately was surprising.

“It's the first time I've ever done something like this. I'm glad it turned out the way it did. This is going to become a part of him. We may change our clothes or our hairstyles, but a prosthetic device is something you live with for months.”

The project also was a first for Carrell, who enjoyed seeing Toby use his new hand.

“It's probably a more rewarding type of research experience for Teja,” Carrell said. “A lot of times you get to do the research and you may understand the implications of it, but you don't get to see it applied. He gets to see it applied.”

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