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When Garrison Hayes was 6 years old, his left leg was amputated to cure him of pediatric osteosarcoma, the most common bone cancer among children. While sitting on his grandmother’s lap at Children’s Hospital Colorado, the little patient discussed his pending surgery with his doctor and said he hoped to play soccer after treatment.
And he did. After limb-salvage surgery, Hayes played soccer, then skied, cycled and became a top Paralympic athlete in the javelin throw.
All the while, he found the feet on his prosthetic legs to be imperfect: Hayes has broken many of the devices through wear and tear, and he never walks – or even lounges around the house – without a shoe over his prosthetic foot for cushioning and flexibility.
So, when he became an engineering student, Hayes set out to create a better prosthetic foot.
If it is brought to market, the Goldilocks Foot would cost less than other models of similar quality, could be customized for the needs of the wearer, is more comfortable and, because of its material and latticework design, returns energy to the body. Photo: Hannah Tran/CSU Photography
In August, he teamed up with four other Colorado State University undergraduates, all studying biomedical engineering. The team invented a prosthetic foot that is created with a 3-D printer. It costs less than other models of similar quality, may be customized for the needs of the wearer, is more comfortable and, because of its material and latticework design, returns energy to the body – putting a spring in the step of amputees who wear it.
‘Goldilocks Foot’
The students call their design the Goldilocks Foot because “this foot will fit just right,” explained Eric Gutierrez-Camacho, a first-generation student from Montrose who serves as the team’s design engineer. He has printed prototypes of the Goldilocks Foot on his personal 3-D printer; it takes three days to make each piece.
“It’s not just some rubber shell over an insert. This is actively supporting your leg and your body,” explained Hayes, of Aurora, who has tested each prototype his team has created. “When you apply pressure on it through gait cycles, the material wants to return to its shape, like a spring, and that supplies energy to assist you. It actively supports you and feels more natural.”
These features are a result of the foot’s material, a type of nylon called polyamide. With a 3-D printer, this material is applied layer by layer in a network of latticing, which allows the prosthetic foot to be fully customized according to size, shape and use. For instance, one woman who contacted the student team is interested in a prosthetic foot that could be worn with high heels.
“With the Goldilocks Foot, we can reach infinite markets to address very specific problems with very specific solutions,” Gutierrez-Camacho said. “We can tailor each design to each person.”
‘Totally personalized’
Hayes added: “Our design allows you to skip the standard injection molding process and make something totally personalized.”
Having analyzed the market for prosthetic feet, the team is convinced their prototype could be perfected and sold. So, they have embarked on that very process by applying for a patent for the Goldilocks Foot, which is now pending. And they have established a startup company, called Mediflex Prosthetics LLC, to attract venture funding that would allow them to further develop and eventually market their product.
The team thinks the Goldilocks Foot might retail for something in the range of $2,000, compared to $3,000 or more for prosthetic feet of similar quality.
“We want to revolutionize the prosthetic foot shell,” Gutierrez-Camacho said.
On March 28, the team was declared overall winner of MURALS, the Multicultural Undergraduate Research Art and Leadership Symposium, which highlights student innovations. On Tuesday, April 15, the group will participate in the Venture RAMS Business Showcase, and on Friday, April 18, the team will take part in E-Days, an event showcasing the design work of senior engineering students.
All seniors in the Walter Scott Jr., College of Engineering complete design projects, and a small percentage are designated as entrepreneurial senior design projects; these are centered on innovations fully conceived and created by students, largely without the guidance of industry partners, who assist with other projects.
Entrepreneurial category
The team developing the Goldilocks Foot falls into the entrepreneurial category, said Chase Jackson, an academic adviser in the School of Biomedical Engineering. The school’s students are in a five-year program and graduate with two bachelor’s degrees – in biomedical engineering and in the engineering discipline of their choice.
“It’s amazing seeing what they’re capable of doing. The whole team is exceptional,” Jackson said of Hayes, Gutierrez-Camacho and their teammates. “They are all so passionate about the project and about communicating the difference it can make.”
The other three students on the team are Thomas Leachman, Lily Lindstrom and Justin Rudrow.
Gutierrez-Camacho said he is especially proud of what the team has achieved because he is the son of parents who immigrated to the United States from Mexico and have supported and sacrificed for him throughout his academic journey.
The student team that invented the Goldilocks Foot includes, from left, Eric Gutierrez-Camacho, Garrison Hayes, Lily Lindstrom, Justin Rudrow and Thomas Leachman.
“I’m thrilled with how far we’ve come. It seems really promising,” he said.
Hayes marveled that the group started their project in August and now has the prototype of a novel prosthetic foot and a startup meant to further develop it.
“It’s nice to have affirmations that we’re on the right track. Look at how much we’ve done in less than a year,” he said. “We’ve created a foot that’s functional, and it’s ready for me to wear.”
Faculty advisers to the team are: Bert Vermeulen, Jeff Samson, Nelson Isaacson and Joyce Bohn; Ellen Brennan-Pierce is the group’s professor for senior design.
