This story originally appeared on the Cockrell School of Engineering website.
In the palm of his hand, Mechanical Engineering Professor Rick Neptune holds a smooth and lightweight prosthetic foot. The prosthetic is rounded at the toes, raised at the heel and, at first glance, may not appear that revolutionary.
But look again, and this time for longer. Because it’s the things that take time — that you can’t see with a cursory glance — that make this prosthetic so remarkable: like a soldier who suffers an amputation and, after months of therapy, learns to walk again, play basketball again or even return to active duty by wearing a tailored-made prosthetic like the one Neptune holds. In a way, Neptune is holding more than a prosthetic. He’s holding a second chance.
“It’s so encouraging to see all these individuals who are working hard to return to active duty, and some of the injuries they’ve had are just devastating,” Neptune said. “It’s inspiring for the work that we’re doing, and if we can help in any small way to give them a piece of their lives back — well, there isn’t anything more satisfying than that.”
Neptune has been working the past few years to do just that through research collaborations with the Department of Veteran Affairs Center of Excellence for Limb Loss Prevention and Prosthetic Engineering in Seattle and the San Antonio Military Medical Center’s Center for the Intrepid, a rehabilitation facility treating veterans and active military with amputations, traumatic extremity injuries and severe burns.
Neptune and a team of graduate students are designing prosthetics and parts for ankle-foot orthotic devices, or braces, that not only improve functional mobility, they increase patient comfort, are customized to each patient’s need and could reduce costs.
The prosthetics and orthotics are built to account for variations in each patient’s physical build, such as height and weight, their walking characteristics, and the severity of their injuries so that each device is tailored and optimized for them.
“We’re having them walk over uneven ground, going up and down stairs, running and a whole battery of other tests, to be able to understand how they adapt to the different stiffness levels of these orthotic and prosthetic devices,” Neptune said. “One of the challenges though is that everybody has a different injury.”
Providing the best treatment
Because protective gear and equipment have improved drastically for soldiers in the last few decades, more are surviving traumatic injuries — meaning doctors must respond quickly to treating and rehabilitating injuries that would have previously proved fatal.
Thanks to research by Neptune and others around the country, it’s becoming easier to do this job.
Among those at the forefront of prosthetic and orthotic research is the Center for the Intrepid. Through funding from the U.S. Department of Defense, Dr. Jason Wilken, director of the center’s Military Performance Laboratory, is working collaboratively with Neptune and others around the world to restore functional mobility to the roughly 130 patients being treated at the center each day.
“It’s rewarding to be able to give back to the people who have done so much for our country,” said U.S. Army Colonel Rachel Evans, research director for the Center for the Intrepid, who just returned from a six-month deployment in Afghanistan. “When you watch a patient who’s been injured, walk or run again for the first time, and you see the look on their face, it’s very moving.”
The goal of the center is beyond restoring functional mobility, Evans said. She and others aim to restore soldiers to the highly active lives they had prior to their injuries, and which were a part of their jobs in the military.
That’s where Neptune comes in.
Using a brace designed by Center for the Intrepid prosthetist Ryan Blanck, Neptune and his students are creating struts — the part of an ankle-foot orthotic device that acts like a muscle.
Struts and prosthetic devices built by Blanck, Neptune and his students store and release elastic energy — giving patients the ability to run and jump — and they’re customized to meet the specific needs of a patient unlike many struts and prosthetic devices commonly used. For instance, depending on how tall a patient is and how quick and spread out his gait is, he may need an orthotic device that’s longer or more elastic.
Neptune and his students can account for these specific needs through cutting-edge design technology developed at The University of Texas at Austin.
Known as selective laser sintering (SLS), the technique allows he and his students to design a prosthetic limb or orthotic device on a computer, and then replicate the 3D design with a laser process that melts, or “sinters” a special nylon powder. The powder is transformed layer by layer into a hard, but elastic prosthetic device that is specific to each individual’s physical and walking characteristics.
While the research is currently focused on prosthetics and orthotics for military personnel, its applications are far-reaching and come at a crucial time. The number of people living with major lower limb amputations in the U.S. is projected to dramatically increase over the next 40 years due to complications associated with diabetes.
Because of these startling projections, more researchers are focusing on improved prosthetics and orthotics, and The University of Texas at Austin stands to be a leader in the field.
“When I think about the things and new skills I have learned in this program in the last year, it’s phenomenal,” said Nicole Guckert, a second-year mechanical engineering graduate student who is designing ankle-foot orthoses for troops.
For she and Neptune, the end goal is to improve the lives of patients and give doctors better guidance on treating them.
“In the end, we want to be able to understand the relationship between these design characteristics and the gait performance of the individual, so that clinicians are better informed when prescribing an appropriate orthotic device or prosthetic device for each patient,” Neptune said.