Nathan Wallace Takes Steps to Advance Prosthetics

Nathan Wallace was born with proximal femoral focal deficiency, a congenital limb disorder, which led to the amputation of his left foot at 8 months old. He was fitted for his first prosthetic at 13 months.

Now, the third-year biomedical engineering student is using his life experience to develop advanced prostheses as a member of the Exoskeleton and Prosthetic Intelligent Controls (EPIC) Lab. Wallace is part of the development and machine learning teams on an ongoing vertically integrated project led by Associate Professor Aaron Young and senior research scientist Kinsey Herrin. The teams are engineering a microprocessor-powered leg and ankle capable of mimicking gait and providing stability in walking patterns across various surfaces.

Traditional prosthetics, like the one Wallace uses, don't provide ankle flexion, but the current iteration of the lab's leg offers something that he views as an evolution of products on the market today. The latest tests allowed Wallace, while wearing the leg, to walk up a ramp with the ankle and knee adapting to the slope.

"A lot of our power comes from the ankle, and our version of the leg better recreates a complete gait cycle, which includes the knee and ankle flexion and everything in between. With my current prosthetic, I don't have that same gait control, so I'm swinging my foot around and overcompensating on my right leg. With our leg, I'm walking up the ramp normally, and it's creating a movement that I've never felt before," he said.

Along with the improved performance of the leg, Wallace and the team intend to use machine learning to assist in fitting patients with prosthetics that meet their unique needs.

"We're trying to get away from patients having to spend hours in an office tuning a prosthetic to their preferences. Instead, it allows the machine learning model to learn as the person walks on it. This can help reduce costs related to both time and personnel," he said.

Growing up, Wallace was an active child at recess and eventually became a high school wrestler. While there were times he felt he couldn't keep up with his classmates, he found ways to adapt. He credits his condition for helping him develop a strong work ethic and a desire to help others find the same confidence he has found as he's gotten older.

"Learning to embrace who I am has made me the person I am today. It's given me perspective and a capacity for empathy and sympathy for others in the disabled community," he said. "My past and my condition have driven me to where I am today, and I feel privileged to be at Georgia Tech. It touches a special place in my heart to know that this kind of work is going on, and that I can be a part of it."

Outside of the lab, Wallace is a member of the student organization Tikkun Olam Makers, which develops open-source solutions for members of disabled communities. He also creates props for DramaTech, and, continuing to push himself beyond his comfort zone, he recently starred in the student-run theater's production of Eurydice.