In control of life and limb
Growing up in Guadalajara, Mexico, Mario Romero-Ortega never imagined that a childhood friend’s accident would eventually shape his career. The tragedy led the UT Arlington bioengineer to study neural interfacing and technology that one day could enable amputees to control and feel bionic limbs.
Working with a $2.2 million grant from DARPA, the research and development office for the Department of Defense, Dr. Romero-Ortega is helping thousands of U.S. soldiers who have been wounded and lost one or more limbs by understanding why current peripheral nerve interfaces fail. He hopes his neural interface will lead to a better prosthetic arm with more movement and even sensation.
Research like Romero-Ortega’s offers hope for recent social work graduate Anthony Pone. “It’s like a bright light and gives us another option,” says the Army veteran and wheelchair basketball player, who uses a prosthetic and a wheelchair.
Even though the research could greatly enhance veterans’ lives, broader populations—like Romero-Ortega’s childhood friend who lost the use of her legs in that car wreck—also could benefit.
“I wanted to do something about it,” he says. “This work could eventually lead to solutions for people so negatively affected in car accidents.”
The work has national appeal, too. The $2.2 million grant is part of the RENET (reliable neural interfacing) program led by Jack Judy, program director of DARPA’s Microsystems Technology Office in Arlington, Va.
“WHAT MAKES OUR RESEARCH DIFFERENT IS THAT WE'RE PUTTING THE NEURAL INTERFACE IN THE LIMB ITSELF.”
Robotic prosthetics have advanced from simple hooks in the 1850s to multi-finger, electronically controlled hands with 22 degrees of freedom. Modern devices closely resemble a human hand. But neural interfaces are required to give amputees the most natural control and sensory perception. The process involves connecting the robotic prosthetic to the user’s nervous system, and current technology is unreliable.
Thousands of nerve channels allow the human limb, hand, and fingers to operate independently and precisely. The channels enable motion and sensory control.
By contrast, the most advanced neural interface in peripheral nerves for prosthetic arms uses six to eight channels and allows only simple movement without sensation. Neural interfaces implanted directly in the brain can provide hundreds more channels, but this requires surgery.
“What makes our research different is that we’re putting the neural interface in the limb itself,” says Romero-Ortega, who explains that the tiny interfaces allow the arm to interpret what the brain is telling it to do and the brain to interpret what the arm is doing.
His research moves away from the head and into the appendage itself, looking for neural reliability and stability. It integrates the nerve into electrodes through nerve regeneration.
Romero-Ortega’s team includes mathematics Assistant Professor Yan Li, a specialist in biostatistics and biometrics, and bioengineering Assistant Professor Young-tae Kim, who works with markers of inflammation, neurointerfaces, and histology. The project also involves Harvey Wiggins, president and founder of Dallas-based Plexon, and research scientist Edward Keefer. Both bring expertise in neurophysiology, multi-electrode electrophysiology, and biochemistry.
Romero-Ortega says initial testing shows the potential to open up hundreds of nerve channels to a prosthetic. These open channels would enable the body to control the prosthetic as if it were real, giving new functionality to amputees.
That’s exactly what Pone, who lost his right leg in a car accident, hopes will happen. “I think the research could give you more feeling, make you more independent. That’s what we’re all after.”