Students Step Closer to Technological Breakthrough in Paralysis Treatment

After his spinal cord injury, the late actor Christopher Reeve committed his life to finding treatments and cures for paralysis caused by injuries and other neurological disorders. He would be very proud of and interested in the project that Joe Sturgis and his Drury University classmates are working on.

A physics major from Springfield, Mo., Sturgis is part of a student team guided by Professor Gregory Ojakangas that is developing a program capable of sending computer commands to servo-motors to move a mechanical arm they have constructed. The arm is part of a plastic human skeleton replica nicknamed "Son of Toby."

While still theoretical, a variant of such a program could be put on a computer chip and interfaced with the brain of a paraplegic. Computer signals triggered by the disabled person would bypass the spinal cord and move the arm.

Sturgis is helping to develop a graphic simulation program to visualize the theoretically expected and observed motions of the arm. "We are calling it the 'Drury Holodeck,' just like in Star Trek," says Sturgis. "It can show movies of the arm in motion. I'm interested in learning more about the math and physics behind the project, and I will be flying with the experimentation team on NASA's Weightless Wonder this August."

Ojakangas explains that he and his students are studying the complex physics of the three-dimensional motion of a true human arm, with 12 of the human arm's actual muscle geometries reconstructed as closely as possible from elastic materials and servo-motors. Some of the students will fly the experiment aboard NASA's Weightless Wonder aircraft in August to study the differences between how muscles move human arms in weightlessness versus on earth under normal gravity conditions. The Drury team is part of NASA's Reduced Gravity Student Flight Opportunities Program.

"Imagine if the computer program and microcontroller system could be interfaced with a human mind," says Sturgis, a sophomore. "You just think what you want the arm to do, and it would move through the action of a control interface. There are many potential applications, and we are taking our first step in learning what we can about how computers can control human-like movement. I would be lying if I said I was any sort of authority on this project, but what I've come to understand thus far has been intriguing."

Ojakangas says the students are doing math typically learned in graduate school, and that the project is related to an exciting field called computational neuroscience. In this field, people in many laboratories have been making remarkable progress in recent years in the development of brain-machine interfaces - hardware that can allow the human brain to directly manipulate machinery. "I want to understand how muscles control the three-dimensional movement of this critically important piece of biological machinery - the human arm," says Ojakangas. "The best way I could think of doing this was to build a synthetic arm with essentially the same muscles that we use to move ours. The equations necessary to describe this movement turn out to be a mathematical wonderland, full of fascinating dynamics and peppered, like a conceptual minefield, with snares known as singularities. It's enthralling." His interest in this field was stimulated by a sister who works in neuroscience and a brother-in-law who is a neurosurgeon. He is also working with collaborators at the University of Chicago, Northwestern University, and the University of Oklahoma in developing mathematical models relating arm motion to brain activity in monkeys.