Bretl receives $400,000 NSF CAREER Award to improve prosthetic device design
Tim Bretl believes modern prosthetic device design doesn’t have it quite right.
“The game today is to make a functional prosthetic limb with as few motor degrees of freedom as possible, with the theory that it’ll be easier to control,” said Bretl, an assistant professor of Aerospace Engineering and CSL researcher. “There’s evidence from both neuroscience and robotics that this implicit assumption is not true, and that we should think much more carefully about the interface between the person and the device.”
Bretl’s unique interdisciplinary background in aerospace engineering, robotics and neuroscience – areas that traditionally do not go together – makes him well equipped to handle some of today’s greatest challenges in prosthetic device design.
The National Science Foundation has taken note of Bretl’s interdisciplinary interest and awarded him a 2010 Faculty Early Career Development (CAREER) Award. The award carries a $400,000 monetary value and spans five years.
Bretl and his team of graduate students will begin by using the money to accelerate research on brain-machine interfaces (BMIs). These interfaces enable people to control prosthetic devices through direct measurement of brain activity. For example, in collaboration with colleagues Todd Coleman in CSL and Ed Maclin in the Beckman Institute, Bretl’s team uses electroencephalography (EEG) to predict motor intent. If an individual imagines moving his right arm, specific electrodes will be stimulated, which the BMI can read. This technique may produce novel prosthetic devices that improve quality of life for people with disabilities due to amputation, spinal cord injury and stroke.
“Successful use of BMIs will allow individuals with impaired sensory-motor function to control a prosthetic limb by thought alone,” Bretl said.
To improve the performance of BMIs, Bretl aims to derive new models of human motor control and learning. These models are based on the observation that motor control resembles a process of communication between the brain and the rest of the body and that motor commands are like words in a language. The key is to understand this language and how it can be used to describe human motion.
Bretl’s students are also involved in other projects related to his work on BMIs. For example, a recent focus has involved robotic manipulation of deformable objects, such as a piece of paper without a fixed shape. Bretl believes that finding a simple way to describe this shape is similar to finding a simple way to describe human motion.
“It’s a challenge but we’ve developed a principled approach to come up with the right set of parameters to describe these infinite-dimensional objects,” said Bretl. “It’s gratifying to see links between different parts of our work become more concrete. It makes future development that much easier.”
The CAREER Award includes an educational component. BMIs will be demonstrated at Engineering Open House and at the Neuroscience Program’s “Brain Day” to educate the elementary school level. With Diane Jeffers of AE, Bretl also co-directs the Illinois Aerospace Institute, a week-long program introducing high-school students to topics in aerospace engineering, including space robot teleoperation, which is directly relevant to Bretl’s research.
“We get an amazing reaction from students who participate,” Bretl said. “One of my students last year said the program changed her career direction, prompting her to go into neuroscience and pre-med. These students see the potential applications for this in 10 or 20 years, which is exactly what I’m going for.”
At the collegiate level, undergraduate classes will be offered, with a focus on attracting students from diverse backgrounds. At the graduate level, Bretl plans to teach a neuroscience course within the Illinois IGERT (Integrative Graduate Education and Research Traineeship) program.
“I hope this is the start of something that will carry through my entire career,” Bretl said. “There are so many interesting questions to be answered.”