The specialized mouse wheel incorporates features similar to a device called a force platform, which measures the force of movement in human patients, Griffin said. He came up with the idea for a force-sensing mouse wheel based on a force platform treadmill used to study human movement, which he helped develop as a graduate student at the University of California at Berkeley.
In addition to capturing force data, the wheel includes a high-speed infrared camera to film the mice running, since they prefer to exercise in the dark. Griffin's team designed software that tells the camera to only record images when the mice step on the force-sensing part of the wheel. The video and force data are collected and stored automatically, which allows the researchers to collect these data while they are at home sleeping.
Griffin said the next step will involve fitting the wheel with a motor, almost like a treadmill, to see how movement patterns change when the mouse walks and runs at set speeds.
“The current systems for measuring osteoarthritis disability in mice during movement are time-consuming and not particularly sensitive,” he said. “This new wheel lets us easily collect highly sensitive data from voluntary, spontaneous movement. Now we're seeing how they move when they want to move.”
Griffin said he hopes this new method of study will lead to better treatments for patients suffering with osteoarthritis.
Funding for the project was provided through a grant from the Oklahoma Center for the Advancement of Science & Technology. Engineering students Grahm Roach and Mangesh Edke assisted in the design of the wheel.