MISSOULA, Mont. — Ryan Mizner has a patent pending for a device called The Bridge, a physical therapy tool developed by the University of Montana associate professor and one of his students.The apparatus, developed over the course of some four years, reduces the effect of gravity on patients. At UM, Mizner primarily uses it to help rehabilitate athletes who have had reconstruction on their anterior cruciate ligament or ACL.In recent years, UM has pushed marketable research as a priority, but Mizner did not go in …