There are about 185,000 lower limb amputations in the United States each year. Lower limb prosthetics often slow amputees’ gaits. Current active prosthetics are unable to optimize themselves to large changes in pace: For example, a motorized device optimized for stair climbing has a high transmission ratio that is unable to move fast enough to provide assistance walking.
Inventors at the University of Utah’s Bionic Engineering Lab have developed an actively variable transmission system capable of actively changing the crank length, and therefore, transmission ratio. The system incorporates sensors and microprocessors to transition automatically between locomotion modes such as walking, running, ascent, and