The device has independent knee and ankle/foot modules. The research team wanted an articulated toe joint to better replicate key biomechanical function but wanted to avoid adding weight to the prosthesis with a dedicated actuator at the toe. Having actuator power for the ankle and toe met both goals.
The powered knee joint uses a “unique torque-sensitive mechanism combining the benefits of elastic actuators with that of variable transmissions,” according to the researchers, who are from the University of Utah’s Department of Mechanical Engineering and Robotics Center. Preclinical tests showed that the device allowed the users to walk with kinematics and kinetics close to that of people without amputations. The prosthesis also has a passive mode that lets users can walk on level ground indefinitely without charging the battery, which the researchers say is unique to their device.
The read the open-access article, “A lightweight robotic leg prosthesis replicating the biomechanics of the knee, ankle, and toe joint,” visit Science Robotics.
