Abstract: A prosthetic knee can include a variable-torque magnetorheological (MR) actuator assembly or braking system, a frame and an electronics assembly or system that also serves as a mount for the knee actuator and facilitates in monitoring and controlling the operation of the knee actuator. The prosthetic knee system advantageously provides resistive forces to substantially simulate the position and motion of a natural knee joint during ambulation and/or other locomotory activities performed by the amputee. The prosthetic knee can be enclosed in a waterproof compartment. An outer cover can be configured to fit around the waterproof cover of the prosthetic knee.

Abstract: A prosthetic knee can include a variable-torque magnetorheological (MR) actuator assembly or braking system, a frame and an electronics assembly or system that also serves as a mount for the knee actuator and facilitates in monitoring and controlling the operation of the knee actuator. The prosthetic knee system advantageously provides resistive forces to substantially simulate the position and motion of a natural knee joint during ambulation and/or other locomotory activities performed by the amputee. The prosthetic knee can be enclosed in a waterproof compartment. An outer cover can be configured to fit around the waterproof cover of the prosthetic knee.

Abstract: A prosthetic or orthotic device has an elongate frame that houses electronics and an actuator rotatably mounted to the frame. The actuator can rotate in an anterior-posterior direction about a medial-lateral axis and includes magnetorheological (MR) fluid and a coil operable to selectively apply a magnetic field to the MR fluid to vary its viscosity and thereby vary a torsional resistance of the actuator about the medial-lateral axis. Circuitry controls an amplitude and a direction of a current applied to the coil. The circuitry can switch a direction of current passing through the coil, and to apply a reverse direction current pulse to the coil to reduce a time period over which a resistive torque of the actuator decreases to a baseline resistance amount.

Abstract: A prosthetic knee can include a variable-torque magnetorheological (MR) actuator assembly or braking system, a frame and an electronics assembly or system that also serves as a mount for the knee actuator and facilitates in monitoring and controlling the operation of the knee actuator. The prosthetic knee system advantageously provides resistive forces to substantially simulate the position and motion of a natural knee joint during ambulation and/or other locomotory activities performed by the amputee. The prosthetic knee can have a series of internal blades for providing resistive forces. A locking ratchet can be used to lock knee position. A dynamic seal with a protective shim can be disposed in the knee actuator. A coil with a non-circular cross-section can be used.

Abstract: A prosthetic knee can include a variable-torque magnetorheological (MR) actuator assembly or braking system, a frame and an electronics assembly or system that also serves as a mount for the knee actuator and facilitates in monitoring and controlling the operation of the knee actuator. The prosthetic knee system advantageously provides resistive forces to substantially simulate the position and motion of a natural knee joint during ambulation and/or other locomotory activities performed by the amputee. The prosthetic knee can be enclosed in a waterproof compartment. An outer cover can be configured to fit around the waterproof cover of the prosthetic knee.