Variable mechanical-impedance artificial legs
AssigneeiWalk, Inc.
InventorHugh M. Herr
Life of this patent
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Abstract
In one aspect, the invention provides methods and apparatus facilitating an adjustable-stiffness prosthesis or orthosis (including approximations to arbitrarily definable non-linear spring functions). Spring rates may be varied under no-load conditions during a walking gate cycle to minimize power consumption. In another aspect, the invention provides methods and apparatus for outputting positive power from a prosthesis or orthosis, facilitating high-performance artificial limbs. In one embodiment of the invention, the positive power is transferred from a functioning muscle to the prosthesis or orthosis, which mimics or assists a non-functioning or impaired muscle. In another embodiment of the invention, the positive power comes from an on-board power source in the prosthesis or orthosis.
Claims25
An autonomous motorized powered-catapult device having a mounted end adapted to be attached to a wearer's residual limb and an opposite distal end, said device comprising:
- a leg prosthesis having an ankle joint;
- an electromechanical actuator adapted to power the leg prosthesis, comprising:
- an elastic element configured to store elastic energy, and
- a motor operatively coupled to the elastic element;
- a sensor for sensing gait information;
- and
- a control system configured to cause the motor to store additional elastic energy in the elastic element as a function of information from the sensor for later release of stored energy from the elastic element to cause ankle powered plantar-flexion of the leg prosthesis thereby providing net positive mechanical work.
Dependencies are inferred from the claim text.