Prosthetic foot with energy transfer medium including variable viscosity fluid
AssigneeRoland J. Christensen
InventorRoland J. Christensen
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Abstract
A device prosthetic foot device with variable stiffness response includes a variable energy transfer medium disposed between first and second foot members to transfer at least some energy from the second member to the first member during use. The energy transfer medium includes a variable viscosity fluid such that the variable viscosity fluid, and thus the energy transfer medium, variably transfers energy between the first and second members to vary stiffness of the prosthetic foot device. The variable viscosity fluid can include a shear stiffening material that increases in viscosity as a load or strain, or rate of loading or rate of strain, applied, or a magneto or electro rheologic fluid responsive to a magnetic or electric field.
Claims23
A prosthetic foot device with variable stiffness response, the device comprising:
- a) first and second foot members, configured to be coupled to an amputee;
- b) at least one of the first and second foot members being a resilient member capable of storing energy during deflection;
- c) a flexible bladder, disposed between the first and second foot members;
- and
- d) a variable viscosity fluid, disposed in the flexible bladder, to variably transfer energy between the first and second foot members during use, the variable viscosity fluid being capable of increasing viscosity with an increase in a load factor to transfer more load between the first and second foot members during the increase in the load factor, and being capable of decreasing viscosity during a decrease in the load factor to transfer less load between the first and second foot members during the decrease in the load factor.
A method for varying a stiffness response of a prosthetic foot device, comprising the steps of:
- a) coupling the prosthetic foot device to an amputee, the prosthetic foot device including i) first and second foot members, at least one of the first and second foot members being coupled to the amputee, and at least one of the first and second foot members contacting ground during use, and ii) a variable viscosity fluid disposed in a bladder between the first and second foot members, the first and second foot members being configured to selectively transfer load between the first and second foot members;
- and
- b) varying the viscosity of the fluid while in the bladder in response to a load factor so that the load transferred between the first and second foot members varies, including increasing viscosity during an increase in the load factor to transfer more load between the first and second foot members during the increase in load factor, and decreasing viscosity during a decrease in load factor to transfer less load between the first and second foot members during the decrease in the load factor.
A prosthetic foot device with variable stiffness response, the device comprising:
- a) an upper forefoot member having an attachment section configured to be coupled to a socket of an amputee, and extending downwardly therefrom configured to contact the ground during use;
- b) a forefoot reinforcement member, disposed above the upper forefoot member;
- c) the upper forefoot member and the forefoot reinforcement member being resilient members capable of storing energy during deflection;
- d) a bladder, disposed between the upper forefoot member and the forefoot reinforcement member;
- and
- e) a variable viscosity fluid, disposed in the bladder, to variably transfer energy between the upper forefoot member and the forefoot reinforcement member during use, the variable viscosity fluid being capable of increasing viscosity with an increase in a load factor to transfer more load between the upper forefoot member and the forefoot reinforcement member during the increase in the load factor, and being capable of decreasing viscosity during a decrease in the load factor to transfer less load between the upper forefoot member and the forefoot reinforcement member during the decrease in the load factor.
Dependencies are inferred from the claim text.