Patent ID: 7341603

Claim:
A prosthetic foot device with variable stiffness response, the device comprising: a) a primary elongated foot member, couplable to the stump of an amputee, and extending therefrom, defining an elongated spring capable of storing energy during deflection and having a resistance response to an applied force; b) a secondary foot member, defining a secondary elongated resilient spring, disposed adjacent to the primary foot member; c) an enclosure, disposed between the primary foot member and the secondary foot member; d) a fluid path, in fluid communication with the enclosure; e) a reservoir, in fluid communication with the fluid path; f) a fluid, disposed in the enclosure and displaceable between the reservoir and the enclosure through the fluid path in response to the applied force; and g) a variable orifice, operatively disposed in the fluid path, having a variable size operable to change the size of the variable orifice between a relatively larger size in response to a relatively smaller applied force from the primary foot member such that more fluid flows therethrough, and a relatively smaller size in response to a relatively larger applied force from the primary foot member such that less fluid flows therethrough to provide variable resistance against fluid flow therethrough, and to variably transfer the applied force from the primary foot member to the secondary foot member.