Patent ID: 7799091

Claim:
A method of adaptively controlling a prosthetic joint worn by an amputee, comprising: measuring speed indicative data with sensors local to said prosthetic joint as said amputee moves at various speeds; storing said data in a memory of said prosthetic joint in bins corresponding to the speed of said amputee; iteratively modulating the damping to achieve a predetermined and/or computed target until the damping converges within each bin; and controlling said prosthetic joint by utilizing the converged damping values to control the damping of said prosthetic joint by varying the viscosity of a magnetorheological fluid contained in said prosthetic joint that provides variable resistance to flexion and/or extension, wherein said damping is created primarily by shear forces, wherein said prosthetic joint comprises a prosthetic knee, and wherein said method further comprises controlling said prosthetic knee worn by said amputee using a controller which transitions between a plurality of states of biological gait including a first state generally corresponding to stance flexion, a second state generally corresponding to stance extension, a third state generally corresponding to knee break, a fourth state generally corresponding to swing flexion, and a fifth state generally corresponding to swing extension, said method further comprising: measuring sensory information and providing said sensory information to said controller for computation of axial force, extension moment, knee angle and velocity; transitioning from said first state to said second state under condition C 12 and said condition C 12 being satisfied when said prosthetic knee achieves a predetermined extension velocity; transitioning from said second state to said third state under condition C 23 and said condition C 23 being satisfied when said extension moment is below a first threshold; transitioning from said third state to said fourth state under condition C 34 and said condition C 34 being satisfied when said axial force falls below a second threshold; transitioning from said fourth state to said fifth state under condition C 45 and said condition C 45 being satisfied when said prosthetic knee begins to extend; transitioning from said fifth state to said first state under condition C 51 and said condition C 51 being satisfied when said axial force climbs above a third threshold; and controlling operation of said prosthetic knee in said states of biological gait by processing said sensory information to provide a controlled and variable resistance to flexion and/or extension.