University of South Florida

Tyagi Ramakrishnan

Kyle Brandon Reed

Millicent Kay Schlafly

Christina-Anne Kathleen Lahiff

Seok Hun Kim

A prosthetic knee having a passive knee locking mechanism that uses the same four-bar mechanics found in a natural knee. The flexible four-bar mechanism guides the motion of the knee, aids in the return of the knee from full flexion to extension, and connects a femoral gear to a tibial gear. The gears have a circular radius and are connected using parallel links to keep the femur and tibia together when the knee is active. The knee stays locked throughout the stance phase. At toe off, no weight is applied on the prosthetic knee allowing the knee to flex. The flexible links are stretched, thereby increasing the stiffness in the springs, and at terminal swing phase, moments before heel strike, the flexible links in the four-bar mechanism snap back to the extended/locking position and lockout once the user applies his/her weight on the knee.

Biomimetic transfemoral knee with gear mesh locking mechanism

A small, lightweight, adjustable knee orthosis for restoring gait symmetry. The orthosis includes a rotary damper for variable damping at the knee joint of the user, and a spring member for variable stiffness at the knee joint of the user. An exemplary application of the device is as a rehabilitation device for individuals who have had a stroke, as the device is designed to induce larger knee flexion as an aftereffect.

Knee orthosis with variable stiffness and damping

A passive knee locking mechanism using the position of the shank and the weight of the user to lock. The mechanism has translational motion, which allows the shank to move linearly along the sagittal/vertical plane, which locks and unlocks the knee, and rotational motion for the shank to swing when unlocked. The knee block, which is disposed at the top of the shank, has a spur gear that locks with a matching gear rack on the top plate of the knee housing. The side plates for the knee housing have a linear path that makes for the translational motion. During heel strike, the stopper in the front plate of the knee housing positions the shank in a straight position. When the user applies their weight for initiating stance phase, the knee block traverses up the path and the spur gear meshes with the matching rack, locking the knee.

Position/weight-activated knee locking mechanism

A prosthetic device includes a phalanges portion, a metatarsals portion that is movably coupled to the phalanges portion, an ankle portion that is movably coupled to the metatarsals portion, and a calcaneus portion that is movably coupled to the ankle portion.

Growing community of inventors

Tampa, FL, United States of America

Tyagi Ramakrishnan