Abstract: A prosthetic knee uses a hydraulic damper to regulate the rotation of the prosthetic knee joint. A magnetic rotary on-axis position sensor located at the joint between the upper and lower portions of the prosthetic knee measures the motion of the upper portion of the knee by detecting the magnetic field which is generated by a diametrically polarized magnet. A microprocessor correlates the measured motion to a knee joint angle, and adjusts the resistance provided by the hydraulic damper according to a corresponding stage of gait.

Abstract: A hydraulic valve assembly includes a valve core with one or more valve core ports, the valve core rotatably housed in a valve sleeve having one or more valve sleeve ports. A hydraulic resistance of the hydraulic valve assembly varies approximately linearly with a change in valve position caused by rotating the valve core relative to the valve sleeve to vary an alignment between the one or more valve core ports and one or more valve sleeve ports. The valve assembly optionally includes a motor coupler and a gearmotor, the gearmotor operable to rotate the valve core relative to the valve sleeve via the motor coupler.

Abstract: A unibody (e.g., seamless single-piece, monolithic) cylinder for a prosthetic knee defines a hydraulic cylinder in which a piston travels, defines fluid pathways for a hydraulic fluid, and defines bores that house embedded gearmotors and valves operable to actively control a damping rate of flexion and extension of the prosthetic knee. The unibody cylinder also houses sensors and electronics (e.g., circuit board) and cabling connecting them to the gearmotors. The unibody cylinder minimizing surfaces or junctions that come into contact with the hydraulic fluid to reduce sealing requirements, inhibit (e.g., prevent) hydraulic leaks and facilitate waterproofing of the unibody cylinder.

Abstract: A prosthetic ankle device is disclosed herein. The prosthetic ankle device includes a hydraulic cylinder with a first chamber, a second chamber, and a piston separating the first chamber and the second chamber. The chambers are filled with hydraulic fluid. During plantarflexion, the hydraulic fluid flows between the first chamber and the second chamber via a first passage and a first check valve. During dorsiflexion, the hydraulic fluid flows between the first chamber and the second chamber via a second passage and a second check valve.

Abstract: A prosthetic ankle device is disclosed herein. The prosthetic ankle device includes a hydraulic cylinder with a first chamber, a second chamber, and a piston separating the first chamber and the second chamber. The chambers are filled with hydraulic fluid. During plantarflexion, the hydraulic fluid flows between the first chamber and the second chamber via a first passage and a first check valve. During dorsiflexion, the hydraulic fluid flows between the first chamber and the second chamber via a second passage and a second check valve. The ankle device includes a third passage and a third check valve, where the third passage diverts flow of the hydraulic fluid from the second passage based at least in part on a system status.

Abstract: Disclosed herein are systems and methods for document based query and information retrieval which rapidly locate similar documents within a document corpora providing a document based search result to the search initiator including one or more estimated measures of similarity for each search result item and appropriate search result document metadata. After providing document based similarity approximation search results, the system also rapidly retrieves and determines more accurate measures of similarity, including the relevant document terms and term statistics used to determine an exact measure of similarity, between the document based query document term collection and individual search result document term collections using one or more computing devices, that are application and platform independent, participating in a distributed multicore processing environment.