Lower limb prosthesis
Inventors
Zahedi, Mir Saeed • Harris, Graham • Lang, Stephen Terry • Painter, Robert Michael Andrew • Moser, David
Assignees
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Publication Number
US-10039652-B2
Publication Date
2018-08-07
Expiration Date
Abstract
A prosthetic ankle has an ankle joint body (10A) constituting a shin component and a foot component (12). The ankle joint body (10A) is pivotally connected to the foot component (12) by a first pivotal connection (14) defining a medial-lateral ankle joint flexion axis. The ankle joint body (10A) also forms the cylinder of an ankle joint piston and cylinder assembly with a superior-inferior central axis, the cylinder housing a piston (16) with upper and lower piston rods (16A, 16B). The lower piston rod (16B) is pivotally connected to the foot component (12) at a second pivotal connection (18). As the ankle joint body (10A) pivots about the ankle joint flexion axis, the piston (16) moves substantially linearly in the cylinder formed by the ankle joint body. The cylinder is divided into upper and lower chambers (20A, 20B). These chambers are linked by an hydraulic circuit (22) incorporating passages (22A, 22B) in the ankle joint body (10A), and an energy conversion device in the form of a slave piston and cylinder assembly (24) having a piston (24P) and piston rods (24R) which project beyond the cylinder (24C) of the assembly (24).
Core Innovation
The invention relates to a lower limb prosthesis or orthosis in which at least first and second interconnected structural members pivot relative to each other about a joint flexion axis when the prosthesis or orthosis is loaded, together with a movement control system. The movement control system includes a hydraulic movement control device with a first piston assembly and a second piston assembly, each having a piston, a cylinder, and first and second chambers. The hydraulic movement control device further includes a control valve having first, second, and third positions, and hydraulic passages interconnecting the piston assemblies and the control valve to route hydraulic flow between defined chambers.
Electrical energy is converted into fluid flow energy in the hydraulic passages by an energy conversion device engaged with the second piston assembly. The prosthesis or orthosis also includes an electrical energy storage element, at least one sensor configured to sense a kinetic or kinematic parameter of locomotion, and a processor coupled to the sensor and movement control device. In response to sensor signals, the processor controls storage of electrical energy associated with relative movement arising from application of a load, controls the position of the control valve, and controls release of electrical energy to urge the relative movement of the structural members.
The integrated powered lower-limb implementation described includes an ankle joint body forming a piston/cylinder assembly with upper and lower chambers linked by a hydraulic circuit and a slave piston/cylinder assembly. A hydraulic circuit with solenoid valves and associated hydraulic restrictions/non-return valves routes energy between chambers, while a processor uses sensor signals to determine gait phase and control valve operation and energy routing so that fluid flow is generated for energy storage and later released to urge flexion and/or related joint movement. In an integrated transfemoral/through-knee architecture, the knee and ankle share a common hydraulic circuit with solenoid valves, pressure intensification, and a pressure accumulator system configured to vary back pressure and manage energy recovery/power delivery during different portions of the gait cycle.
Claims Coverage
The provided independent claim is clm-00001. The main inventive features are directed to an interconnected, pivoting lower limb prosthesis/orthosis controlled by a multi-position hydraulic device that routes between chamber combinations, with electrical-to-hydraulic and hydraulic-to-electrical energy conversion coordinated by a sensor/processor to store and release electrical energy to urge relative joint movement.
Interconnected pivoting structural members about a joint flexion axis
A lower limb prosthesis or orthosis comprising at least first and second interconnected structural members configured to pivot relative to each other about a joint flexion axis when the prosthesis or orthosis is loaded, and a movement control system.
Hydraulic movement control device with first and second piston assemblies and multi-position control valve chamber routing
A hydraulic movement control device having a first piston assembly connected to the joint flexion axis with first and second piston assembly chambers, a second piston assembly with first and second chambers, a control valve having a first position, a second position, and a third position, and hydraulic passages connecting the piston assemblies and the control valve to connect specific chamber combinations via plurality of hydraulic passages depending on the control valve position.
Energy conversion device converting electrical energy into fluid flow energy in hydraulic passages
An energy conversion device engaged with the second piston assembly, configured to convert electrical energy into fluid flow energy in the hydraulic passages while the hydraulic movement control device interconnects the first and second structural members about the joint flexion axis and controls the relative movement.
Sensor and processor controlling energy storage, control-valve position, and release to urge relative movement
An electrical energy storage element, at least one sensor configured to sense a kinetic or kinematic parameter of locomotion, and a processor configured to control operation of the hydraulic movement control device in response to sensor signals to control storage of electrical energy associated with relative movement, the position of the control valve, and release of electrical energy to urge relative movement of the structural members.
Overall, clm-00001 covers a pivoting lower limb prosthesis/orthosis whose joint motion is driven by a hydraulic movement control device with first and second piston assemblies and a multi-position valve that routes between chamber combinations, coordinated with an energy conversion device and an electrical energy storage element. Sensor signals and a processor control valve position and the storage/release of electrical energy so that relative movement about the joint flexion axis is urged in response to locomotion.
Stated Advantages
Documented Applications
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