Computer controlled hydraulic resistance device for a prosthesis and other apparatus
First Claim
1. A device for producing a controlled variable resistance to apparatus including a first member moveable relative to a second member, said device comprising hydraulic actuator connecting said first member to said second member, said actuator including a housing enclosing a moveable resistance applying member separating a first chamber and a second chamber within said housing, hydraulic fluid passages connected to said chambers, hydraulic fluid within said chambers and said passages, a solenoid controlled valve connected to control the flow of hydraulic fluid through said passages, a magnet and a magnetically actuated electronic sensor arranged to sense changes in the hydraulic fluid pressure within at least one of said chambers, and a computer controlled electronic system responsive to said sensor for actuating said valve to control precisely the flow of said fluid through said valve and into and out of said first and second chambers.
4 Assignments
0 Petitions
Accused Products
Abstract
A computer controlled hydraulic resistance device for apparatus such as a prosthetic knee for above knee amputees, includes a two stage pilot operated solenoid valve connected to control the flow of hydraulic fluid to and from a hydraulic actuator which applies resistance to the prosthetic knee or other apparatus through a coupling. Hydraulic pressure is sensed on the high and low side of the actuator by a spring biased magnet and a magnetically actuated electronic sensor and is used by a micro-controller in a closed-loop manner to compensate automatically for variations in the device and in the hydraulic fluid viscosity. The device also has magnetically actuated electronic sensors which sense positions of the apparatus and feed back to the micro-controller for applying a predetermined resistance profile to the apparatus.
211 Citations
17 Claims
- 1. A device for producing a controlled variable resistance to apparatus including a first member moveable relative to a second member, said device comprising hydraulic actuator connecting said first member to said second member, said actuator including a housing enclosing a moveable resistance applying member separating a first chamber and a second chamber within said housing, hydraulic fluid passages connected to said chambers, hydraulic fluid within said chambers and said passages, a solenoid controlled valve connected to control the flow of hydraulic fluid through said passages, a magnet and a magnetically actuated electronic sensor arranged to sense changes in the hydraulic fluid pressure within at least one of said chambers, and a computer controlled electronic system responsive to said sensor for actuating said valve to control precisely the flow of said fluid through said valve and into and out of said first and second chambers.
- 10. A device for producing a controlled variable resistance to apparatus including a first member moveable relative to a second member, said device comprising hydraulic actuator connecting said first member to said second member, said actuator including a housing enclosing a moveable resistance applying member separating a first chamber and a second chamber within said housing, hydraulic fluid passages connected to said chambers, hydraulic fluid within said chambers and said passages, a two stage pilot operated solenoid valve connected to control the flow of hydraulic fluid through said passages, an electronic sensor arranged to sense changes in the hydraulic fluid pressure within at least one of said chambers, and a computer controlled electronic system responsive to said sensor for actuating said valve to control precisely the flow of said fluid through said valve and into and out of said first and second chambers.
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17. A device adopted for producing a controlled variable resistance to apparatus including a first member moveable relative to a second member, an actuator connecting said first member to said second member, said device comprising a housing enclosing a moveable displacement member separating a first chamber and a second chamber within said housing, fluid passages connected to said chambers and a fluid within said chambers and said passages, a solenoid controlled valve connected to control the flow of fluid through said passages, a position sensor for sensing the position of said first member relative to said second member and including a magnet and a magnetically actuated electronic sensor, a variable shutter connected for movement with said first member and spaced between said magnet and said electronic sensor for variably restricting the magnetic field in response to relative movement between said first and second members, and a computer controlled electronic system responsive to said sensor for actuating said valve to control the flow of said fluid through said valve and into and out of said first and second chambers.
Specification