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Computer controlled hydraulic resistance device for a prosthesis and other apparatus

  • US 5,888,212 A
  • Filed: 06/26/1997
  • Issued: 03/30/1999
  • Est. Priority Date: 06/26/1997
  • Status: Expired due to Term
First Claim
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1. A device for producing a controlled variable resistance to apparatus including a first member moveable relative to a second member, said device comprising means including a hydraulic actuator for 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, a hydraulic fluid within said chambers, means defining hydraulic fluid passages connected to said chambers, a solenoid controlled valve connected to control the flow of hydraulic fluid through said passages, means for independently sensing the hydraulic fluid pressure within each of said first and second chambers, and a computer control system responsive to said pressure sensing means 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 and to compensate for variations in said device and in said fluid viscosity.

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