Hydraulic dampener for a prosthetic device

A hydraulic valve assembly comprising:

• a valve spool having one or more valve spool ports and a plurality of recessed axial grooves;
• and
• a valve sleeve surrounding the valve spool so that the valve spool is rotatable relative to the valve sleeve, the valve sleeve comprising one or more valve sleeve ports,
• wherein a hydraulic resistance of the valve assembly varies approximately exponentially with a change in valve position of the valve assembly caused by rotating the valve spool relative to the valve sleeve to vary an alignment between the one or more valve spool ports and one or more valve sleeve ports.

A device for actuation of a prosthetic device, comprising:

• a hydraulic cylinder;
• a piston movably coupled to the hydraulic cylinder and configured to linearly move within the hydraulic cylinder;
• and
• a motorized valve system, the motorized valve system comprising:
• a motor, and
• a valve assembly, comprising:
• a valve spool having one or more valve spool ports and a plurality of recessed axial grooves;
• and
• a valve sleeve surrounding the valve spool so that the valve spool is rotatable relative to the valve sleeve, the valve sleeve comprising one or more valve sleeve ports,
• wherein a hydraulic resistance of the valve assembly varies approximately exponentially with a change in valve position of the valve assembly caused by rotating the valve spool relative to the valve sleeve to vary an alignment between the one or more valve spool ports and one or more valve sleeve ports.