Patent ID: 7402171

Claim:
An implantable medical device that provides a valve for regulating fluid flow through a body vessel, comprising: a support frame having radially compressed and radially expanded configurations; and at least one leaflet at least partially defining a valve orifice that regulates said fluid flow, the at least one leaflet having first and second edges and being moveable between a first position that permits said fluid flow in a first direction and a second position that substantially prevents said fluid flow in a second, opposite direction, the first edge attached to the support frame and the second edge being free of the support frame; wherein a portion of the support frame and the second edge of the at least one leaflet cooperatively define an opening that permits a controlled amount of fluid flow to pass through said medical device in the second, opposite direction, the opening having a size that remains substantially fixed in the first and second positions of the at least one leaflet and being spaced from the valve orifice along an axis of said implantable medical device.