Venous valve apparatus, system, and method

A valve, comprising:

• a tubular frame having a first frame end and an opposing second frame end, the tubular frame comprising:
• a first serpentine ring of struts interconnected by turns, the turns comprising first turns forming a first frame end and second turns positioned between the first frame end and the second frame end;
• a plurality of zig-zagging frame members arrayed sequentially toward the second frame end from the first serpentine ring, the zig-zagging frame members including a first frame member fixed to the first serpentine ring, and one or more additional frame members, each fixed to an immediately preceding frame member of the plurality of zig-zagging frame members;
• and
• a second serpentine ring of struts interconnected by turns, the turns comprising third turns positioned between the first frame end and the second frame end and fourth turns forming the second frame end;
• and
• a cover disposed over at least a portion of an outer surface of the tubular frame and at least a portion of an inner surface of the tubular frame, wherein the cover wraps from the outer surface around the first frame end to the inner surface, the first frame end being an inflow end of the valve;
• wherein the cover forms first and second valve leaflets within and movable relative to the tubular frame, the valve leaflets defining a reversibly sealable opening for unidirectional flow of a liquid through the valve;
• wherein at least a portion of the cover extends along and is supported by the inner surface of the tubular frame between the first frame end and the first and second valve leaflets.