There are three kinds of heart valves: the Mechanical Valve, the Tissue Valve, and the homograft or allograft.  

A mechanical valve has a ring to support the leaflets. It opens and closes with each heartbeat, permitting proper blood flow through the heart.

The tissue valve is a natural valve taken from an animal. Once the tissue is explanted (removed), it is chemically treated and prepared for human use. Some tissue valves have a frame, or stent to supports the valve, and some valves are stentless.

The new design of the heart valve frame  could reduce the number of parts by 30%, simplify structure, and enhance product durability.