A substitute valve used to replace a diseased valve. There are two main types of prostheses: those made from biological tissues (e.g., the heart valves of animals, esp. pigs) and those made from biocompatible materials (e.g., metals or polymers). Biocompatible mechanical valves may be constructed in a variety of ways, e.g., from a ball that moves up and down in a cage; with bileaflet valves that close in the midline; or with a single leaflet (which tilts to open and close).





Figure: TYPES OF MECHANICAL HEART VALVES
A. caged ball valve; B. monoleaflet. C. bileaflet

Main entry:
valve