A key to identify heart valve prostheses.

A system for the identification of heart valve prostheses has been developed. A series of observations is made on the structure of a prosthesis. Following each the most appropriate choice of two or three alternative findings is made. One is then directed to the next observation until a genus of prostheses is found with structural characteristics like the unknown one. Positive identification is aided by a brief description of each prosthesis in the genus.