The smaller version of the two pictured here is a sample of an actual product at actual size.  It is intriguing to discover the size of our aortic heart valve, isn’t it?  It’s huge!  In a way, this model looks much simpler than it was to actually make.  Any time you start with flat parts that have to form into a 3-dimensional shape, it is a little tricky.  Without wanting to reveal our mathematical or trade secrets, this model was made of metal and the diaphragm was cast in rubber.  It opened when something was pushed through it and closed naturally.  The model was a total success.  Phew!