These glass molds, in various sizes, were used to form a component, a "heart cuff", from a high-tech polymer. The final assembly will support and pump a human heart outside the body during open heart surgery(!!!)

The picture shows three sizes of glass medical molds, and the teflon and stainless steel support shaft for dipping and venting; the amber vessel at the back is a coated glass mold. The final design was a result of much collaboration between us and the customer. 

The large variations in size between the molds, which parallel size variations among individual human hearts, was of particular interest to us.