Development of tests to evaluate candidate elastomers for artificial heart diaphragms

Blood pump diaphragms are required to be biocompatible and must be capable of long-term flexing without failure. There are currently only a few elastomers that are competing for acceptance in this application. Introduction of other candidate elastomers (including modifications to currently used materials) for these applications is hindered by a lack of accepted short-term in vitro testing methodology to evaluate alternate materials. Accelerated fatigue testing methodology has been developed that will predict long-term in vivo performance of candidate materials for artificial heart diaphragms. A 100-position fatigue testing machine was designed and built for operation in a controlled environment. This machine, along with a previously constructed 30-position fatigue tester, has allowed the generation of fatigue data on 13 elastomeric materials under a wide variety of conditions. The results of the relatively short-term fatigue tests have been shown to correlate well with longer-term fatigue tests.