Endurance test on a textured diaphragm for the auxiliary total artificial heart (ATAH)

We performed an endurance test on a textured diaphragm made of polyurethane (BioSpan, The Polymer Technology Group, San Francisco, CA, U.S.A.) to be used in the auxiliary total artificial heart (ATAH), an electromechanical device that can be totally implantable without removing the natural heart due to the device's reduced dimension. The objective of this endurance test was to predict whether this diaphragm would be capable of resisting in vivo tests with the ATAH implanted for fifteen days in calves. In this study, a mock loop system simulating the human circulatory system was used. The test protocol was elaborated to reproduce extreme physiological conditions. The technique to produce the textured diaphragms made of polyurethane is shown. The textured surface is used as basis to fix a layer of calf-skin gelatin. The technique used to make the diaphragm guaranteed a totally textured surface without cracking. The diaphragm demonstrated enough resistance to be used at the 15 day in vivo experiments.