A BIOMECHANICAL DOUBLE SAC (PERICARDIUM-PEBAX) FOR SPECIALLY SHAPED ARTIFICIAL VENTRICLES - A COMPUTERIZED STUDY TO EVALUATE ITS MECHANICALAND VOLUMETRIC PROPERTIES

For original ovoid shaped artificial ventricles, a biomechanical doubl e sac consisting of a biological sac (porcine pericardium) as the bloo d contact interface and a synthetic sac (Pebax 3533) as the mechanical support to assume systolic-diastolic dynamic constraints was conceive d. The volumetric and mechanical properties were assessed with a three -dimensional modeling of Pebax sacs and computerized simulations of th eir systolic distortions for both right and left ventricular configura tions. The stresses and strains of these sacs were represented as quan titative mappings for a maximum end-systolic state and were below the respective threshold values above which the Pebau material is jeopardi zed for permanent structure impairment. After fatigue tests applied on Pebau strips under the alleged working conditions of Pebax sacs, the material structure was unchanged and maintained its intrinsic mechanic al properties. The theoretical maximum stroke volumes were 74.4 cm(3) and 62.4 cm(3) for the left and right ventricular configurations, resp ectively. With these mechanical and volumetric features, the biomechan ical double sac concept was considered valid and could be provided for a consequent specific total artificial heart.