title: Finite element analysis of stresses developed in the blood sac of a left ventricular assist device.
abstract: The goal of this research is to develop a 3D finite element (FE) model of a left ventricular assist device (LVAD) to predict stresses in the blood sac. The hyperelastic stress-strain curves for the segmented poly(ether polyurethane urea) (SPEUU) blood sac were determined in both tension and compression using a servo-hydraulic testing system at various strain rates. Over the range of strain rates studied, the sac was not strain rate sensitive, however the material response was different for tension versus compression. The experimental tension and compression properties were used in a FE model that consisted of the pusher plate, blood sac and pump case. A quasi-static analysis was used to allow for nonlinearities due to contact and material deformation. The 3D FE model showed that blood sac stresses are not adversely affected by the location of the inlet and outlet ports of the device and that over the systolic ejection phase of the simulation the prediction of blood sac stresses from the full 3D model and an axisymmetric model are the same. Minimizing stresses in the blood sac will increase the longevity of the blood sac in vivo.
authors.affiliation: Department of Mechanical Engineering, Michigan Technological University, Houghton, MI 49931, USA. thdonahu@mtu.edu
authors.forename: T L
authors.initials: TL
authors.lastname: Haut Donahue
authors.forename: W
authors.initials: W
authors.lastname: Dehlin
authors.forename: J
authors.initials: J
authors.lastname: Gillespie
authors.forename: W J
authors.initials: WJ
authors.lastname: Weiss
authors.forename: G
authors.initials: G
authors.lastname: Rosenberg
mesh_terms: D001790:Blood Physiological Phenomena; D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D020342:Finite Element Analysis; D006353:Heart-Assist Devices; D006801:Humans; D008955:Models, Cardiovascular; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical; D016277:Ventricular Function, Left / Q000502:physiology*