Evaluation of mechanical loading of a trileaflet polyurethane blood pump valve by finite element analysis

The mechanical loading of the leaflets of a polyurethane blood pump valve at closing pressure (max 300 mmHg) and during the opening phase can be numerically calculated by the finite element method. Geometrical and physical non-linearities, supporting forces by neighbouring leaflets and manufacturing-related thickness distribution are taken into account. The valve housing is assumed to be rigid. Volume forces are neglected. The calculations showed that the critical strain limit of 4.5% (long-term failure limit) was exceeded at closing pressure and during valve opening. During valve operation the connection between leaflet and valve housing and the central leaflet region seem to be the critical areas.