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To better understand the flow pattern and the mechanical environment induced by the single leaflet mechanical heart valves, both experimental and theoretical studies have been conducted. A pulse duplicator was used for driving two mechanical heart valves (Medtronic Hall and Omniscience) and a high speed video camera (500 frames per second) tracked their motion. Several tests, at different heart rates and cardiac outputs (stroke volumes) have been performed. Using a 2D image segmentation tool, developed in Matlab, the information about the instantaneous position of the valve was extracted from each frame of the video data. The pressure drop across the valve and the transvalvular flow has also been measured. The experimental results were in good agreement with the theoretical ones, previously obtained and reported by the authors.

Detailed flow dynamic analysis in the vicinity of the leaflets and the housing during the valve-closure phase (including the rebound) is of interest for the assessment of both the thrombogenic and the cavitational potential of a candidate valve. A newly developed lumped parameter model of the left ventricle contraction and a computational fluid dynamics (CFD) representation of the fluid structure interaction (FSI) are coupled, allowing for the investigation of the valve closure under different conditions. The platelet activation potential is related to the velocity profile in the clearance region and to the duration for which the platelets are exposed to wall shear stress (WSS). The cavitational potential is related to the negative pressure transients at the leaflet edge and to the vorticity of the flow during valve closure and rebound.