title: Optimization and investigation of a novel cardiac assist valve with a purge flow.
abstract: Clinical applications of cardiac assist systems still suffer from thromboembolic complications due to thrombus formation behind the valve's leaflets. Wherever the flow is stagnant such as in the sinus, a thrombus is likely to form. The valve design in this study avoids stagnation zones behind the leaflets by a purge flow during systole. This purge flow is separated from the valve's main flow by a flow divider directing a part of the main flow into the sinus behind the leaflet. The optimization was performed on a monoleaflet valve because of its simple geometry. Relevant geometric parameters were systematically varied. Thirty-two models were designed and numerically investigated. The models with the best results were preselected and investigated in a computer-controlled valve tester. The washout of a dye filled in the sinus was digitally recorded and quantified. The results show that a sinus purge flow minimizes stagnation areas in the sinus and thus may avoid thrombus formation.
authors.affiliation: Biofluidmechanics Lab., Charité, Humboldt University Berlin, Germany. tobias.timmel@charite.de
authors.forename: T
authors.initials: T
authors.lastname: Timmel
authors.forename: L
authors.initials: L
authors.lastname: Goubergrits
authors.forename: K
authors.initials: K
authors.lastname: Affeld
mesh_terms: D003198:Computer Simulation; D003326:Coronary Circulation; D006350:Heart Valve Prosthesis / Q000592:standards*; D006801:Humans; D011474:Prosthesis Design / Q000379:methods*