title: A novel computational model for the hemodynamics of bileaflet mechanical valves in the opening phase.
abstract: A powerful alternative means to study the hemodynamics of bileaflet mechanical heart valves is the computational fluid dynamics method. It is well recognized that computational fluid dynamics allows reliable physiological blood flow simulation and measurements of flow parameters. To date, in almost all of the modeling studies on the hemodynamics of bileaflet mechanical heart valves, a velocity (mass flow)-based boundary condition and an axisymmetric geometry for the aortic root have been assigned, which, to some extent, are erroneous. Also, there have been contradictory reports of the profile of velocity in downstream of leaflets, that is, in some studies, it is suggested that the maximum blood velocity occurs in the lateral orifice, and in some other studies, it is postulated that the maximum velocities in the main and lateral orifices are identical. The reported values for the peak velocities range from 1 to 3 m/s, which highly depend on the model assumptions. The objective of this study is to demonstrate the importance of the exact anatomical model of the aortic root and the realistic boundary conditions in the hemodynamics of the bileaflet mechanical heart valves. The model considered in this study is based on the St Jude Medical valve in a novel modeling platform. Through a more realistic geometrical model for the aortic root and the St Jude Medical valve, we have developed a new set of boundary conditions in order to be used for the assessment of the hemodynamics of aortic bileaflet mechanical heart valves. The results of this study are significant for the design improvement of conventional bileaflet mechanical heart valves and for the design of the next generation of prosthetic valves.
authors.affiliation: The Heart Valve Performance Laboratory, School of Engineering, Faculty of Applied Science, The University of British Columbia, Kelowna, BC, Canada.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Jahandardoost
authors.affiliation: The Heart Valve Performance Laboratory, School of Engineering, Faculty of Applied Science, The University of British Columbia, Kelowna, BC, Canada Department of Surgery, Faculty of Medicine, The University of British Columbia, Vancouver, BC, Canada.
authors.forename: Guy
authors.initials: G
authors.lastname: Fradet
authors.affiliation: The Heart Valve Performance Laboratory, School of Engineering, Faculty of Applied Science, The University of British Columbia, Kelowna, BC, Canada Department of Surgery, Faculty of Medicine, The University of British Columbia, Vancouver, BC, Canada Biomedical Engineering Graduate Program, Faculty of Applied Science, The University of British Columbia, Vancouver, BC, Canada hadi.mohammadi@ubc.ca.
authors.forename: Hadi
authors.initials: H
authors.lastname: Mohammadi
mesh_terms: D000465:Algorithms; D019295:Computational Biology; D006350:Heart Valve Prosthesis; D006351:Heart Valves / Q000502:physiology*; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008955:Models, Cardiovascular; D011673:Pulsatile Flow / Q000502:physiology; D015203:Reproducibility of Results; D013314:Stress, Mechanical
keywords: Computational fluid dynamics; Reynolds averaging Navier–Stokes equation; St Jude Medical valve; boundary conditions; heart valve prostheses; shear stress transport; turbulence modeling; vascular hemodynamics