title: Fluid dynamic assessment of three polymeric heart valves using particle image velocimetry.
abstract: Polymeric heart valves have the potential to reduce thrombogenic complications associated with current mechanical valves and overcome fatigue-related problems experienced by bioprosthetic valves. In this paper we characterize the in vitro velocity and Reynolds Shear Stress (RSS) fields inside and downstream of three different prototype trileaflet polymeric heart valves. The fluid dynamic differences are then correlated with variations in valve design parameters. The three valves differ in leaflet thickness, ranging from 80 to 120 mum, and commisural design, either closed, opened, or semi-opened. The valves were subjected to aortic flow conditions and the velocity measured using three-dimensional stereo Particle Image Velocimetry. The peak forward flow phase in the three valves was characterized by a strong central orifice jet of approximately 2 m/s with a flat profile along the trailing edge of the leaflets. Leakage jets, with principle RSS magnitudes exceeding 4,500 dyn/cm(2), were observed in all valves with larger leaflet thicknesses and also corresponded to larger leakage volumes. Additional leakage jets were observed at the commissural region of valves with the open and the semi-open commissural designs. The results of the present study indicate that commissural design and leaflet thickness influence valve fluid dynamics and thus the thrombogenic potential of trileaflet polymeric valves.
authors.affiliation: Wallace H. Coulter School of Biomedical Engineering, Georgia Institute of Technology, Atlanta, 30332-0535, USA.
authors.forename: Hwa Liang
authors.initials: HL
authors.lastname: Leo
authors.forename: Lakshmi Prasad
authors.initials: LP
authors.lastname: Dasi
authors.forename: Josie
authors.initials: J
authors.lastname: Carberry
authors.forename: Hélène A
authors.initials: HA
authors.lastname: Simon
authors.forename: Ajit P
authors.initials: AP
authors.lastname: Yoganathan
mesh_terms: D001783:Blood Flow Velocity / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006350:Heart Valve Prosthesis; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008863:Microspheres; D010316:Particle Size; D011108:Polymers; D011673:Pulsatile Flow / Q000502:physiology*; D012212:Rheology / Q000295:instrumentation / Q000379:methods*
chemical_list: D011108:Polymers