A comparison of steady flow downstream of the ST. Jude bileaflet heart valve: using two-dimensional LDV and PIV techniques

摘要

Both Laser Doppler Velocimetry (LDV) and Particle Image Velocimetry (PIV) have grown in popularity as noninvasive measurement techniques for biomedical fluid applications. Each method has its own distinct advantages where LDV provides excellentstatistical accuracy for point to point measurements while PIV can instantaneously characterize an entire flow field. However, the temporal and spatial resolutions of PIV are often limited for a detailed statistical analysis of turbulent flow.The purpose of this study was to assess differences and limitations between LDV and PIV results while investigating the steady flow through a prosthetic heart valve. More specifically, the Maximum turbulent Shear Stresses (MTSS) are compared because itcan characterize the potential for platelet activation and hemolysis. Using the same aortic model and heart valve, 2-D LDV and PIV measurements were made at similar locations across two planes downstream of the valve. This provided a direct comparisonbetween the techniques where specific differences between results can be found. A clinical quality St. Jude 27mm bi-leaflet mechanical heart valve was used in this study.