Abstract
Since atherosclerotic lesions tend to be localized at bends and branching points, knowledge of wall shear rate patterns in models of these geometries may help elucidate the mechanism of atherogenesis. This study uses the photochromic method of flow visualization to determine both the mean and amplitude of the wall shear rate wavefront in straight and curved elastic arterial models to demonstrate the effects of curvature, elasticity, and the phase angle between the flow and pressure waveforms (impedance phase angle). Under sinusoidal flow conditions characteristic of large arteries, the mean shear rate at the inner wall of the curved tube is reduced 40-56% from its steady flow value, depending on the phase angle. Wall shear rate amplitudes in the curved tube are significantly reduced by wall motion (36-55% of the Womersley amplitude for a straight rigid tube). The shear rate amplitude at the outer wall decreases 30% as the phase angle is reduced from -20 degrees to -66 degrees, while the shear rate amplitude at the inner wall increases 45%. As a result, the oscillatory nature of flow at the outer wall decreases with decreasing negative phase angle, but flow at the inner wall becomes much more oscillatory. At large negative phase...Continue Reading
References
Jun 1, 1978·Circulation Research·S E RittgersJ S Vasko
Feb 1, 1992·Journal of Biomechanical Engineering·A DuttaJ M Tarbell
Apr 1, 1990·Circulation Research·T Asakura, T Karino
Jun 1, 1990·Circulation Research·M KlancharD M Wang
Jan 1, 1988·Journal of Biomechanics·L J Chang, J M Tarbell
May 1, 1985·Arteriosclerosis : an Official Journal of the American Heart Association, Inc·D N KuS Glagov
Apr 1, 1983·Annals of Surgery·F W LoGerfoC C Haudenschild
Nov 1, 1982·Cardiovascular Research·J P MerillonR R Gourgon
Jun 1, 1981·Atherosclerosis·M H FriedmanF F Mark
Aug 1, 1981·Journal of Biomechanical Engineering·B Fox, W A Seed
Feb 1, 1995·Journal of Biomechanical Engineering·D M Wang, J M Tarbell
Oct 1, 1994·Circulation Research·K C WhiteJ M Tarbell
Mar 1, 1994·Journal of Biomechanics·K Rhee, J M Tarbell
Jun 1, 1994·Circulation Research·M Ojha
Feb 1, 1996·Journal of Biomechanics·M W WestonJ M Tarbell
Aug 1, 1997·Journal of Biomechanical Engineering·C S Lee, J M Tarbell
Citations
May 3, 2000·Journal of Biomechanical Engineering·Y Qiu, J M Tarbell
May 4, 2005·Ultrasound in Medicine & Biology·R KramsP Tortoli
Aug 7, 1999·Journal of Vascular Surgery·M HeiseH Scholz
Oct 18, 2005·Proceedings of the Institution of Mechanical Engineers. Part H, Journal of Engineering in Medicine·T O'BrienT McGloughlin