Effect of catheter placement on 3-D velocity profiles in curved tubes resembling the human coronary system
| Autor: | I. Cespedes, Stephane Carlier, R. Vinke, A.F.W. van der Steen, Charles T. Lancée, C. J. Slager, Jolanda J. Wentzel, Rob Krams |
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| Přispěvatelé: | Cardiology |
| Rok vydání: | 1999 |
| Předmět: |
Materials science
Acoustics and Ultrasonics Biophysics Lumen (anatomy) Inflow Slip (materials science) Coronary Artery Disease Curved Tube Catheterization Peripheral Shear stress Humans Radiology Nuclear Medicine and imaging Computer Simulation Boundary value problem Ultrasonography Interventional Radiological and Ultrasound Technology Phantoms Imaging Models Cardiovascular Mechanics Anatomy Coronary Vessels Vortex Catheter Vascular Resistance Stress Mechanical Rheology Blood Flow Velocity |
| Zdroj: | Ultrasound in Medicine and Biology, 25(5), 803-810. Elsevier Inc. |
| ISSN: | 0301-5629 |
| Popis: | Novel measurement techniques based on intravenous ultrasound (IVUS) technology (‘IVUS-Flowmetry’) require the location of a catheter inside the coronary bed. The present study quantifies disturbances in the 3-D velocity profile induced by catheter placement inside a tube, applying computational fluid dynamics. Two curved, circular meshes (radius K = 0.025 m and K = 0.035 m) with and without a catheter inside the lumen were applied. The catheter was located at the inner curve, the outer curve and at the top position. Boundary conditions were: no slip on the wall, zero stress at the outlet, uniform inflow with entrance velocities of 0.1, 0.2 and 0.4 m/s. Curvature-associated centrifugal forces shifted the maximal velocity to the outer curve and introduced two symmetrical vortices. Additional catheter placement redistributed the 3-D axial velocity field away from the catheter, which was accompanied by the appearance of multiple low-strength vortices. In addition, peak axial velocity increased, peak secondary velocities decreased, axial pressure drop increased and shear stress increased. Flow calculations simulated to resemble IVUS-based flowmetry changed by only 1% after considering secondary velocity. In conclusion , placement of a catheter inside a curved tube resembling the human coronary system changes the velocity field and reduces secondary patterns. The present study supports the usefulness of catheter-based flowmetry during resting flow conditions. During hyperemic flow conditions, flow measurements might be accompanied by large axial pressure drops because the catheter, itself, might act as a significant stenosis. |
| Databáze: | OpenAIRE |
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