LDA Measurements of Mean Velocity and Reynolds Stress Fields Within an Artificial Heart Ventricle
| Autor: | John M. Tarbell, S. Deutsch, J. T. Baldwin, David B. Geselowitz |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
Aortic valve
Materials science Cardiac cycle Turbulence Heart Ventricles Models Cardiovascular Biomedical Engineering Diastole Mechanical engineering Heart Artificial Mechanics Reynolds stress medicine.anatomical_structure Evaluation Studies as Topic Ventricle Thromboembolism Physiology (medical) Mitral valve Hemorheology Laser-Doppler Flowmetry medicine Humans Heart-Assist Devices Blood Flow Velocity Body orifice |
| Zdroj: | Journal of Biomechanical Engineering. 116:190-200 |
| ISSN: | 1528-8951 0148-0731 |
| DOI: | 10.1115/1.2895719 |
| Popis: | Laser Doppler Anemometry measurements of mean (ensemble average) velocities and turbulent (Reynolds) stresses at 140 locations within the left ventricle of the Penn State 70 cc electric artificial heart/ventricular assist device are reported at 8 times during the cardiac cycle. Mean velocity patterns indicate that the surfaces of the blood sac and valve tracts are exposed to significant levels of wall shear stress (good wall washing) during some portion of the flow cycle, and there is no location where the flow is stagnant over the entire flow cycle. This implies that thrombus deposition within the artificial heart should be suppressed. Turbulent stresses in the main pumping chamber and the outflow tracts of the tilting disk valves do not exceed 2000 dynes/cm2. The highest turbulent stresses (20,000 dynes/cm2) and smallest turbulent microscales (6 μm) are found in the regurgitant jets on the minor orifice side of the aortic valve during diastole and the mitral valve during systole. Taken together, the data suggest that improvements in artificial heart fluid mechanics will come through valve design and pump operating conditions, not pumping chamber design. |
| Databáze: | OpenAIRE |
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