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Additional file 3. Velocity data for the performed experiments.
of Integrated strategy for in vitro characterization of a bileaflet mechanical aortic valve
Additional file 1. Pressure data.
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In recent years, there has been a renewed interest in the impact of turbulence on aquatic organisms. In response to this interest, a novel instrument has been constructed, TURBOGEN, that generates turbulence in water volumes up to 13 l.... more
In recent years, there has been a renewed interest in the impact of turbulence on aquatic organisms. In response to this interest, a novel instrument has been constructed, TURBOGEN, that generates turbulence in water volumes up to 13 l. TURBOGEN is fully computer controlled, thus, allowing for a high level of reproducibility and for variations of the intensity and characteristics of turbulence during the experiment. The calibration tests, carried out by particle image velocimetry, showed TURBOGEN to be successful in generating isotropic turbulence at the typical relatively low levels of the marine environment. TURBOGEN and its sizing have been devised with the long-term scope of analyzing in detail the molecular responses of plankton to different mixing regimes, which is of great importance in both environmental and biotechnological processes.
Research Interests: Engineering, Environmental Science, Oceanography, Kinetics, Particle Image Velocimetry, and 15 moreMedicine, Scientific Instruments, Computers, Calibration, Plankton, Physical sciences, Hydrodynamics, Isotropic Turbulence, CHEMICAL SCIENCES, Mesocosms, Aquatic organisms, Marine Environment, Equipment Design, Isotropy, and Calibration Tests
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ABSTRACT We present the results of a computational study of coronary trees obtained from CT acquisition at resolution of 0.35mm x 0.35mm x 0.4mm and presenting significant stenotic plaques. We analyze the cardiovascular implications of... more
ABSTRACT We present the results of a computational study of coronary trees obtained from CT acquisition at resolution of 0.35mm x 0.35mm x 0.4mm and presenting significant stenotic plaques. We analyze the cardiovascular implications of stenotic plaques for a sizeable number of patients and show that the standard clinical criterion for surgical or percutaneous intervention, based on the Fractional Flow Reserve (FFR), is well reproduced by simulations in a range of inflow conditions that can be finely controlled. The relevance of the present study is related to the reproducibility of FFR data by simulating the coronary trees at global level via high performance simulation methods together with an independent assessment based on in vitro hemodynamics. The data show that controlling the flow Reynolds number is a viable procedure to account for FFR as heart-cycle time averages and maximal hyperemia, as measured in vivo. The reproducibility of the clinical data with simulation offers a systematic approach to measuring the functional implications of stenotic plaques.
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Mechanical heart valves implanted in mitral position have a great effect on the ventricular flow. Changes include alteration of the dynamics of the vortical structures generated during the diastole and the onset of turbulence, possibly... more
Mechanical heart valves implanted in mitral position have a great effect on the ventricular flow. Changes include alteration of the dynamics of the vortical structures generated during the diastole and the onset of turbulence, possibly affecting the efficiency of the heart pump or causing blood cell damage. Modifications to the hemodynamics in the left ventricle, when the inflow through the mitral orifice is altered, were investigated in vitro using a silicone rubber, flexible ventricle model. Velocity fields were measured in space and time by means of an image analysis technique: feature tracking. Three series of experiments were performed: one with a top hat inflow velocity profile (schematically resembling physiological conditions), and two with mechanical prosthetic valves of different design, mounted in mitral position—one monoleaflet and the other bileaflet. In each series of runs, two different cardiac outputs have been examined by changing the stroke volume. The flow was inv...