Jayme P. Ortiz

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In the development of a ventricular assist device, computational fluid dynamics (CFD) analysis is an efficient tool to obtain the best design before making the final prototype. In this study, different designs of a centrifugal blood pump were developed to investigate flow characteristics and performance. This study assumed the blood flow as being an(More)
BACKGROUND Since most complications related to the operation of prosthetic heart valves is due to disturbances of flow, its hydrodynamic characterization is a useful aid in the design of new prostheses. Simulations of pulsatile flow in cardiac prostheses began nearly 40 years ago, through the development of different mock human circulatory systems,(More)
Toms (1949) discovered that if a very small amount of drag reducing polymers (DRP) are added in the flow, approximately 10 ppm by weight or less, a substancial reduction in pressure drop at a given flow rate resulted. Then, since 1948, the phenomenon of drag reduction have been studied by many researchers with the objective of understand the drag reduction(More)
OBJECTIVE To complement the ISO 5840 standards concerning the duration of left ventricular systole and diastole as a function of changes in heart rates according to in vivo studies from the physiologic literature review. METHODS The systolic and diastolic durations from three in vivo studies were compared with the durations of systole proposed by the ISO(More)
INTRODUCTION In vitro hydrodynamic characterization of prosthetic heart valves provides important information regarding their operation, especially if performed by noninvasive techniques of anemometry. Once velocity profiles for each valve are provided, it is possible to compare them in terms of hydrodynamic performance. In this first experimental study(More)
PURPOSE Besides ventricular parameters, the design and angular orientation of a prosthetic heart valve induce a specific flow field. The aim of this study was to know the inflow characteristics of a left ventricular model (LVM), investigating the behavior of tricuspid bioprosthetic mitral valves in terms of velocity profiles and related valve aperture areas(More)
OBJECTIVE This work describes the experimental validation of a cardiac simulator for three heart rates (60, 80 and 100 beats per minute), under physiological conditions, as a suitable environment for prosthetic heart valves testing in the mitral or aortic position. METHODS In the experiment, an aortic bileaflet mechanical valve and a mitral bioprosthesis(More)
Introduction: In vitro hydrodynamic characterization of prosthetic heart valves provides important information regarding their operation, especially if performed by noninvasive techniques of anemometry. Once velocity profiles for each valve are provided, it is possible to compare them in terms of hydrodynamic performance. In this first experimental study(More)