The purpose of this study is to develop a test method to non-invasively measure the development of subclinical atherosclerosis through acoustic sound wave analysis. This test method involves the manufacturing and use of silicone arteries with varying relative roughness values in their inner diameters to mimic arterial plaque buildup, a flow model, ...
In this Masters thesis, the dynamics of pipes conveying pulsating flow are investigated. The initial-boundary value problem associated with the linear beam equations of motions governing the pipe system is derived using the principles of Lagrangian mechanics. In this thesis, the fluid flow is assumed to have a small velocity with harmonic time depe...
Published in Brazilian journal of cardiovascular surgery
Extracorporeal perfusion flow type requires further investigation. The aim of this study is to compare the effects of pulsatile and nonpulsatile flow on oxygenator fibers that were analyzed by scanning electron microscope (SEM) and to extensively study patients' coagulation profiles, inflammatory markers, and functional blood tests. Twelve patients...
Published in Clinical imaging
To compare the accuracy of real-time phase-contrast echo-planar MRI (EPI-PC) and conventional cine phase-contrast MRI (Conv-PC) and to assess the influence of spatial resolutions (pixel size) and velocity encoding on flow measurements obtained with the two sequences. Flow quantification was assessed using a pulsatile flow phantom (diameter: 9.5 mm;...
ObjectiveFetal cerebrovascular resistance is influenced by several factors in the setting of intact autoregulation to allow for normal cerebral blood flow and oxygenation. Maternal hyperoxygenation (MH) allows for acute alterations in fetal physiology and can be a tool to test cerebrovascular reactivity in late-gestation fetuses. In this study, we ...
ObjectivesCongenital diaphragmatic hernia (CDH) can cause a significant mass effect in the fetal thorax, displacing the heart into the opposite hemithorax. In left-sided CDH (L-CDH), this is associated with smaller left-sided cardiac structures and reduced left-ventricular cardiac output (LVCO). The effect of these physiologic changes on cerebral b...
Published in Annals of Transplantation
Background Congestive heart failure is a challenging problem due to increasing prevalence in developed countries. Patients admitted due to decompensated congestive heart failure symptoms who do not respond to medical treatment require mechanical circulatory support. Patients with biventricular failure are at particularly high mortality risk. Materi...
Unsteady and pulsatile flows receive increasing attention due to their potential to enhance various microscale processes. Further, they possess significant relevance for microfluidic studies under physiological flow conditions. However, generating a precise time-dependent flow field with commercial, pneumatically operated pressure controllers remai...
Published in Annals of Transplantation
Background The present study analyzed the impact of hypothermic pulsatile machine perfusion (MP) following a long period of static cold (SC) storage in the peculiar Brazilian scenario of high incidence of delayed graft function (DGF), despite good donor characteristics. Material/Methods A retrospective analysis, with a 1-year follow-up, of 206 reci...
Published in Medical Science Monitor : International Medical Journal of Experimental and Clinical Research
Background Left ventricular assist devices (LVADs) with counter-pulsation mode have been widely used to support left ventricular function and improve coronary circulation. However, the frequency characteristics of the coronary system have not been considered. The aim of this study was to investigate the effects of pulsatile frequency of LVADs on co...
