Purpose – The purpose of this paper is to investigate the geometric effects and pulsatile characteristics during the stenotic flows in tapering arteries. Design/methodology/approach – The low Reynolds number k ! turbulence model is applied to describe the stenotic flows in the tapering arteries in this paper. The results are divided into two sections. The first section characterizes the geometr...

The influence of pulsatile diameter changes on calculation of volume flow has been studied. In vitro studies and an animal study were carried out with a real-time imaging and pulsed Doppler velocity measurement system. For precise pulsatile diameter information a wall motion tracking device was incorporated. Whereas in vitro a high degree of accuracy was found for the measurements of volume flo...

Dear Editor, I read the article “Choroidal blood flow change in eyes with high myopia” by Yang and Koh [1] with great interest. The authors investigated pulsatile ocular blood f low and found it to be decreased in high myopia. I commend the authors for this well organized study and want to make some contributions. The eyeball is enlarged in high myopia. This enlargement provides a larger area o...

BACKGROUND Published studies of the past decades have established that mass transfer across the dialyzer membrane is governed by diffusion, convection and osmosis. While the former is independent of the pressure in the liquids, the latter two are pressure dependent and are enhanced when the pressure difference across the membrane is increased. The goal of the present study is to examine the imp...

We numerically investigate the pulsatile flow and heat transfer of a micropolar fluid through a Darcy-Forchhmeir porous channel in the presence of wall transpiration. We use the central difference approximations for the spatial derivatives, whereas the time integration has been performed by employing the three steps explicit Runge-Kutta method to obtain the numerical solution. It i...

Evaluating the in vivo accuracy of magnetic resonance phase velocity mapping (PVM) is not straightforward because of the absence of a validated clinical flow quantification technique. The aim of this study was to evaluate PVM by investigating its precision, both in vitro and in vivo, in a 1.5 Tesla scanner. In the former case, steady and pulsatile flow experiments were conducted using an aortic...

OBJECTIVES We investigated the integrity of dystrophin in left ventricle (LV) and right ventricle (RV) of patients with end-stage heart failure due to ischemic cardiomyopathy (IHD) or dilated cardiomyopathy (DCM), and compared the efficacy of pulsatile or continuous flow assist devices on dystrophin reverse remodeling. BACKGROUND Recently we demonstrated that the amino (N)-terminus of dystrop...

Title of dissertation: DIRECT NUMERICAL SIMULATIONS OF TRANSITIONAL PULSATILE FLOWS IN STENOTIC VESSELS Nikolaos Beratlis Doctor of Philosophy, 2008 Dissertation directed by: Professor Elias Balaras Department of Mechanical Engineering In the present work a numerical study of transitional pulsatile flow through planar and cylindrical constrictions is presented. First, a simulation carefully coo...

The Hemodynamic Importance of the Geometry of Bifurcations in the Circle of Willis (Glass Model Studies) • The critical Reynolds number, Rec, at which turbulence developed in glass model bifurcations was measured with an Evans blue indicator for bifurcations with a branch/trunk area ratio of unity, and bifurcation angles of 45°, 90°, 135°, and 180°. The Rec dropped from 2,500 in a straight tube...

BACKGROUND AND OBJECTIVE In endodontics, a major diagnostic challenge is the accurate assessment of pulp status. In this study, we designed and characterized a fiber-based laser speckle imaging system to study pulsatile blood flow in the tooth. STUDY DESIGN/MATERIALS AND METHODS To take transilluminated laser speckle images of the teeth, we built a custom fiber-based probe. To assess our abil...