ÐThe unsteady ̄ow of blood in a straight, long, rigid pipe, driven by an oscillatory pressure gradient is studied. Three di€erent non±newtonian models for blood are considered and compared. One of them turns out to o€er the best ®t of experimental data, when the rheological parameters are suitably ®xed. Numerical results are obtained by a spectral collocation method in space and the implicit tr...

BACKGROUND Extracorporeal circulation (ECC) can induce alterations in blood viscoelasticity and cause red blood cell (RBC) aggregation. In this study, the authors evaluated the effects of pump flow pulsatility on blood viscoelasticity and RBC aggregation. METHODS Mongrel dogs were randomly assigned to two groups: a nonpulsatile pump group (n=6) or a pulsatile pump group (n=6). After ECC was s...

Nakano, Toshihide, Ryuji Tominaga, Ichiro Nagano, Hayato Okabe, and Hisataka Yasui. Pulsatile flow enhances endothelium-derived nitric oxide release in the peripheral vasculature. Am J Physiol Heart Circ Physiol 278: H1098–H1104, 2000.—The effects of pulsatility in blood flow on endothelium-derived nitric oxide (EDNO) release in the peripheral vasculature were investigated. The basal and flow-s...

Background: Numerical study of angulation effects of renal arteries on blood flow has been of great interest for many researchers.Objective: This paper aims at numerically determining the angulation effects of stenosed renal arteries on blood flow velocity and renal mass flow.Method: An anatomically realistic model of abdominal aorta and renal arteries is reconstructed from CT-scan images and u...

In this paper, we propose a dynamical model for pulsatile flow estimation of an iRBP. Noninvasive measurements of the motor power (V I) and pump impeller rotational speed (ω) were acquired from the pump controller and used together with blood hematocrit (HCT ) values as inputs to the model. A circulatory mock loop was operated with different aqueous glycerol solutions, mimicking different value...

Instead of pulsatile ventricular assist devices an increasing number of nonpulsatile ventricular assist devices are introduced to clinical practice. The different flow characteristics of this new technique lead to alteration in shear stress on blood components, which may affect the coagulation system. Repeated von Willebrand factor analyses were performed in a patient who first was implanted wi...

background: numerical study of angulation effects of renal arteries on blood flow has been of great interest for many researchers. objective: this paper aims at numerically determining the angulation effects of stenosed renal arteries on blood flow velocity and renal mass flow. method: an anatomically realistic model of abdominal aorta and renal arteries is reconstructed from ct-scan images and...

Background: The interaction between the blood and the vessel wall is of great clinical interest in studying cardiovascular diseases, the major causes of death in developed countries.Objective: To understand the effects of incorporating fluid-structure interaction into the simulation of blood flow through an anatomically realistic model of abdominal aorta and renal arteries reconstructed from CT...

We introduce, validate and demonstrate a new software correlator for high-speed measurement of blood flow in deep tissues based on diffuse correlation spectroscopy (DCS). The software correlator scheme employs standard PC-based data acquisition boards to measure temporal intensity autocorrelation functions continuously at 50 - 100 Hz, the fastest blood flow measurements reported with DCS to dat...

BACKGROUND For blood purification systems using a semipermeable membrane, the convective mass transfer by ultrafiltration plays an important role in toxin removal. The increase in the ultrafiltration rate can improve the toxin removal efficiency of the device, ultimately reducing treatment time and cost. In this study, we assessed the effects of pulsatile flow on the efficiency of the convectiv...