In continuing the investigation of AAA hemodynamics, unsteady flow-induced stresses are presented for pulsatile blood flow through the double-aneurysm model described in Part I. Physiologically realistic aortic blood flow is simulated under pulsatile conditions for the range of time-average Reynolds numbers 50< or =Re(m) < or =300. Hemodynamic disturbance is evaluated for a modified set of indi...

Objective: Patients with single functional ventricles have a bad prognostic; most result in heart failure even after operation. The right heart bypass operations, except for right atrium and right ventricle connections, lack pulsatile flow and the volume returning to the common ventricle is low. To solve this problem, we tried to experimentally create a pulmonary ventricle which produces pulsat...

BACKGROUND Small studies have reported women to have worse outcomes and more adverse events after implantation of mechanical circulatory support device compared with men. To further evaluate sex differences in outcome, we used the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS). METHODS AND RESULTS There were 401 women (pulsatile devices=78) and 1535 men (pulsat...

The shortage of donor hearts and the physiological impact of pulsatile perfusion have driven technical innovation research efforts to create a positive displacement total artificial heart that can produce pulsatile flow and has a reasonable size for long-term assist in chronic heart failure. Such a product is the Scandinavian Real Heart 8 (SRH8); a new pulsatile total artificial heart. We here ...

The objective of this study was to compare the effects of pulsatile and nonpulsatile extracorporeal membrane oxygenation (ECMO) on hemodynamic energy and systemic microcirculation in an acute cardiac failure model in piglets. Fourteen piglets with a mean body weight of 6.08 ± 0.86 kg were divided into pulsatile (N = 7) and nonpulsatile (N = 7) ECMO groups. The experimental ECMO circuit consiste...

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...

The Virtual Intracranial Stenting Challenge 2007 (VISC'07) is becoming a standard test case in computational minimally invasive cerebrovascular intervention. Following views expressed in the literature and consistent with the recommendations of a report, the effects of non-Newtonian viscosity and pulsatile flow are reported. Three models of stented cerebral aneurysms, originating from VISC'07 a...

We show that suitable initial disturbances to steady or long-period pulsatile flows in a straight tube with an axisymmetric 75%-occlusion stenosis can produce very large transient energy growths. The global optimal disturbances to an initially axisymmetric state found by linear analyses are three-dimensional wave packets that produce localized sinuous convective instability in extended shear la...

OBJECTIVE To determine the effect of endotracheal-tube cuff deflation on airflow and F(IO2) during high-frequency percussive ventilation (HFPV), and explore methods of correcting the cuff-deflation-associated decrease in mean airway pressure and F(IO2) at the carina. METHODS Using a mechanical lung model in our respiratory research laboratory, we measured circuit pressure near the connection ...

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...