Search results for " flow"

In-vitro assessment of centrifugal pumps for ventricular assist.

1990

Currently two major types of centrifugal pumps are commercially available for ventricular assist: the Biomedicus-cone (Group I) and the Centrimed-impeller pump (now Sarns 3M) (Group II). To compare them for blood trauma and hemolysis, an in-vitro experiment was designed with a Stockert roller pump as a standard control (Group III). The in-vitro circuit was constructed consisting of a pump head, electromagnetic flow probe, polyvinyl chloride tubing and a reservoir, identical for all groups. Human ACD blood was used for priming and was circulated with a flow rate of 2 L/min for 24 h. Blood samples were taken at 0, 1, 3, 6, 12, and 24 h and zero control values were subtracted from the resultin…

Resistance Training with Blood Flow Restriction Compared to Traditional Resistance Training on Strength and Muscle Mass in Non-Active Older Adults: A…

2021

Low-intensity training with blood flow restriction (LI-BFR) has been suggested as an alternative to high-intensity resistance training for the improvement of strength and muscle mass, becoming advisable for individuals who cannot assume such a load. The systematic review aimed to determine the effectiveness of the LI-BFR compared to dynamic high-intensity resistance training on strength and muscle mass in non-active older adults. A systematic review was conducted according to the Cochrane Handbook and reportedly followed the PRISMA statement. MEDLINE, EMBASE, Web of Science Core Collection, and Scopus databases were searched between September and October 2020. Two reviewers independently se…

Quantification of myocardial blood flow and blood flow reserve in the presence of arterial dispersion: A simulation study

2002

Myocardial blood flow (MBF) can be quantified using dynamic T1-weighted MRI of diffusible tracers and a mathematical model of underlying vasculature. Quantification of MBF by means of T1- weighted MRI requires knowledge of the arterial input function (AIF). The AIF can be estimated from the left ventricular (LV) cavity. However, dispersion may occur between the LV and the tissue of interest because of the laminar blood flow profiles, branching of venules, and because of stenosis. To evaluate the influence of dispersion on the results of MBF quantification, a simulation study was performed. The dispersion was described as a convolution of the AIF with an exponential residue function. Synthet…

The Effects of Restriction Pressures on the Acute Responses to Blood Flow Restriction Exercise

2019

Purpose: No current guidelines or recommendations exist informing the selection of restriction pressure during blood flow restriction exercise (BFRE). Moreover, the effects of specific relative restriction pressures on the acute muscle, metabolic and cardiopulmonary responses to BFRE are unclear. The purpose of this study was to characterize these acute responses at different levels of restriction pressure. Methods: Participants (n = 10) completed rhythmic isometric knee extension exercise across five experimental trials in a balanced randomized order. Three were BFRE trials {B-40 [restriction pressure set to 40% LOP (total limb occlusion pressure)]; B-60 (60% LOP); and B-80 (80% LOP)) with…

The effect of urine volume and nitric oxide on basal bladder blood flow: Response to catheterization and drainage

2000

Preliminary studies demonstrated that catheterization and drainage of the urinary bladder resulted in a significant increase in blood flow to the bladder. The objectives of this study were to determine 1) the relationship between urine volume and basal blood flow to the bladder smooth muscle and mucosa, 2) the effect of acute catheterization and drainage on bladder mucosal and smooth muscle blood flow, and 3) whether nitric oxide was involved in regulation of basal blood flow or the increase in blood flow observed after catheterization and bladder drainage. Twenty-four rabbits were separated into two groups: group 1 (14 rabbits) and group 2 (10 rabbits) treated with L-NAME (NOS inhibitor) 3…

Is losartan able to improve renal haemodynamics in hypertensives? a long term study

2000

Future perspectives in gastroenterology: laser.

1997

Effect of high-flow nasal therapy on dyspnea, comfort, and respiratory rate

2019

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Bowel resection reduces aortic pulse wave velocity in patients with ulcerative colitis. A longitudinal study.

2020

NA

Quantitative myocardial perfusion magnetic resonance imaging: the impact of pulsatile flow on contrast agent bolus dispersion.

2011

Myocardial blood flow (MBF) can be quantified using T1-weighted first-pass magnetic resonance imaging (MRI) in combination with a tracer-kinetic model, like MMID4. This procedure requires the knowledge of an arterial input function which is usually estimated from the left ventricle (LV). Dispersion of the contrast agent bolus may occur between the LV and the tissue of interest. The aim of this study was to investigate the dispersion under conditions of physiological pulsatile blood flow, and to simulate its effect on MBF quantification. The dispersion was simulated in coronary arteries using a computational fluid dynamics (CFD) approach. Simulations were accomplished on straight vessels wit…