The vortex/swirl flowmeters are meant to measure the flowrate based on the measurement of the flow frequency. Due to the frequency-dependent computation of the flowrate, noflow pulsation causes a false positive, i.e., it indicates certain amount of flowrate when actually there is no flow. This happens when for example, the valves of the flow pipe are closed causing no flow, but some pumps are w...

The SynCardia total artificial heart (TAH) is the only Food and Drug Administration (FDA) approved device for replacing hearts in patients with congestive heart failure. It pumps blood via pneumatically driven diaphragms and controls the flow with mechanical valves. While it has been successfully implanted in more than 1300 patients, its size precludes implantation in smaller patients. This stu...

This paper studies the energy-saving adaptive robust precision motion control of a single-rod hydraulic cylinder through the use of programmable valves. The programmable valves used in this study is a unique combination of five proportional cartridge valves connected in such a way that the meter-in and meter-out flows can be independently controlled by four of the valves as well as a true cross...

The scope of this document is to summarize the field trial Expro FlowCaT? and Geoservices GEM-Valve? Wireless Electromagnetic Surface Controlled Sub-surface Safety Valve in Fiume Treste field, sud Italyt provide a final technical evaluation. In 2007, COMP started study about existing Valve, have complete knowledge their status worldwide wells make statistic analysis most common failures.The con...

1. Artificial heart valves have been in use for over five decades to replace diseased heart valves. Since the first heart valve replacement performed with a caged-ball valve, more than 50 valve designs have been developed, differing principally in valve geometry, number of leaflets and material. To date, all artificial heart valves are plagued with complications associated with haemolysis, coag...

OBJECTIVES This prospective-randomized study investigated the effect of aortic valve design and patient-prosthesis mismatch (PPM) on coronary flow reserve (CFR) after mechanical or biological aortic valve replacement (AVR) in patients with aortic stenosis (AS). BACKGROUND Coronary flow reserve may be an important parameter of long-term survival after AVR in patients with AS. Reduced CFR may c...

Calcification of the mitral annulus has long been considered as a benign condition. However, recent investigations have shed a light on this condition. According to the severity of the disease, the result may be regurgitation or rarely stenosis of the mitral valve. In addition to the local effects, mitral annular calcification is considered as a surrogate for systemic inflammation, widespread c...

Background Bicuspid aortic valves (BAV) are associated with aneurysms of the ascending aorta (AAA). It is unclear whether these aneurysms are caused by tissue alterations of the aortic wall or by alterations of blood flow in the ascending aorta due to the bicuspid valve morphology. In this study we analyzed the phase contrast 4D flow characteristics in normal tricuspid aortic valves (TAV) in a ...