Between December 1981 and April 1984, five children ranging in age from 1 month to 5 1/2 years examined by two-dimensional echocardiography appeared to have a double orifice mitral valve. The diagnosis was verified in one patient at surgery, one patient by angiography and one patient by necropsy. Associated malformations included mitral stenosis and regurgitation, coarctation of the aorta, osti...

The orifice area of the functioning aortic valve was measured roentgenographically and related to flow across the valve in 27 patients (12 with normal valves). The orifice area of normal valves was linearly related to stroke index and to left ventricular ejection rate. Less than half of the cross-sectional area of the valve was utilized in most patients during the resting state. A larger percen...

The main objective of this work is to examine the impac.1 of jet interactions in arrays of micropropulsion devices on thrust performance. Rarefied flow of nitrogen and helium from a single orifice and orifice arrays into vacuum was studied experimentally and numerically. The chamber pressure was changed in the range from 10 milli-torr to 40 torr, the orifice diameter was 1 mm, and the center-to...

While color Doppler flow mapping has yielded a quick and relatively sensitive method for visualizing the turbulent jets generated in valvular insufficiency, quantification of the degree of valvular insufficiency has been limited by the dependence of visualization of turbulent jets on hemodynamic as well as instrument-related factors. Color Doppler flow imaging, however, does have the capability...

In the present numerical study, thermal performance and fluid flow properties have been investigated to show effect of single-orifice multiple-orifice impingement synthetic jets for dimensionless orifice-toplate distance (H/D) lower than one. Investigations done an actuation frequency f=500 Hz, 0.10 ≤ H/D 0.75, pitch ratio 1.25 Do/D 1.75. The results were validated with experimental from litera...

UNLABELLED As is commonly understood, the root canal morphology of the maxillary molars is usually complex and variable. It is sometimes difficult to detect the distobuccal root canal orifice of a maxillary second molar with root canal treatment. No literature related to the distobuccal root canals of the maxillary second molars has been published. OBJECTIVE To investigate the position of the...

BACKGROUND The Doppler-derived energy loss coefficient (ELCo), which can take into account the pressure recovery phenomenon and reconcile discrepancies between the aortic valve effective orifice area (EOA) obtained by the Gorlin formula using a catheter (EOAcath) and the EOA obtained by the Doppler continuity equation (EOADop), is proposed as an equivalent index to represent EOAcath. Therefore,...

BACKGROUND The regurgitant volume in aortic regurgitation is determined by the diastolic filling period, the pressure gradient between the left ventricle and aorta, and the hemodynamic size of the regurgitant orifice area. METHODS AND RESULTS To test the hypothesis that the aortic regurgitant orifice area is related to aortic pressure and aortic root size, 16 fresh calf heart and aorta specim...

OBJECTIVES The purpose of the study was to develop and validate an automated method for calculating regurgitant flow rate using color Doppler echocardiography. BACKGROUND The proximal flow convergence method is a promising approach to quantitate valvular regurgitation noninvasively because it allows one to calculate regurgitant flow rate and regurgitant orifice area; however, defining the loc...