Computing the volume occupied by individual atoms in macromolecular structures has been the subject of research for several decades. This interest has grown in the recent years, because weighted volumes are widely used in implicit solvent models. Applications of the latter in molecular mechanics simulations require that the derivatives of these weighted volumes be known. In this article, we giv...

Volumes reconstructed from tracked planar ultrasound images often contain regions where no information was recorded. Existing interpolation methods introduce image artifacts and tend to be slow in filling large missing regions. Our goal was to develop a computationally efficient method that fills missing regions while adequately preserving image features. We use directional sticks to interpolat...

We developed a novel method for estimating a single parameter (τD) which summarizes the diastolic filling dynamics of the ventricle that governs the effects of diastolic filling time on stroke volume. The method involves the analysis of beat-to-beat fluctuations in heart rate, arterial blood pressure, and left ventricular stroke volume, each of which may be measured noninvasively in humans. In ...

Immersed, isolated turtle ventricles were allowed to beat when filling only by suction. Obstruction of ejection at various volumes showed an inverse relationship between residual volume and volume aspirated. Diastolie aspiration occurred even with residual volumes of at least 0.55 ml. Ventricles, filling by suction only, maintained continuous output of up to 3 ml./min. working against pressures...

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BACKGROUND Pericardial adhesions are a pathophysiological marker of constrictive pericarditis (CP), which impairs cardiac filling by limiting the total cardiac volume compliance and diastolic filling function. We studied diastolic transmitral flow efficiency as a new parameter of filling function in a pericardial adhesion animal model. We hypothesized that vortex formation time (VFT), an index ...

Left ventricular performance in 19 patients with acute myocardial infarction has been evaluated by measuring left ventricular response in terms of cardiac output, stroke volume, work, and power to progressive elevation of filling pressure accomplished by progressive expansion of blood volume with rapid infusion of low molecular weight dextran. Such infusion can elevate the cardiac output, strok...

Unequivocal evidence in favor of the concept that a ventricular diastolic vis a fronte contributes to ventricular filling has been established only in the following conditions: a. When the ventricle contains an abnormnlly small residual volume (rat, dog, turtle) ; b. When the ventricle contains a more nearly normal, residual volume due to ejection against the resistance of a fluid column (dog, ...

BACKGROUND In this paper a new non-invasive, operator-free, continuous ventricular stroke volume monitoring device (Hemodynamic Cardiac Profiler, HCP) is presented, that measures the average stroke volume (SV) for each period of 20 seconds, as well as ventricular volume-time curves for each cardiac cycle, using a new electric method (Ventricular Field Recognition) with six independent electrode...