Corrected systolic time intervals of the left ventricle: the interval between the onset of the Q wave and the first heart sound (Q-MI), isovolumic contraction time (IVCT), and left ventricular ejection time (LVET) have been measured by noninvasive techniques in 26 patients with valvular aortic stenosis and in 25 patients with idiopathic hypertrophic subaortic stenosis. The results were compared...

Nine cases of combined double-chambered right ventricle (DCRV) and discrete subaortic stenosis (DSAS) are presented. A review of 1077 consecutively catheterized patients indicates an association of these two uncommon anomalies nine times greater than expected. One or both obstructive lesions may be hemodynamically significant and require surgery. Whenever DCRV or DSAS is suspected or identified...

Echographic features of three patients with discrete subvalvular aortic stenosis are presented. These include a narrowed area of the left ventricular outflow tract just below the aortic valve cusps in all cases. A high-intensity but thin echo was seen in the high left ventricular outflow tract at the level of the mitral annulus in one patient with a subaortic diaphragm. In one of the three pati...

When calculating the focusing properties of cylindrically symmetric focusing optics, numerical wave propagation calculations can be carried out using the quasi-discrete Hankel transform (QDHT). We describe here an implementation of the QDHT where a partial transform matrix can be stored to speed up repeated wave propagations over specified distances, with reduced computational memory requiremen...

We explore the feasibility of using a local spectral time-domain (LSTD) method to solve Maxwell's equations that arise in optical and electromagnetic applications. The discrete singular convolution (DSC) algorithm is implemented in the LSTD method for spatial derivatives. Fourier analysis of the dispersive error of the DSC algorithm indicates that its grid density requirement for accurate simul...

We employ a discrete computational model to study the entanglement transition of non-cross-linked semiflexible fibers during isostatic compressions. We determine, as a function of the fiber aspect ratio, packing densities and caging numbers, i.e., the density and number of contacts per fiber at the entanglement transition. The caging number is found to be 8 for short fibers and to drop down to ...

This paper derives the channel estimation of a discrete cosine transform-(DCT-) based orthogonal frequency-division multiplexing (OFDM) system over a frequency-selective multipath fading channel. Channel estimation has been proved to improve system throughput and performance by allowing for coherent demodulation. Pilot-aided methods are traditionally used to learn the channel response. Least sq...