Pulse Compression Techniques are used in Radar systems to avail the benefits of large range detection capability of long duration pulse and high range resolution capability of short duration pulse with low power consumption. In this paper, details of these techniques are given which achieves high range resolution and low peak sidelobe levels under various noise conditions, Doppler shift and mul...

Kathryn Vowden, Peter Vowden Doppler ultrasound is frequently used as a screening tool when assessing patients for arterial disease. The use of Doppler ultrasound to calculate the ankle brachial pressure index (ABPI) has been tested for reliability and reproducibility and has been found to be an accurate technique when used regularly by appropriately trained practitioners. An alternative to Dop...

We discuss range and Doppler processing for FMCW radar using only a single pulse or frequency sweep. The first step is correlation processing, for which the range and Doppler resolution are limited by the ambiguity function. We show that this resolution can be optimized with an additional inverse filtering step. The method is demonstrated for sinusoidal FMCW radar measurements. Several regulari...

AIMS This study uses pulsed Doppler tissue imaging to analyse right ventricular myocardial function and its interaction with left ventricle in hypertrophic cardiomyopathy involving ventricular septum. METHODS AND RESULTS Thirty-four patients with septal hypertrophic cardiomyopathy and 30 normal subjects, comparable for sex, age, body mass index and heart rate, underwent complete standard Dopp...

Abstract For pulse compression characteristics and not easily affected by noise, linear frequency modulation signal are widely used in underwater acoustic communication. This paper analyzes the characteristics of hyperbolic frequency modulation signal over underwater acoustic channels. Compared with linear frequency modulation signal, hyperbolic frequency modulation has the same performance of ...

Background: Transmitral Doppler flow indices are used to evaluate diastolic function. Recently, velocities measured by Doppler tissue imaging have been used as an index of left ventricular relaxation. Objective: To determine whether Doppler tissue velocities are influenced by alterations in preload. Methods: Left ventricular preload was altered in 17 patients (all men, mean (SD) age, 49 (8) yea...

Background: Matrix metalloproteinases (MMPs) and their inhibitors, tissue inhibitors of metalloproteinases (TIMPs) are regulators of extracellular matrix (ECM). Diabetes Mellitus (DM) is associated with abnormal cardiac ECM composition, which may contribute to the high incidence of myocardial dysfunction (typically diastolic dysfunction). We hypothesised that plasma MMP-9, TIMP1 & -2, by regula...

BACKGROUND We hypothesized that longitudinal pulmonary arterial deformation during the cardiac cycle reflects pulmonary arterial capacitance. To examine this hypothesis, we assessed whether tissue Doppler-derived pulmonary annular motion could serve as a novel way to evaluate pulmonary arterial capacitance in pediatric patients with ventricular septal defect (VSD). METHODS In this prospective...