Because of the very high chip rate of global positioning system (GPS), P-code acquisition at GPS receiver will be challenging. A variety of methods for increasing the probability of detection and reducing the average time of acquisition have been provided, among which the method of Zero Padding (ZP) is the most essential and the most widely used. The method using the Fast Fourier Transform (FFT...

This review aims to provide the reader with an update on the present and potential clinical applications in Doppler ultrasound in perinatal medicine. Umbilical artery Doppler plays an important role in the management of intrauterine growth restriction (IUGR) and pre-eclampsia and aids in twin-to-twin transfusion syndrome management while notching in the waveform is a predictor of umbilical cord...

background: iron-mediated cardiomyopathy is the main complication of thalassemia major (tm) patients. therefore, there is an important clinical need in the early diagnosis and risk stratification of patients. the aim of this study was to evaluate the efficacy of tissue doppler imaging (tdi) to study cardiac iron overload in patients with tm using t2* magnetic resonance (mr) as the gold-standard...

background: ischemic mitral regurgitation (imr) is a common complication after acute myocardial infarction (ami). we aimed to investigate the frequency of imr following first-time ami and its association with infarct location, in-hospital mortality, and complications. methods: from september 2011 to november 2012, all patients with a diagnosis of first-time acute st-elevation mi were enrolled i...

conclusion in cases with critical atherosclerotic disease of anterior tibial artery, pta-based biphasic or triphasic retrograde collateral flow prevents ischemia, whereas monophasic support or no retrograde flow remains incapable. results in the patient group, 31 lower limb arteries, of total of 17 cases, were included. after compression maneuver, dpa in 11 cases (six right, five left) showed r...

background: considering suggested formula in the references and pcwp measured by catheterism, in the present study the relation between pulmonary capillary wedge pressure (pcwp) measured the flow velocity of mitral valve and mitral annulus motion through tissue doppler imaging is evaluated methods: 52 cases of severe ms were admitted for balloon mitral valvolotomy (bmv) are included in this stu...

conclusions neither of studied variables was perfect to differentiate cirrhotic patients with and without evs. endoscopy is still the gold standard diagnostic method for diagnosing esophageal varices in patients with cirrhosis. it seems that some of the splenoportal doppler indices are promising, but more research and evaluation is necessary. results forty-four patients were male and 22 female....

background: the goal of this study was to determine the reliability of tcd in evaluation of vertebrobasilar arteries in comparison with brain mra in patients suffering from acute vertebrobasilar stroke. methods: samples were patients with definite clinical diagnosis of vertebrobasilar stroke. for all patients brain mri, mra and tcd were performed during the first 48 hours of admission. basilar ...

background abnormalities in the velocity and pattern of myocardial shortening on tissue doppler imaging (tdi) have been proposed to aid in the noninvasive diagnosis of coronary artery disease (cad). objectives we investigated the diagnostic value of post-systolic shortening (pss), a delayed ejection velocity of the myocardium after the closure of the aortic valve, on tdi in the diagnosis of cad...

Polyphase is a common class of pulse compression waveforms in the radar systems. Oppermann code is one of the used codes with polyphone pattern. After compression, this code has little tolerant against Doppler shift in addition to its high side lobe level. This indicates that the use of Oppermann code is an unsuitable scheme to radars applications. This paper shows that the use of amplitude wei...