Search results for "speckle"

Experimental analysis of flexural behaviour of glued lamellar wood by speckle interferometry

2009

Speckle based sensing device for fast detection of malaria

2012

We propose a new technique for malaria detection. It is based upon extraction of correlation based statistics of speckle patterns generated while illuminating red blood cells with a laser and inspecting them under a microscope.

Optoelectronic Information Encryption with Incoherent Light

2005

Echocardiographic Image Analysis Based on the Evaluation of first Order Speckle Statistics

1992

Basic theoretical considerations on the statistical properties of the speckle phenomenon indicate that a conventional quantization (intervals of uniform width) of the received and envelope detected RF — signal is not adequate. We therefore propose a quantization scheme which is based on the application of quantization intervals producing always the same confidence level (adaptive quantization). The advantages are: homogenous distribution of speckle noise reduction to about 10 – 20 significant quantization levels (with neglectable loss of morphological information) quantitative measure (confidence level) of the separability of regions represented with different quantization levels. We furthe…

P1450Effect of overweight and obesity on left ventricular longitudinal multi-layer strain: a speckle tracking two-dimensional echocardiographic study

2017

Assessment of image quality of intracoronary ultrasound systems with tissue-equivalent vessel phantoms

2002

Imaging of vascular structures by intracoronary ultrasound (ICUS) is finding more and more applications in coronary diagnosis and in the assessment of interventional access. The authors describe a method for easy and quick production of tissue-equivalent vessel phantoms from a special hydrocolloid. The mechanical tolerance is less than 3/100 mm. With these phantoms the authors tested the calibration and measured the resolution properties of the SONOS intravascular ultrasonic system (Hewlett Packard). The measurements revealed a slight space related underestimation of diameters up to 280 /spl mu/m. Using cross correlation and auto correlation functions the authors analyzed digitized ultrason…

IS A 3D SPECKLE TRACKING ALGORITHM SYNONYMOUS WITH BETTER ESTIMATION OF LEFT VENTRICULAR FUNCTION?

2012

Multi-speckle autocorrelation spectroscopy — a new strategy to monitor ultraslow dynamics in dense and nonergodic media

2007

We present a modification of the conventional dynamic light scattering set-up which allows to monitor the intensity fluctuations of many independent spatial Fourier components of the density fluctuations, i.e. “speckles”, simultaneously by using a charge-coupled device (CCD) camera as area detector. By averaging over the intensity autocorrelation function the final 10–20% decay of the intermediate scattering function in very dense colloidal dispersions is obtained with much higher accuracy. At the same time this multi-speckle autocorrelation spectroscopy provides an alternative route for constructing ensemble-averaged intermediate scattering functions in nonergodic media by replacing the av…

Displacements measurement in a building model using the speckle photography technique

2005

The use of reduced scale models in civil engineering has made it possible to study large structures such as buildings. Using non-destructive optical techniques such as double-exposure speckle photography, extremely valuable results can be obtained, where mathematical methods are often not very exact. This work studies the model of an eighteen-storey building in which displacements can be measured at each storey of each view. It also presents a comparison of the displacement field, which was obtained with the Finite Element Method.

Speckle tracking analysis: a new tool for left atrial function analysis in systemic hypertension: an overview

2014

Speckle tracking echocardiography (STE) is an imaging technique applied to the analysis of left atrial function. STE provides a non-Doppler, angle-independent and objective quantification of left atrial myocardial deformation. Data regarding feasibility, accuracy and clinical applications of left atrial strain are rapidly gathering. This review describes the fundamental concepts of left atrial STE, illustrates its pathophysiological background and discusses its emerging role in systemic arterial hypertension.