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Sample records for resolution speckle tracking

  1. Tracking speckle displacement by double Kalman filtering

    Institute of Scientific and Technical Information of China (English)

    Donghui Li; Li Guo

    2006-01-01

    @@ A tracking technique using two sequentially-connected Kalman filter for tracking laser speckle displacement is presented. One Kalman filter tracks temporal speckle displacement, while another Kalman filter tracks spatial speckle displacement. The temporal Kalman filter provides a prior for the spatial Kalman filter, and the spatial Kalman filter provides measurements for the temporal Kalman filter. The contribution of a prior to estimations of the spatial Kalman filter is analyzed. An optical analysis system was set up to verify the double-Kalman-filter tracker's ability of tracking laser speckle's constant displacement.

  2. Speckle Tracking and Transthyretin Amyloid Cardiomyopathy

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    Alexandre Marins Rocha

    Full Text Available Abstract Background: Amyloidosis is a disease caused by deposits of insoluble fibrils in extracellular spaces. The most common type of familial amyloidosis is mediated by mutation of transthyretin, especially Val30Met. Symptoms and ejection fraction decrease may occur in cardiac amyloidosis only in case of poor prognosis. Myocardial strain detected by two-dimensional speckle tracking echocardiography can indicate changes in myocardial function at early stages of the disease. Objective: To determine the accuracy of left ventricular longitudinal strain by two-dimensional speckle tracking echocardiography in patients with familial amyloidosis caused by Val30Met transthyretin mutation. Methods: Eighteen consecutive patients, carriers of transthyretin mutation, were evaluated by two-dimensional speckle tracking echocardiography, by which myocardial strain curves were obtained, following the American Society of Echocardiography recommendations. Results: Patients were divided into three groups: 1- Val30Met with cardiac amyloidosis; 2-Val30Met with extracardiac amyloidosis; 3 - Val30Met without evidence of disease. As the three groups were compared by the Mann-Whitney test, we found a statistically significant difference between groups 1 and 2 in the mean longitudinal tension (p=0.01, mean basal longitudinal strain (p=0.014; in mean longitudinal tension and mean longitudinal strain between groups 1 and 3 (p=0.005; and in the ratio of longitudinal strain of apical septum segment to longitudinal strain of basal septum (p=0.041 between groups 2 and 3. Conclusion: Left ventricular longitudinal strain detected by two-dimensional speckle tracking echocardiography is able to diagnose left ventricular dysfunction in early stages of familial amyloidosis caused by transthyretin Val30Met mutation.

  3. MODERN POSSIBILITIES OF SPECKLE TRACKING ECHOCARDIOGRAPHY IN CLINICAL PRACTICE

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    V. S. Nikiforov

    2017-01-01

    Full Text Available Speckle-tracking echocardiography is promising modern technique for evaluation of structural and functional changes in the myocardium. It evaluates the indicator of global longitudinal myocardial deformation, which is more sensitive than ejection fraction to early changes of left ventricular contractility. The diagnostic capabilities of speckle tracking echocardiography are reflected in clinical recommendations and consensus statements of European Society of Cardiology (ESC, European Association of Cardiovascular Imaging (EACVI and American Society of Echocardiography (ASE. The aim of this paper is describe basic principles of speckle tracking echocardiography and clinical applications of this new technology. Attention is paid to the use of speckle tracking echocardiography in such heart pathologies as heart failure, coronary heart disease and myocardial infarction, left ventricular hypertrophy in arterial hypertension, hypertrophic cardiomyopathy and amyloidosis of the heart, valvular heart disease, constrictive pericarditis and cancer therapy-induced cardiotoxicity.

  4. X-ray pulse wavefront metrology using speckle tracking

    International Nuclear Information System (INIS)

    Berujon, Sebastien; Ziegler, Eric; Cloetens, Peter

    2015-01-01

    The theoretical description and experimental implementation of a speckle-tracking-based instrument which permits the characterisation of X-ray pulse wavefronts. An instrument allowing the quantitative analysis of X-ray pulsed wavefronts is presented and its processing method explained. The system relies on the X-ray speckle tracking principle to accurately measure the phase gradient of the X-ray beam from which beam optical aberrations can be deduced. The key component of this instrument, a semi-transparent scintillator emitting visible light while transmitting X-rays, allows simultaneous recording of two speckle images at two different propagation distances from the X-ray source. The speckle tracking procedure for a reference-less metrology mode is described with a detailed account on the advanced processing schemes used. A method to characterize and compensate for the imaging detector distortion, whose principle is also based on speckle, is included. The presented instrument is expected to find interest at synchrotrons and at the new X-ray free-electron laser sources under development worldwide where successful exploitation of beams relies on the availability of an accurate wavefront metrology

  5. Impact of transducer frequency setting on speckle tracking measures

    DEFF Research Database (Denmark)

    Olsen, Flemming Javier; Svendsen, Jesper Hastrup; Køber, Lars

    2018-01-01

    .5/3.0 MHz. The images were obtained immediately after each other at the exact same position for the two settings. Speckle tracking was performed in three apical projections, allowing for acquisition of layered global longitudinal strain (GLS) and strain rate measures. Concordance between the frequency...

  6. Multiple speckle illumination for optical-resolution photoacoustic imaging

    Science.gov (United States)

    Poisson, Florian; Stasio, Nicolino; Moser, Christophe; Psaltis, Demetri; Bossy, Emmanuel

    2017-03-01

    Optical-resolution photoacoustic microscopy offers exquisite and specific contrast to optical absorption. Conventional approaches generally involves raster scanning a focused spot over the sample. Here, we demonstrate that a full-field illumination approach with multiple speckle illumination can also provide diffraction-limited optical-resolution photoacoustic images. Two different proof-of-concepts are demonstrated with micro-structured test samples. The first approach follows the principle of correlation/ghost imaging,1, 2 and is based on cross-correlating photoacoustic signals under multiple speckle illumination with known speckle patterns measured during a calibration step. The second approach is a speckle scanning microscopy technique, which adapts the technique proposed in fluorescence microscopy by Bertolotti and al.:3 in our work, spatially unresolved photoacoustic measurements are performed for various translations of unknown speckle patterns. A phase-retrieval algorithm is used to reconstruct the object from the knowledge of the modulus of its Fourier Transform yielded by the measurements. Because speckle patterns naturally appear in many various situations, including propagation through biological tissue or multi-mode fibers (for which focusing light is either very demanding if not impossible), speckle-illumination-based photoacoustic microscopy provides a powerful framework for the development of novel reconstruction approaches, well-suited to compressed sensing approaches.2

  7. Speckle tracking echocardiography in mature Irish Wolfhound dogs

    DEFF Research Database (Denmark)

    Westrup, Ulrik; McEvoy, Fintan

    2013-01-01

    Two-dimensional strain measurements obtained by speckle tracking echocardiography (STE) have been reported in both humans and dogs. Incorporation of this technique into canine clinical practice requires the availability of measurements from clinically normal dogs, ideally of the same breed, taken...... under normal clinical conditions.The aims of this prospective study were to assess if it is possible to obtain STE data during a routine echocardiographic examination in Irish Wolfhound dogs and that these data will provide reference values and an estimation of measurement error....

  8. 3D Characterization of corneal deformation using ultrasound speckle tracking

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    Keyton Clayson

    2017-11-01

    Full Text Available The three-dimensional (3D mechanical response of the cornea to intraocular pressure (IOP elevation has not been previously reported. In this study, we use an ultrasound speckle tracking technique to measure the 3D displacements and strains within the central 5.5mm of porcine corneas during the whole globe inflation. Inflation tests were performed on dextran-treated corneas (treated with a 10% dextran solution and untreated corneas. The dextran-treated corneas showed an inflation response expected of a thin spherical shell, with through-thickness thinning and in-plane stretch, although the strain magnitudes exhibited a heterogeneous spatial distribution from the central to more peripheral cornea. The untreated eyes demonstrated a response consistent with swelling during experimentation, with through-thickness expansion overriding the inflation response. The average volume ratios obtained in both groups was near 1 confirming general incompressibility, but local regions of volume loss or expansion were observed. These results suggest that biomechanical measurements in 3D provide important new insight to understand the mechanical response of ocular tissues such as the cornea.

  9. [Speckle tracking--a new ultrasound tool for the assessment of fetal myocardial function].

    Science.gov (United States)

    Willruth, A; Geipel, A; Merz, W; Gembruch, U

    2012-06-01

    Speckle tracking is a new ultrasound tool to assess 2D ventricular global and segmental myocardial velocity and deformation (strain, strain rate). Multiple factors such as fetal motion, high heart rates, low blood pressure, small size of the heart, physiological cardiac translation, filling and maturational changes of myocardium, polyhydramnion, maternal obesity and aortic pulsation can degrade the image quality and result in artifacts and measurement errors which may have an impact on the final analysis. Therefore deformation indices such as strain and strain rate offer a quantitative technique for the estimation of global and segmental myocardial function and contractility. At present longitudinal peak systolic strain is the most commonly applied deformation parameter used to analyse segmental and global myocardial contractility in adults. When obtained using Doppler methods, these measurements are angle dependent, whereas speckle tracking techniques overcome the limitations of Doppler echocardiography which is a particular advantage in foetal echocardiography. Nevertheless, the time and training necessary to acquire high-quality video clips limit the implementation of speckle tracking into clinical routine. It is not yet clear whether this new technique will identify subclinical myocardial impairment earlier than with current techniques or allow for better discrimination between healthy fetuses and fetuses with congenital heart disease. The clinical use of speckle tracking will have to be demonstrated in larger groups of complicated pregnancies. © Georg Thieme Verlag KG Stuttgart · New York.

  10. Real-time three-dimensional speckle tracking echocardiography: technical aspects and clinical applications

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    Sorrentino R

    2016-11-01

    Full Text Available Regina Sorrentino, Roberta Esposito, Enrica Pezzullo, Maurizio Galderisi Department of Advanced Biomedical Sciences, Interdepartmental Laboratory of Cardiac Imaging, Federico II University Hospital, Naples, Italy Abstract: Three-dimensional speckle tracking echocardiography (3D STE is a novel technique for the quantification of cardiac deformation based on tracking of ultrasonic speckles in gray scale full-volume 3D images. Developments in ultrasound technologies have made 3D speckle tracking widely available. Two-dimensional echocardiography has intrinsic limitations regarding estimation of left ventricular (LV volumes, ejection fraction, and LV mechanics, due to its inherent foreshortening errors and dependency on geometric models. The development of 3D echocardiography has improved reproducibility and accuracy. Data regarding the feasibility, accuracy, and clinical applications of 3D STE are rapidly assembling. From the tracking results, 3D STE derives several parameters, including longitudinal, circumferential and radial strain, as well as a combined assessment of longitudinal and circumferential strain, termed area strain. 3D STE can also quantify LV rotational movements such as rotation, twist, and torsion. 3D STE provides a better insight on global and regional myocardial deformation. Main applications include detection of subclinical myocardial involvement in heart failure, arterial hypertension, dyssynchrony, and ischemic heart disease. Emerging areas of application include a large spectrum of heart-involving systemic conditions, such as prediction of rejection in heart transplant patients, early detection of cardiotoxicity in patients receiving chemotherapy for cancer, and deeper physiological understanding of LV contraction mechanics in different types of athletes. Aim of this review is to discuss background, technical acquisition and processing aspects as well as recognized and developing clinical applications of this emerging

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

    Science.gov (United States)

    Cameli, Matteo; Ciccone, Marco M; Maiello, Maria; Modesti, Pietro A; Muiesan, Maria L; Scicchitano, Pietro; Novo, Salvatore; Palmiero, Pasquale; Saba, Pier S; Pedrinelli, Roberto

    2016-05-01

    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.

  12. Clinical utility of speckle-tracking echocardiography in cardiac resynchronisation therapy.

    Science.gov (United States)

    Khan, Sitara G; Klettas, Dimitris; Kapetanakis, Stam; Monaghan, Mark J

    2016-03-01

    Cardiac resynchronisation therapy (CRT) can profoundly improve outcome in selected patients with heart failure; however, response is difficult to predict and can be absent in up to one in three patients. There has been a substantial amount of interest in the echocardiographic assessment of left ventricular dyssynchrony, with the ultimate aim of reliably identifying patients who will respond to CRT. The measurement of myocardial deformation (strain) has conventionally been assessed using tissue Doppler imaging (TDI), which is limited by its angle dependence and ability to measure in a single plane. Two-dimensional speckle-tracking echocardiography is a technique that provides measurements of strain in three planes, by tracking patterns of ultrasound interference ('speckles') in the myocardial wall throughout the cardiac cycle. Since its initial use over 15 years ago, it has emerged as a tool that provides more robust, reproducible and sensitive markers of dyssynchrony than TDI. This article reviews the use of two-dimensional and three-dimensional speckle-tracking echocardiography in the assessment of dyssynchrony, including the identification of echocardiographic parameters that may hold predictive potential for the response to CRT. It also reviews the application of these techniques in guiding optimal LV lead placement pre-implant, with promising results in clinical improvement post-CRT. © 2016 The authors.

  13. Strain measurement of abdominal aortic aneurysm with real-time 3D ultrasound speckle tracking.

    Science.gov (United States)

    Bihari, P; Shelke, A; Nwe, T H; Mularczyk, M; Nelson, K; Schmandra, T; Knez, P; Schmitz-Rixen, T

    2013-04-01

    Abdominal aortic aneurysm rupture is caused by mechanical vascular tissue failure. Although mechanical properties within the aneurysm vary, currently available ultrasound methods assess only one cross-sectional segment of the aorta. This study aims to establish real-time 3-dimensional (3D) speckle tracking ultrasound to explore local displacement and strain parameters of the whole abdominal aortic aneurysm. Validation was performed on a silicone aneurysm model, perfused in a pulsatile artificial circulatory system. Wall motion of the silicone model was measured simultaneously with a commercial real-time 3D speckle tracking ultrasound system and either with laser-scan micrometry or with video photogrammetry. After validation, 3D ultrasound data were collected from abdominal aortic aneurysms of five patients and displacement and strain parameters were analysed. Displacement parameters measured in vitro by 3D ultrasound and laser scan micrometer or video analysis were significantly correlated at pulse pressures between 40 and 80 mmHg. Strong local differences in displacement and strain were identified within the aortic aneurysms of patients. Local wall strain of the whole abdominal aortic aneurysm can be analysed in vivo with real-time 3D ultrasound speckle tracking imaging, offering the prospect of individual non-invasive rupture risk analysis of abdominal aortic aneurysms. Copyright © 2013 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

  14. Acute myocarditis with normal wall motion detected with 2D speckle tracking echocardiography

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    Thomas Sturmberger

    2016-05-01

    Full Text Available We present the case of a 26-year-old male with acute tonsillitis who was referred for coronary angiography because of chest pain, elevated cardiac biomarkers, and biphasic T waves. The patient had no cardiovascular risk factors. Echocardiography showed no wall motion abnormalities and no pericardial effusion. 2D speckle tracking revealed distinct decreased regional peak longitudinal systolic strain in the lateral and posterior walls. Ischemic disease was extremely unlikely in view of his young age, negative family history regarding coronary artery disease, and lack of regional wall motion abnormalities on the conventional 2D echocardiogram. Coronary angiography was deferred as myocarditis was suspected. To confirm the diagnosis, cardiac magnetic resonance tomography (MRT was performed, showing subepicardial delayed hyperenhancement in the lateral and posterior walls correlating closely with the strain pattern obtained by 2D speckle tracking echocardiography. With a working diagnosis of acute myocarditis associated with acute tonsillitis, we prescribed antibiotics and nonsteroidal anti-inflammatory drugs. The patient’s clinical signs resolved along with normalization of serum creatine kinase (CK levels, and the patient was discharged on the third day after admission. Learning points: • Acute myocarditis can mimic acute coronary syndromes. • Conventional 2D echocardiography lacks specific features for detection of subtle regional wall motion abnormalities. • 2D speckle tracking expands the scope of echocardiography in identifying myocardial dysfunction derived from edema in acute myocarditis.

  15. Evaluation of Subclinical Left Ventricular Systolic Dysfunction in Chronic Asymptomatic Alcoholics by Speckle Tracking Echocardiography

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    Murathan Kucuk

    2017-01-01

    Full Text Available By using two-dimensional speckle tracking echocardiography, we aimed to investigate the structural and functional changes on myocardium in chronic asymptomatic alcoholics without any cardiovascular disease. Forty-one consecutive asymptomatic male alcoholics who were admitted to the outpatient alcoholism unit and 30 age matched healthy male volunteers selected as the control group were enrolled in the study. The study group were investigated by using standard two-dimensional echocardiography and speckle tracking echocardiography. The left ventricular (LV global longitudinal strain and LV global circumferential strain were significantly lower in alcoholics when compared with control subjects. There was no difference in global radial strain between the two groups. To demonstrate the effect of total life time dose of ethanol (TLDE on echocardiographic abnormalities, we assessed the correlation analysis. There was a nonsignificant weak correlation between global LV circumferential strain and TLDE (r=0.27, p=0.083. Speckle tracking echocardiography derived left ventricular systolic function was impaired in chronic alcoholic patients when compared with healthy controls.

  16. Speckle correlation resolution enhancement of wide-field fluorescence imaging (Conference Presentation)

    Science.gov (United States)

    Yilmaz, Hasan

    2016-03-01

    Structured illumination enables high-resolution fluorescence imaging of nanostructures [1]. We demonstrate a new high-resolution fluorescence imaging method that uses a scattering layer with a high-index substrate as a solid immersion lens [2]. Random scattering of coherent light enables a speckle pattern with a very fine structure that illuminates the fluorescent nanospheres on the back surface of the high-index substrate. The speckle pattern is raster-scanned over the fluorescent nanospheres using a speckle correlation effect known as the optical memory effect. A series of standard-resolution fluorescence images per each speckle pattern displacement are recorded by an electron-multiplying CCD camera using a commercial microscope objective. We have developed a new phase-retrieval algorithm to reconstruct a high-resolution, wide-field image from several standard-resolution wide-field images. We have introduced phase information of Fourier components of standard-resolution images as a new constraint in our algorithm which discards ambiguities therefore ensures convergence to a unique solution. We demonstrate two-dimensional fluorescence images of a collection of nanospheres with a deconvolved Abbe resolution of 116 nm and a field of view of 10 µm × 10 µm. Our method is robust against optical aberrations and stage drifts, therefore excellent for imaging nanostructures under ambient conditions. [1] M. G. L. Gustafsson, J. Microsc. 198, 82-87 (2000). [2] H. Yilmaz, E. G. van Putten, J. Bertolotti, A. Lagendijk, W. L. Vos, and A. P. Mosk, Optica 2, 424-429 (2015).

  17. Estudo da Mecânica Cardíaca pelo Speckle Tracking

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    Maria Cristina Donadio Abduch

    2014-04-01

    Full Text Available Speckles, ou marcadores naturais do miocárdio, originam se da interferência construtiva e destrutiva do feixe de ultrassom que incide sobre os tecidos, podem fornecer um diagnóstico precoce das alterações miocárdicas e atuar na predição de certos eventos cardíacos. Devido à sua relativa estabilidade temporal, os speckles podem ser rastreados durante o ciclo cardíaco por software dedicados, promovendo a análise da função sistólica e diastólica. São identificados tanto pela escala de cinza da ecocardiografia 2D convencional quanto pela ecocardiografia 3D, sendo independentes do ângulo de incidência do ultrassom, permitindo assim a avaliação da mecânica cardíaca nos três planos espaciais: longitudinal, circunferencial e radial. O objetivo do presente artigo é discutir o papel e o significado da deformação cardíaca obtida por meio do speckle tracking durante a avaliação da fisiologia cardíaca, e discutir as aplicações clínicas desta tecnologia ecocardiográfica inovadora.

  18. Clinical utility of speckle-tracking echocardiography in cardiac resynchronisation therapy

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    Sitara G Khan

    2016-05-01

    Full Text Available Cardiac resynchronisation therapy (CRT can profoundly improve outcome in selected patients with heart failure; however, response is difficult to predict and can be absent in up to one in three patients. There has been a substantial amount of interest in the echocardiographic assessment of left ventricular dyssynchrony, with the ultimate aim of reliably identifying patients who will respond to CRT. The measurement of myocardial deformation (strain has conventionally been assessed using tissue Doppler imaging (TDI, which is limited by its angle dependence and ability to measure in a single plane. Two-dimensional speckle-tracking echocardiography is a technique that provides measurements of strain in three planes, by tracking patterns of ultrasound interference (‘speckles’ in the myocardial wall throughout the cardiac cycle. Since its initial use over 15 years ago, it has emerged as a tool that provides more robust, reproducible and sensitive markers of dyssynchrony than TDI. This article reviews the use of two-dimensional and three-dimensional speckle-tracking echocardiography in the assessment of dyssynchrony, including the identification of echocardiographic parameters that may hold predictive potential for the response to CRT. It also reviews the application of these techniques in guiding optimal LV lead placement pre-implant, with promising results in clinical improvement post-CRT.

  19. Myocardial function in long distance runners: Assessment by echocardiography, tissue Doppler and speckle tracking

    OpenAIRE

    Pons, Jaume; Forteza, Josep Francesc; Riverso, Daniel; Aceña, Marta; Rodriguez, Antonio; Gómez, Alfredo; Fernández-Palomeque, Carlos; Bethencourt, Armando

    2014-01-01

    Introducción y objetivos: El ejercicio físico provoca respuestas adaptativas y cambios morfológico-funcionales en el corazón del atleta. El objetivo del presente estudio es caracterizar dichos cambios mediante ecocardiografía convencional y las nuevas técnicas de deformación miocárdica mediante speckle tracking. Material y métodos: Se estudiaron prospectivamente a 68 varones, 38 corredores de fondo (42±8 años), y 30 controles (40±7 años). Se les realizó estudio ecocardiográfico convencional m...

  20. Speckle-tracking echocardiography for predicting outcome in chronic aortic regurgitation during conservative management and after surgery

    DEFF Research Database (Denmark)

    Olsen, Niels Thue; Søgaard, Peter; Larsson, Henrik B W

    2011-01-01

    Objectives The aim of this study was to test myocardial deformation imaging using speckle-tracking echocardiography for predicting outcomes in chronic aortic regurgitation. Background In chronic aortic regurgitation, left ventricular (LV) dysfunction must be detected early to allow timely surgery....... Speckle-tracking echocardiography has been proposed for this purpose, but the clinical value of this method in aortic regurgitation has not been established. Methods A longitudinal study was performed in 64 patients with moderate to severe aortic regurgitation. Thirty-five patients were managed...... conservatively with frequent clinical visits and sequential echocardiography and followed for an average of 19 ± 8 months, while 29 patients underwent surgery for the valve lesion and were followed for 6 months post-operatively. Baseline LV function by speckle-tracking and conventional echocardiography...

  1. Strain dyssynchrony index determined by three-dimensional speckle area tracking can predict response to cardiac resynchronization therapy

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    Onishi Tetsuari

    2011-04-01

    Full Text Available Abstract Background We have previously reported strain dyssynchrony index assessed by two-dimensional speckle tracking strain, and a marker of both dyssynchrony and residual myocardial contractility, can predict response to cardiac resynchronization therapy (CRT. A newly developed three-dimensional (3-D speckle tracking system can quantify endocardial area change ratio (area strain, which coupled with the factors of both longitudinal and circumferential strain, from all 16 standard left ventricular (LV segments using complete 3-D pyramidal datasets. Our objective was to test the hypothesis that strain dyssynchrony index using area tracking (ASDI can quantify dyssynchrony and predict response to CRT. Methods We studied 14 heart failure patients with ejection fraction of 27 ± 7% (all≤35% and QRS duration of 172 ± 30 ms (all≥120 ms who underwent CRT. Echocardiography was performed before and 6-month after CRT. ASDI was calculated as the average difference between peak and end-systolic area strain of LV endocardium obtained from 3-D speckle tracking imaging using 16 segments. Conventional dyssynchrony measures were assessed by interventricular mechanical delay, Yu Index, and two-dimensional radial dyssynchrony by speckle-tracking strain. Response was defined as a ≥15% decrease in LV end-systolic volume 6-month after CRT. Results ASDI ≥ 3.8% was the best predictor of response to CRT with a sensitivity of 78%, specificity of 100% and area under the curve (AUC of 0.93 (p Conclusions ASDI can predict responders and LV reverse remodeling following CRT. This novel index using the 3-D speckle tracking system, which shows circumferential and longitudinal LV dyssynchrony and residual endocardial contractility, may thus have clinical significance for CRT patients.

  2. Breast cancer early detection via tracking of skin back-scattered secondary speckle patterns

    Science.gov (United States)

    Bennett, Aviya; Sirkis, Talia; Beiderman, Yevgeny; Agdarov, Sergey; Beiderman, Yafim; Zalevsky, Zeev

    2018-02-01

    Breast cancer has become a major cause of death among women. The lifetime risk of a woman developing this disease has been established as one in eight. The most useful way to reduce breast cancer death is to treat the disease as early as possible. The existing methods of early diagnostics of breast cancer are mainly based on screening mammography or Magnetic Resonance Imaging (MRI) periodically conducted at medical facilities. In this paper the authors proposing a new approach for simple breast cancer detection. It is based on skin stimulation by sound waves, illuminating it by laser beam and tracking the reflected secondary speckle patterns. As first approach, plastic balls of different sizes were placed under the skin of chicken breast and detected by the proposed method.

  3. Archeological Echocardiography: Digitization and Speckle Tracking Analysis of Archival Echocardiograms in the HyperGEN Study.

    Science.gov (United States)

    Aguilar, Frank G; Selvaraj, Senthil; Martinez, Eva E; Katz, Daniel H; Beussink, Lauren; Kim, Kwang-Youn A; Ping, Jie; Rasmussen-Torvik, Laura; Goyal, Amita; Sha, Jin; Irvin, Marguerite R; Arnett, Donna K; Shah, Sanjiv J

    2016-03-01

    Several large epidemiologic studies and clinical trials have included echocardiography, but images were stored in analog format and these studies predated tissue Doppler imaging (TDI) and speckle tracking echocardiography (STE). We hypothesized that digitization of analog echocardiograms, with subsequent quantification of cardiac mechanics using STE, is feasible, reproducible, accurate, and produces clinically valid results. In the NHLBI HyperGEN study (N = 2234), archived analog echocardiograms were digitized and subsequently analyzed using STE to obtain tissue velocities/strain. Echocardiograms were assigned quality scores and inter-/intra-observer agreement was calculated. Accuracy was evaluated in: (1) a separate second study (N = 50) comparing prospective digital strain versus post hoc analog-to-digital strain, and (2) in a third study (N = 95) comparing prospectively obtained TDI e' velocities with post hoc STE e' velocities. Finally, we replicated previously known associations between tissue velocities/strain, conventional echocardiographic measurements, and clinical data. Of the 2234 HyperGEN echocardiograms, 2150 (96.2%) underwent successful digitization and STE analysis. Inter/intra-observer agreement was high for all STE parameters, especially longitudinal strain (LS). In accuracy studies, LS performed best when comparing post hoc STE to prospective digital STE for strain analysis. STE-derived e' velocities correlated with, but systematically underestimated, TDI e' velocity. Several known associations between clinical variables and cardiac mechanics were replicated in HyperGEN. We also found a novel independent inverse association between fasting glucose and LS (adjusted β = -2.4 [95% CI -3.6, -1.2]% per 1-SD increase in fasting glucose; P echocardiography, the digitization and speckle tracking analysis of archival echocardiograms, is feasible and generates indices of cardiac mechanics similar to contemporary studies. © 2015, Wiley Periodicals, Inc.

  4. Variability of global left ventricular deformation analysis using vendor dependent and independent two-dimensional speckle-tracking software in adults

    DEFF Research Database (Denmark)

    Risum, Niels; Ali, Sophia; Olsen, Niels T

    2012-01-01

    Evaluation of myocardial deformation by two-dimensional speckle-tracking is useful for clinical and research purposes. However, differences may exist among different ultrasound machines, software packages, frame rates, and observers.......Evaluation of myocardial deformation by two-dimensional speckle-tracking is useful for clinical and research purposes. However, differences may exist among different ultrasound machines, software packages, frame rates, and observers....

  5. Modeled and Measured Partially Coherent Illumination Speckle Effects from Sloped Surfaces for Tactical Tracking

    Science.gov (United States)

    2015-03-26

    the number of speckle samples obtained, laser power and coherence length, spot size, target reflectance, speckle size, and pixels per speckle width...gated imaging systems,” Proc. SPIE, 6542: 654218, April 2007. 90 St. Pierre, Randall J. and others. “Active Tracker Laser (ATLAS),” IEEE J. Sel...numerical model developed here and existing theory developed by Hu. A 671 nm diode laser source with coherence length of 259 +/- 7 µm is reflected

  6. Speckle tracking echocardiography in chronic obstructive pulmonary disease and overlapping obstructive sleep apnea.

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    Pizarro, Carmen; van Essen, Fabian; Linnhoff, Fabian; Schueler, Robert; Hammerstingl, Christoph; Nickenig, Georg; Skowasch, Dirk; Weber, Marcel

    2016-01-01

    COPD and congestive heart failure represent two disease entities of growing global burden that share common etiological features. Therefore, we aimed to identify the degree of left ventricular (LV) dysfunction in COPD as a function of COPD severity stages and concurrently placed particular emphasis on the presence of overlapping obstructive sleep apnea (OSA). A total of 85 COPD outpatients (64.1±10.4 years, 54.1% males) and 20 controls, matched for age, sex, and smoking habits, underwent speckle tracking echocardiography for LV longitudinal strain imaging. Complementary 12-lead electrocardiography, laboratory testing, and overnight screening for sleep-disordered breathing using the SOMNOcheck micro(®) device were performed. Contrary to conventional echocardiographic parameters, speckle tracking echocardiography revealed significant impairment in global LV strain among COPD patients compared to control smokers (-13.3%±5.4% vs -17.1%±1.8%, P=0.04). On a regional level, the apical septal LV strain was reduced in COPD (P=0.003) and associated with the degree of COPD severity (P=0.02). With regard to electrocardiographic findings, COPD patients exhibited a significantly higher mean heart rate than controls (71.4±13.0 beats per minute vs 60.3±7.7 beats per minute, P=0.001) that additionally increased over Global Initiative for Chronic Obstructive Lung Disease stages (P=0.01). Albeit not statistically significant, COPD led to elevated N-terminal pro-brain natriuretic peptide levels (453.2±909.0 pg/mL vs 96.8±70.0 pg/mL, P=0.08). As to somnological testing, the portion of COPD patients exhibiting overlapping OSA accounted for 5.9% and did not significantly vary either in comparison to controls (P=0.07) or throughout the COPD Global Initiative for Chronic Obstructive Lung Disease stages (P=0.49). COPD-OSA overlap solely correlated with nocturnal hypoxemic events, whereas LV performance status was unrelated to coexisting OSA. To conclude, COPD itself seems to be

  7. Early detection of myocardial dysfunction using two-dimensional speckle tracking echocardiography in a young cat with hypertrophic cardiomyopathy

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    Ryohei Suzuki

    2018-02-01

    Full Text Available Case summary A 5-month-old intact female Scottish Fold cat was presented for cardiac evaluation. Careful auscultation detected a slight systolic murmur (Levine I/VI. The findings of electrocardiography, thoracic radiography, non-invasive blood pressure measurements and conventional echocardiographic studies were unremarkable. However, two-dimensional speckle tracking echocardiography revealed abnormalities in myocardial deformations, including decreased early-to-late diastolic strain rate ratios in longitudinal, radial and circumferential directions, and deteriorated segmental systolic longitudinal strain. At the follow-up examinations, the cat exhibited echocardiographic left ventricular hypertrophy and was diagnosed with hypertrophic cardiomyopathy using conventional echocardiography. Relevance and novel information This is the first report on the use of two-dimensional speckle tracking echocardiography for the early detection of myocardial dysfunction in a cat with hypertrophic cardiomyopathy; the myocardial dysfunction was detected before the development of hypertrophy. The findings from this case suggest that two-dimensional speckle tracking echocardiography can be useful for myocardial assessment when conventional echocardiographic and Doppler findings are ambiguous.

  8. Strain and strain rate by two-dimensional speckle tracking echocardiography in a maned wolf

    Directory of Open Access Journals (Sweden)

    Matheus M. Mantovani

    2012-12-01

    Full Text Available The measurement of cardiovascular features of wild animals is important, as is the measurement in pets, for the assessment of myocardial function and the early detection of cardiac abnormalities, which could progress to heart failure. Speckle tracking echocardiography (2D STE is a new tool that has been used in veterinary medicine, which demonstrates several advantages, such as angle independence and the possibility to provide the early diagnosis of myocardial alterations. The aim of this study was to evaluate the left myocardial function in a maned wolf by 2D STE. Thus, the longitudinal, circumferential and radial strain and strain rate were obtained, as well as, the radial and longitudinal velocity and displacement values, from the right parasternal long axis four-chamber view, the left parasternal apical four chamber view and the parasternal short axis at the level of the papillary muscles. The results of the longitudinal variables were -13.52±7.88, -1.60±1.05, 4.34±2.52 and 3.86±3.04 for strain (%, strain rate (1/s, displacement (mm and velocity (cm/s, respectively. In addition, the radial and circumferential Strain and Strain rate were 24.39±14.23, 1.86±0.95 and -13.69±6.53, -1.01±0.48, respectively. Thus, the present study provides the first data regarding the use of this tool in maned wolves, allowing a more complete quantification of myocardial function in this species.

  9. Two-dimensional speckle tracking echocardiography prognostic parameters in patients after acute myocardial infarction.

    Science.gov (United States)

    Haberka, Maciej; Liszka, Jerzy; Kozyra, Andrzej; Finik, Maciej; Gąsior, Zbigniew

    2015-03-01

    The aim of the study was to evaluate the left ventricle (LV) function with speckle tracking echocardiography (STE) and to assess its relation to prognosis in patients after acute myocardial infarction (AMI). Sixty-three patients (F/M = 16/47 pts; 62.33 ± 11.85 years old) with AMI (NSTEMI/STEMI 24/39 pts) and successful percutaneous coronary intervention (PCI) with stent implantation (thrombolysis in myocardial infarction; TIMI 3 flow) were enrolled in this study. All patients underwent baseline two-dimensional conventional echocardiography and STE 3 days (baseline) and 30 days after PCI. All patients were followed up for cardiovascular clinical endpoints, major adverse cardiovascular endpoint (MACE), and functional status (Canadian Cardiovascular Society and New York Heart Association). During the follow-up (31.9 ± 5.1 months), there were 3 cardiovascular deaths, 15 patients had AMI, 2 patients had cerebral infarction, 24 patients reached the MACE. Baseline LV torsion (P = 0.035), but none of the other strain parameters were associated with the time to first unplanned cardiovascular hospitalization. Univariate analysis showed that baseline longitudinal two-chamber and four-chamber strain (sLa2 0 and sLa4 0) and the same parameters obtained 30 days after the AMI together with transverse four-chamber strain (sLa2 30, sLa4 30, and sTa4 30) were significantly associated with combined endpoint (MACE). The strongest association in the univariate analysis was found for the baseline sLa2. However, in multivariable analysis only a left ventricular remodeling (LVR - 27% pts) was significantly associated with MACE and strain parameters were not associated with the combined endpoint. The assessment of LV function with STE may improve cardiovascular risk prediction in postmyocardial infarction patients. © 2014, Wiley Periodicals, Inc.

  10. Early Detection of Subclinical Uremic Cardiomyopathy Using Two-Dimensional Speckle Tracking Echocardiography.

    Science.gov (United States)

    Hassanin, Noha; Alkemary, Alkhateeb

    2016-04-01

    Overhydration has a deleterious effect on cardio myocytes. This study was designated to evaluate left ventricular (LV) systolic and diastolic dysfunction in patients with various stages of chronic kidney disease (CKD) using conventional, tissue Doppler and two-dimensional speckle tracking echocardiography (2DSTE). Forty controls and 90 CKD patients, aged 49.3 ± 14 years old, were enrolled in the study. Patients were divided into 3 groups depending on their glomerular filtration rate. Group 1 (≥60 mL/min per 1.73 m(2) ), group 2 (≤60 mL/min per 1.73 m(2) ), and group 3 (≤60 mL/min per 1.73 m(2) and on regular dialysis for at least 12 months). Pulsed-Doppler and tissue Doppler studies were used to estimate LV filling pressure E/E'. Using 2DSTE, circumferential, radial, and longitudinal functions of the LV have been measured. LV longitudinal systolic strain, early, and late diastolic strain rates were significantly reduced in CKD patients (-16.9 ± 3.8%, 1.6 ± 0.5%, and 1.3 ± 0.4% in CKD vs. -22.5 ± 0.6%, 2.3 ± 0.2%, and 1.9 ± 0.1% in controls, P < 0.001 for all), and no difference was observed in terms of the circumferential LV functions (-22.4 ± 1.7 vs. -22.5 ± 1.4, P = 0.567). Severity of the kidney dysfunction appears to parallel with the rise of E/E' significantly (P < 0.001). In CKD, although the longitudinal and radial systolic functions were reduced, LV ejection fraction may remain within normal limits due to the preservation of the circumferential functions. Early detection of uremic cardiomyopathy might provide useful information for the risk stratification and decide the proper dialysis therapy in these patients. © 2015, Wiley Periodicals, Inc.

  11. Feasibility, Reproducibility, and Agreement between Different Speckle Tracking Echocardiographic Techniques for the Assessment of Longitudinal Deformation

    Directory of Open Access Journals (Sweden)

    Sergio Buccheri

    2013-01-01

    Full Text Available Background. Left ventricular (LV longitudinal deformation can be assessed with new echocardiographic techniques like triplane echocardiography (3PE and four-dimensional echocardiography (4DE. We aimed to assess the feasibility, reproducibility, and agreement between these different speckle-tracking techniques for the assessment of longitudinal deformation. Methods. 101 consecutive subjects underwent echocardiographic examination. 2D cine loops from the apical views, a triplane view, and an LV 4D full volume were acquired in all subjects. LV longitudinal strain was obtained for each imaging modality. Results. 2DE analysis of LV strain was feasible in 90/101 subjects, 3PE strain in 89/101, and 4DE strain in 90/101. The mean value of 2DE and 3PE longitudinal strains was significantly higher with respect to 4DE. The relationship between 2DE and 3PE derived strains (r=0.782 was significantly higher (z=3.72, P<0.001 than that between 2DE and 4DE (r=0.429 and that between 3PE and 4DE (r=0.510; z=3.09, P=0.001. The mean bias between 2DE and 4DE strains was -6.61±7.31% while -6.42±6.81% between 3PE and 4DE strains; the bias between 2DE and 3PE strain was of 0.21±4.16%. Intraobserver and interobserver variabilities were acceptable among the techniques. Conclusions. Echocardiographic techniques for the assessment of longitudinal deformation are not interchangeable, and further studies are needed to assess specific reference values.

  12. Speckle tracking echocardiography in acute lupus myocarditis: comparison to conventional echocardiography

    Directory of Open Access Journals (Sweden)

    Riëtte Du Toit

    2017-07-01

    Full Text Available Aims: Lupus myocarditis occurs in 5–10% of patients with systemic lupus erythematosus (SLE. No single feature is diagnostic of lupus myocarditis. Speckle tracking echocardiography (STE can detect subclinical left ventricular dysfunction in SLE patients, with limited research on its utility in clinical lupus myocarditis. We report on STE in comparison to conventional echocardiography in patients with clinical lupus myocarditis. Methods and results: A retrospective study was done at a tertiary referral hospital in South Africa. SLE patients with lupus myocarditis were included and compared to healthy controls. Echocardiographic images were reanalyzed, including global longitudinal strain through STE. A poor echocardiographic outcome was defined as final left ventricular ejection fraction (LVEF <40%. 28 SLE patients fulfilled the criteria. Global longitudinal strain correlated with global (LVEF: r = −0.808; P = 0.001 and regional (wall motion score: r = 0.715; P < 0.001 function. In patients presenting with a LVEF ≥50%, global longitudinal strain (P = 0.023, wall motion score (P = 0.005 and diastolic function (P = 0.004 were significantly impaired vs controls. Following treatment, LVEF (35–47% (P = 0.023 and wall motion score (1.88–1.5 (P = 0.017 improved but not global longitudinal strain. Initial LVEF (34%; P = 0.046 and global longitudinal strain (−9.5%; P = 0.095 were lower in patients with a final LVEF <40%. Conclusions: This is the first known report on STE in a series of patients with clinical lupus myocarditis. Global longitudinal strain correlated with regional and global left ventricular function. Global longitudinal strain, wall motion score and diastolic parameters may be more sensitive markers of lupus myocarditis in patients presenting with a preserved LVEF ≥50%. A poor initial LVEF and global longitudinal strain were associated with a persistent LVEF <40%. Echocardiography is a non-invasive tool with diagnostic and

  13. Two-dimensional speckle tracking echocardiography demonstrates no effect of active acromegaly on left ventricular strain.

    Science.gov (United States)

    Volschan, I C M; Kasuki, L; Silva, C M S; Alcantara, M L; Saraiva, R M; Xavier, S S; Gadelha, M R

    2017-06-01

    Speckle tracking echocardiography (STE) allows for the study of myocardial strain (ε), a marker of early and subclinical ventricular systolic dysfunction. Cardiac disease may be present in patients with acromegaly; however, STE has never been used to evaluate these patients. To evaluate left ventricular (LV) global longitudinal strain in patients with active acromegaly with normal LV systolic function. Cross-sectional clinical study. Patients with active acromegaly with no detectable heart disease and a control group were matched for age, gender, arterial hypertension and diabetes mellitus underwent STE. Global LV longitudinal ε (GLS), left ventricular mass index (LVMi), left ventricular ejection fraction (LVEF) and relative wall thickness (RWT) were obtained via two-dimensional (2D) echocardiography using STE. Thirty-seven patients with active acromegaly (mean age 45.6 ± 13.8; 48.6% were males) and 48 controls were included. The mean GLS was not significantly different between the acromegaly group and the control group (in %, -20.1 ± 3.1 vs. -19.4 ± 2.2, p = 0.256). Mean LVMi was increased in the acromegaly group (in g/m 2 , 101.6 ± 27.1 vs. 73.2 ± 18.6, p Acromegaly patients, despite presenting with a higher LVMi when analyzed by 2D echocardiography, did not present with impairment in the strain when compared to a control group; this finding indicates a low chance of evolution to systolic dysfunction and agrees with recent studies that show a lower frequency of cardiac disease in these patients.

  14. Quantitative Evaluation of the Fetal Right and Left Ventricular Fractional Area Change Using Speckle Tracking Technology.

    Science.gov (United States)

    DeVore, Greggory R; Klas, Berthold; Satou, Gary; Sklansky, Mark

    2018-03-14

    The purpose of this study was to measure the fractional area change (FAC) of the right and left ventricles in normal fetal hearts between 20 and 40 weeks of gestation using speckle-tracking software. The 4-chamber view of the fetal heart was obtained in 200 control fetuses between 20 and 40 weeks of gestation. The FAC was computed from the ventricular areas [((end-diastolic area) - (end-systolic area)/(end-diastolic area)) x 100] for the right and left ventricles and regressed against 7 independent biometric and age variables. The FAC was correlated with longitudinal fractional shortening (LFS) [((end-diastolic longitudinal length) - (end-systolic longitudinal length) /(end-diastolic longitudinal length)) x 100] obtained from the mid ventricular basal-apical lengths of the right and left ventricular chambers and the transverse fractional shortening (TFS) [((end-diastolic transverse length) - (end-systolic transverse length)/(end-diastolic transverse length)) x 100] from three transverse positions (base, mid, apical) located within each ventricular chamber. To evaluate potential clinical utility, the FAC, LFS, and TFS results were examined in 9 fetuses with congenital heart defects (CHD). Regression analysis demonstrated significant associations between the FAC and the biometric and age independent variables (R 2 = 0.13 - 0.15). The FAC was significantly correlated with the LFS (R 2 =0.18 to 0.28) and TFS (R 2 = 0.13 to 0.33). The 9 fetuses with CHD illustrated the interrelationship between the FAC, LFS, and TFS when identifying abnormal ventricular function. This study reports results from measuring the FAC of the right and left ventricles, and demonstrates a correlation with longitudinal fractional shortening (LFS) and transverse fractional shortening (TFS). This article is protected by copyright. All rights reserved.

  15. Speckle-tracking strain assessment of left ventricular dysfunction in synthetic cannabinoid and heroin users.

    Science.gov (United States)

    Demirkıran, Aykut; Albayrak, Neslihan; Albayrak, Yakup; Zorkun, Cafer Sadık

    2018-06-01

    There is growing evidence regarding the numerous adverse effects of synthetic cannabinoids (SCBs) on the cardiovascular system; however, no studies have shown the cardiovascular effects of opioids using strain echocardiography. This study examines the cardiac structure and function using echocardiographic strain imaging in heroin and synthetic cannabinoid users. This double-blind study included patients who were admitted or referred to a rehabilitation center for heroin (n=31) and synthetic cannabinoid users (n=30). Heroin users and synthetic cannabinoid users were compared with healthy volunteers (n=32) using two-dimensional (2D) speckle-tracking (ST) echocardiography. No differences were found in the baseline characteristics and 2D echocardiography values. The mean global longitudinal strain value was -20.5%±2.4% for SCB users, -22.3%±2.4% for opioid users, and -22.5%±2.2% for healthy volunteers (p=0.024). The mean apical 2-chamber (AP2C) L-strain values were -20.1%±3.1%, -22.4%±3.0%, and -22.3%±2.8% for SCB users, opioid users, and healthy volunteers, respectively (p=0.032). The mean apical 4-chamber (AP4C) L-strain values were -20.7%±2.5% for SCB users, -23.2%±3.2% for opioid users, and -23.8%±3.1% for healthy volunteers (p<0.001). SCBs are potential causes of subclinical left ventricular dysfunction.

  16. High tracking resolution detectors. Final Technical Report

    International Nuclear Information System (INIS)

    Vasile, Stefan; Li, Zheng

    2010-01-01

    High-resolution tracking detectors based on Active Pixel Sensor (APS) have been valuable tools in Nuclear Physics and High-Energy Physics research, and have contributed to major discoveries. Their integration time, radiation length and readout rate is a limiting factor for the planed luminosity upgrades in nuclear and high-energy physics collider-based experiments. The goal of this program was to demonstrate and develop high-gain, high-resolution tracking detector arrays with faster readout, and shorter radiation length than APS arrays. These arrays may operate as direct charged particle detectors or as readouts of high resolution scintillating fiber arrays. During this program, we developed in CMOS large, high-resolution pixel sensor arrays with integrated readout, and reset at pixel level. Their intrinsic gain, high immunity to surface and moisture damage, will allow operating these detectors with minimal packaging/passivation requirements and will result in radiation length superior to APS. In Phase I, we designed and fabricated arrays with calorimetric output capable of sub-pixel resolution and sub-microsecond readout rate. The technical effort was dedicated to detector and readout structure development, performance verification, as well as to radiation damage and damage annealing.

  17. Comet Shoemaker-Levy 9/Jupiter collision observed with a high resolution speckle imaging system

    Energy Technology Data Exchange (ETDEWEB)

    Gravel, D. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    During the week of July 16, 1994, comet Shoemaker-Levy 9, broken into 20 plus pieces by tidal forces on its last orbit, smashed into the planet Jupiter, releasing the explosive energy of 500 thousand megatons. A team of observers from LLNL used the LLNL Speckle Imaging Camera mounted on the University of California`s Lick Observatory 3 Meter Telescope to capture continuous sequences of planet images during the comet encounter. Post processing with the bispectral phase reconstruction algorithm improves the resolution by removing much of the blurring due to atmospheric turbulence. High resolution images of the planet surface showing the aftermath of the impact are probably the best that were obtained from any ground-based telescope. We have been looking at the regions of the fragment impacts to try to discern any dynamic behavior of the spots left on Jupiter`s cloud tops. Such information can lead to conclusions about the nature of the comet and of Jupiter`s atmosphere. So far, the Hubble Space Telescope has observed expanding waves from the G impact whose mechanism is enigmatic since they appear to be too slow to be sound waves and too fast to be gravity waves, given the present knowledge of Jupiter`s atmosphere. Some of our data on the G and L impact region complements the Hubble observations but, so far, is inconclusive about spot dynamics.

  18. Three-dimensional Speckle Tracking Echocardiography in Light Chain Cardiac Amyloidosis: Examination of Left and Right Ventricular Myocardial Mechanics Parameters.

    Science.gov (United States)

    Urbano-Moral, Jose Angel; Gangadharamurthy, Dakshin; Comenzo, Raymond L; Pandian, Natesa G; Patel, Ayan R

    2015-08-01

    The study of myocardial mechanics has a potential role in the detection of cardiac involvement in patients with amyloidosis. This study aimed to characterize 3-dimensional-speckle tracking echocardiography-derived left and right ventricular myocardial mechanics in light chain amyloidosis and examine their relationship with brain natriuretic peptide. In patients with light chain amyloidosis, left ventricular longitudinal and circumferential strain (n=40), and right ventricular longitudinal strain and radial displacement (n=26) were obtained by 3-dimensional-speckle tracking echocardiography. Brain natriuretic peptide levels were determined. All myocardial mechanics measurements showed differences when compared by brain natriuretic peptide level tertiles. Left and right ventricular longitudinal strain were highly correlated (r=0.95, P<.001). Left ventricular longitudinal and circumferential strain were reduced in patients with cardiac involvement (-9±4 vs -16±2; P<.001, and -24±6 vs -29±4; P=.01, respectively), with the most prominent impairment at the basal segments. Right ventricular longitudinal strain and radial displacement were diminished in patients with cardiac involvement (-9±3 vs -17±3; P<.001, and 2.7±0.8 vs 3.8±0.3; P=.002). On multivariate analysis, left ventricular longitudinal strain was associated with the presence of cardiac involvement (odds ratio = 1.6; 95% confidence interval, 1.04 to 2.37; P=.03) independent of the presence of brain natriuretic peptide and troponin I criteria for cardiac amyloidosis. Three-dimensional-speckle tracking echocardiography-derived left and right ventricular myocardial mechanics are increasingly altered as brain natriuretic peptide increases in light chain amyloidosis. There appears to be a strong association between left ventricular longitudinal strain and cardiac involvement, beyond biomarkers such as brain natriuretic peptide and troponin I. Copyright © 2015 Sociedad Española de Cardiología. Published by

  19. Left Ventricular Deformation by Speckle Tracking Echocardiography at 2-year Follow-up in Treatment Naive Rheumatoid Arthritis Patients

    DEFF Research Database (Denmark)

    Løgstrup, Brian Bridal; Masic, D; Laurberg, Trine Bay

    2015-01-01

    -CCP titers were evaluated by standardized techniques at baseline and 2-year follow-up. We performed a novel advanced echocardiography by speckle tracking in means of global LV systolic deformation (GLS) imaging. One experienced senior rheumatologist and one experienced cardiologist performed all the clinical...... assessments as well as all the echocardiography including the LV deformation analysis at baseline and by 2-year follow-up. Results: Disease activity scores before treatment at baseline and at 2-year follow-up were respectively: number of swollen joints (28): 7.1+/-2.9 (SD) and 0.4+/-0.3, number of tender...

  20. Quantification of global myocardial function by cine MRI deformable registration-based analysis: Comparison with MR feature tracking and speckle-tracking echocardiography.

    Science.gov (United States)

    Lamacie, Mariana M; Thavendiranathan, Paaladinesh; Hanneman, Kate; Greiser, Andreas; Jolly, Marie-Pierre; Ward, Richard; Wintersperger, Bernd J

    2017-04-01

    To evaluate deformable registration algorithms (DRA)-based quantification of cine steady-state free-precession (SSFP) for myocardial strain assessment in comparison with feature-tracking (FT) and speckle-tracking echocardiography (STE). Data sets of 28 patients/10 volunteers, undergoing same-day 1.5T cardiac MRI and echocardiography were included. LV global longitudinal (GLS), circumferential (GCS) and radial (GRS) peak systolic strain were assessed on cine SSFP data using commercially available FT algorithms and prototype DRA-based algorithms. STE was applied as standard of reference for accuracy, precision and intra-/interobserver reproducibility testing. DRA showed narrower limits of agreement compared to STE for GLS (-4.0 [-0.9,-7.9]) and GCS (-5.1 [1.1,-11.2]) than FT (3.2 [11.2,-4.9]; 3.8 [13.9,-6.3], respectively). While both DRA and FT demonstrated significant differences to STE for GLS and GCS (all pcine MRI. • Inverse DRA demonstrated superior reproducibility compared to feature-tracking (FT) methods. • Cine MR DRA and FT analysis demonstrate differences to speckle-tracking echocardiography • DRA demonstrated better correlation with STE than FT for MR-derived global strain data.

  1. Capillary detectors for high resolution tracking

    International Nuclear Information System (INIS)

    Annis, P.; Bay, A.; Bonekaemper, D.; Buontempo, S.; Ereditato, A.; Fabre, J.P.; Fiorillo, G.; Frekers, D.; Frenkel, A.; Galeazzi, F.; Garufi, F.; Goldberg, J.; Golovkin, S.; Hoepfner, K.; Konijn, J.; Kozarenko, E.; Kreslo, I.; Liberti, B.; Martellotti, G.; Medvedkov, A.; Mommaert, C.; Panman, J.; Penso, G.; Petukhov, Yu.; Rondeshagen, D.; Tyukov, V.; Vasilchenko, V.; Vilain, P.; Vischers, J.L.; Wilquet, G.; Winter, K.; Wolff, T.; Wong, H.

    1997-01-01

    We present a new tracking device based on glass capillary bundles or layers filled with highly purified liquid scintillator and read out at one end by means of image intensifiers and CCD devices. A large-volume prototype consisting of 5 x 10 5 capillaries with a diameter of 20 μm and a length of 180 cm and read out by a megapixel CCD has been tested with muon and neutrino beams at CERN. With this prototype a two track resolution of 33 μm was achieved with passing through muons. Images of neutrino interactions in a capillary bundle have also been acquired and analysed. Read-out chains based on electron bombarded CCD (EBCCD) and image pipeline devices are also investigated. Preliminary results obtained with a capillary bundle read out by an EBCCD are presented. (orig.)

  2. Capillary detectors for high resolution tracking

    CERN Document Server

    Annis, P

    1997-01-01

    We present a new tracking device based on glass capillary bundles or layers filled with highly purified liquid scintillator and read out at one end by means of image intensifiers and CCD devices. A large-volume prototype consisting of 5 × 105 capillaries with a diameter of 20 μm and a length of 180 cm and read out by a megapixel CCD has been tested with muon and neutrino beams at CERN. With this prototype a two track resolution of 33 μm was achieved with passing through muons. Images of neutrino interactions in a capillary bundle have also been acquired and analysed. Read-out chains based on Electron Bombarded CCD (EBCCD) and image pipeline devices are also investigated. Preliminary results obtained with a capillary bundle read out by an EBCCD are presented.

  3. Determination of multidirectional myocardial deformations in cats with hypertrophic cardiomyopathy by using two-dimensional speckle-tracking echocardiography.

    Science.gov (United States)

    Suzuki, Ryohei; Mochizuki, Yohei; Yoshimatsu, Hiroki; Teshima, Takahiro; Matsumoto, Hirotaka; Koyama, Hidekazu

    2017-12-01

    Objectives Hypertrophic cardiomyopathy, a primary disorder of the myocardium, is the most common cardiac disease in cats. However, determination of myocardial deformation with two-dimensional speckle-tracking echocardiography in cats with various stages of hypertrophic cardiomyopathy has not yet been reported. This study was designed to measure quantitatively multidirectional myocardial deformations of cats with hypertrophic cardiomyopathy. Methods Thirty-two client-owned cats with hypertrophic cardiomyopathy and 14 healthy cats serving as controls were enrolled and underwent assessment of myocardial deformation (peak systolic strain and strain rate) in the longitudinal, radial and circumferential directions. Results Longitudinal and radial deformations were reduced in cats with hypertrophic cardiomyopathy, despite normal systolic function determined by conventional echocardiography. Cats with severely symptomatic hypertrophic cardiomyopathy also had lower peak systolic circumferential strain, in addition to longitudinal and radial strain. Conclusions and relevance Longitudinal and radial deformation may be helpful in the diagnosis of hypertrophic cardiomyopathy. Additionally, the lower circumferential deformation in cats with severe hypertrophic cardiomyopathy may contribute to clinical findings of decompensation, and seems to be related to severe cardiac clinical signs. Indices of multidirectional myocardial deformations by two-dimensional speckle-tracking echocardiography may be useful markers and help to distinguish between cats with hypertrophic cardiomyopathy and healthy cats. Additionally, they may provide more detailed assessment of contractile function in cats with hypertrophic cardiomyopathy.

  4. Functional assessment of the diaphragm by speckle tracking ultrasound during inspiratory loading

    NARCIS (Netherlands)

    Mos-Oppersma, Eline; Hatam, Nima; Doorduin, Jonne; van der Hoeven, Johannes G.; Marx, Gernot; Goetzenich, Andreas; Fritsch, Sebastian; Heunks, Leo M.A.; Bruells, Christian S.

    2017-01-01

    Assessment of diaphragmatic effort is challenging, especially in critically ill patients in the phase of weaning. Fractional thickening during inspiration assessed by ultrasound has been used to estimate diaphragm effort. It is unknown whether more sophisticated ultrasound techniques such as speckle

  5. Abnormal biventricular performance in asymptomatic adolescents late after repaired Tetralogy of Fallot: Combined two-dimensional speckle tracking and three-dimensional echocardiography study

    Directory of Open Access Journals (Sweden)

    Ken-Pen Weng

    2018-02-01

    Conclusion: Our results suggest asymptomatic adolescents with repaired TOF had abnormal biventricular myocardial performance, as demonstrated by combined 2D speckle-tracking and 3D echocardiography. The implications of these findings for management of adolescents late after repaired TOF remain to be determined.

  6. Noninvasive model including right ventricular speckle tracking for the evaluation of pulmonary hypertension.

    Science.gov (United States)

    Mahran, Yossra; Schueler, Robert; Weber, Marcel; Pizarro, Carmen; Nickenig, Georg; Skowasch, Dirk; Hammerstingl, Christoph

    2016-08-26

    To find parameters from transthorathic echocardiography (TTE) including speckle-tracking (ST) analysis of the right ventricle (RV) to identify precapillary pulmonary hypertension (PH). Forty-four patients with suspected PH undergoing right heart catheterization (RHC) were consecutively included (mean age 63.1 ± 14 years, 61% male gender). All patients underwent standardized TTE including ST analysis of the RV. Based on the subsequent TTE-derived measurements, the presence of PH was assessed: Left ventricular ejection fraction (LVEF) was calculated by Simpsons rule from 4Ch. Systolic pulmonary artery pressure (sPAP) was assessed with continuous wave Doppler of systolic tricuspid regurgitant velocity and regarded raised with values ≥ 30 mmHg as a surrogate parameter for RA pressure. A concomitantly elevated PCWP was considered a means to discriminate between the precapillary and postcapillary form of PH. PCWP was considered elevated when the E/e' ratio was > 12 as a surrogate for LV diastolic pressure. E/e' ratio was measured by gauging systolic and diastolic velocities of the lateral and septal mitral valve annulus using TDI mode. The results were then averaged with conventional measurement of mitral valve inflow. Furthermore, functional testing with six minutes walking distance (6MWD), ECG-RV stress signs, NT pro-BNP and other laboratory values were assessed. PH was confirmed in 34 patients (precapillary PH, n = 15, postcapillary PH, n = 19). TTE showed significant differences in E/e' ratio (precapillary PH: 12.3 ± 4.4, postcapillary PH: 17.3 ± 10.3, no PH: 12.1 ± 4.5, P = 0.02), LV volumes (ESV: 25.0 ± 15.0 mL, 49.9 ± 29.5 mL, 32.2 ± 13.6 mL, P = 0.027; EDV: 73.6 ± 24.0 mL, 110.6 ± 31.8 mL, 87.8 ± 33.0 mL, P = 0.021) and systolic pulmonary arterial pressure (sPAP: 61.2 ± 22.3 mmHg, 53.6 ± 20.1 mmHg, 31.2 ± 24.6 mmHg, P = 0.001). STRV analysis showed significant differences for apical RV longitudinal strain (RVAS: -7.5% ± 5.6%, -13.3% ± 4.3%, -14

  7. Assessment of Subclinical Doxorubicin-induced Cardiotoxicity in a Rat Model by Speckle-Tracking Imaging.

    Science.gov (United States)

    Kang, Yu; Wang, Wei; Zhao, Hang; Qiao, Zhiqing; Shen, Xuedong; He, Ben

    2017-07-10

    Despite their clear therapeutic benefits, anthracycline-induced cardiotoxicity is a major concern limiting the ability to reduce morbidity and mortality associated with cancers. The early identification of anthracycline-induced cardiotoxicity is of vital importance to assess the cardiac risk against the potential cancer treatment. To investigate whether speckle-tracking analysis can provide a sensitive and accurate measurement when detecting doxorubicin-induced left ventricular injury. Wistar rats were divided into 4 groups with 8 rats each, given doxorubicin intraperitoneally at weekly intervals for up to 4 weeks. Group 1: 2.5 mg/kg/week; group 2: 3 mg/kg/week; group 3: 3.5mg/kg/week; group 4: 4mg/kg/week. An additional 5 rats were used as controls. Echocardiographic images were obtained at baseline and 1 week after the last dose of treatment. Radial (Srad) and circumferential (Scirc) strains, radial (SRrad) and circumferential (SRcirc) strain rates were analyzed. After the experiment, cardiac troponin I (cTnI) was analyzed and the heart samples were histologically evaluated. After doxorubicin exposure, LVEF was significantly reduced in group 4 (p = 0.006), but remained stable in the other groups. However, after treatment, Srads were reduced in groups 2, 3 and 4 (p all grupos de 8 ratos cada, e doxorrubicina foi administrada intraperitonealmente em intervalos semanais de até 4 semanas. Grupo 1: 2,5 mg/kg/semana; Grupo 2: 3 mg/kg/semana; Grupo 3: 3,5 mg/kg/semana; Grupo 4: 4 mg/kg/semana. Foram utilizados 5 ratos adicionais como controles. As imagens ecocardiográficas foram obtidas na linha basal e 1 semana após a última dose do tratamento. Foram analisados o strain radial (Srad) e circunferencial (Scirc) e as taxas de strain radial (TSrad) e circunferencial (TScirc). Após o experimento, a troponina cardíaca I (cTnI) foi analisada e as amostras cardíacas foram avaliadas histologicamente. Após a exposição à doxorrubicina, a FEVE foi significativamente

  8. Super-resolution imaging applied to moving object tracking

    Science.gov (United States)

    Swalaganata, Galandaru; Ratna Sulistyaningrum, Dwi; Setiyono, Budi

    2017-10-01

    Moving object tracking in a video is a method used to detect and analyze changes that occur in an object that being observed. Visual quality and the precision of the tracked target are highly wished in modern tracking system. The fact that the tracked object does not always seem clear causes the tracking result less precise. The reasons are low quality video, system noise, small object, and other factors. In order to improve the precision of the tracked object especially for small object, we propose a two step solution that integrates a super-resolution technique into tracking approach. First step is super-resolution imaging applied into frame sequences. This step was done by cropping the frame in several frame or all of frame. Second step is tracking the result of super-resolution images. Super-resolution image is a technique to obtain high-resolution images from low-resolution images. In this research single frame super-resolution technique is proposed for tracking approach. Single frame super-resolution was a kind of super-resolution that it has the advantage of fast computation time. The method used for tracking is Camshift. The advantages of Camshift was simple calculation based on HSV color that use its histogram for some condition and color of the object varies. The computational complexity and large memory requirements required for the implementation of super-resolution and tracking were reduced and the precision of the tracked target was good. Experiment showed that integrate a super-resolution imaging into tracking technique can track the object precisely with various background, shape changes of the object, and in a good light conditions.

  9. Wall-motion tracking in fetal echocardiography-Influence of frame rate on longitudinal strain analysis assessed by two-dimensional speckle tracking.

    Science.gov (United States)

    Enzensberger, Christian; Achterberg, Friederike; Graupner, Oliver; Wolter, Aline; Herrmann, Johannes; Axt-Fliedner, Roland

    2017-06-01

    Frame rates (FR) used for strain analysis assessed by speckle tracking in fetal echocardiography show a considerable variation. The aim of this study was to investigate the influence of the FR on strain analysis in 2D speckle tracking. Fetal echocardiography was performed prospectively on a Toshiba Aplio 500 system and a Toshiba Artida system, respectively. Based on an apical or basal four-chamber view of the fetal heart, cine loops were stored with a FR of 30 fps (Aplio 500) and 60 fps (Artida/Aplio 500). For both groups (30fps and 60fps), global and segmental longitudinal peak systolic strain (LPSS) values of both, left (LV) and right ventricle (RV), were assessed by 2D wall-motion tracking. A total of 101 fetuses, distributed to three study groups, were included. The mean gestational age was 25.2±5.0 weeks. Mean global LPSS values for RV in the 30 fps group and in the 60 fps group were -16.07% and -16.47%, respectively. Mean global LPSS values for LV in the 30 fps group and in the 60 fps group were -17.54% and -17.06%, respectively. Comparing global and segmental LPSS values of both, the RV and LV, did not show any statistically significant differences within the two groups. Performance of myocardial 2D strain analysis by wall-motion tracking was feasible with 30 and 60 fps. Obtained global and segmental LPSS values of both ventricles were relatively independent from acquisition rate. © 2017, Wiley Periodicals, Inc.

  10. Measurement of left ventricular torsion using block-matching-based speckle tracking for two-dimensional echocardiography

    Science.gov (United States)

    Sun, Feng-Rong; Wang, Xiao-Jing; Wu, Qiang; Yao, Gui-Hua; Zhang, Yun

    2013-01-01

    Left ventricular (LV) torsion is a sensitive and global index of LV systolic and diastolic function, but how to noninvasively measure it is challenging. Two-dimensional echocardiography and the block-matching based speckle tracking method were used to measure LV torsion. Main advantages of the proposed method over the previous ones are summarized as follows: (1) The method is automatic, except for manually selecting some endocardium points on the end-diastolic frame in initialization step. (2) The diamond search strategy is applied, with a spatial smoothness constraint introduced into the sum of absolute differences matching criterion; and the reference frame during the search is determined adaptively. (3) The method is capable of removing abnormal measurement data automatically. The proposed method was validated against that using Doppler tissue imaging and some preliminary clinical experimental studies were presented to illustrate clinical values of the proposed method.

  11. Postsystolic Shortening by Speckle Tracking Echocardiography Is an Independent Predictor of Cardiovascular Events and Mortality in the General Population

    DEFF Research Database (Denmark)

    Brainin, Philip; Biering-Sørensen, Sofie Reumert; Møgelvang, Rasmus

    2018-01-01

    BACKGROUND: Postsystolic shortening (PSS) has been proposed as a novel marker of contractile dysfunction in the myocardium. Our objective was to assess the prognostic potential of PSS on cardiovascular events and death in the general population. METHODS AND RESULTS: The study design consisted...... of a prospective cohort study of 1296 low-risk participants from the general population, who were examined by speckle tracking echocardiography. The primary end point was the composite of heart failure, myocardial infarction, and cardiovascular death, defined as major adverse cardiovascular events (MACEs...... as having MACEs and 236 participants (18%) died. Increasing number of walls with PSS predicted both end points, an association that persisted after adjustment for age, sex, estimated glomerular filtration rate, global longitudinal strain, hypertension, heart rate, left ventricular ejection fraction, LV mass...

  12. [Assessment of left ventricular twist in type 2 diabetes mellitus by using two-dimensional ultrasound speckle tracking imaging].

    Science.gov (United States)

    Zhu, Pei-hua; Huang, Jing-yuan; Ye, Meng; Zheng, Zhe-lan

    2014-09-01

    To evaluate the left ventricular twist characteristics in patients with type 2 diabetes by using two-dimensional speckle tracking imaging (STI). Ninety-three patients with type 2 diabetes admitted in Zhejiang Hospital from May 2012 to September 2013 were enrolled. According to left ventricular ejection fraction (LVEF), patients were divided into two groups: normal left ventricular systolic function group (group A, LVEF≥0.50, n=46) and abnormal left ventricular systolic function group (group B, LVEF Consistency check for STI was conducted to assess its stability and reliability. The Peaktw, AVCtw, and MVOtw in group A were significantly elevated than those in normal controls (Pconsistency limit=-2.8-2.7; within measurer: R=0.964, bias=-0.2, 95% consistency limits=-2.7-2.2). STI can be used for early recognition of abnormal changes of cardiac function in type 2 diabetic mellitus patients, with high stability and reliability.

  13. Normal left ventricular mechanics by two-dimensional speckle-tracking echocardiography. Reference values in healthy adults.

    Science.gov (United States)

    Kocabay, Gonenc; Muraru, Denisa; Peluso, Diletta; Cucchini, Umberto; Mihaila, Sorina; Padayattil-Jose, Seena; Gentian, Denas; Iliceto, Sabino; Vinereanu, Dragos; Badano, Luigi P

    2014-08-01

    Two-dimensional speckle-tracking echocardiography is a novel tool to assess myocardial function. The purpose of this study was to evaluate left ventricular myocardial strain and rotation parameters by two-dimensional speckle-tracking echocardiography in a large group of healthy adults across a wide age range to establish their reference values and to assess the influence of age, sex, and hemodynamic factors. Transthoracic echocardiograms were acquired in 247 healthy volunteers (139 women, 44 years [standard deviation, 16 years old] (range, 18-80 years). We measured longitudinal, circumferential, and radial peak systolic strain values, and left ventricular rotation and twist. Average values of global longitudinal, radial, and circumferential strain were -21.5% (standard deviation, 2.0%), 40.1% (standard deviation, 11.8%) and -22.2% (standard deviation, 3.4%), respectively. Longitudinal strain was significantly more negative in women, whereas radial and circumferential strain and rotational parameters were similar in both sexes. Accordingly, lower limits of normality for the strain components were -16.9% in men and -18.5% in women for longitudinal strain, and -15.4% for circumferential and 24.6% for radial strain, irrespective of sex. Longitudinal strain values were more negative at the base than at apical segments. Mean rotational values were -6.9° (standard deviation, 3.5°) for the base, 13.0° (standard deviation, 6.5°) for apical rotation, and 20.0° (standard deviation, 7.3°) for net twist. We report the comprehensive assessment of normal myocardial deformation and rotational mechanics in a large cohort of healthy volunteers. We found that women have more negative longitudinal strain, accounting for their higher left ventricular ejection fraction. Availability of reference values for these parameters may foster their implementation in the clinical routine. Copyright © 2013 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

  14. Optimal Analysis of Left Atrial Strain by Speckle Tracking Echocardiography: P-wave versus R-wave Trigger.

    Science.gov (United States)

    Hayashi, Shuji; Yamada, Hirotsugu; Bando, Mika; Saijo, Yoshihito; Nishio, Susumu; Hirata, Yukina; Klein, Allan L; Sata, Masataka

    2015-08-01

    Left atrial (LA) strain analysis using speckle tracking echocardiography is useful for assessing LA function. However, there is no established procedure for this method. Most investigators have determined the electrocardiographic R-wave peak as the starting point for LA strain analysis. To test our hypothesis that P-wave onset should be used as the starting point, we measured LA strain using 2 different starting points and compared the strain values with the corresponding LA volume indices obtained by three-dimensional (3D) echocardiography. We enrolled 78 subjects (61 ± 17 years, 25 males) with and without various cardiac diseases in this study and assessed global longitudinal LA strain by two-dimensional speckle tracking strain echocardiography using EchoPac software. We used either R-wave peak or P-wave onset as the starting point for determining LA strains during the reservoir (Rres, Pres), conduit (Rcon, Pcon), and booster pump (Rpump, Ppump) phases. We determined the maximum, minimum, and preatrial contraction LA volumes, and calculated the LA total, passive, and active emptying fractions using 3D echocardiography. The correlation between Pres and LA total emptying fraction was better than the correlation between Rres and LA total emptying fraction (r = 0.458 vs. 0.308, P = 0.026). Pcon and Ppump exhibited better correlation with the corresponding 3D echocardiographic parameters than Rcon (r = 0.560 vs. 0.479, P = 0.133) and Rpump (r = 0.577 vs. 0.345, P = 0.003), respectively. LA strain in any phase should be analyzed using P-wave onset as the starting point rather than R-wave peak. © 2014, Wiley Periodicals, Inc.

  15. Archeological Echocardiography: Digitization and Speckle-Tracking Analysis of Archival Echocardiograms in the HyperGEN Study

    Science.gov (United States)

    Aguilar, Frank G.; Selvaraj, Senthil; Martinez, Eva E.; Katz, Daniel H.; Beussink, Lauren; Kim, Kwang-Youn A.; Ping, Jie; Rasmussen-Torvik, Laura; Goyal, Amita; Sha, Jin; Irvin, Marguerite R.; Arnett, Donna K.; Shah, Sanjiv J.

    2015-01-01

    Background Several large epidemiologic studies and clinical trials have included echocardiography, but images were stored in analog format and these studies predated tissue Doppler imaging (TDI) and speckle-tracking echocardiography (STE). We hypothesized that digitization of analog echocardiograms, with subsequent quantification of cardiac mechanics using STE, is feasible, reproducible, accurate, and produces clinically valid results. Methods In the NHLBI HyperGEN study (N=2234), archived analog echocardiograms were digitized and subsequently analyzed using STE to obtain tissue velocities/strain. Echocardiograms were assigned quality scores and inter/intraobserver agreement was calculated. Accuracy was evaluated in (1) a separate second study (N=50) comparing prospective digital strain vs. post-hoc analog-to-digital strain; and (2) in a third study (N=95) comparing prospectively-obtained TDI e′ velocities with post-hoc STE e′ velocities. Finally, we replicated previously known associations between tissue velocities/strain, conventional echocardiographic measurements, and clinical data. Results Of the 2234 HyperGEN echocardiograms, 2150 (96.2%) underwent successful digitization and STE analysis. Inter/intraobserver agreement was high for all STE parameters, especially longitudinal strain (LS). In accuracy studies, LS performed best when comparing post-hoc STE to prospective digital STE for strain analysis. STE-derived e′ velocities correlated with, but systematically underestimated, TDI e′ velocity. Several known associations between clinical variables and cardiac mechanics were replicated in HyperGEN. We also found a novel independent inverse association between fasting glucose and LS (adjusted β =−2.4 [95% CI −3.6,−1.2]% per 1-SD increase in fasting glucose; Pechocardiography, the digitization and speckle-tracking analysis of archival echocardiograms, is feasible and generates parameters of cardiac mechanics similar to contemporary studies. PMID

  16. Left Ventricular Function in Patients with Pulmonary Arterial Hypertension: The Role of Two-Dimensional Speckle Tracking Strain.

    Science.gov (United States)

    de Amorim Corrêa, Ricardo; de Oliveira, Fernanda Brito; Barbosa, Marcia M; Barbosa, Jose Augusto A; Carvalho, Taís Soares; Barreto, Michele Campos; Campos, Frederico Thadeu A F; Nunes, Maria Carmo Pereira

    2016-09-01

    Pulmonary arterial hypertension (PAH) is characterized by elevated mean pulmonary arterial pressure with abnormal right ventricular (RV) pressure overload that may alter left ventricular (LV) function. The aim of this study was to assess the impact of RV pressure overload on LV function in PAH patients using two-dimensional (2D) speckle tracking strain. The study enrolled 37 group 1 PAH patients and 38 age- and gender-matched healthy controls. LV longitudinal and radial 2D strains were measured with and without including the ventricular septum. Six-minute walk test (6MWT) and brain natriuretic peptide (BNP) levels were also obtained in patients with PAH. The mean age of patients was 46.4 ± 14.8 years, 76% women, and 16 patients (43%) had schistosomiasis. Sixteen patients (43%) were in WHO class III or IV under specific treatment for PAH. The overall 6MWT distance was 441 meters, and the BNP levels were 80 pg/mL. Patients with PAH more commonly presented with LV diastolic dysfunction and impairment of RV function when compared to controls. LV global longitudinal and radial strains were lower in patients than in controls (-17.9 ± 2.8 vs. -20.5 ± 1.9; P < 0.001 and 30.8 ± 10.5 vs. 49.8 ± 15.4; P < 0.001, respectively). After excluding septal values, LV longitudinal and radial strains remained lower in patients than in controls. The independent factors associated with global LV longitudinal strain were LV ejection fraction, RV fractional area change, and tricuspid annular systolic motion. This study showed impaired LV contractility in patients with PAH assessed by speckle tracking strain, irrespective of ventricular septal involvement. Global LV longitudinal strain was associated independently with RV fractional area change and tricuspid annular systolic motion, after adjustment for LV ejection fraction. © 2016, Wiley Periodicals, Inc.

  17. Assessment of atrial fibrillation and vulnerability in patients with Wolff-Parkinson-White syndrome using two-dimensional speckle tracking echocardiography.

    Science.gov (United States)

    Li, Jing-Jie; Wei, Fang; Chen, Ju-Gang; Yu, Yan-Wei; Gu, Hong-Yue; Jiang, Rui; Wu, Xiu-Li; Sun, Qian

    2014-01-01

    The aim was to assess atrial fibrillation (AF) and vulnerability in Wolff-Parkinson-White (WPW) syndrome patients using two-dimensional speckle tracking echocardiography (2D-STE). All patients were examined via transthoracic echocardiography and 2D-STE in order to assess atrial function 7 days before and 10 days after RF catheter ablation. A postoperative 3-month follow-up was performed via outpatient visit or telephone calls. Results showed significant differences in both body mass index (BMI) and supraventricular tachycardia (SVT) duration between WPW patients and DAVNP patients (both Psyndrome may result in increased atrial vulnerability and contribute to the development of AF. Further, RF catheter ablation of AAV pathway can potentially improve atrial function in WPW syndrome patients. Two-dimensional speckle tracking echocardiography imaging in WPW patients would be necessary in the evaluation and improvement of the overall function of RF catheter ablation in a long-term follow-up period.

  18. Speckle-Tracking Echocardiography in Dogs With Patent Ductus Arteriosus: Effect of Percutaneous Closure on Cardiac Mechanics.

    Science.gov (United States)

    Spalla, I; Locatelli, C; Zanaboni, A M; Brambilla, P; Bussadori, C

    2016-05-01

    Patent ductus arteriosus (PDA) is 1 of the most common congenital heart defects in dogs and percutaneous closure is effective in achieving ductal closure; PDA closure is associated with abrupt hemodynamic changes. A marked decrease in standard parameters of systolic function as assessed by M- or B-mode echocardiography after PDA closure was identified in previous studies. Speckle tracking echocardiography can provide further insight into the effect of PDA closure on cardiac mechanics in dogs affected by PDA. Twenty-five client-owned dogs with PDA. Prospective study. Dogs were recruited over a 2-year period. Complete echocardiographic evaluation was performed before and 24 hours after PDA closure, including standard (end-diastolic volumes indexed to body surface area in B- and M-mode [EDVIB /M ], end-systolic volumes indexed to body surface area in B- and M-mode [ESVIB /M ], allometric scaling in diastole [AlloD] and systole [AlloS], pulmonary flow to systemic flow [Qs/Qp], ejection fraction [EF], and fractional shortening [FS]), and advanced speckle-tracking echocardiography (STE): global longitudinal, radial, circumferential and transverse strain (S), and strain rate (SR). Patent ductus arteriosus closure was associated with statistically significant decreases in EDVIM /B and ESVIM /B , AlloD and AlloS, SI, EF, and FS. A statistically significant decrease in the absolute values of radial, transverse, and circumferential S and SR was observed, whereas longitudinal S and SR did not change significantly. Patent ductus arteriosus closure by percutaneous approach is associated with marked decreases of conventional echocardiographic parameters as a result of the changes in loading conditions, but no evidence of systolic dysfunction was identified by means of STE, as none of the S and SR values were below reference ranges. In the short term, contractility is enhanced in the long axis (long S/SR values were not statistically different before and after closure) and

  19. Type I Diabetic Akita Mouse Model is Characterized by Abnormal Cardiac Deformation During Early Stages of Diabetic Cardiomyopathy with Speckle-Tracking Based Strain Imaging.

    Science.gov (United States)

    Zhou, Yingchao; Xiao, Hong; Wu, Jianfei; Zha, Lingfeng; Zhou, Mengchen; Li, Qianqian; Wang, Mengru; Shi, Shumei; Li, Yanze; Lyu, Liangkun; Wang, Qing; Tu, Xin; Lu, Qiulun

    2018-01-01

    Diabetes mellitus (DM) has been demonstrated to have a strong association with heart failure. Conventional echocardiographic analysis cannot sensitively monitor cardiac dysfunction in type I diabetic Akita hearts, but the phenotype of heart failure is observed in molecular levels during the early stages. Male Akita (Ins2WT/C96Y) mice were monitored with echocardiographic imaging at various ages, and then with conventional echocardiographic analysis and speckle-tracking based strain analyses. With speckle-tracking based strain analyses, diabetic Akita mice showed changes in average global radial strain at the age of 12 weeks, as well as decreased longitudinal strain. These changes occurred in the early stage and remained throughout the progression of diabetic cardiomyopathy in Akita mice. Speckle-tracking showed that the detailed and precise changes of cardiac deformation in the progression of diabetic cardiomyopathy in the genetic type I diabetic Akita mice were uncoupled. We monitored early-stage changes in the heart of diabetic Akita mice. We utilize this technique to elucidate the underlying mechanism for heart failure in Akita genetic type I diabetic mice. It will further advance the assessment of cardiac abnormalities, as well as the discovery of new drug treatments using Akita genetic type I diabetic mice. © 2018 The Author(s). Published by S. Karger AG, Basel.

  20. Global Longitudinal Strain Using Speckle-Tracking Echocardiography as a Mortality Predictor in Sepsis: A Systematic Review.

    Science.gov (United States)

    Vallabhajosyula, Saraschandra; Rayes, Hamza A; Sakhuja, Ankit; Murad, Mohammad Hassan; Geske, Jeffrey B; Jentzer, Jacob C

    2018-01-01

    The data on speckle-tracking echocardiography (STE) in patients with sepsis are limited. This systematic review from 1975 to 2016 included studies in adults and children evaluating cardiovascular dysfunction in sepsis, severe sepsis, and septic shock utilizing STE for systolic global longitudinal strain (GLS). The primary outcome was short- or long-term mortality. Given the significant methodological and statistical differences between published studies, combining the data using meta-analysis methods was not appropriate. A total of 120 studies were identified, with 5 studies (561 patients) included in the final analysis. All studies were prospective observational studies using the 2001 criteria for defining sepsis. Three studies demonstrated worse systolic GLS to be associated with higher mortality, whereas 2 did not show a statistically significant association. Various cutoffs between -10% and -17% were used to define abnormal GLS across studies. This systematic review revealed that STE may predict mortality in patients with sepsis; however, the strength of evidence is low due to heterogeneity in study populations, GLS technologies, cutoffs, and timing of STE. Further dedicated studies are needed to understand the optimal application of STE in patients with sepsis.

  1. Improvement of continuous subcutaneous insulin infusion on patients with type 2 diabetes mellitus by 3-dimensional speckle tracking echocardiography.

    Science.gov (United States)

    Luo, Hong-Xia; Zhou, Xiao-Ling; Kou, Hong-Ju; Ni, Xian-Wei; Wu, Qing; Zou, Chun-Peng; Wu, Dao-Zhu; Liu, Yong-Fang

    2018-03-01

    Three-dimensional speckle tracking echocardiography (3D-STE) was used to evaluate the improvement of continuous subcutaneous insulin infusion on the left ventricular (LV) systolic function of patients with type 2 diabetes mellitu (T2DM). We recruited T2DM patients (38 cases, diabetic group) and healthy volunteers (35 cases, control group) to collect LV full volume imaging. TomTec software was used for calculating LV global longitudinal strain (LVGLS), global circumferential strain (LVGCS), peak twist (LVTW), peak apical rotation (LVPAR), ejection fraction (LVEF), and torsion (LVT). All indices were re-tested 2 weeks later after intensive treatment of insulin pump. LVGLS, LVGCS, LVTW and LVPAR in diabetic group were significantly decreased than control group. LVGLS and LVGCS in pre-treatment diabetic group were significantly increased than post-treatment. LVGLS, LVGCS, LVTW and LVPAR had correlations among control, pre-treatment and post-treatment diabetic groups. There were no significant differences in LVEDV, LVESV, LVEF, LVT and R-R. LV systolic function of patients with T2DM complicated with microangiopathy was improved after treatment of continuous subcutaneous insulin infusion. In addition, therapeutic effect could be accurately evaluated by 3D-STE which had vital clinical application.

  2. Influence of Positive End-Expiratory Pressure on Myocardial Strain Assessed by Speckle Tracking Echocardiography in Mechanically Ventilated Patients

    Directory of Open Access Journals (Sweden)

    Federico Franchi

    2013-01-01

    Full Text Available Purpose. The effects of mechanical ventilation (MV on speckle tracking echocardiography- (STE-derived variables are not elucidated. The aim of the study was to evaluate the effects of positive end-expiratory pressure (PEEP ventilation on 4-chamber longitudinal strain (LS analysis by STE. Methods. We studied 20 patients admitted to a mixed intensive care unit who required intubation for MV and PEEP titration due to hypoxia. STE was performed at three times: (T1 PEEP = 5 cmH2O; (T2 PEEP = 10 cmH2O; and (T3 PEEP = 15 cmH2O. STE analysis was performed offline using a dedicated software (XStrain MyLab 70 Xvision, Esaote. Results. Left peak atrial-longitudinal strain (LS was significantly reduced from T1 to T2 and from T2 to T3 (. Right peak atrial-LS and right ventricular-LS showed a significant reduction only at T3 (. Left ventricular-LS did not change significantly during titration of PEEP. Cardiac chambers’ volumes showed a significant reduction at higher levels of PEEP (. Conclusions. We demonstrated for the first time that incremental PEEP affects myocardial strain values obtained with STE in intubated critically ill patients. Whenever performing STE in mechanically ventilated patients, care must be taken when PEEP is higher than 10 cmH2O to avoid misinterpreting data and making erroneous decisions.

  3. The importance of speckle tracking echocardiography in the early detection of left ventricular dysfunction in patients with polycystic ovary syndrome.

    Science.gov (United States)

    Demirelli, Selami; Degirmenci, Husnu; Ermis, Emrah; Inci, Sinan; Nar, Gokay; Ayhan, Mehmet Emin; Fırtına, Serdar; Hamur, Hikmet; Durmaz, Senay Arikan

    2015-10-19

    Polycystic ovary syndrome (PCOS) is characterized by hormonal and metabolic abnormalities and is thought to increase a risk for cardiovascular diseases. In this study we use speckle tracking echocardiography (STE) to evaluate left ventricular (LV) dysfunction in the early period of the disease. We enrolled 31 patients with PCOS and 32 healthy volunteers as a control group. The participants' ages ranged between 18 and 40 years. PCOS was diagnosed according to the Rotterdam criteria. LV strain (LS) and strain rate (SR) were evaluated using apical two-chamber (2C), three-chamber (3C), and four-chamber (4C) imaging. Global LS and SR were calculated as average of three apical views. The waist-to-hip ratio, homeostasis model assessment-insulin resistance (HOMA-IR), and fasting insulin and triglyceride levels were higher in the PCOS group than in the controls (p=0.001, p=0.001, p=0.001, and p=0.005, respectively). In the PCOS group, the mitral A wave, deceleration time (DT), and isovolumetric relaxation time (IVRT) were significantly higher than in the controls (all pPCOS patient group (both p= 0.001). There were strong negative correlations between GLS and both fasting insulin (r=-0.64) and DT (r=-0.62) (both pPCOS patients had decreased LV function using STE. Therefore, STE imaging appears to be useful for the early detection of subclinical LV dysfunction in patients with PCOS.

  4. Assessment of left ventricular regional function in affected and carrier dogs with duchenne muscular dystrophy using speckle tracking echocardiography

    Directory of Open Access Journals (Sweden)

    Yugeta Naoko

    2011-05-01

    Full Text Available Abstract Background Two-dimensional speckle tracking echocardiography (STE is a relatively new method to detect regional myocardial dysfunction. To assess left ventricular (LV regional myocardial dysfunction using STE in Duchenne muscular dystrophy model dogs (CXMDJ without overt clinical signs of heart failure. Methods Six affected dogs, 8 carrier dogs with CXMDJ, and 8 control dogs were used. Conventional echocardiography, systolic and diastolic function by Doppler echocardiography, tissue Doppler imaging (TDI, and strain indices using STE, were assessed and compared among the 3 groups. Results Significant differences were seen in body weight, transmitral E wave and E' wave derived from TDI among the 3 groups. Although no significant difference was observed in any global strain indices, in segmental analysis, the peak radial strain rate during early diastole in posterior segment at chordae the tendineae level showed significant differences among the 3 groups. Conclusions The myocardial strain rate by STE served to detect the impaired cardiac diastolic function in CXMDJ without any obvious LV dilation or clinical signs. The radial strain rate may be a useful parameter to detect early myocardial impairment in CXMDJ.

  5. SU-D-210-05: The Accuracy of Raw and B-Mode Image Data for Ultrasound Speckle Tracking in Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    O’Shea, T; Bamber, J; Harris, E [The Institute of Cancer Research & Royal Marsden, Sutton and London (United Kingdom)

    2015-06-15

    Purpose: For ultrasound speckle tracking there is some evidence that the envelope-detected signal (the main step in B-mode image formation) may be more accurate than raw ultrasound data for tracking larger inter-frame tissue motion. This study investigates the accuracy of raw radio-frequency (RF) versus non-logarithmic compressed envelope-detected (B-mode) data for ultrasound speckle tracking in the context of image-guided radiation therapy. Methods: Transperineal ultrasound RF data was acquired (with a 7.5 MHz linear transducer operating at a 12 Hz frame rate) from a speckle phantom moving with realistic intra-fraction prostate motion derived from a commercial tracking system. A normalised cross-correlation template matching algorithm was used to track speckle motion at the focus using (i) the RF signal and (ii) the B-mode signal. A range of imaging rates (0.5 to 12 Hz) were simulated by decimating the imaging sequences, therefore simulating larger to smaller inter-frame displacements. Motion estimation accuracy was quantified by comparison with known phantom motion. Results: The differences between RF and B-mode motion estimation accuracy (2D mean and 95% errors relative to ground truth displacements) were less than 0.01 mm for stable and persistent motion types and 0.2 mm for transient motion for imaging rates of 0.5 to 12 Hz. The mean correlation for all motion types and imaging rates was 0.851 and 0.845 for RF and B-mode data, respectively. Data type is expected to have most impact on axial (Superior-Inferior) motion estimation. Axial differences were <0.004 mm for stable and persistent motion and <0.3 mm for transient motion (axial mean errors were lowest for B-mode in all cases). Conclusions: Using the RF or B-mode signal for speckle motion estimation is comparable for translational prostate motion. B-mode image formation may involve other signal-processing steps which also influence motion estimation accuracy. A similar study for respiratory-induced motion

  6. Track resolution in the RPC chamber

    International Nuclear Information System (INIS)

    Cardarelli, R.; Aielli, G.; Camarri, P.; Di Ciaccio, A.; Liberti, B.; Santonico, R.

    2007-01-01

    A new very promising read out, in addition to the well-known charge centroid method, is proposed for improving the space resolution in the Resistive Plate Chamber (RPC) in the sub-millimeter range. The method is based on the read out of the signal propagating in the graphite electrode which was simulated using a distributed resistance-capacitance model in SPICE. The results show that a good space-time correlation in the diffusion process is only possible by suitable signal processing. Three RPC detectors with the new layout and dedicated electronics were tested. The measured space resolution was in the order of a few 100μm

  7. Quantification of global myocardial function by cine MRI deformable registration-based analysis: Comparison with MR feature tracking and speckle-tracking echocardiography

    International Nuclear Information System (INIS)

    Lamacie, Mariana M.; Thavendiranathan, Paaladinesh; Hanneman, Kate; Greiser, Andreas; Jolly, Marie-Pierre; Ward, Richard; Wintersperger, Bernd J.

    2017-01-01

    To evaluate deformable registration algorithms (DRA)-based quantification of cine steady-state free-precession (SSFP) for myocardial strain assessment in comparison with feature-tracking (FT) and speckle-tracking echocardiography (STE). Data sets of 28 patients/10 volunteers, undergoing same-day 1.5T cardiac MRI and echocardiography were included. LV global longitudinal (GLS), circumferential (GCS) and radial (GRS) peak systolic strain were assessed on cine SSFP data using commercially available FT algorithms and prototype DRA-based algorithms. STE was applied as standard of reference for accuracy, precision and intra-/interobserver reproducibility testing. DRA showed narrower limits of agreement compared to STE for GLS (-4.0 [-0.9,-7.9]) and GCS (-5.1 [1.1,-11.2]) than FT (3.2 [11.2,-4.9]; 3.8 [13.9,-6.3], respectively). While both DRA and FT demonstrated significant differences to STE for GLS and GCS (all p<0.001), only DRA correlated significantly to STE for GLS (r=0.47; p=0.006). However, good correlation was demonstrated between MR techniques (GLS:r=0.74; GCS:r=0.80; GRS:r=0.45, all p<0.05). Comparing DRA with FT, intra-/interobserver coefficient of variance was lower (1.6 %/3.2 % vs. 6.4 %/5.7 %) and intraclass-correlation coefficient was higher. DRA GCS and GRS data presented zero variability for repeated observations. DRA is an automated method that allows myocardial deformation assessment with superior reproducibility compared to FT. (orig.)

  8. Quantification of global myocardial function by cine MRI deformable registration-based analysis: Comparison with MR feature tracking and speckle-tracking echocardiography

    Energy Technology Data Exchange (ETDEWEB)

    Lamacie, Mariana M. [University Health Network, Department of Medical Imaging, Toronto, Ontario (Canada); Thavendiranathan, Paaladinesh [University Health Network, Department of Medical Imaging, Toronto, Ontario (Canada); University of Toronto, Department of Medicine, Division of Cardiology, Toronto, Ontario (Canada); Hanneman, Kate [University Health Network, Department of Medical Imaging, Toronto, Ontario (Canada); University of Toronto, Department of Medical Imaging, Toronto, Ontario (Canada); Greiser, Andreas [Siemens Healthcare, Erlangen (Germany); Jolly, Marie-Pierre [Medical Imaging Technologies, Siemens Healthcare, Princeton, NJ (United States); Ward, Richard [University of Toronto, Department of Medicine, Division of Cardiology, Toronto, Ontario (Canada); Wintersperger, Bernd J. [University Health Network, Department of Medical Imaging, Toronto, Ontario (Canada); University of Toronto, Department of Medical Imaging, Toronto, Ontario (Canada); Toronto General Hospital, Department of Medical Imaging, Toronto, Ontario (Canada)

    2017-04-15

    To evaluate deformable registration algorithms (DRA)-based quantification of cine steady-state free-precession (SSFP) for myocardial strain assessment in comparison with feature-tracking (FT) and speckle-tracking echocardiography (STE). Data sets of 28 patients/10 volunteers, undergoing same-day 1.5T cardiac MRI and echocardiography were included. LV global longitudinal (GLS), circumferential (GCS) and radial (GRS) peak systolic strain were assessed on cine SSFP data using commercially available FT algorithms and prototype DRA-based algorithms. STE was applied as standard of reference for accuracy, precision and intra-/interobserver reproducibility testing. DRA showed narrower limits of agreement compared to STE for GLS (-4.0 [-0.9,-7.9]) and GCS (-5.1 [1.1,-11.2]) than FT (3.2 [11.2,-4.9]; 3.8 [13.9,-6.3], respectively). While both DRA and FT demonstrated significant differences to STE for GLS and GCS (all p<0.001), only DRA correlated significantly to STE for GLS (r=0.47; p=0.006). However, good correlation was demonstrated between MR techniques (GLS:r=0.74; GCS:r=0.80; GRS:r=0.45, all p<0.05). Comparing DRA with FT, intra-/interobserver coefficient of variance was lower (1.6 %/3.2 % vs. 6.4 %/5.7 %) and intraclass-correlation coefficient was higher. DRA GCS and GRS data presented zero variability for repeated observations. DRA is an automated method that allows myocardial deformation assessment with superior reproducibility compared to FT. (orig.)

  9. Noninvasive Localization of Accessory Pathways in Wolff-Parkinson-White Syndrome by Three-Dimensional Speckle Tracking Echocardiography.

    Science.gov (United States)

    Ishizu, Tomoko; Seo, Yoshihiro; Igarashi, Miyako; Sekiguchi, Yukio; Machino-Ohtsuka, Tomoko; Ogawa, Kojiro; Kuroki, Kenji; Yamamoto, Masahiro; Nogami, Akihiko; Kawakami, Yasushi; Aonuma, Kazutaka

    2016-06-01

    We have developed a noninvasive isochrone activation imaging (AI) system with 3-dimensional (3D) speckle tracking echocardiography (STE), which allows visualization of the wavefront image of mechanical propagation of the accessory pathway (ACP) in Wolff-Parkinson-White syndrome. Patients with manifest Wolff-Parkinson-White syndrome were imaged in 3D-STE AI mode, which quantified the time from QRS onset to regional endocardial deformation. In 2 patients with left- and right-side ACP, we confirmed that intraoperative contact endocardial electric mapping and the 3D-STE AI system showed comparable images pre- and postablation. In normal heart assessment by 3D-echo AI, the earliest activation sites were found at the attachment of the papillary muscles in the left ventricle and midseptum in the right ventricle, and none showed earliest activation at the peri-atrioventricular valve annuli. An analyzer who was unaware of the clinical information assessed 39 ACP locations in 38 Wolff-Parkinson-White syndrome patients using 3D-STE. All showed abnormal perimitral or tricuspid annular activations, and the location of 34 ACP (87%) showed agreement with the successful ablation sites within a 2-o'clock range. Especially for left free wall ACP, 17/18 (94%) showed consistency with the ablation site within a 2 o'clock range. Among 15 ACP at the ventricular septum, 9 (60%) showed early local activation in both right and left sides of the septum. Isochrone AI with 3D-STE may be a promising noninvasive imaging tool to assess cardiac synchronized activation in normal hearts and detect abnormal breakthrough of mechanical activation from both atrioventricular annuli in Wolff-Parkinson-White syndrome. © 2016 American Heart Association, Inc.

  10. Left Ventricular Myocardial Deformation Parameters Are Affected by Coronary Slow Flow Phenomenon: A Study of Speckle Tracking Echocardiography.

    Science.gov (United States)

    Gulel, Okan; Akcay, Murat; Soylu, Korhan; Aksan, Gokhan; Yuksel, Serkan; Zengin, Halit; Meric, Murat; Sahin, Mahmut

    2016-05-01

    The coronary slow flow phenomenon (CSFP) is defined as a delayed distal vessel contrast opacification in the absence of obstructive epicardial coronary artery disease during coronary angiography. There is conflicting data in medical literature regarding the effects of CSFP on the left ventricular functions assessed by conventional echocardiography or tissue Doppler imaging. Therefore, we aimed to evaluate whether there is any abnormality in the myocardial deformation parameters (strain, strain rate (SR), rotation, twist) of the left ventricle obtained by speckle tracking echocardiography (STE) in patients with CSFP. Twenty patients with CSFP were included prospectively in the study. Another 20 patients with similar demographics and cardiovascular risk factors as well as normal coronary angiography were used as the control group. Two-dimensional echocardiographic images of the left ventricle from the apical long-axis, two-chamber, four-chamber, and parasternal short-axis views were used for STE analysis. The analysis of left ventricular circumferential deformation parameters showed that the averaged peak systolic strain, systolic SR, and early diastolic SR values were significantly lower in patients with CSFP (P = 0.009, P = 0.02, and P = 0.02, respectively). Among the left ventricular rotation and twist values, apical rotation was significantly lower in patients with CSFP (P = 0.02). Further, the mean thrombolysis in myocardial infarction frame count value was found to be negatively correlated with the averaged peak circumferential early diastolic SR (r = -0.35, P = 0.03). It was positively correlated with the averaged peak circumferential systolic strain (r = 0.47, P = 0.003) and circumferential systolic SR (r = 0.46, P = 0.005). Coronary slow flow phenomenon leads to significant alterations in the myocardial deformation parameters of the left ventricle as assessed by STE. Specifically, circumferential deformation parameters are affected in CSFP patients. © 2015

  11. Mechanical dispersion and global longitudinal strain by speckle tracking echocardiography: Predictors of appropriate implantable cardioverter defibrillator therapy in hypertrophic cardiomyopathy.

    Science.gov (United States)

    Candan, Ozkan; Gecmen, Cetin; Bayam, Emrah; Guner, Ahmet; Celik, Mehmet; Doğan, Cem

    2017-06-01

    In this study, we investigated whether mechanical dispersion which reflects electrical abnormality and other echocardiographic and clinic parameters predict appropriate ICD shock in patients undergone ICD implantation for hypertrophic cardiomyopathy. Sixty-three patients who received ICD implantation for primary or secondary prevention were included in the study. Patients' clinical, electrocardiographic, 2D classic, and speckle tracking echocardiographic data were collected. Mechanical dispersion was defined as the standard deviation of time to peak negative strain in 18 left ventricular segments. Appropriate ICD therapy was defined as cardioversion or defibrillation due to ventricular tachycardia or fibrillation. Patients were divided into two groups as occurrence or the absence of appropriate ICD therapy. A total of 17 (26.9%) patients were observed to have an appropriate ICD therapy during follow-up periods. In patients who performed appropriate ICD therapy, a larger left atrial volume index, higher sudden cardiac death (SCD)-Risk Score, longer mechanical dispersion, and decreased global longitudinal peak strain (GLPS) were observed. In multivariate logistic regression analysis, including (GLPS, mechanical dispersion, LAVi, and SCD-Risk Score) was used to determine independent predictors of occurrence of appropriate ICD therapy during the follow-up. Mechanical dispersion, GLPS, and SCD-Risk Score were found to be independent predictors of occurrence of appropriate ICD therapy. Mechanical dispersion, GLPS, and SCD-Risk Score were found to be predictive for appropriate ICD therapy in patients receiving ICD implantation. Readily measurable mechanical dispersion and GLPS could be helpful to distinguish patients at high risk who could optimally benefit from ICD therapy. © 2017, Wiley Periodicals, Inc.

  12. Gestational changes in left ventricular myocardial contractile function: new insights from two-dimensional speckle tracking echocardiography.

    Science.gov (United States)

    Sengupta, Shantanu P; Bansal, Manish; Hofstra, Leonard; Sengupta, Partho P; Narula, Jagat

    2017-01-01

    The goal of this study was to evaluate the impact of pregnancy and labor on left ventricular (LV) myocardial mechanics using speckle tracking echocardiography (STE). Pregnancy is characterized by profound hormonal and hemodynamic alterations that directly or indirectly influence cardiac structure and function. However, the impact of these changes on left ventricular (LV) myocardial contractile function has not been fully elucidated. In this prospective, longitudinal study, 35 pregnant women underwent serial clinical and echocardiographic evaluation during each trimester and at labor. Two dimensional STE was performed to measure global LV longitudinal, circumferential and radial strain (GLS, GCS and GRS, respectively). Similar data obtained from 20 nulliparous, age-matched women were used as control. All strain values during pregnancy were adjusted for age and hemodynamic parameters. There was a progressive increase in heart rate, systolic and diastolic blood pressure, cardiac output and LV stroke-work during pregnancy. LV end-diastolic and end-systolic volumes also increased progressively but LV ejection fraction remained unaltered, except for slight reduction during the second trimester. Compared to the controls, GLS and GCS were reduced in the first trimester itself (GLS -22.39 ± 5.43 % vs. -18.66 ± 0.64 %, P 0.0002; GCS -20.84 ± 3.20 vs. -17.88 ± 0.09, P counterbalancing changes in the myocardial mechanics. LV longitudinal and circumferential strain are reduced whereas radial strain is increased. These counterbalancing changes serve to maintain overall LV ejection performance within a normal range and enable the maternal heart to meet the hemodynamic demands of pregnancy and labor.

  13. Overweight causes left ventricular diastolic asynchrony and diastolic dysfunction: a study based on speckle tracking echocardiography in healthy subjects.

    Science.gov (United States)

    Nakabachi, Masahiro; Mikami, Taisei; Okada, Kazunori; Onozuka, Hisao; Kaga, Sanae; Inoue, Mamiko; Yokoyama, Shinobu; Nishida, Mutsumi; Shimizu, Chikara; Matsuno, Kazuhiko; Iwano, Hiroyuki; Yamada, Satoshi; Tsutsui, Hiroyuki

    2012-09-01

    Left ventricular (LV) diastolic dysfunction is often observed in healthy subjects and can be a cause of heart failure with preserved ejection fraction (EF). We aimed to investigate the role of LV diastolic asynchrony as a cause of diastolic dysfunction in healthy subjects. In 40 healthy subjects, two-dimensional speckle tracking imaging (2DSTI) was performed to measure the peak early diastolic longitudinal strain rates (Esr) of the apical, mid-ventricular, and basal segments of the septum and posterior wall. A mean value of the Esr of the 6 segments (mEsr) was calculated. The time from aortic valve closure to the Esr was measured for each segment, and the standard deviation (SDTEsr) was calculated. The peak global early diastolic strain rate (gEsr) was measured with a region of interest (ROI) on the whole LV myocardium. LV flow propagation velocity (FPV) was measured using conventional Doppler techniques. SDTEsr was not correlated with age, but was significantly correlated with body mass index (BMI) (r = 0.41, p < 0.01). Although no significant correlation was observed between mEsr and FPV, gEsr and SDTEsr significantly correlated with FPV (r = 0.41, p < 0.01; r = -0.54, p < 0.001). As a result of the multiple regression analysis, SDTEsr was the single determinant of FPV. Diastolic asynchrony, associated with overweight but not with aging, may contribute to diastolic dysfunction in healthy subjects.

  14. Does global longitudinal speckle-tracking strain predict left ventricular remodeling in patients with myocardial infarction? a systematic review

    Directory of Open Access Journals (Sweden)

    Afsoon Fazlinejad

    2016-07-01

    Full Text Available Introduction: Left ventricular remodeling is a relatively prevalent complication of acute myocardial infarction (AMI, and it is associated with higher rates of medical issues and mortality. Left ventricle ejection fraction (LVEF and wall motion score index (WMSI are unable to detect accurately minor lesions following AMI. Global longitudinal strain (GLS, which is obtained through 2D-speckle tracking echocardiography (2D-STE, provides an angle-dependent measurement by which the infarcted area can be assessed as a means of identifying potential dysfunction. The main objective of this study was to evaluate whether GLS could adequately predict LV remodeling in AMI patients. Methods: The MEDLINE database from database inception to May 6th, 2015, was searched for relevant keywords and the reference lists of systematic reviews and eligible studies were also screened. All studies involving patients with their first reported case of AMI were examined for GLS by 2D-STE and were evaluated for LV remodeling at a three-month follow-up point.  Four English-language prospective cohort studies were eligible for inclusion in this study.Result: A total of 291 AMI patients (mean age=57.92 years were investigated across four different studies. The main finding of this study was that the most reliable and consistent measurement for the purposes of predicting LV remodeling in AMI patients is GLS obtained at the time of discharge, especially in STEMI patients.Discussion: In addition to their poor reproducibility, inability to stratify risks, and inter-observer variability, compensatory hyperkinesis of intact myocytes and myocardial stunning after an AMI are among the main reasons why LVEF and WMSI may not be the most effective predictors of LV remodeling in AMI.Conclusion: GLS obtained by 2D-STE at the time of discharge could be used as a reliable predictor of LV remodeling in AMI patients.

  15. 2D speckle tracking echocardiography of the right ventricle free wall in SCUBA divers after single open sea dive.

    Science.gov (United States)

    Susilovic-Grabovac, Zora; Obad, Ante; Duplančić, Darko; Banić, Ivana; Brusoni, Denise; Agostoni, Piergiuseppe; Vuković, Ivica; Dujic, Zeljko; Bakovic, Darija

    2018-03-01

    The presence of circulating gas bubbles and their influence on pulmonary and right heart hemodynamics was reported after uncomplicated self-contained underwater breathing apparatus (SCUBA) dive(s). Improvements in cardiac imaging have recently focused great attention on the right ventricle (RV). The aim of our study was to evaluate possible effects of a single air SCUBA dive on RV function using 2D speckle tracking echocardiography in healthy divers after single open sea dive to 18 meters of seawater, followed by bottom stay of 47 minutes with a direct ascent to the surface. Twelve experienced male divers (age 39.5 ± 10.5 years) participated in the study. Echocardiographic assessment of the right ventricular function (free wall 2 D strain, tricuspid annular planes systolic excursion [TAPSE], lateral tricuspid annular peak systolic velocity [RV s`] and fractional area change [FAC]) was performed directly prior to and 30, 60, 90 and 120 minutes after surfacing. Two-dimensional strain of all three segments of free right ventricular wall showed a significant increase in longitudinal shortening in post-dive period for maximally 26% (basal), 15.4% (mid) and 16.3% (apical) as well as TAPSE (11.6%), RV FAC (19.2%), RV S` (12.7%) suggesting a rise in systolic function of right heart. Mean pulmonary arterial pressure (mean PAP) increased post-dive from 13.3 mmHg to maximally 23.5 mmHg (P = .002), indicating increased RV afterload. Our results demonstrated that single dive with significant bubble load lead to increase in systolic function and longitudinal strain of the right heart in parallel with increase in mean PAP. © 2017 John Wiley & Sons Australia, Ltd.

  16. The importance of speckle tracking echocardiography in the early detection of left ventricular dysfunction in patients with polycystic ovary syndrome

    Directory of Open Access Journals (Sweden)

    Selami Demirelli

    2015-10-01

    Full Text Available Polycystic ovary syndrome (PCOS is characterized by hormonal and metabolic abnormalities and is thought to increase a risk for cardiovascular diseases. In this study we use speckle tracking echocardiography (STE to evaluate left ventricular (LV dysfunction in the early period of the disease. We enrolled 31 patients with PCOS and 32 healthy volunteers as a control group. The participants’ ages ranged between 18 and 40 years. PCOS was diagnosed according to the Rotterdam criteria. LV strain (LS and strain rate (SR were evaluated using apical two-chamber (2C, three-chamber (3C, and four-chamber (4C imaging. Global LS and SR were calculated as average of three apical views. The waist-to-hip ratio, homeostasis model assessment-insulin resistance (HOMA-IR, and fasting insulin and triglyceride levels were higher in the PCOS group than in the controls (p = 0.001, p = 0.001, p = 0.001, and p = 0.005, respectively. In the PCOS group, the mitral A wave, deceleration time (DT, and isovolumetric relaxation time (IVRT were significantly higher than in the controls (all p< 0.05. The LV global longitudinal strain (GLS and global longitudinal SR systolic (GLSRS were significantly lower in the PCOS patient group (both p = 0.001. There were strong negative correlations between GLS and both fasting insulin (r = −0.64 and DT (r = –0.62 (both p < 0.05. The study demonstrated that PCOS patients had decreased LV function using STE. Therefore, STE imaging appears to be useful for the early detection of subclinical LV dysfunction in patients with PCOS.

  17. Speckle Interferometry

    Science.gov (United States)

    Chiang, F. P.; Jin, F.; Wang, Q.; Zhu, N.

    Before the milestone work of Leedertz in 1970 coherent speckles generated from a laser illuminated object are considered noise to be eliminated or minimized. Leedertz shows that coherent speckles are actually information carriers. Since then the speckle technique has found many applications to fields of mechanics, metrology, nondestructive evaluation and material sciences. Speckles need not be coherent. Artificially created socalled white light speckles can also be used as information carriers. In this paper we present two recent developments of speckle technique with applications to micromechanics problems using SIEM (Speckle Interferometry with Electron Microscopy), to nondestructive evaluation of crevice corrosion and composite disbond and vibration of large structures using TADS (Time-Average Digital Specklegraphy).

  18. Track fitting and resolution with digital detectors

    International Nuclear Information System (INIS)

    Duerdoth, I.

    1982-01-01

    The analysis of data from detectors which give digitised measurements, such as MWPCs, is considered. These measurements are necessarily correlated and it is shown that the uncertainty in the combination of N measurements may fall faster than the canonical 1/√N. A new method of track fitting is described which exploits the digital aspects and which takes the correlations into account. It divides the parameter space into cells and the centroid of a cell is taken as the best estimate. The method is shown to have some advantages over the standard least-squares analysis. If the least-squares method is used for digital detectors the goodness-of-fit may not be a reliable estimate of the accuracy. The cell method is particularly suitable for implementation on microcomputers which lack floating point and divide facilities. (orig.)

  19. Usefulness of right ventricular and right atrial two-dimensional speckle tracking strain to predict late arrhythmic events in adult patients with repaired Tetralogy of Fallot.

    Science.gov (United States)

    Timóteo, Ana T; Branco, Luísa M; Rosa, Sílvia A; Ramos, Ruben; Agapito, Ana F; Sousa, Lídia; Galrinho, Ana; Oliveira, José A; Oliveira, Mário M; Ferreira, Rui C

    2017-01-01

    To determine whether right ventricular and/or atrial speckle tracking strain is associated with previous arrhythmic events in patients with repaired tetralogy of Fallot. We studied right ventricular and atrial strain in 100 consecutive patients with repaired tetralogy of Fallot referred for routine echocardiographic evaluation. Patients were divided into two groups, one with previous documentation of arrhythmias (n=26) and one without arrhythmias, in a median follow-up of 22 years. Patients with arrhythmias were older (pFallot, although a prospective study is required. Copyright © 2016 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.

  20. Quantification of biventricular myocardial function using cardiac magnetic resonance feature tracking, endocardial border delineation and echocardiographic speckle tracking in patients with repaired tetralogy of fallot and healthy controls

    Science.gov (United States)

    2012-01-01

    Background Parameters of myocardial deformation have been suggested to be superior to conventional measures of ventricular function in patients with tetralogy of Fallot (ToF), but have required non-routine, tagged cardiovascular magnetic resonance (CMR) techniques. We assessed biventricular myocardial function using CMR cine-based feature tracking (FT) and compared it to speckle tracking echocardiography (STE) and to simple endocardial border delineation (EBD). In addition, the relation between parameters of myocardial deformation and clinical parameters was assessed. Methods Overall, 28 consecutive adult patients with repaired ToF (age 40.4 ± 13.3 years) underwent standard steady-state-free precession sequence CMR, echocardiography, and cardiopulmonary exercise testing. In addition, 25 healthy subjects served as controls. Myocardial deformation was assessed by CMR based FT (TomTec Diogenes software), CMR based EBD (using custom written software) and STE (TomTec Cardiac Performance Analysis software). Results Feature tracking was feasible in all subjects. A close agreement was found between measures of global left (LV) and right ventricular (RV) global strain. Interobserver agreement for FT and STE was similar for longitudinal LV global strain, but FT showed better inter-observer reproducibility than STE for circumferential or radial LV and longitudinal RV global strain. Reproducibility of regional strain on FT was, however, poor. The relative systolic length change of the endocardial border measured by EBD yielded similar results to FT global strain. Clinically, biventricular longitudinal strain on FT was reduced compared to controls (P < 0.0001) and was related to the number of previous cardiac operations. In addition, FT derived RV strain was related to exercise capacity and VE/VCO2-slope. Conclusions Although neither the inter-study reproducibility nor accuracy of FT software were investigated, and its inter-observer reproducibility for regional

  1. Speckle imaging of globular clusters

    International Nuclear Information System (INIS)

    Sams, B.J. III

    1990-01-01

    Speckle imaging is a powerful tool for high resolution astronomy. Its application to the core regions of globular clusters produces high resolution stellar maps of the bright stars, but is unable to image the faint stars which are most reliable dynamical indicators. The limits on resolving these faint, extended objects are physical, not algorithmic, and cannot be overcome using speckle. High resolution maps may be useful for resolving multicomponent stellar systems in the cluster centers. 30 refs

  2. Direct comparison of cardiac magnetic resonance feature tracking and 2D/3D echocardiography speckle tracking for evaluation of global left ventricular strain.

    Science.gov (United States)

    Obokata, Masaru; Nagata, Yasufumi; Wu, Victor Chien-Chia; Kado, Yuichiro; Kurabayashi, Masahiko; Otsuji, Yutaka; Takeuchi, Masaaki

    2016-05-01

    Cardiac magnetic resonance (CMR) feature tracking (FT) with steady-state free precession (SSFP) has advantages over traditional myocardial tagging to analyse left ventricular (LV) strain. However, direct comparisons of CMRFT and 2D/3D echocardiography speckle tracking (2/3DEST) for measurement of LV strain are limited. The aim of this study was to investigate the feasibility and reliability of CMRFT and 2D/3DEST for measurement of global LV strain. We enrolled 106 patients who agreed to undergo both CMR and 2D/3DE on the same day. SSFP images at multiple short-axis and three apical views were acquired. 2DE images from three levels of short-axis, three apical views, and 3D full-volume datasets were also acquired. Strain data were expressed as absolute values. Feasibility was highest in CMRFT, followed by 2DEST and 3DEST. Analysis time was shortest in 3DEST, followed by CMRFT and 2DEST. There was good global longitudinal strain (GLS) correlation between CMRFT and 2D/3DEST (r = 0.83 and 0.87, respectively) with the limit of agreement (LOA) ranged from ±3.6 to ±4.9%. Excellent global circumferential strain (GCS) correlation between CMRFT and 2D/3DEST was observed (r = 0.90 and 0.88) with LOA of ±6.8-8.5%. Global radial strain showed fair correlations (r = 0.69 and 0.82, respectively) with LOA ranged from ±12.4 to ±16.3%. CMRFT GCS showed least observer variability with highest intra-class correlation. Although not interchangeable, the high GLS and GCS correlation between CMRFT and 2D/3DEST makes CMRFT a useful modality for quantification of global LV strain in patients, especially those with suboptimal echo image quality. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  3. Development of left ventricular longitudinal speckle tracking echocardiography in very low birth weight infants with and without bronchopulmonary dysplasia during the neonatal period.

    Directory of Open Access Journals (Sweden)

    Christoph Czernik

    Full Text Available OBJECTIVES: In preterm infants, postnatal myocardial adaptation may be complicated by bronchopulmonary dysplasia (BPD. We aimed to describe the development of left ventricular function by serial 2D, Doppler, and speckle tracking echocardiography (2D-STE in infants with and without BPD during the neonatal period and compare these to anthropometric and conventional hemodynamic parameters. STUDY DESIGN: Prospective echocardiography on day of life (DOL 1, 7, 14, and 28 in 119 preterm infants 10% were seen for the apical segment. While anthropometric parameters show rapid development during the first 4 weeks of life, the speckle tracking parameters did not differ statistically significantly during the neonatal period. Infants with and without BPD differed significantly (p<0.001 in the development of anthropometric parameters, conventional hemodynamic parameters except for heart rate, and 2D-STE parameters: global longitudinal systolic strain rate (GLSSR and longitudinal systolic strain for the mid left wall (LSSR. The largest differences were seen at DOL 1 and 7 in GLSSR (p<0.001 and in LSSR (p<0.01. CONCLUSIONS: Reproducible 2D-STE measurements are possible in preterm infants <1500 g. Cardiac deformation reveals early (DOL 1 and 7 ventricular changes (GLSSR and LSSR in very low birth weight infants who develop BPD.

  4. Changes in Speckle Tracking Echocardiography Measures of Ventricular Function after Percutaneous Implantation of the Edwards SAPIEN Transcatheter Heart Valve in the Pulmonary Position

    Science.gov (United States)

    Chowdhury, Shahryar M.; Hijazi, Ziyad M.; Rhodes, John F.; Kar, Saibal; Makkar, Raj; Mullen, Michael; Cao, Qi-Ling; Mandinov, Lazar; Buckley, Jason; Pietris, Nicholas P.; Shirali, Girish S.

    2015-01-01

    Background Patients with free pulmonary regurgitation or mixed pulmonary stenosis and regurgitation and severely dilated right ventricles (RV) show little improvement in ventricular function after pulmonary valve replacement when assessed by traditional echocardiographic markers. We evaluated changes in right and left ventricular (LV) function using speckle tracking echocardiography in patients after SAPIEN transcatheter pulmonary valve (TPV) placement. Methods Echocardiograms were evaluated at baseline, discharge, 1 and 6 months after TPV placement in 24 patients from 4 centers. Speckle tracking measures of function included peak longitudinal strain, strain rate, and early diastolic strain rate. RV fractional area change, tricuspid annular plane systolic excursion, and left ventricular LV ejection fraction were assessed. Routine Doppler and tissue Doppler velocities were measured. Results At baseline, all patients demonstrated moderate to severe pulmonary regurgitation; this improved following TPV placement. No significant changes were detected in conventional measures of RV or LV function at 6 months. RV longitudinal strain (−16.9% vs. −19.6%, P echocardiography may be more sensitive than traditional measures in detecting changes in systolic function after TPV implantation. (Echocardiography 2015;32:461–469) PMID:25047063

  5. Left ventricular strain and strain rate by 2D speckle tracking in chronic thromboembolic pulmonary hypertension before and after pulmonary thromboendarterectomy

    Directory of Open Access Journals (Sweden)

    Waltman Thomas J

    2010-09-01

    Full Text Available Abstract Background Echocardiographic evaluation of left ventricular (LV strain and strain rate (SR by 2D speckle tracking may be useful tools to assess chronic thromboembolic pulmonary hypertension (CTEPH severity as well as response to successful pulmonary thromboendarterectomy (PTE. Methods We evaluated 30 patients with CTEPH before and after PTE using 2D speckle tracking measurements of LV radial and circumferential strain and SR in the short axis, and correlated the data with right heart catheterization (RHC. Results PTE resulted in a decrease in mean PA pressure (44 ± 15 to 29 ± 9 mmHg, decrease in PVR (950 ± 550 to 31 ± 160 [dyne-sec]/cm5, and an increase in cardiac output (3.9 ± 1.0 to 5.0 ± 1.0 L/min, p change in circumferential strain and change in posterior wall radial strain correlated moderately well with changes in PVR, mean PA pressure and cardiac output (r = 0.69, 0.76, and 0.51 for circumferential strain [p Conclusions LV circumferential and posterior wall radial strain change after relief of pulmonary arterial obstruction in patients with CTEPH, and these improvements occur rapidly. These changes in LV strain may reflect effects from improved LV diastolic filling, and may be useful non-invasive markers of successful PTE.

  6. Robust microbubble tracking for super resolution imaging in ultrasound

    DEFF Research Database (Denmark)

    Hansen, Kristoffer B.; Villagómez Hoyos, Carlos Armando; Brasen, Jens Christian

    2016-01-01

    Currently ultrasound resolution is limited by diffraction to approximately half the wavelength of the sound wave employed. In recent years, super resolution imaging techniques have overcome the diffraction limit through the localization and tracking of a sparse set of microbubbles through...... the vasculature. However, this has only been performed on fixated tissue, limiting its clinical application. This paper proposes a technique for making super resolution images on non-fixated tissue by first compensating for tissue movement and then tracking the individual microbubbles. The experiment is performed...... on the kidney of a anesthetized Sprage-Dawley rat by infusing SonoVue at 0.1× original concentration. The algorithm demonstrated in vivo that the motion compensation was capable of removing the movement caused by the mechanical ventilator. The results shows that microbubbles were localized with a higher...

  7. Estimation of reactogenicity of preparations produced on the basis of photoinactivated live vaccines against brucellosis and tularaemia on the organismic level.2. Using the method of speckle-microscopy with high spatial resolution

    Science.gov (United States)

    Ulianova, O. V.; Uianov, S. S.; Li, Pengcheng; Luo, Qingming

    2011-04-01

    The method of speckle microscopy was adapted to estimate the reactogenicity of the prototypes of vaccine preparations against extremely dangerous infections. The theory is proposed to describe the mechanism of formation of the output signal from the super-high spatial resolution speckle microscope. The experimental studies show that bacterial suspensions, irradiated in different regimes of inactivation, do not exert negative influence on the blood microcirculations in laboratory animals.

  8. Estimation of reactogenicity of preparations produced on the basis of photoinactivated live vaccines against brucellosis and tularaemia on the organismic level. 2. Using the method of speckle-microscopy with high spatial resolution

    International Nuclear Information System (INIS)

    Ulianova, O V; Uianov, S S; Li Pengcheng; Luo Qingming

    2011-01-01

    The method of speckle microscopy was adapted to estimate the reactogenicity of the prototypes of vaccine preparations against extremely dangerous infections. The theory is proposed to describe the mechanism of formation of the output signal from the super-high spatial resolution speckle microscope. The experimental studies show that bacterial suspensions, irradiated in different regimes of inactivation, do not exert negative influence on the blood microcirculations in laboratory animals. (optical technologies in biophysics and medicine)

  9. Proposal for a semiconductor high resolution tracking detector

    International Nuclear Information System (INIS)

    Rehak, P.

    1983-01-01

    A 'new' concept for detection and tracking of charged particles in high energy physics experiments is proposed. It combines a well known high purity semiconductor diode detector (HPSDD) with a heterojunction structure (HJ) and a negative electron affinity (NEA) surface. The detector should be capable of providing a two dimensional view (few cm 2 ) of multi-track events with the following properties: a) position resolution down to a few μm (10 8 position elements); b) high density of information (10 2 -10 3 dots per mm of minimum ionizing track); c) high rate capabilities (few MHz); d) live operation with options to be triggered and/or the information from the detector can be used as an input for the decision to record an event. (orig.)

  10. Clinical feasibility and validation of 3D principal strain analysis from cine MRI: comparison to 2D strain by MRI and 3D speckle tracking echocardiography.

    Science.gov (United States)

    Satriano, Alessandro; Heydari, Bobak; Narous, Mariam; Exner, Derek V; Mikami, Yoko; Attwood, Monica M; Tyberg, John V; Lydell, Carmen P; Howarth, Andrew G; Fine, Nowell M; White, James A

    2017-12-01

    Two-dimensional (2D) strain analysis is constrained by geometry-dependent reference directions of deformation (i.e. radial, circumferential, and longitudinal) following the assumption of cylindrical chamber architecture. Three-dimensional (3D) principal strain analysis may overcome such limitations by referencing intrinsic (i.e. principal) directions of deformation. This study aimed to demonstrate clinical feasibility of 3D principal strain analysis from routine 2D cine MRI with validation to strain from 2D tagged cine analysis and 3D speckle tracking echocardiography. Thirty-one patients undergoing cardiac MRI were studied. 3D strain was measured from routine, multi-planar 2D cine SSFP images using custom software designed to apply 4D deformation fields to 3D cardiac models to derive principal strain. Comparisons of strain estimates versus those by 2D tagged cine, 2D non-tagged cine (feature tracking), and 3D speckle tracking echocardiography (STE) were performed. Mean age was 51 ± 14 (36% female). Mean LV ejection fraction was 66 ± 10% (range 37-80%). 3D principal strain analysis was feasible in all subjects and showed high inter- and intra-observer reproducibility (ICC range 0.83-0.97 and 0.83-0.98, respectively-p analysis is feasible using routine, multi-planar 2D cine MRI and shows high reproducibility with strong correlations to 2D conventional strain analysis and 3D STE-based analysis. Given its independence from geometry-related directions of deformation this technique may offer unique benefit for the detection and prognostication of myocardial disease, and warrants expanded investigation.

  11. Adaptive optics with pupil tracking for high resolution retinal imaging.

    Science.gov (United States)

    Sahin, Betul; Lamory, Barbara; Levecq, Xavier; Harms, Fabrice; Dainty, Chris

    2012-02-01

    Adaptive optics, when integrated into retinal imaging systems, compensates for rapidly changing ocular aberrations in real time and results in improved high resolution images that reveal the photoreceptor mosaic. Imaging the retina at high resolution has numerous potential medical applications, and yet for the development of commercial products that can be used in the clinic, the complexity and high cost of the present research systems have to be addressed. We present a new method to control the deformable mirror in real time based on pupil tracking measurements which uses the default camera for the alignment of the eye in the retinal imaging system and requires no extra cost or hardware. We also present the first experiments done with a compact adaptive optics flood illumination fundus camera where it was possible to compensate for the higher order aberrations of a moving model eye and in vivo in real time based on pupil tracking measurements, without the real time contribution of a wavefront sensor. As an outcome of this research, we showed that pupil tracking can be effectively used as a low cost and practical adaptive optics tool for high resolution retinal imaging because eye movements constitute an important part of the ocular wavefront dynamics.

  12. Three-dimensional speckle tracking echocardiography allows detailed evaluation of left atrial function in hypertrophic cardiomyopathy--insights from the MAGYAR-Path Study.

    Science.gov (United States)

    Domsik, Péter; Kalapos, Anita; Chadaide, Számi; Sepp, Róbert; Hausinger, Péter; Forster, Tamás; Nemes, Attila

    2014-11-01

    Hypertrophic cardiomyopathy (HCM) represents a generalized myopathic process affecting both ventricular and atrial myocardium. Reduced left atrial (LA) function was demonstrated in HCM by different methods. Three-dimensional (3D) speckle tracking echocardiography (STE) has just been introduced for the evaluation of LA. This study was designed to compare 3DSTE-derived LA volumetric and strain parameters in HCM with healthy controls. The study comprised 23 consecutive HCM patients (mean age: 48.5 ± 15.1 years, 14 men). Their results were compared to 23 age- and gender-matched healthy controls. Complete two-dimensional Doppler echocardiography and 3DSTE have been performed in all cases. Calculated LA maximum (66.4 ± 20.4 mL vs. 36.0 ± 6.1 mL, P echocardiography allows detailed evaluation of LA (dys) function in HCM by volumetric and strain measurements. © 2014, Wiley Periodicals, Inc.

  13. Assessment of atrial fibrillation and vulnerability in patients with Wolff-Parkinson-White syndrome using two-dimensional speckle tracking echocardiography.

    Directory of Open Access Journals (Sweden)

    Jing-Jie Li

    Full Text Available PURPOSE: The aim was to assess atrial fibrillation (AF and vulnerability in Wolff-Parkinson-White (WPW syndrome patients using two-dimensional speckle tracking echocardiography (2D-STE. METHODS: All patients were examined via transthoracic echocardiography and 2D-STE in order to assess atrial function 7 days before and 10 days after RF catheter ablation. A postoperative 3-month follow-up was performed via outpatient visit or telephone calls. RESULTS: Results showed significant differences in both body mass index (BMI and supraventricular tachycardia (SVT duration between WPW patients and DAVNP patients (both P<0.05. Echocardiography revealed that the maximum left atrial volume (LAVmax and the left ventricular mass index (LVMI in diastole increased noticeably in patients with WPW compared to patients with DAVNP both before and after ablation (all P<0.05. Before ablation, there were obvious differences in the levels of SRs, SRe, and SRa from the 4-chamber view (LA in the WPW patients group compared with patients in the DAVNP group (all P<0.05. In the AF group, there were significant differences in the levels of systolic strain rate (SRs, early diastolic strain rate (SRe, and late diastolic strain rate (SRa from the 4-chamber view (LA both before and after ablation (all P<0.05. In the non-AF group, there were decreased SRe levels from the 4-chamber view (LA/RA pre-ablation compared to post-ablation (all P<0.05. CONCLUSION: Our findings provide convincing evidence that WPW syndrome may result in increased atrial vulnerability and contribute to the development of AF. Further, RF catheter ablation of AAV pathway can potentially improve atrial function in WPW syndrome patients. Two-dimensional speckle tracking echocardiography imaging in WPW patients would be necessary in the evaluation and improvement of the overall function of RF catheter ablation in a long-term follow-up period.

  14. Three-dimensional speckle tracking imaging assessment of left ventricular change in patient with coronary heart disease and its correlation with serum indexes

    Directory of Open Access Journals (Sweden)

    Jian-Li Fu

    2016-10-01

    Full Text Available Objective: To analyze the three-dimensional speckle tracking imaging assessment of left ventricular change in patient with coronary heart disease and its correlation with serum indexes. Methods: A total of 152 patients first diagnosed with coronary heart disease were the observation group of the study and 117 healthy subjects were the control group. Threedimensional speckle tracking imaging (3D-STI was used to evaluate the left ventricular function parameters of two groups, the serum content of endothelial function indexes and platelet function indexes were detected, and the correlation between left ventricular function parameters under 3D-STI and serum indexes was further analyzed. Results: Absolute values of left ventricular function parameters LVGLS, LVGRS, LVGCS and LVGAS from 3D-STI of observation group were significantly less than those of control group while Ptw and Torsion levels were greater than those of control group; endothelial function indexes vWF, sICAM-1, sVCAM-1 and ET-1 content in serum were significantly higher than those of control group while vWF-cp and NO content were significantly lower than those of control group; platelet function indexes CD62P, GMP-140, CD63, sP-selectin, sCD40L and PAC-1 content in serum were significantly higher than those of control group. The levels of left ventricular function parameters from 3D-STI in patients with coronary heart disease were directly correlated with serum indexes. Conclusion: 3D-STI can accurately assess the left ventricular function and the overall disease severity in patients with coronary heart disease, and it is expected to become an effective method for early diagnosis of diseases and guidance of clinical treatment.

  15. Fine grained nuclear emulsion for higher resolution tracking detector

    Energy Technology Data Exchange (ETDEWEB)

    Naka, T., E-mail: naka@flab.phys.nagoya-u.ac.jp [Institute of Advanced Research, Nagoya University, Nagoya (Japan); Asada, T.; Katsuragawa, T.; Hakamata, K.; Yoshimoto, M.; Kuwabara, K.; Nakamura, M.; Sato, O.; Nakano, T. [Graduated School of Science, Nagoya University, Nagoya (Japan); Tawara, Y. [Division of Energy Science, EcoTopia Science Institute, Nagoya University, Nagoya (Japan); De Lellis, G. [INFN Sezione di Napoli, Napoli (Italy); Sirignano, C. [INFN Sezione di Padova, Padova (Italy); D' Ambrossio, N. [INFN, Laboratori Nazionali del Gran Sasso, Assergi (L' Aquila) (Italy)

    2013-08-01

    Fine grained nuclear emulsion with several 10 nm silver halide crystals can detect submicron tracks. This detector is expected to be worked as dark matter detector with directional sensitive. Now, nuclear emulsion became possible to be produced at Nagoya University, and extreme fine grained nuclear emulsion with 20 nm diameter was produced. Using this emulsion and new reading out technique with expansion technique, for optical selection and X-ray microscopy, recoiled tracks induced by dark matter can be detected automatically. Then, readout efficiency is larger than 80% at 120 nm, and angular resolution for final confirmation with X-ray microscopy is 20°. In addition, we started to construct the R and D underground facility in Gran Sasso.

  16. Diamond detector time resolution for large angle tracks

    Energy Technology Data Exchange (ETDEWEB)

    Chiodini, G., E-mail: chiodini@le.infn.it [INFN - Sezione di Lecce (Italy); Fiore, G.; Perrino, R. [INFN - Sezione di Lecce (Italy); Pinto, C.; Spagnolo, S. [INFN - Sezione di Lecce (Italy); Dip. di Matematica e Fisica “Ennio De Giorgi”, Uni. del Salento (Italy)

    2015-10-01

    The applications which have stimulated greater interest in diamond sensors are related to detectors close to particle beams, therefore in an environment with high radiation level (beam monitor, luminosity measurement, detection of primary and secondary-interaction vertices). Our aims is to extend the studies performed so far by developing the technical advances needed to prove the competitiveness of this technology in terms of time resolution, with respect to more usual ones, which does not guarantee the required tolerance to a high level of radiation doses. In virtue of these goals, measurements of diamond detector time resolution with tracks incident at different angles are discussed. In particular, preliminary testbeam results obtained with 5 GeV electrons and polycrystalline diamond strip detectors are shown.

  17. Speckle interferometry

    Science.gov (United States)

    Sirohi, Rajpal S.

    2002-03-01

    Illumination of a rough surface by a coherent monochromatic wave creates a grainy structure in space termed a speckle pattern. It was considered a special kind of noise and was the bane of holographers. However, its information-carrying property was soon discovered and the phenomenon was used for metrological applications. The realization that a speckle pattern carried information led to a new measurement technique known as speckle interferometry (SI). Although the speckle phenomenon in itself is a consequence of interference among numerous randomly dephased waves, a reference wave is required in SI. Further, it employs an imaging geometry. Initially SI was performed mostly by using silver emulsions as the recording media. The double-exposure specklegram was filtered to extract the desired information. Since SI can be configured so as to be sensitive to the in-plane displacement component, the out-of-plane displacement component or their derivatives, the interferograms corresponding to these were extracted from the specklegram for further analysis. Since the speckle size can be controlled by the F number of the imaging lens, it was soon realized that SI could be performed with electronic detection, thereby increasing its accuracy and speed of measurement. Furthermore, a phase-shifting technique can also be incorporated. This technique came to be known as electronic speckle pattern interferometry (ESPI). It employed the same experimental configurations as SI. ESPI found many industrial applications as it supplements holographic interferometry. We present three examples covering diverse areas. In one application it has been used to measure residual stress in a blank recordable compact disk. In another application, microscopic ESPI has been used to study the influence of relative humidity on paint-coated figurines and also the effect of a conservation agent applied on top of this. The final application is to find the defects in pipes. These diverse applications

  18. Strain and strain rate by two-dimensional speckle tracking echocardiography in a maned wolf Strain e strain rate por meio de ecocardiogratia speckle traking bidimensional em um lobo-guará

    Directory of Open Access Journals (Sweden)

    Matheus M. Mantovani

    2012-12-01

    Full Text Available The measurement of cardiovascular features of wild animals is important, as is the measurement in pets, for the assessment of myocardial function and the early detection of cardiac abnormalities, which could progress to heart failure. Speckle tracking echocardiography (2D STE is a new tool that has been used in veterinary medicine, which demonstrates several advantages, such as angle independence and the possibility to provide the early diagnosis of myocardial alterations. The aim of this study was to evaluate the left myocardial function in a maned wolf by 2D STE. Thus, the longitudinal, circumferential and radial strain and strain rate were obtained, as well as, the radial and longitudinal velocity and displacement values, from the right parasternal long axis four-chamber view, the left parasternal apical four chamber view and the parasternal short axis at the level of the papillary muscles. The results of the longitudinal variables were -13.52±7.88, -1.60±1.05, 4.34±2.52 and 3.86±3.04 for strain (%, strain rate (1/s, displacement (mm and velocity (cm/s, respectively. In addition, the radial and circumferential Strain and Strain rate were 24.39±14.23, 1.86±0.95 and -13.69±6.53, -1.01±0.48, respectively. Thus, the present study provides the first data regarding the use of this tool in maned wolves, allowing a more complete quantification of myocardial function in this species.A obtenção de parâmetros cardiovasculares em animais selvagens são importantes de serem avaliados, assim como em animais de companhia, para a obtenção da função miocárdica e determinação precoce de alterações cardíacas que poderiam evoluir para insuficiência cardíaca . A ecocardiografia speckle tracking (2D STE é uma ferramenta nova que tem sido utilizada em medicina veterinária, a qual tem demonstrado várias vantagens quanto ao seu uso, como a independência do ângulo de insonação e a possibilidade de se obter o diagnóstico precoce de altera

  19. Speckle tracking in a phantom and feature-based tracking in liver in the presence of respiratory motion using 4D ultrasound

    International Nuclear Information System (INIS)

    Harris, Emma J; Miller, Naomi R; Bamber, Jeffrey C; Symonds-Tayler, J Richard N; Evans, Philip M

    2010-01-01

    We have evaluated a 4D ultrasound-based motion tracking system developed for tracking of abdominal organs during therapy. Tracking accuracy and precision were determined using a tissue-mimicking phantom, by comparing tracked motion with known 3D sinusoidal motion. The feasibility of tracking 3D liver motion in vivo was evaluated by acquiring 4D ultrasound data from four healthy volunteers. For two of these volunteers, data were also acquired whilst simultaneously measuring breath flow using a spirometer. Hepatic blood vessels, tracked off-line using manual tracking, were used as a reference to assess, in vivo, two types of automated tracking algorithm: incremental (from one volume to the next) and non-incremental (from the first volume to each subsequent volume). For phantom-based experiments, accuracy and precision (RMS error and SD) were found to be 0.78 mm and 0.54 mm, respectively. For in vivo measurements, mean absolute distance and standard deviation of the difference between automatically and manually tracked displacements were less than 1.7 mm and 1 mm respectively in all directions (left-right, anterior-posterior and superior-inferior). In vivo non-incremental tracking gave the best agreement. In both phantom and in vivo experiments, tracking performance was poorest for the elevational component of 3D motion. Good agreement between automatically and manually tracked displacements indicates that 4D ultrasound-based motion tracking has potential for image guidance applications in therapy.

  20. Assessment of inter-atrial, inter-ventricular, and atrio-ventricular interactions in tetralogy of Fallot patients after surgical correction. Insights from two-dimensional speckle tracking and three-dimensional echocardiography.

    Science.gov (United States)

    Abd El Rahman, Mohamed; Raedle-Hurst, Tanja; Rentzsch, Axel; Schäfers, Hans-Joachim; Abdul-Khaliq, Hashim

    2015-10-01

    We aimed to assess biatrial size and function, interactions on atrial and ventricular levels, and atrio-ventricular coupling in patients after tetralogy of Fallot repair. A total of 34 patients with a mean age of 20.9±9 years, and 35 healthy controls, underwent two-dimensional speckle tracking echocardiography for ventricular and atrial strain measurements and real-time three-dimensional echocardiography to assess ventricular and atrial volumes. When compared with controls, tetralogy of Fallot patients had significantly reduced right atrial peak atrial longitudinal strain (ptetralogy of Fallot group, left ventricular ejection fraction was negatively related to the right ventricular end-systolic volume normalised to body surface area (r=-0.62, ptetralogy of Fallot patients, biatrial dysfunction exists and can be quantified via two-dimensional speckle tracking echocardiography as well as real-time three-dimensional echocardiography. Different forms of interactions on atrial and ventricular levels are evident among such cohorts.

  1. Assessment value of 3-dimensional speckle tracking imaging for changes of early left ventricular longitudinal systolic function in patients with primary hypertension

    Directory of Open Access Journals (Sweden)

    Jing Yu

    2016-08-01

    Full Text Available Objective: To study the assessment value of 3-dimensional speckle tracking imaging for changes of early left ventricular longitudinal systolic function in patients with primary hypertension. Methods: Patients with primary hypertension who were treated in our hospital from May 2012 to October 2015 were selected, and 40 patients with left ventricular normal (LVN primary hypertension and 40 patients with left ventricular remodeling (LVR primary hypertension were screened according to Ganau typing and enrolled in the LVN group and LVR group of the study respectively; 40 cases of healthy volunteers who received physical examination in our hospital during the same period were selected as control group. Ultrasonic testing was conducted to determine conventional ultrasonic indicators and 3D-STI parameters, and serum was collected to determine AngII, ALD, TGF-β1 and Ang1-7 levels. Results: LVEDd, LVPWT and LVEF of LVN group were not significantly different from those of control group, LVEF of LVR group was not significantly different from those of LVN group and control group, and LVEDd and LVPWT of LVR group were significantly higher than those of LVN group and control group; absolute values of GLS, GCS, GRS and GAS as well as serum Ang1-7 level of LVN group was significantly lower than those of control group, serum AngII, ALD and TGF-β1 levels were higher than those of control group, absolute values of GLS, GCS, GRS and GAS as well as serum Ang1-7 level of LVR group was significantly lower than those of LVN group and control group, and serum AngII, ALD and TGF-β1 levels were higher than those of LVN group and control group; absolute values of GLS, GCS, GRS and GAS were negatively correlated with serum AngII, ALD and TGF-β1 levels, and positively correlated with serum Ang1-7 level. Conclusion: 3-dimensional speckle tracking imaging can be used for early evaluation of left ventricular longitudinal systolic function in patients with primary

  2. Phase-processing as a tool for speckle reduction in pulse-echo images

    DEFF Research Database (Denmark)

    Healey, AJ; Leeman, S; Forsberg, F

    1991-01-01

    . Traditional speckle reduction procedures regard speckle correction as a stochastic process and trade image smoothing (resolution loss) for speckle reduction. Recently, a new phase acknowledging technique has been proposed that is unique in its ability to correct for speckle interference with no image......Due to the coherent nature of conventional ultrasound medical imaging systems interference artefacts occur in pulse echo images. These artefacts are generically termed 'speckle'. The phenomenon may severely limit low contrast resolution with clinically relevant information being obscured...

  3. Speckle tracking echocardiography derived 2-dimensional myocardial strain predicts left ventricular function and mass regression in aortic stenosis patients undergoing aortic valve replacement.

    Science.gov (United States)

    Staron, Adam; Bansal, Manish; Kalakoti, Piyush; Nakabo, Ayumi; Gasior, Zbigniew; Pysz, Piotr; Wita, Krystian; Jasinski, Marek; Sengupta, Partho P

    2013-04-01

    Regression of left ventricular (LV) mass in severe aortic stenosis (AS) following aortic valve replacement (AVR) reduces the potential risk of sudden death and congestive heart failure associated with LV hypertrophy. We investigated whether abnormalities of resting LV deformation in severe AS can predict the lack of regression of LV mass following AVR. Two-dimensional speckle tracking echocardiography (STE) was performed in a total of 100 subjects including 60 consecutive patients with severe AS having normal LV ejection fraction (EF > 50 %) and 40 controls. STE was performed preoperatively and at 4 months following AVR, including longitudinal strain assessed from the apical 4-chamber and 2-chamber views and the circumferential and rotational mechanics measured from the apical short axis view. In comparison with controls, the patients with AS showed a significantly lower LV longitudinal (p regression (>10 %) following AVR. In conclusion, STE can quantify the burden of myocardial dysfunction in patients with severe AS despite the presence of normal LV ejection fraction. Furthermore, resting abnormalities in circumferential strain at LV apex is related with a hemodynamic milieu associated with the lack of LV mass regression during short-term follow up after AVR.

  4. Role of Three-Dimensional Speckle Tracking Echocardiography in the Quantification of Myocardial Iron Overload in Patients with Beta-Thalassemia Major.

    Science.gov (United States)

    Li, Shu-Juan; Hwang, Yu-Yan; Ha, Shau-Yin; Chan, Godfrey C F; Mok, Amanda S P; Wong, Sophia J; Cheung, Yiu-Fai

    2016-09-01

    The new three-dimensional speckle tracking echocardiography (3DSTE) may enable comprehensive quantification of global left ventricular (LV) myocardial mechanics. Twenty-four patients aged 29.3 ± 5.2 years and 22 controls were studied. 3DSTE was performed to assess LV 3D global strain, twist and torsion, ejection fraction, and systolic dyssynchrony index (SDI). The LV SDI was calculated as % of SD of times-to-peak strain of 16 segments/RR interval. The global performance index (GPI) was calculated as (global 3D strain·torsion)/SDI. Area under the receiver operating characteristic curve (AUC) was calculated to determine the capability of 3DSTE parameters to discriminate between patients with (cardiac magnetic resonance T2* overload. Compared with controls, patients had significantly lower LV global 3D strain (P overload. The LV composite index of strain, torsion, and dyssynchrony derived from 3DSTE enables sensitive detection of myocardial iron overload in patients with thalassemia. © 2016, Wiley Periodicals, Inc.

  5. Two-Dimensional Speckle Tracking Echocardiography Detects Subclinical Left Ventricular Systolic Dysfunction among Adult Survivors of Childhood, Adolescent, and Young Adult Cancer

    Directory of Open Access Journals (Sweden)

    Anthony F. Yu

    2016-01-01

    Full Text Available Two-dimensional speckle tracking echocardiography (2DSTE provides a sensitive measure of left ventricular (LV systolic function and may aid in the diagnosis of cardiotoxicity. 2DSTE was performed in a cross-sectional study of 134 patients (mean age: 31.4±8.8 years; 55% male; mean time since diagnosis: 15.4±9.4 years previously treated with anthracyclines (mean cumulative dose: 320±124 mg/m2, with (n=52 or without (n=82 mediastinal radiotherapy. The prevalence of LV systolic dysfunction, defined as fractional shortening < 27%, LV ejection fraction (LVEF < 55%, and global longitudinal strain (GLS ≤ 16%, was 5.2%, 6.0%, and 23.1%, respectively. Abnormal GLS was observed in 24 (18% patients despite a normal LVEF. Indices of LV systolic function were similar regardless of anthracycline dose. However, GLS was worse (18.0 versus 19.0, p=0.003 and prevalence of abnormal GLS was higher (36.5% versus 14.6%, p=0.004 in patients treated with mediastinal radiotherapy. Mediastinal radiotherapy was associated with reduced GLS (p=0.040 after adjusting for sex, age, and cumulative anthracycline dose. In adult survivors of childhood, adolescent, and young adult cancer, 2DSTE frequently detects LV systolic dysfunction despite a normal LVEF and may be useful for the long-term cardiac surveillance of adult cancer survivors.

  6. 2-D left ventricular flow estimation by combining speckle tracking with Navier-Stokes-based regularization: an in silico, in vitro and in vivo study.

    Science.gov (United States)

    Gao, Hang; Bijnens, Nathalie; Coisne, Damien; Lugiez, Mathieu; Rutten, Marcel; D'hooge, Jan

    2015-01-01

    Despite the availability of multiple ultrasound approaches to left ventricular (LV) flow characterization in two dimensions, this technique remains in its childhood and further developments seem warranted. This article describes a new methodology for tracking the 2-D LV flow field based on ultrasound data. Hereto, a standard speckle tracking algorithm was modified by using a dynamic kernel embedding Navier-Stokes-based regularization in an iterative manner. The performance of the proposed approach was first quantified in synthetic ultrasound data based on a computational fluid dynamics model of LV flow. Next, an experimental flow phantom setup mimicking the normal human heart was used for experimental validation by employing simultaneous optical particle image velocimetry as a standard reference technique. Finally, the applicability of the approach was tested in a clinical setting. On the basis of the simulated data, pointwise evaluation of the estimated velocity vectors correlated well (mean r = 0.84) with the computational fluid dynamics measurement. During the filling period of the left ventricle, the properties of the main vortex obtained from the proposed method were also measured, and their correlations with the reference measurement were also calculated (radius, r = 0.96; circulation, r = 0.85; weighted center, r = 0.81). In vitro results at 60 bpm during one cardiac cycle confirmed that the algorithm properly measures typical characteristics of the vortex (radius, r = 0.60; circulation, r = 0.81; weighted center, r = 0.92). Preliminary qualitative results on clinical data revealed physiologic flow fields. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  7. Understanding gastric forces calculated from high-resolution pill tracking.

    Science.gov (United States)

    Laulicht, Bryan; Tripathi, Anubhav; Schlageter, Vincent; Kucera, Pavel; Mathiowitz, Edith

    2010-05-04

    Although other methods exist for monitoring gastrointestinal motility and contractility, this study exclusively provides direct and quantitative measurements of the forces experienced by an orally ingested pill. We report motive forces and torques calculated from real-time, in vivo measurements of the movement of a magnetic pill in the stomachs of fasted and fed humans. Three-dimensional net force and two-dimensional net torque vectors as a function of time data during gastric residence are evaluated using instantaneous translational and rotational position data. Additionally, the net force calculations described can be applied to high-resolution pill tracking acquired by any modality. The fraction of time pills experience ranges of forces and torques are analyzed and correlate with the physiological phases of gastric digestion. We also report the maximum forces and torques experienced in vivo by pills as a quantitative measure of the amount of force pills experience during the muscular contractions leading to gastric emptying. Results calculated from human data are compared with small and large animal models with a translational research focus. The reported magnitude and direction of gastric forces experienced by pills in healthy stomachs serves as a baseline for comparison with pathophysiological states. Of clinical significance, the directionality associated with force vector data may be useful in determining the muscle groups associated with gastrointestinal dysmotility. Additionally, the quantitative comparison between human and animal models improves insight into comparative gastric contractility that will aid rational pill design and provide a quantitative framework for interpreting gastroretentive oral formulation test results.

  8. Testing of Track Point Resolution of Gas Electron Multiplier with Pion Beam at CERN SPS

    CERN Document Server

    Adak, R P; Das, S; Dubey, A K; Ganti, M S; Saini, J; Singaraju, R

    2015-01-01

    A muon detection system using segmented and instrumented absorber has been designed for high-energy heavy-ion collision experiments to be held at GSI, Darmstadt, Germany. The muon detector system is mounted downstream of a Silicon Tracking System. The reconstructed tracks from the STS are to be matched to the hits in the GEM detector. For reconstructing track in the GEM Detector, track point resolution is an important issue. We report her first time the track point resolution of the GEM detector.

  9. Speckle imaging algorithms for planetary imaging

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, E. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    I will discuss the speckle imaging algorithms used to process images of the impact sites of the collision of comet Shoemaker-Levy 9 with Jupiter. The algorithms use a phase retrieval process based on the average bispectrum of the speckle image data. High resolution images are produced by estimating the Fourier magnitude and Fourier phase of the image separately, then combining them and inverse transforming to achieve the final result. I will show raw speckle image data and high-resolution image reconstructions from our recent experiment at Lick Observatory.

  10. Enhanced Right-Chamber Remodeling in Endurance Ultra-Trail Athletes Compared to Marathon Runners Detected by Standard and Speckle-Tracking Echocardiography

    Directory of Open Access Journals (Sweden)

    Kristian Ujka

    2017-07-01

    Full Text Available Background: Strenuous and endurance exercise training have been associated with morphological and functional heart remodeling. Two-dimensional speckle-tracking echocardiography (STE is a novel technique that allows an accurate quantification of global myocardium deformation. Our aim was to evaluate together left and right cardiac remodeling in different long-distance running athletes: marathon runners (42 km (M and endurance mountain runners (>300 Km (UT.Methods: A total of 92 athletes (70 males, 76% including 47 M [age 45 ± 7 years; training: 18 (9–53 years*days/week], 45 UT [age 42 ± 9, training: 30 (15–66 years*days/week] underwent conventional echocardiography and STE (Beyond Diogenes 2.0, AMID during the agonistic season.Results: Right ventricle (RV end-diastolic area (p = 0.026, fractional area changing (FAC (p = 0.008 and RV global longitudinal strain (GLS were significantly increasedin UT athletes. Furthermore, UT showed larger right atrium (RA volume (p = 0.03, reduced RA GLS and significantly increased RA global circumferential strain (GCS compared to M. After adjustment for age, sex, and HR as covariates, UT showed a reduced RA GLS (OR 0.907; CI 0.856–0.961 and increased RV FAC (OR 1.172; CI: 1.044–1.317 compared to M.Conclusion: Athletes enrolled in UT endurance activities showed RV and RA morphological and functional remodeling to increased preload in comparison with M runners characterized by increased RV FAC and reduced RA GLS. Follow-up studies are needed to better assess the long-term clinical impact of these modifications. 2D STE is a useful tool for investigating the deformation dynamic in different sports specialties.

  11. Left Atrial Deformation Analysis in Patients with Corrected Tetralogy of Fallot by 3D Speckle-Tracking Echocardiography (from the MAGYAR-Path Study

    Directory of Open Access Journals (Sweden)

    Kálmán Havasi

    Full Text Available Abstract Background: Three-dimensional (3D echocardiography coupled with speckle-tracking echocardiographic (STE capability is a novel methodology which has been demontrated to be useful for the assessment of left atrial (LA volumes and functional properties. There is increased scientific interest on myocardial deformation analysis in adult patients with corrected tetralogy of Fallot (cTOF. Objectives: To compare LA volumes, volume-based functional properties and strain parameters between cTOF patients and age- and gender-matched healthy controls. Methods: The study population consisted of 19 consecutive adult patients with cTOF in sinus rhythm nursing at the University of Szeged, Hungary (mean age: 37.9 ± 11.3 years, 8 men, who had repair at the age of 4.1 ± 2.5 years. They all had undergone standard transthoracic two-dimensional Doppler echocardiographic study extended with 3DSTE. Their results were compared to 23 age- and gender-matched healthy controls (mean age: 39.2 ± 10.6 years, 14 men. Results: Increased LA volumes and reduced LA emptying fractions respecting cardiac cycle could be demonstrated in cTOF patients compared to controls. LA stroke volumes featuring all LA functions showed no differences between the 2 groups examined. LA global and mean segmental uni- and multidirectional peak strains featuring LA reservoir function were found to be diminished in adult patients with cTOF as compared to controls. Similarly to peak strains reduced global and mean segmental LA strains at atrial contraction characterizing atrial booster pump function could be demonstrated in cTOF patients as compared to controls. Conclusions: Significant deterioration of all LA functions could be demonstrated in adult patients with cTOF late after repair.

  12. Realistic Vendor-Specific Synthetic Ultrasound Data for Quality Assurance of 2-D Speckle Tracking Echocardiography: Simulation Pipeline and Open Access Database.

    Science.gov (United States)

    Alessandrini, Martino; Chakraborty, Bidisha; Heyde, Brecht; Bernard, Olivier; De Craene, Mathieu; Sermesant, Maxime; D'Hooge, Jan

    2018-03-01

    Two-dimensional (2-D) echocardiography is the modality of choice in the clinic for the diagnosis of cardiac disease. Hereto, speckle tracking (ST) packages complement visual assessment by the cardiologist by providing quantitative diagnostic markers of global and regional cardiac function (e.g., displacement, strain, and strain-rate). Yet, the reported high vendor-dependence between the outputs of different ST packages raises clinical concern and hampers the widespread dissemination of the ST technology. In part, this is due to the lack of a solid commonly accepted quality assurance pipeline for ST packages. Recently, we have developed a framework to benchmark ST algorithms for 3-D echocardiography by using realistic simulated volumetric echocardiographic recordings. Yet, 3-D echocardiography remains an emerging technology, whereas the compelling clinical concern is, so far, directed to the standardization of 2-D ST only. Therefore, by building upon our previous work, we present in this paper a pipeline to generate realistic synthetic sequences for 2-D ST algorithms. Hereto, the synthetic cardiac motion is obtained from a complex electromechanical heart model, whereas realistic vendor-specific texture is obtained by sampling a real clinical ultrasound recording. By modifying the parameters in our pipeline, we generated an open-access library of 105 synthetic sequences encompassing: 1) healthy and ischemic motion patterns; 2) the most common apical probe orientations; and 3) vendor-specific image quality from seven different systems. Ground truth deformation is also provided to allow performance analysis. The application of the provided data set is also demonstrated in the benchmarking of a recent academic ST algorithm.

  13. Impact of surgical correction of tetralogy of fallot on short-term right and left ventricular function as determined by 2-dimensional speckle tracking echocardiography

    Science.gov (United States)

    Li, Yuman; Wang, Xinfang; Lv, Qing; Wang, Jing; Yang, YaLi; He, Lin; Yuan, Li; Zhang, Li; Xie, Mingxing

    2016-01-01

    Abstract Right ventricular (RV) and left ventricular (LV) dysfunction is an important determinant of poor clinical status in repaired patients with tetralogy of Fallot (TOF). The purpose of our study is to assess the impact of surgical repair on short-term RV and LV function by 2-dimensional speckle tracking echocardiography (STE). Sixty-seven patients (median age 12 months) with TOF before and 6 months after repair and 35 healthy subjects were studied. The patients were divided into the younger (age at surgery ≤12 months) and older (age at surgery >12 months) subgroups. RV and LV global longitudinal systolic strain and strain rate (SR), and LV global circumferential and radial systolic strain and SR were measured by STE. After repair, RV longitudinal strain and SR increased in the younger patients, whereas RV longitudinal SR was decreased in the older patients. LV deformation parameters were unchanged in all patients. In the multivariate analysis, patients with better RV and LV deformation parameters preoperatively were identified to have better RV and LV strain and SR postoperatively (P < 0.05 for all). The surgical approach of the pulmonary valve ring was predictive of RV and LV systolic function postoperatively (P < 0.05 for all). After TOF repair, short-term RV function improvement is identified in the younger but not in the older patients, whereas LV function is unchanged in all patients. The preoperative RV and LV deformational indices are the determinant of postoperative biventricular function improvement. STE appears to be a valuable tool for assessment of biventricular function after congenital heart disease surgery. PMID:27495064

  14. Left Atrial Deformation Analysis in Patients with Corrected Tetralogy of Fallot by 3D Speckle-Tracking Echocardiography (from the MAGYAR-Path Study)

    Science.gov (United States)

    Havasi, Kálmán; Domsik, Péter; Kalapos, Anita; McGhie, Jackie S.; Roos-Hesselink, Jolien W.; Forster, Tamás; Nemes, Attila

    2017-01-01

    Background Three-dimensional (3D) echocardiography coupled with speckle-tracking echocardiographic (STE) capability is a novel methodology which has been demontrated to be useful for the assessment of left atrial (LA) volumes and functional properties. There is increased scientific interest on myocardial deformation analysis in adult patients with corrected tetralogy of Fallot (cTOF). Objectives To compare LA volumes, volume-based functional properties and strain parameters between cTOF patients and age- and gender-matched healthy controls. Methods The study population consisted of 19 consecutive adult patients with cTOF in sinus rhythm nursing at the University of Szeged, Hungary (mean age: 37.9 ± 11.3 years, 8 men, who had repair at the age of 4.1 ± 2.5 years). They all had undergone standard transthoracic two-dimensional Doppler echocardiographic study extended with 3DSTE. Their results were compared to 23 age- and gender-matched healthy controls (mean age: 39.2 ± 10.6 years, 14 men). Results Increased LA volumes and reduced LA emptying fractions respecting cardiac cycle could be demonstrated in cTOF patients compared to controls. LA stroke volumes featuring all LA functions showed no differences between the 2 groups examined. LA global and mean segmental uni- and multidirectional peak strains featuring LA reservoir function were found to be diminished in adult patients with cTOF as compared to controls. Similarly to peak strains reduced global and mean segmental LA strains at atrial contraction characterizing atrial booster pump function could be demonstrated in cTOF patients as compared to controls. Conclusions Significant deterioration of all LA functions could be demonstrated in adult patients with cTOF late after repair. PMID:28327874

  15. Changes in cardiac function and structure in newly diagnosed Graves' disease. A conventional and 2D-speckle tracking echocardiography study.

    Science.gov (United States)

    Aroditis, K; Pikilidou, M; Vourvouri, E; Hadjistavri, L; Zebekakis, P; Yovos, J; Efthimiadis, G; Karvounis, H

    2017-02-01

    Overproduction of thyroid hormones leads to structural as well as functional cardiac changes. Conventional echocardiography but also recently developed sophisticated two-dimensional echocardiography speckle (2D-STE) tracking allow elaborate evaluation of these changes. Our purpose was to investigate the effects of thyroid hormones overproduction on the heart in patients with Graves' disease and changes that occur after 6 months thyrostatic therapy. We conducted a prospective, case-control study of 6 months duration. Full echocardiographic assessment at diagnosis and after 6 months of thyrostatic therapy were performed in 44 patients with Graves' disease, aged 37.6 ± 9.1 years. Additionally, 43 euthyroid controls were studied for the same time period. Left ventricular end diastolic diameter (LVEDD) and left ventricular end systolic diameter (LVESD) were higher in the patient group while triscupid annular plane systolic excursion (TAPSE) was lower in the patient group. Moreover, left ventricular (LV) mass index and left atrium (LA) volume index were higher in the Graves' disease group. Diastolic impairment as assessed with conventional echocardiography including tissue Doppler was present in the patient group (E/A ratio 0.87 ± 0.10,). 2D-STE analysis, revealed an increase in the strain rate at the isovolumic relaxation time (SRIVRT, 0.310 ± 0.07 patients versus 0.298 ± 0.09 s -1 controls). Improvement in diastolic and right systolic function as well as in left ventricular structural parameters was observed after restoration of euthyroidism (E/A ratio from 0.87 ± 0.10 versus 0.9 ± 0.08, p < 0.05). Patients with newly diagnosed Graves' showed an improvement in diastolic function, right systolic function and structural parameters after 6 months of thyrostatic treatment.

  16. Evaluation of Left Ventricular Diastolic Dysfunction with Early Systolic Dysfunction Using Two-Dimensional Speckle Tracking Echocardiography in Canine Heart Failure Model.

    Science.gov (United States)

    Wu, Wei-Chun; Ma, Hong; Xie, Rong-Ai; Gao, Li-Jian; Tang, Yue; Wang, Hao

    2016-04-01

    This study evaluated the role of two-dimensional speckle tracking echocardiography (2DSTE) for predicting left ventricular (LV) diastolic dysfunction in pacing-induced canine heart failure. Pacing systems were implanted in 8 adult mongrel dogs, and continuous rapid right ventricular pacing (RVP, 240 beats/min) was maintained for 2 weeks. The obtained measurements from 2DSTE included global strain rate during early diastole (SRe) and during late diastole (SRa) in the longitudinal (L-SRe, L-SRa), circumferential (C-SRe, C-SRa), and radial directions (R-SRe, R-SRa). Changes in heart morphology were observed by light microscopy and transmission electron microscopy at 2 weeks. The onset of LV diastolic dysfunction with early systolic dysfunction occurred 3 days after RVP initiation. Most of the strain rate imaging indices were altered at 1 or 3 days after RVP onset and continued to worsen until heart failure developed. Light and transmission electron microscopy showed myocardial vacuolar degeneration and mitochondrial swelling in the left ventricular at 2 weeks after RVP onset. Pearson's correlation analysis revealed that parameters of conventional echocardiography and 2DSTE showed moderate correlation with LV pressure parameters, including E/Esep' (r = 0.58, P echocardiography and strain rate imaging could effectively predict LV diastolic dysfunction (area under the curve: E/Esep' 0.78; L-SRe 0.84; E/L-SRe 0.80; R-SRe 0.80). 2DSTE was a sensitive and accurate technique that could be used for predicting LV diastolic dysfunction in canine heart failure model. © 2015, Wiley Periodicals, Inc.

  17. Characteristics of Left Atrial Deformation Parameters and Their Prognostic Impact in Patients with Pathological Left Ventricular Hypertrophy: Analysis by Speckle Tracking Echocardiography.

    Science.gov (United States)

    Iio, Chiharuko; Inoue, Katsuji; Nishimura, Kazuhisa; Fujii, Akira; Nagai, Takayuki; Suzuki, Jun; Okura, Takafumi; Higaki, Jitsuo; Ogimoto, Akiyoshi

    2015-12-01

    The pathological process of left ventricular (LV) hypertrophy is associated with left atrial (LA) remodeling. This study was aimed to evaluate the prognostic value of LA strain parameters in patients with pathological LV hypertrophy. This study included 95 patients with hypertensive heart disease (HHD: n = 24), hypertrophic cardiomyopathy (HCM: n = 56), cardiac amyloidosis (CA: n = 15), and control subjects (n = 20). We used two-dimensional speckle tracking echocardiography (STE) to analyze LA global strain. LA electromechanical conduction time (EMT) at the septal (EMT-septal) and lateral wall (EMT-lateral), and their time difference (EMT-diff) were calculated. The incidence of cardiac death and heart failure hospitalization was defined as major cardiac events and that of atrial fibrillation as secondary outcome. Left atrial volume index was increased and LA booster strain was decreased in the HCM and CA groups compared with the HHD group. EMT-lateral was increased in the diseased groups compared with the control. EMT-diff was prolonged in the CA group compared with the HCM group. During the follow-up period (mean 3.4 years), major cardiac events and atrial fibrillation occurred in 17 and 13 patients, respectively. The occurrence of atrial fibrillation was associated with CA etiology, E/e', LA volume index, LAa, and EMT-lateral. The incidence of major cardiac events was independently correlated with LA volume index and EMT-diff in multivariate analysis. This study suggested that the EMT-diff could discriminate patients with a high risk of cardiac events among patients with pathological LV hypertrophy. © 2015, Wiley Periodicals, Inc.

  18. Early Impairment of Cardiac Function and Asynchronization of Systemic Amyloidosis with Preserved Ejection Fraction Using Two-Dimensional Speckle Tracking Echocardiography.

    Science.gov (United States)

    Huang, He; Jing, Xian-chao; Hu, Zhang-xue; Chen, Xi; Liu, Xiao-qin

    2015-12-01

    To observe the ventricular global and regional function of the patients with systemic amyloidosis using two-dimensional speckle tracking echocardiography. The study enrolled 31 consecutive biopsy-proved patients with systemic amyloidosis who underwent echocardiographic examination and EF ≥ 55% and 37 age- and gender-matched healthy controls. We compared systolic strain and strain rate, diastolic strain rate, time to peak strain, peak delay time in longitudinal, radial, circumferential directions in 16 left ventricular segments. The global peak systolic longitudinal and radial strain of left ventricle, peak systolic longitudinal strain and strain rate, diastolic strain rate of right ventricular free wall were also compared. (1) Global peak systolic longitudinal strain (GPSLS), peak systolic longitudinal strain (PSLS) and strain rate (PSLSR), peak early diastolic longitudinal strain rate (PELSR) in 16 segments were decreased in case (P < 0.05). (2) Peak systolic radial strain and strain rate of inferoseptum and inferolateral at the level of papillary muscle were lower (P < 0.05), and peak early diastolic radial strain rate (PERSR) was reduced (P < 0.05). (3) Peak early diastolic circumferential strain rate was lower (P < 0.05). (4) Time to peak systolic longitudinal, radial, circumferential strain was longer, and peak delay time at the same level retarded (P < 0.05). (5) Into right ventricular wall, PSLS and PSLSR at mid-segment, and PSLSR, PELSR, peak atrial systolic longitudinal strain rate (PALSR) at basal were reduced (P < 0.05). (6) Inverse correlation between interventricular septum (IVS) thickness and GPSLS and GPSRS was found (P < 0.05). Systolic and diastolic dysfunction existed in systemic amyloidosis with preserved EF. Mechanical contraction disorder may be one reason for systolic dysfunction. GPLSR and GPRSR were negatively related to IVS thickness. © 2015, Wiley Periodicals, Inc.

  19. A new method to estimate left ventricular circumferential midwall systolic function by standard echocardiography: Concordance between models and validation by speckle tracking.

    Science.gov (United States)

    Ballo, Piercarlo; Nistri, Stefano; Bocelli, Arianna; Mele, Donato; Dini, Frank L; Galderisi, Maurizio; Zuppiroli, Alfredo; Mondillo, Sergio

    2016-01-15

    Assessment of left ventricular circumferential (LVcirc) systolic function by standard echocardiography can be performed by estimating midwall fractional shortening (mFS) and stress-corrected mFS (ScmFS). Their determination is based on spherical or cylindrical LV geometric models, which often yield discrepant values. We developed a new model based on a more realistic truncated ellipsoid (TE) LV shape, and explored the concordance between models among hypertensive patients. We also compared the relationships of different mFS and ScmFS estimates with indexes of LVcirc systolic strain. In 364 hypertensive subjects, mFS was determined using the spherical (mFSspher), cylindrical (mFScyl), and TE model (mFSTE). Corresponding values of ScmFSspher, ScmFScyl, and ScmFSTE were obtained. Global circumferential strain (GCS) and systolic strain rate (GCSR) were also measured by speckle tracking. The three models showed poor concordance for the estimation of mFS, with average differences ranging between 11% and 30% and wide limits of agreement. Similar results were found for ScmFS, where reclassification rates for the identification of abnormal LVcirc systolic function ranged between 18% and 29%. When tested against strain indexes, mFSTE and ScmFSTE showed the best correlations (R=0.81 and R=0.51, p<0.0001 for both) with GCS and GCSR. Multivariable analysis confirmed that mFSTE and ScmFSTE showed the strongest independent associations with LVcirc strain measures. Substantial discrepancies in LVcirc midwall systolic indexes exist between different models, supporting the need of model-specific normative data. The use of the TE model might provide indexes that show the best associations with established strain measures of LVcirc systolic function. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  20. 2D-speckle tracking right ventricular strain to assess right ventricular systolic function in systolic heart failure. Analysis of the right ventricular free and posterolateral walls.

    Science.gov (United States)

    Mouton, Stéphanie; Ridon, Héléne; Fertin, Marie; Pentiah, Anju Duva; Goémine, Céline; Petyt, Grégory; Lamblin, Nicolas; Coisne, Augustin; Foucher-Hossein, Claude; Montaigne, David; de Groote, Pascal

    2017-10-15

    Right ventricular (RV) systolic function is a powerful prognostic factor in patients with systolic heart failure. The accurate estimation of RV function remains difficult. The aim of the study was to determine the diagnostic accuracy of 2D-speckle tracking RV strain in patients with systolic heart failure, analyzing both free and posterolateral walls. Seventy-six patients with dilated cardiopathy (left ventricular end-diastolic volume≥75ml/m 2 ) and left ventricular ejection fraction≤45% had an analysis of the RV strain. Feasibility, reproducibility and diagnostic accuracy of RV strain were analyzed and compared to other echocardiographic parameters of RV function. RV dysfunction was defined as a RV ejection fraction≤40% measured by radionuclide angiography. RV strain feasibility was 93.9% for the free-wall and 79.8% for the posterolateral wall. RV strain reproducibility was good (intra-observer and inter-observer bias and limits of agreement of 0.16±1.2% [-2.2-2.5] and 0.84±2.4 [-5.5-3.8], respectively). Patients with left heart failure have a RV systolic dysfunction that can be unmasked by advanced echocardiographic imaging: mean RV strain was -21±5.7% in patients without RV dysfunction and -15.8±5.1% in patients with RV dysfunction (p=0.0001). Mean RV strain showed the highest diagnostic accuracy to predict depressed RVEF (area under the curve (AUC) 0.75) with moderate sensitivity (60.5%) but high specificity (87.5%) using a cutoff value of -16%. RV strain seems to be a promising and more efficient measure than previous RV echocardiographic parameters for the diagnosis of RV systolic dysfunction. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Assessment of strain and strain rate by two-dimensional speckle tracking in mice: comparison with tissue Doppler echocardiography and conductance catheter measurements.

    Science.gov (United States)

    Ferferieva, V; Van den Bergh, A; Claus, P; Jasaityte, R; La Gerche, A; Rademakers, F; Herijgers, P; D'hooge, J

    2013-08-01

    This study was designed in order to compare the strain and strain rate deformation parameters assessed by speckle tracking imaging (STI) with those of tissue Doppler imaging (TDI) and conductance catheter measurements in chronic murine models of left ventricular (LV) dysfunction. Twenty-four male C57BL/6J mice were assigned to wild-type (n = 8), myocardial infarction (n = 8) and transaortic constriction (n = 8) groups. Echocardiographic and conductance measurements were simultaneously performed at rest and during dobutamine infusion (5 µg/kg/min) in all animals 10 weeks post-surgery. The LV circumferential strain (Scirc) and the strain rate (SRcirc) were derived from grey scale and tissue Doppler data at frame rates of 224 and 375 Hz, respectively. Scirc and SRcirc by TDI/STI correlated well with the preload recruitable stroke work (PRSW) (r = -0.64 and -0.71 for TDI; r = -0.46 and -0.50 for STI, P < 0.05). Both modalities showed a good agreement with respect to Scirc and SRcirc (r = 0.60 and r = 0.63, P < 0.05). During stress, however, TDI-estimated Scirc and SRcirc values were predominantly higher than those measured by STI (P < 0.05). The similarity of Scirc and SRcirc measurements with respect to the STI/TDI data was examined by the Bland-Altman analysis. In mice, the STI- and TDI-derived strain and strain rate deformation parameters relate closely to intrinsic myocardial function. At low heart rate-to-frame rate ratios (HR/FR), both STI and TDI are equally acceptable for assessing the LV function non-invasively in these animals. At HR/FR (e.g. dobutamine challenge), however, these methods cannot be used interchangeably as STI underestimates S and SR at high values.

  2. Use of three-dimensional speckle tracking to assess left ventricular myocardial mechanics: inter-vendor consistency and reproducibility of strain measurements.

    Science.gov (United States)

    Badano, Luigi P; Cucchini, Umberto; Muraru, Denisa; Al Nono, Osama; Sarais, Cristiano; Iliceto, Sabino

    2013-03-01

    Since there is insufficient data available about the inter-vendor consistency of three-dimensional (3D) speckle-tracking (STE) measurements, we undertook this study to (i) assess the inter-vendor consistency of 3D LV global strain values obtained using two different scanners; (ii) identify the sources of inter-vendor inconsistencies, if any; and (iii) compare their respective intrinsic variability. Sixty patients (38 ± 12 years, 64% males) with a wide range of LV end-diastolic volumes (from 74 to 205 ml) and ejection fractions (from 17 to 70%) underwent two 3D LV data set acquisitions using VividE9 and Artida ultrasound systems. Global longitudinal (Lε), radial (Rε), circumferential (Cε) and area (Aε) strain values were obtained offline using the corresponding 3D STE softwares. Despite being significantly different, Lε showed the closest values between the two platforms (bias = 1.5%, limits of agreement (LOA) from -2.9 to -5.9%, P < 0.05). Artida produced significantly higher values of both Cε and Aε than VividE9 (bias = 6.6, LOA: -14.1 to 0.9%, and bias = 6.0, LOA = -28.2-8.6%, respectively, P < 0.001). Conversely, Rε values obtained with Artida were significantly lower than those measured using VividE9 platform (bias = -24.2, LOA: 1.5-49.9, P < 0.001). All strain components showed good reproducibility (intra-class correlation coefficients: 0.82-0.98), except for Rε by Artida, which showed only a moderate reproducibility. Apart from Lε, the inter-vendor agreement of Rε, Cε and Aε measured with Artida and VividE9 was poor. Reference values should be specific for each system and baseline and follow-up data in longitudinal studies should be obtained using the same 3D STE platform.

  3. Track-based improvement in the jet transverse momentum resolution for ATLAS

    CERN Document Server

    Marshall, Z; Schwartzmann, A

    2011-01-01

    We present a track-based method for improving the jet momentum resolution in ATLAS. Information is added to the reconstructed jet after the standard jet energy scale corrections have been applied. Track-based corrections are implemented, and a 10 − 15% improvement in the jet transverse momentum resolution at low pT is achieved. The method is explained, and some validation and physics results are presented. Additional variables are described and analyzed for their resolution improvement potential.

  4. Overview of Single-Molecule Speckle (SiMS) Microscopy and Its Electroporation-Based Version with Efficient Labeling and Improved Spatiotemporal Resolution

    Science.gov (United States)

    Yamashiro, Sawako; Watanabe, Naoki

    2017-01-01

    Live-cell single-molecule imaging was introduced more than a decade ago, and has provided critical information on remodeling of the actin cytoskeleton, the motion of plasma membrane proteins, and dynamics of molecular motor proteins. Actin remodeling has been the best target for this approach because actin and its associated proteins stop diffusing when assembled, allowing visualization of single-molecules of fluorescently-labeled proteins in a state specific manner. The approach based on this simple principle is called Single-Molecule Speckle (SiMS) microscopy. For instance, spatiotemporal regulation of actin polymerization and lifetime distribution of actin filaments can be monitored directly by tracking actin SiMS. In combination with fluorescently labeled probes of various actin regulators, SiMS microscopy has contributed to clarifying the processes underlying recycling, motion and remodeling of the live-cell actin network. Recently, we introduced an electroporation-based method called eSiMS microscopy, with high efficiency, easiness and improved spatiotemporal precision. In this review, we describe the application of live-cell single-molecule imaging to cellular actin dynamics and discuss the advantages of eSiMS microscopy over previous SiMS microscopy. PMID:28684722

  5. Overview of Single-Molecule Speckle (SiMS) Microscopy and Its Electroporation-Based Version with Efficient Labeling and Improved Spatiotemporal Resolution.

    Science.gov (United States)

    Yamashiro, Sawako; Watanabe, Naoki

    2017-07-06

    Live-cell single-molecule imaging was introduced more than a decade ago, and has provided critical information on remodeling of the actin cytoskeleton, the motion of plasma membrane proteins, and dynamics of molecular motor proteins. Actin remodeling has been the best target for this approach because actin and its associated proteins stop diffusing when assembled, allowing visualization of single-molecules of fluorescently-labeled proteins in a state specific manner. The approach based on this simple principle is called Single-Molecule Speckle (SiMS) microscopy. For instance, spatiotemporal regulation of actin polymerization and lifetime distribution of actin filaments can be monitored directly by tracking actin SiMS. In combination with fluorescently labeled probes of various actin regulators, SiMS microscopy has contributed to clarifying the processes underlying recycling, motion and remodeling of the live-cell actin network. Recently, we introduced an electroporation-based method called eSiMS microscopy, with high efficiency, easiness and improved spatiotemporal precision. In this review, we describe the application of live-cell single-molecule imaging to cellular actin dynamics and discuss the advantages of eSiMS microscopy over previous SiMS microscopy.

  6. Dynamical properties of speckled speckles

    DEFF Research Database (Denmark)

    Hanson, Steen Grüner; Iversen, Theis Faber Quist; Hansen, Rene Skov

    2010-01-01

    the static diffuser and the plane of observation consist of an optical system that can be characterized by a complex-valued ABCD-matrix (e.g. simple and complex imaging systems, free space propagation in both the near-and far-field, and Fourier transform systems). The use of the complex ABCD-method means...... to be Gaussian but the derived expressions are not restricted to a plane incident beam. The results are applicable for speckle-based systems for determining mechanical displacements, especially for long-range systems, and for analyzing systems for measuring biological activity beyond a diffuse layer, e.g. blood...

  7. Evaluation of right atrial dysfunction in patients with corrected tetralogy of Fallot using 3D speckle-tracking echocardiography. Insights from the CSONGRAD Registry and MAGYAR-Path Study.

    Science.gov (United States)

    Nemes, Attila; Havasi, Kálmán; Domsik, Péter; Kalapos, Anita; Forster, Tamás

    2015-11-01

    In recent studies, alterations in ventricular deformations were demonstrated in adult patients with corrected tetralogy of Fallot by three-dimensional speckle-tracking echocardiography. The present study was designed to assess three-dimensional speckle-tracking echocardiography-derived right atrial volumetric and strain parameters in corrected tetralogy of Fallot. A total of 17 patients with corrected tetralogy of Fallot were included in the study. Their results were compared with 18 age- and gender-matched healthy controls. Complete two-dimensional echocardiography and three-dimensional speckle-tracking echocardiography were performed in all cases. Significantly increased right atrial volumes respecting heart cycle were detected in patients with corrected tetralogy of Fallot. Total and passive atrial emptying fractions proved to be significantly decreased in patients with corrected tetralogy of Fallot (26.4 ± 12.4 % vs. 39.1 ± 8.8 %, p = 0.001 and 11.2 ± 6.8 % vs. 19.8 ± 9.0 %, p = 0.003, respectively). Global and mean segmental peak longitudinal (17.3 ± 9.2 % vs. 30.8 ± 11.2 %, p = 0.0007 and 20.6 ± 10.7 % vs. 34.4 ± 10.5 %, p = 0.0005) and area strains (20.1 ± 17.6 % vs. 41.0 ± 19.8 %, p = 0.004 and 28.1 ± 19.8 % vs. 49.1 ± 19.7 %, p = 0.004) as well as global radial peak strain (-9.1 ± 5.1 % vs. -15.0 ± 10.0 %, p = 0.05) were reduced in patients with corrected tetralogy of Fallot compared with controls. The complexity of right atrial dysfunction can be demonstrated by three-dimensional speckle-tracking echocardiography in patients with corrected tetralogy of Fallot.

  8. High Momentum Resolution tracking In a Linear Collider

    CERN Document Server

    Ljunggren, M; Oskarsson, A

    2011-01-01

    The work in this thesis has been made within the LCTPC-collaboration, an international collaboration for studying the technical aspects af a possible tracking detector at a linear collider. The collaboration has built a prototype Time Projection Chamber (TPC) for testing the properties of dierent readout structures. A TPC is a tracking detector consisting of a gas lled drift volume placed in a solenoidal magnetic eld where the readout is made using a segmented plane of so called pads. When a char...

  9. Markerless 3D Head Tracking for Motion Correction in High Resolution PET Brain Imaging

    DEFF Research Database (Denmark)

    Olesen, Oline Vinter

    relying on markers. Data-driven motion correction is problematic due to the physiological dynamics. Marker-based tracking is potentially unreliable, and it is extremely hard to validate when the tracking information is correct. The motion estimation is essential for proper motion correction of the PET......This thesis concerns application specific 3D head tracking. The purpose is to improve motion correction in position emission tomography (PET) brain imaging through development of markerless tracking. Currently, motion correction strategies are based on either the PET data itself or tracking devices...... images. Incorrect motion correction can in the worst cases result in wrong diagnosis or treatment. The evolution of a markerless custom-made structured light 3D surface tracking system is presented. The system is targeted at state-of-the-art high resolution dedicated brain PET scanners with a resolution...

  10. Antineoplastic-related cardiotoxicity, morphofunctional aspects in a murine model: contribution of the new tool 2D-speckle tracking

    Directory of Open Access Journals (Sweden)

    Coppola C

    2016-11-01

    Full Text Available Carmela Coppola,1 Gennaro Riccio,1 Antonio Barbieri,2 Maria Gaia Monti,3 Giovanna Piscopo,1 Domenica Rea,2 Claudio Arra,2 Carlo Maurea,1 Claudia De Lorenzo,4,5 Nicola Maurea1 1Division of Cardiology, Istituto Nazionale per lo Studio e la Cura dei Tumori “Fondazione G. Pascale”, IRCCS, Naples, Italy; 2Animal Facility Unit, Department of Experimental Oncology, Istituto Nazionale per lo Studio e la Cura dei Tumori “Fondazione G. Pascale”, IRCCS, Naples, Italy; 3Department of Translational Medical Sciences, University Federico II, Naples, Italy; 4Department of Molecular Medicine and Medical Biotechnology, University Federico II, Naples, Italy; 5CEINGE Biotecnologie Avanzate, Naples, Italy Objective: Considering that global left ventricular systolic radial strain is a sensitive technique for the early detection of left ventricular dysfunction due to antineoplastics and the analysis of segmental myocardial contractility, we evaluated this technique for early detection of trastuzumab-related cardiotoxicity by comparing it with cardiac structural damage.Methods: Groups of six mice were injected with trastuzumab or doxorubicin, used either as single agents or in combination. Cardiac function was evaluated by transthoracic echocardiography measurements before and after treatment for 2 or 7 days, by using a Vevo 2100 high-resolution imaging system. After echocardiography, mice were euthanized, and hearts were processed for histological evaluations, such as cardiac fibrosis, apoptosis, capillary density, and inflammatory response.Results: Trastuzumab-related cardiotoxicity was detected early by 2D strain imaging. Radial strain was reduced after 2 days in mice treated with trastuzumab alone (21.2%±8.0% vs 40.5%±4.8% sham; P<0.01. Similarly, trastuzumab was found to induce apoptosis, capillary density reduction, and inflammatory response in cardiac tissue after 2 days of treatment, in a fashion similar to doxorubicin. On the contrary, fractional

  11. X-ray speckle correlation interferometer

    International Nuclear Information System (INIS)

    Eisenhower, Rachel; Materlik, Gerhard

    2000-01-01

    Speckle Pattern Correlation Interferometry (SPCI) is a well-established technique in the visible-light regime for observing surface disturbances. Although not a direct imaging technique, SPCI gives full-field, high-resolution information about an object's motion. Since x-ray synchrotron radiation beamlines with high coherent flux have allowed the observation of x-ray speckle, x-ray SPCI could provide a means to measure strains and other quasi-static motions in disordered systems. This paper therefore examines the feasibility of an x-ray speckle correlation interferometer

  12. Left ventricular systolic dysfunction in asymptomatic Marfan syndrome patients is related to the severity of gene mutation: insights from the novel three dimensional speckle tracking echocardiography.

    Directory of Open Access Journals (Sweden)

    Mohamed Abd El Rahman

    Full Text Available In asymptomatic Marfan syndrome (MFS patients we evaluated the relationship between the types of fibrillin-1 (FBN1 gene mutation and possible altered left ventricular (LV function as assessed by three-dimensional speckle tracking echocardiography (3D-STE.Forty-five MFS patients (mean age 24 ± 15 years and 40 age-matched healthy controls were studied. Genetic evaluation for the FBN1 gene was carried on 32 MFS patients. Gene mutation (n = 15, 47% was classified as mild when the mutation resulted in nearly normally functioning protein, while mutations resulting in abnormally function protein were considered to be severe (n = 17, 53%. All patients and controls underwent 3D-STE for evaluation of LV function by an echocardiographer blinded to the results of the genetic testing. Compared to controls, MFS patients had significantly lower 3D-STE derived LV ejection fraction (EF, 57.43 ± 7.51 vs. 62.69 ± 4.76%, p = 0.0001, global LV longitudinal strain (LS, 14.85 ± 2.89 vs. 17.90 ± 2.01%, p = 0.0001, global LV circumferential strain (CS, 13.93 ± 2.81 vs. 16.82 ± 2.17%, p = 0.0001 and global LV area strain (AS, 25.76 ± 4.43 vs. 30.51 ± 2.61%, p = 0.0001. Apart from the global LV LS all these parameters were significantly lower in patients with severe gene mutation than in those with mild mutation (p < 0.05. In the multivariate linear regression analysis only the type of mutation had a significant influence on the 3D-STE derived LVEF (p = 0.017, global CS (p = 0.005 and global AS (p = 0.03.In asymptomatic MFS patients latent LV dysfunction can be detected using 3D STE. The LV dysfunction is mainly related to the severity of gene mutation, suggesting possible primary cardiomyopathy in MFS patients.

  13. Left Ventricular Function after Arterial Switch Operation as Assessed by Two-Dimensional Speckle-Tracking Echocardiography in Patients with Simple Transposition of the Great Arteries.

    Science.gov (United States)

    Malakan Rad, Elaheh; Ghandi, Yazdan; Kocharian, Armen; Mirzaaghayan, Mohammadreza

    2016-07-06

    Background: The late postoperative course for children with transposition of the great arteries (TGA) with an intact ventricular septum (IVS) is very important because the coronary arteries may be at risk of damage during arterial switch operation (ASO). We sought to investigate left ventricular function in patients with TGA/IVS by echocardiography. Methods: From March 2011 to December 2012, totally 20 infants (12 males and 8 females) with TGA/IVS were evaluated via 2-dimensional speckle-tracking echocardiography (2D STE) more than 6 months after they underwent ASO. A control group of age-matched infants and children was also studied. Left ventricular longitudinal strain (S), strain rate (SR), time to peak systolic longitudinal strain (TPS), and time to peak systolic longitudinal strain rate (TPSR) were measured and compared between the 2 groups. Results: Mean ± SD of age at the time of study in the patients with TGA/IVS was 15 ± 5 months, and also age at the time of ASO was 12 ± 3 days. Weight was 3.13 ± 0.07 kg at birth and 8.83 ± 1.57 kg at the time of ASO. Global strain (S), Time to peak strain rate (TPSR), and Time to peak strain (TPS) were not significantly different between the 2 groups, whereas global strain rate (SR) was significantly different (p value < 0.001). In the 3-chamber view, the values of S in the lateral, septal, inferior, and anteroseptal walls were significantly different between the 2 groups (p value < 0.001), and SR in the posterior wall was significantly different between the 2 groups (p value < 0.001). There were no positive correlations between S and SR in terms of the variables of heart rate, total cardiopulmonary bypass time, and aortic cross-clamp time. There were no statistically significant differences between the 2 groups regarding S, SR, TPS, and TPSR in the anteroseptal and posterior walls in the 3-chamber view and in the lateral and septal walls in the 4-chamber view. Conclusion: We showed that between 6 and 18 months after

  14. Impact of revascularization of coronary chronic total occlusion on left ventricular function and electrical stability: analysis by speckle tracking echocardiography and signal-averaged electrocardiogram.

    Science.gov (United States)

    Sotomi, Yohei; Okamura, Atsunori; Iwakura, Katsuomi; Date, Motoo; Nagai, Hiroyuki; Yamasaki, Tomohiro; Koyama, Yasushi; Inoue, Koichi; Sakata, Yasushi; Fujii, Kenshi

    2017-06-01

    The present study aimed to assess the mechanisms of effects of percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) from two different aspects: left ventricular (LV) systolic function assessed by two-dimensional speckle tracking echocardiography (2D-STE) and electrical stability evaluated by late potential on signal-averaged electrocardiogram (SAECG). We conducted a prospective observational study with consecutive CTO-PCI patients. 2D-STE and SAECG were performed before PCI, and after 1-day and 3-months of procedure. 2D-STE computed global longitudinal strain (GLS) and regional longitudinal strain (RLS) in CTO area, collateral blood-supplying donor artery area, and non-CTO/non-donor area. A total of 37 patients (66 ± 11 years, 78% male) were analyzed. RLS in CTO and donor areas and GLS were significantly improved 1-day after the procedure, but these improvements diminished during 3 months. The improvement of RLS in donor area remained significant after 3-months the index procedure (pre-PCI -13.4 ± 4.8% vs. post-3M -15.1 ± 4.5%, P = 0.034). RLS in non-CTO/non-donor area and LV ejection fraction were not influenced. Mitral annulus velocity was improved at 3-month follow-up (5.0 ± 1.4 vs. 5.6 ± 1.7 cm/s, P = 0.049). Before the procedure, 12 patients (35%) had a late potential. All components of the late potential (filtered QRS duration, root-mean-square voltage in the terminal 40 ms, and duration of the low amplitude signal <40 μV) were not improved. CTO-PCI improved RLS in the donor area at 3-month follow-up without changes of LV ejection fraction. Although higher prevalence of late potential in the current population compared to healthy population was observed, late potential as a surrogate of arrhythmogenic substrate was not influenced by CTO-PCI.

  15. Prognosis of Light Chain Amyloidosis With Preserved LVEF: Added Value of 2D Speckle-Tracking Echocardiography to the Current Prognostic Staging System.

    Science.gov (United States)

    Barros-Gomes, Sergio; Williams, Brittney; Nhola, Lara F; Grogan, Martha; Maalouf, Joseph F; Dispenzieri, Angela; Pellikka, Patricia A; Villarraga, Hector R

    2017-04-01

    This study evaluated whether 2-dimensional speckle-tracking echocardiography (2D-STE) has incremental value for prognosis over traditional clinical, echocardiographic, and serological markers-with main focus on the current prognostic staging system-in light-chain (AL) amyloidosis patients with preserved left ventricular ejection fraction. Cardiac amyloidosis (CA) is the major determinant of outcome in AL amyloidosis. The current prognostic staging system is based primarily on serum levels of cardiac troponin T (cTnT), N-terminal pro-B-type natriuretic peptide (NT-proBNP), and free light chain differential (FLC-diff). Consecutive patients with biopsy-proven AL amyloidosis and left ventricular ejection fraction ≥55% were divided into group 1 with CA (n = 63) and group 2 without CA (n = 87). Global longitudinal strain (GLS) by 2D-STE was performed with Vivid E9 (GE Healthcare Co., Milwaukee, Wisconsin) and syngo Velocity Vector Imaging (VVI) software (Siemens Medical Solutions USA, Inc., Malvern, Pennsylvania) (GLS GE and GLS VVI , respectively). Thirty-two deaths (51%) occurred in group 1 and 13 (15%) in group 2 (p ≤ 0.001). Group 1 had thicker walls, lower early diastolic tissue Doppler velocity at septal mitral annulus, and greater left ventricular mass, left atrial volume, glomerular filtration rate, FLC-diff, cTnT, and NT-proBNP (p value over cTnT, NT-proBNP, and FLC-diff. For survival analysis limited to group 2 (non-CA), GLS GE and GLS VVI both predicted all-cause mortality (GLS GE HR: 1.23; 95% CI: 1.03 to 1.47 [p = 0.02]; GLS VVI HR: 1.22; 95% CI: 1.01 to 1.49 [p = 0.04], respectively). 2D-STE predicted outcome and provided incremental prognostic information over the current prognostic staging system, especially in the group without CA. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  16. [Early detection of the cardiotoxicity induced by chemotherapy drug through two-dimensional speckle tracking echocardiography combined with high-sensitive cardiac troponin T].

    Science.gov (United States)

    Wang, W; Kang, Y; Shu, X H; Shen, X D; He, B

    2017-11-23

    Objective: To investigate the clinical value of two-dimensional speckle tracking echocardiography(2D-STE) combined with high-sensitive cardiac troponin T (hs-cTnT) in early detection of the cardiotoxicity induced by chemotherapy drug. Methods: Seventy-five non-Hodgkin's lymphoma patients who received the CHOP regimen were recruited in this study. Conventional echocardiography and 2D-STE were performed on these patients before chemotherapy, the second day after the third course of chemotherapy (during chemotherapy) and the second day after the last course of chemotherapy (after chemotherapy). The parameters included left ventricular ejection fraction (LVEF), global longitudinal strain (LS), global circumferential strain (CS) and global radial strain (RS). The serum hs-cTNT levels were tested simultaneously. Results: Three cycles of CHOP were completed in 30 patients and 6-8 cycles of CHOP were completed in 45 patients. The LVEF of 75 patients before, during and after chemotherapy was (63.8±2.6)%, (63.8±2.8)% and (64.0±3.3)%, respectively, without significant difference ( P =0.91). However, the LS of 75 patients before, during and after chemotherapy was (-18.5±1.7)%, (-16.5±1.9)% and (-16.0±1.6)%, respectively. The CS was (-20.9±2.9)%, (-19.3±3.5)% and (-19.2±3.2)%, respectively. The RS was (39.2±6.4)%, (35.3±5.2)% and (35.0±6.2)%, respectively. The hs-cTnT was (0.001 0±0.002 0)ng/ml, (0.006 3±0.008 9)ng/ml and (0.007 3±0.003 8)ng/ml, respectively. The LS, CS and RS were significantly decreased while hs-cTnT was significantly increased during chemotherapy when compared to those before chemotherapy (all of P chemotherapy were marginally different from those during chemotherapy (all of P >0.05). Moreover, T(LS-SD), T(CS-SD) and T(RS-SD) showed no significant difference before, during and after chemotherapy (all of P >0.05). The reduction of LS was positively associated with the enhancement of hs-cTnT after chemotherapy ( r =0.60, P effectively and

  17. Two-dimensional speckle-tracking strain echocardiography in long-term heart transplant patients: a study comparing deformation parameters and ejection fraction derived from echocardiography and multislice computed tomography.

    Science.gov (United States)

    Syeda, Bonni; Höfer, Peter; Pichler, Philipp; Vertesich, Markus; Bergler-Klein, Jutta; Roedler, Susanne; Mahr, Stephane; Goliasch, Georg; Zuckermann, Andreas; Binder, Thomas

    2011-07-01

    Longitudinal strain determined by speckle tracking is a sensitive parameter to detect systolic left ventricular dysfunction. In this study, we assessed regional and global longitudinal strain values in long-term heart transplants and compared deformation indices with ejection fraction as determined by transthoracic echocardiography (TTE) and multislice computed tomographic coronary angiography (MSCTA). TTE and MSCTA were prospectively performed in 31 transplant patients (10.6 years post-transplantation) and in 42 control subjects. Grey-scale apical views were recorded for speckle tracking (EchoPAC 7.0, GE) of the 16 segments of the left ventricle. The presence of coronary artery disease (CAD) was assessed by MSCTA. Strain analysis was performed in 1168 segments [496 in transplant patients (42.5%), 672 in control subjects (57.7%)]. Global longitudinal peak systolic strain was significantly lower in the transplant recipients than in the healthy population (-13.9 ± 4.2 vs. -17.4 ± 5.8%, PSimpsons method) was 60.7 ± 10.1%/60.2 ± 6.7% in transplant recipients vs. 64.7 ± 6.4%/63.0 ± 6.2% in the healthy population, P=ns. Even though 'healthy' heart transplants without CAD exhibit normal ejection fraction, deformation indices are reduced in this population when compared with control subjects. Our findings suggests that strain analysis is more sensitive than assessment of ejection fraction for the detection of abnormalities of systolic function.

  18. A high resolution scintillating fibre (SCIFI) tracking device with CCD readout

    International Nuclear Information System (INIS)

    Atkinson, M.N.; Crennell, D.J.; Fisher, C.M.; Hughes, P.T.; Kirkby, J.; Fent, J.; Freund, P.; Osthoff, A.; Pretzl, K.

    1987-06-01

    The authors present initial test beam measurements of a high resolution scintillating fibre detector with charge coupled device readout. The analysis procedure is discussed and the performance of the detector and its readout assembly is evaluated. A detected photon density is found along minimum ionising tracks of 2.0 mm -1 , with a straight-line RMS residual of 19.3 +- 2.9 μm, giving rise to a track impact parameter precision of 8.8 +- 2.0 μm. The two-track resolution is found to be 52 μm. (author)

  19. High Resolution Tracking Devices Based on Capillaries Filled with Liquid Scintillator

    CERN Multimedia

    Bonekamper, D; Vassiltchenko, V; Wolff, T

    2002-01-01

    %RD46 %title\\\\ \\\\The aim of the project is to develop high resolution tracking devices based on thin glass capillary arrays filled with liquid scintillator. This technique provides high hit densities and a position resolution better than 20 $\\mu$m. Further, their radiation hardness makes them superior to other types of tracking devices with comparable performance. Therefore, the technique is attractive for inner tracking in collider experiments, microvertex devices, or active targets for short-lived particle detection. High integration levels in the read-out based on the use of multi-pixel photon detectors and the possibility of optical multiplexing allow to reduce considerably the number of output channels, and, thus, the cost for the detector.\\\\ \\\\New optoelectronic devices have been developed and tested: the megapixel Electron Bombarded CCD (EBCCD), a high resolution image-detector having an outstanding capability of single photo-electron detection; the Vacuum Image Pipeline (VIP), a high-speed gateable pi...

  20. Unveiling adaptation using high-resolution lineage tracking

    Science.gov (United States)

    Blundell, Jamie; Levy, Sasha; Fisher, Daniel; Petrov, Dmitri; Sherlock, Gavin

    2013-03-01

    Human diseases such as cancer and microbial infections are adaptive processes inside the human body with enormous population sizes: between 106 -1012 cells. In spite of this our understanding of adaptation in large populations is limited. The key problem is the difficulty in identifying anything more than a handful of rare, large-effect beneficial mutations. The development and use of molecular barcodes allows us to uniquely tag hundreds of thousands of cells and enable us to track tens of thousands of adaptive mutations in large yeast populations. We use this system to test some of the key theories on which our understanding of adaptation in large populations is based. We (i) measure the fitness distribution in an evolving population at different times, (ii) identify when an appreciable fraction of clones in the population have at most a single adaptive mutation and isolate a large number of clones with independent single adaptive mutations, and (iii) use this clone collection to determine the distribution of fitness effects of single beneficial mutations.

  1. Left ventricular torsion assessed by two-dimensional echocardiography speckle tracking as a predictor of left ventricular remodeling and short-term outcome following primary percutaneous coronary intervention for acute myocardial infarction: A single-center experience.

    Science.gov (United States)

    Awadalla, Hany; Saleh, Mohamed Ayman; Abdel Kader, Mohamed; Mansour, Amr

    2017-08-01

    Left ventricular (LV) torsion is a novel method to assess systolic LV function. This study aimed at exploring the utility of 2D speckle tracking-based assessment of left ventricular torsion in patients with acute myocardial infarction (AMI) undertaking primary percutaneous intervention (pPCI) in predicting left ventricular remodeling. The study included 115 patients (mean±SD, age 52.2±9.67, males 84.3%) who underwent pPCI for AMI. Echocardiographic assessment of LV torsion by two-dimensional speckle tracking was performed early after the index pPCI. Patients underwent repeat echocardiography at 6 months to detect remodeling. LV torsion in the acute setting was significantly lower in those who demonstrated LV remodeling at follow-up compared to those without remodeling (7.56±1.95 vs 15.16±4.65; P<.005). Multivariate analysis identified peak CK & CK-MB elevation (β=-0.767 and -0.725; P<.001), SWMA index (β=-0.843; P<.001), and Simpson's derived LV ejection fraction (LVEF; β=0.802; P<.001) as independent predictors of baseline LV torsion. It also identified peak LV torsion (β: 0.27; 95% CI: 0.15-0.5, P=.001) and SWMA index (β: 1.07, 95% CI: 1.03-1.12, P=.005) as independent predictors of LV remodeling. Baseline Killip's grades II and higher (β: 48.6; 95% CI 5.5-428, P<.001) and diabetes mellitus (β: 29.7; 95% CI 1.1-763, P<.05) were independent predictors of mortality. Left ventricular torsion in acute MI setting is impaired and predicts subsequent LV remodeling at 6-month follow-up. © 2017, Wiley Periodicals, Inc.

  2. A simple and rapid method for high-resolution visualization of single-ion tracks

    Directory of Open Access Journals (Sweden)

    Masaaki Omichi

    2014-11-01

    Full Text Available Prompt determination of spatial points of single-ion tracks plays a key role in high-energy particle induced-cancer therapy and gene/plant mutations. In this study, a simple method for the high-resolution visualization of single-ion tracks without etching was developed through the use of polyacrylic acid (PAA-N, N’-methylene bisacrylamide (MBAAm blend films. One of the steps of the proposed method includes exposure of the irradiated films to water vapor for several minutes. Water vapor was found to promote the cross-linking reaction of PAA and MBAAm to form a bulky cross-linked structure; the ion-track scars were detectable at a nanometer scale by atomic force microscopy. This study demonstrated that each scar is easily distinguishable, and the amount of generated radicals of the ion tracks can be estimated by measuring the height of the scars, even in highly dense ion tracks. This method is suitable for the visualization of the penumbra region in a single-ion track with a high spatial resolution of 50 nm, which is sufficiently small to confirm that a single ion hits a cell nucleus with a size ranging between 5 and 20 μm.

  3. A simple and rapid method for high-resolution visualization of single-ion tracks

    Energy Technology Data Exchange (ETDEWEB)

    Omichi, Masaaki [Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Osaka 565-0871 (Japan); Center for Collaborative Research, Anan National College of Technology, Anan, Tokushima 774-0017 (Japan); Choi, Wookjin; Sakamaki, Daisuke; Seki, Shu, E-mail: seki@chem.eng.osaka-u.ac.jp [Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Osaka 565-0871 (Japan); Tsukuda, Satoshi [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi 980-8577 (Japan); Sugimoto, Masaki [Japan Atomic Energy Agency, Takasaki Advanced Radiation Research Institute, Gunma, Gunma 370-1292 (Japan)

    2014-11-15

    Prompt determination of spatial points of single-ion tracks plays a key role in high-energy particle induced-cancer therapy and gene/plant mutations. In this study, a simple method for the high-resolution visualization of single-ion tracks without etching was developed through the use of polyacrylic acid (PAA)-N, N’-methylene bisacrylamide (MBAAm) blend films. One of the steps of the proposed method includes exposure of the irradiated films to water vapor for several minutes. Water vapor was found to promote the cross-linking reaction of PAA and MBAAm to form a bulky cross-linked structure; the ion-track scars were detectable at a nanometer scale by atomic force microscopy. This study demonstrated that each scar is easily distinguishable, and the amount of generated radicals of the ion tracks can be estimated by measuring the height of the scars, even in highly dense ion tracks. This method is suitable for the visualization of the penumbra region in a single-ion track with a high spatial resolution of 50 nm, which is sufficiently small to confirm that a single ion hits a cell nucleus with a size ranging between 5 and 20 μm.

  4. Monte Carlo treatment planning and high-resolution alpha-track autoradiography for neutron capture therapy

    Energy Technology Data Exchange (ETDEWEB)

    Zamenhof, R.G.; Lin, K.; Ziegelmiller, D.; Clement, S.; Lui, C.; Harling, O.K.

    Monte Carlo simulations of thermal neutron flux distributions in a mathematical head model have been compared to experimental measurements in a corresponding anthropomorphic gelatin-based head phantom irradiated by a thermal neutron beam as presently available at the MITR-II Research Reactor. Excellent agreement between Monte Carlo and experimental measurements has encouraged us to employ the Monte Carlo simulation technique to approach treatment planning problems in neutron capture therapy. We have also implemented a high-resolution alpha-track autoradiography technique originally developed in our laboratory at MIT. Initial autoradiograms produced by this technique meet our expectations in terms of the high resolution available and the ability to etch tracks without concommitant destruction of stained tissue. Our preliminary results with computer-aided track distribution analysis indicate that this approach is very promising in being able to quantify boron distributions in tissue at the subcellular level with a minimum amount of operator effort necessary.

  5. Signal Tracking Beyond the Time Resolution of an Atomic Sensor by Kalman Filtering

    Science.gov (United States)

    Jiménez-Martínez, Ricardo; Kołodyński, Jan; Troullinou, Charikleia; Lucivero, Vito Giovanni; Kong, Jia; Mitchell, Morgan W.

    2018-01-01

    We study causal waveform estimation (tracking) of time-varying signals in a paradigmatic atomic sensor, an alkali vapor monitored by Faraday rotation probing. We use Kalman filtering, which optimally tracks known linear Gaussian stochastic processes, to estimate stochastic input signals that we generate by optical pumping. Comparing the known input to the estimates, we confirm the accuracy of the atomic statistical model and the reliability of the Kalman filter, allowing recovery of waveform details far briefer than the sensor's intrinsic time resolution. With proper filter choice, we obtain similar benefits when tracking partially known and non-Gaussian signal processes, as are found in most practical sensing applications. The method evades the trade-off between sensitivity and time resolution in coherent sensing.

  6. Speckle: Friend or foe?

    Science.gov (United States)

    Goodman, Joseph W.

    2013-05-01

    Speckle appears whenever coherent radiation of any kind is used. We review here the basic properties of speckle, the negative effects it has on imaging systems of various kinds, and the positive benefits it offers in certain nondestructive testing and metrology problems.

  7. Speckle-based spectrometer

    DEFF Research Database (Denmark)

    Chakrabarti, Maumita; Jakobsen, Michael Linde; Hanson, Steen Grüner

    2015-01-01

    A novel spectrometer concept is analyzed and experimentally verified. The method relies on probing the speckle displacement due to a change in the incident wavelength. A rough surface is illuminated at an oblique angle, and the peak position of the covariance between the speckle patterns observed...

  8. Entendue invariance in speckle fields

    International Nuclear Information System (INIS)

    Medina, F.F.; Garcia-Sucerquia, J.; Henao, R.; Trivi, M.

    2000-04-01

    Experimental evidence is shown that confirms the Entendue invariance in speckle fields. Because of this condition, the coherence patch of the speckle field can be significantly greater than the mean size of the speckles, as is shown by double exposure speckle interferometry. (author)

  9. Speckle reduction in digital holography with resampling ring masks

    Science.gov (United States)

    Zhang, Wenhui; Cao, Liangcai; Jin, Guofan

    2018-01-01

    One-shot digital holographic imaging has the advantages of high stability and low temporal cost. However, the reconstruction is affected by the speckle noise. Resampling ring-mask method in spectrum domain is proposed for speckle reduction. The useful spectrum of one hologram is divided into several sub-spectra by ring masks. In the reconstruction, angular spectrum transform is applied to guarantee the calculation accuracy which has no approximation. N reconstructed amplitude images are calculated from the corresponding sub-spectra. Thanks to speckle's random distribution, superimposing these N uncorrelated amplitude images would lead to a final reconstructed image with lower speckle noise. Normalized relative standard deviation values of the reconstructed image are used to evaluate the reduction of speckle. Effect of the method on the spatial resolution of the reconstructed image is also quantitatively evaluated. Experimental and simulation results prove the feasibility and effectiveness of the proposed method.

  10. An adaptive Kalman filter for speckle reductions in ultrasound images

    International Nuclear Information System (INIS)

    Castellini, G.; Labate, D.; Masotti, L.; Mannini, E.; Rocchi, S.

    1988-01-01

    Speckle is the term used to describe the granular appearance found in ultrasound images. The presence of speckle reduces the diagnostic potential of the echographic technique because it tends to mask small inhomogeneities of the investigated tissue. We developed a new method of speckle reductions that utilizes an adaptive one-dimensional Kalman filter based on the assumption that the observed image can be considered as a superimposition of speckle on a ''true images''. The filter adaptivity, necessary to avoid loss of resolution, has been obtained by statistical considerations on the local signal variations. The results of the applications of this particular Kalman filter, both on A-Mode and B-MODE images, show a significant speckle reduction

  11. High resolution three-dimensional robotic synthetic tracked aperture ultrasound imaging: feasibility study

    Science.gov (United States)

    Zhang, Haichong K.; Fang, Ting Yun; Finocchi, Rodolfo; Boctor, Emad M.

    2017-03-01

    Three dimensional (3D) ultrasound imaging is becoming a standard mode for medical ultrasound diagnoses. Conventional 3D ultrasound imaging is mostly scanned either by using a two dimensional matrix array or by motorizing a one dimensional array in the elevation direction. However, the former system is not widely assessable due to its cost, and the latter one has limited resolution and field-of-view in the elevation axis. Here, we propose a 3D ultrasound imaging system based on the synthetic tracked aperture approach, in which a robotic arm is used to provide accurate tracking and motion. While the ultrasound probe is moved by a robotic arm, each probe position is tracked and can be used to reconstruct a wider field-of-view as there are no physical barriers that restrict the elevational scanning. At the same time, synthetic aperture beamforming provides a better resolution in the elevation axis. To synthesize the elevational information, the single focal point is regarded as the virtual element, and forward and backward delay-andsum are applied to the radio-frequency (RF) data collected through the volume. The concept is experimentally validated using a general ultrasound phantom, and the elevational resolution improvement of 2.54 and 2.13 times was measured at the target depths of 20 mm and 110 mm, respectively.

  12. Usefulness of left ventricular speckle tracking echocardiography and novel measures of left atrial structure and function in diagnosing paroxysmal atrial fibrillation in ischemic stroke and transient ischemic attack patients.

    Science.gov (United States)

    Skaarup, Kristoffer Grundtvig; Christensen, Hanne; Høst, Nis; Mahmoud, Masti Mahdy; Ovesen, Christian; Olsen, Flemming Javier; Jensen, Jan Skov; Biering-Sørensen, Tor

    2017-12-01

    Asymptomatic paroxysmal atrial fibrillation (PAF) is often assumed to be the cause of cryptogenic ischemic strokes (IS) and transient ischemic attacks (TIA). We examined the usefulness of measures obtained by 2D speckle tracking echocardiography and novel left atrial measurements, in the diagnosis of PAF in patients with IS and TIA. We retrospectively included 205 patients who after acute IS or TIA underwent an echocardiogram in sinus rhythm. Patients were designated as PAF-patients if they had one or more reported incidents of AF before or after their echocardiographic examination. None of the conventional echocardiographic parameters were significantly associated with PAF. Of the speckle tracking measurements, only early diastolic strain rate (0.7±0.2 s -1 vs. 0.8±0.3 s -1 , p = 0.048) and global longitudinal displacement (GLD) (3.15 ± 1.40 mm vs. 3.87 ± 1.56 mm, p = 0.007) proved significantly different. Of the left atrial parameters both minimal and maximal left atrium volume divided by left ventricular length (min LAV/LVL and max LAV/LVL, respectively) were significantly impaired (min LAV/LVL: 3.7 ± 2.1 cm 2 vs. 2.8 ± 1.11 cm 2 , p = 0.012; max LAV/LVL: 6.6 ± 3.1 cm 2 vs. 5.6 ± 1.7 cm 2 , p = 0.012). GLD, min max LAV/LVL proved significant after adjustment for age, gender, CHA 2 DS 2 -VASc and NIHSS. By combining information regarding age, GLD, min and max LAV/LVL the diagnostic accuracy of PAF improved, resulting in a significantly increased area under the curve (p = 0.037). In patients with IS and TIA GLD, min and max LAV/LVL were independently associated with the presence of PAF.

  13. Implementation and performance of an optical motion tracking system for high resolution brain PET imaging

    Science.gov (United States)

    Lopresti, B. J.; Russo, A.; Jones, W. F.; Fisher, T.; Crouch, D. G.; Altenburger, D. E.; Townsend, D. W.

    1999-12-01

    Head motion during PET scanning is widely regarded as a source of image degradation and resolution loss. Recent improvements in the spatial resolution of state-of-the-art tomographs may be compromised by patient motion during scanning, as these high resolution data will be increasingly susceptible to smaller movements of the head. The authors have developed an opto-electronic motion tracking system based on commercially-available technology that is capable of very accurate real-time measurements of the position and orientation of the patient's head. These positions are transformed to the reference frame of the PET scanner, and could potentially be used to provide motion correction of list-mode emission data on an event-by-event basis.

  14. Pedestrian Detection and Tracking from Low-Resolution Unmanned Aerial Vehicle Thermal Imagery

    Directory of Open Access Journals (Sweden)

    Yalong Ma

    2016-03-01

    Full Text Available Driven by the prominent thermal signature of humans and following the growing availability of unmanned aerial vehicles (UAVs, more and more research efforts have been focusing on the detection and tracking of pedestrians using thermal infrared images recorded from UAVs. However, pedestrian detection and tracking from the thermal images obtained from UAVs pose many challenges due to the low-resolution of imagery, platform motion, image instability and the relatively small size of the objects. This research tackles these challenges by proposing a pedestrian detection and tracking system. A two-stage blob-based approach is first developed for pedestrian detection. This approach first extracts pedestrian blobs using the regional gradient feature and geometric constraints filtering and then classifies the detected blobs by using a linear Support Vector Machine (SVM with a hybrid descriptor, which sophisticatedly combines Histogram of Oriented Gradient (HOG and Discrete Cosine Transform (DCT features in order to achieve accurate detection. This research further proposes an approach for pedestrian tracking. This approach employs the feature tracker with the update of detected pedestrian location to track pedestrian objects from the registered videos and extracts the motion trajectory data. The proposed detection and tracking approaches have been evaluated by multiple different datasets, and the results illustrate the effectiveness of the proposed methods. This research is expected to significantly benefit many transportation applications, such as the multimodal traffic performance measure, pedestrian behavior study and pedestrian-vehicle crash analysis. Future work will focus on using fused thermal and visual images to further improve the detection efficiency and effectiveness.

  15. High-resolution tracking using large capillary bundles filled with liquid scintillator

    CERN Document Server

    Annis, P; Benussi, L; Bruski, N; Buontempo, S; Currat, C; D'Ambrosio, N; Van Dantzig, R; Dupraz, J P; Ereditato, A; Fabre, Jean-Paul; Fanti, V; Feyt, J; Frekers, D; Frenkel, A; Galeazzi, F; Garufi, F; Goldberg, J; Golovkin, S V; Gorin, A M; Grégoire, G; Harrison, K; Höpfner, K; Holtz, K; Konijn, J; Kozarenko, E N; Kreslo, I E; Kushnirenko, A E; Liberti, B; Martellotti, G; Medvedkov, A M; Michel, L; Migliozzi, P; Mommaert, C; Mondardini, M R; Panman, J; Penso, G; Petukhov, Yu P; Rondeshagen, D; Siegmund, W P; Tyukov, V E; Van Beek, G; Vasilchenko, V G; Vilain, P; Visschers, J L; Wilquet, G; Winter, Klaus; Wolff, T; Wörtche, H J; Wong, H; Zimyn, K V

    2000-01-01

    We have developed large high-resolution tracking detectors based on glass capillaries filled with organic liquid scintillator of high refractive index. These liquid-core scintillating optical fibres act simultaneously as detectors of charged particles and as image guides. Track images projected onto the readout end of a capillary bundle are visualized by an optoelectronic chain consisting of a set of image-intensifier tubes followed by a photosensitive CCD or by an EBCCD camera. Two prototype detectors, each composed of \\hbox{$\\approx 10^6$} capillaries with \\hbox{20$-$25 $\\mu$m} diameter and \\hbox{0.9$-$1.8 m} length, have been tested, and a spatial resolution of the order of \\hbox{20$-$40 $\\mu$m} has been attained. A high scintillation efficiency and a large light-attenuation length, in excess of 3 m, was achieved through special purification of the liquid scintillator. Along the tracks of minimum-ionizing particles, the hit densities obtained were $\\sim$ 8 hits/mm at the readout window, and \\hbox{$\\sim$ 3 ...

  16. Left ventricular rigid body rotation in a diffuse large B-cell lymphoma patient with cardiac involvement: A case from the three-dimensional speckle-tracking echocardiographic MAGYAR-Path Study.

    Science.gov (United States)

    Földeák, Dóra; Kalapos, Anita; Domsik, Péter; Sinkó, Mária; Szeleczki, Nóra; Bagdi, Enikő; Krenács, László; Forster, Tamás; Borbényi, Zita; Nemes, Attila

    2017-02-01

    Secondary myocardial involvement by diffuse large B-cell lymphoma is a rare occurrence. Left ventricular (LV) twist is considered an essential part of LV function. In normal circumstances LV twist results from the movement of two orthogonally oriented muscular bands of a helical myocardial structure with consequent clockwise rotation of the base and counterclockwise rotation of the apex. Three-dimensional (3D) speckle-tracking echocardiography (3DSTE) has been found to be feasible for non-invasive 3D quantification of LV wall motion and rotational mechanics. The present report aimed to assess LV twisting motion in a patient with diffuse large B-cell lymphoma with positron emission tomography/computer tomography-proven cardiac involvement by 3DSTE. During 3DSTE, reduction in some segmental radial, longitudinal, circumferential, area and 3D LV strains were found. Apical and basal LV rotations were found to be in the same counterclockwise direction, confirming near absence of LV twist - so-called rigid body rotation. Copyright © 2016 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.

  17. Ergotamine-derived dopamine agonists and left ventricular function in Parkinson patients: systolic and diastolic function studied by conventional echocardiography, tissue Doppler imaging, and two-dimensional speckle tracking.

    Science.gov (United States)

    Rasmussen, Vibeke Guldbrand; Poulsen, Steen Hvitfeldt; Dupont, Erik; Ostergaard, Karen; Safikhany, Gholamhossein; Egeblad, Henrik

    2008-11-01

    Ergot-derived dopamine agonists (EDDA) induce fibrotic heart valve disease. We aimed to investigate whether EDDA treatment also affects left ventricular (LV) function. Myocardial function was evaluated in 110 Parkinson patients [mean age (63.4 +/- 9.0 years)] treated for at least 6 months with either EDDA (n = 71) or non-EDDA (n = 39). LV ejection fraction did not differ between EDDA and non-EDDA patients [63 +/- 4% vs. 65 +/- 4% (ns)]. There was no difference in prevalence of diastolic dysfunction between EDDA and non-EDDA patients [7% vs. 8% (ns)]. Finally, averaged LV systolic myocardial strain and longitudinal displacement analysed by means of two-dimensional speckle tracking showed no difference between EDDA and non-EDDA patients [strain: 19 +/- 3% vs. 19 +/- 2% (ns) and longitudinal displacement: 12 +/- 2 mm vs. 12 +/- 2 mm (ns)]. Elevated p-NT-proBNP was found in 38% of EDDA patients and in 59% of non-EDDA patients (ns). In contrast to the well-established association between EDDA treatment and valvular fibrosis, EDDA did not have a detectable adverse impact on myocardial systolic and diastolic function.

  18. The impact of left ventricular deformation and dyssynchrony on improvement of left ventricular ejection fraction following radiofrequency catheter ablation in Wolff-Parkinson-White syndrome: A comprehensive study by speckle tracking echocardiography.

    Science.gov (United States)

    Nagai, Tomoo; Hamabe, Akira; Arakawa, Junko; Tabata, Hirotsugu; Nishioka, Toshihiko

    2017-11-01

    The purpose of this study was to evaluate left ventricular (LV) deformation and LV dyssynchrony in patients with Wolff-Parkinson-White (WPW) syndrome and to identify the factors that affect the efficacy of radiofrequency catheter ablation (RFCA). Thirty patients (26 men, mean age 40 ± 12 years) with WPW syndrome were prospectively recruited for this study. They underwent 2-dimensional transthoracic echocardiography with speckle tracking analysis before RFCA and again within 48 hours after RFCA. Control group consisted of 15 age and sex-matched healthy volunteers. The patients had significantly lower LV ejection fraction (LVEF), global longitudinal strain (S l ), and global circumferential strain (S c ) compared with healthy controls (64% ± 8% vs 68% ± 5%, P = .049; -17.6% ± 3.2% vs -19.9% ± 3.3%, P = .037, -15.2% ± 2.5% vs -19.4% ± 2.5%, P syndrome, impaired LV circumferential deformation can be restored by RFCA with concomitant improvement in LV dyssynchrony and LVEF. © 2017, Wiley Periodicals, Inc.

  19. Right heart function in impaired left ventricular diastolic function: 2D speckle tracking echocardiography-based and Doppler tissue imaging-based analysis of right atrial and ventricular function.

    Science.gov (United States)

    Brand, Anna; Bathe, Marny; Oertelt-Prigione, Sabine; Seeland, Ute; Rücke, Mirjam; Regitz-Zagrosek, Vera; Stangl, Karl; Knebel, Fabian; Stangl, Verena; Dreger, Henryk

    2018-01-01

    The aim of our study was to describe right atrial (RA) and right ventricular (RV) function, assessed by Doppler tissue imaging and 2D speckle tracking echocardiography (2DSTE), in women with signs of early impaired left ventricular diastolic function (DD). In a cross-sectional trial, standard parameters of diastolic and right heart function were investigated in 438 women of the Berlin Female Risk Evaluation (BEFRI) study. In a subset of women, average peak systolic RA strain (RAS), as well as the average peak systolic RV strain of the free wall (RVS free wall) and of all RV segments (average RV strain; RVS Avg), was analyzed using 2DSTE. Compared to women with normal diastolic function (DD0), RAS, RVS free wall and RVS Avg were significantly reduced in DD (43.1% ± 11.9%, -26.7% ± 5.6%, and -23.3% ± 3.5% in DD0; vs 35.1% ± 10.4%, -23.9% ± 5.5%, and -20.6% ± 3.8% in DD; P right heart function is significantly altered in DD. DTI as well as 2DSTE constitute sensitive echocardiographic tools that enable the diagnosis of impaired right heart mechanics in early-staged DD. © 2017 Wiley Periodicals, Inc.

  20. Measurement of eye aberrations in a speckle field

    International Nuclear Information System (INIS)

    Larichev, A V; Ivanov, P V; Iroshnikov, N G; Shmalgauzen, V I

    2001-01-01

    The influence of speckles on the performance of a Shark-Hartmann wavefront sensor is investigated in the eye aberration studies. The dependence of the phase distortion measurement error on the characteristic speckle size is determined experimentally. Scanning of the reference source was used to suppress the speckle structure of the laser beam scattered by the retina. The technique developed by us made it possible to study the time dependence of the human eye aberrations with a resolution of 30 ms. (laser applications and other topics in quantum electronics)

  1. A high-resolution tracking hodoscope based on capillary layers filled with liquid scintillator

    CERN Document Server

    Bay, A; Bruski, N; Buontempo, S; Currat, C; D'Ambrosio, N; Ekimov, A V; Ereditato, A; Fabre, Jean-Paul; Fanti, V; Frekers, D; Frenkel, A; Golovkin, S V; Govorun, V N; Harrison, K; Koppenburg, P; Kozarenko, E N; Kreslo, I E; Liberti, B; Martellotti, G; Medvedkov, A M; Mondardini, M R; Penso, G; Siegmund, W P; Vasilchenko, V G; Vilain, P; Wilquet, G; Winter, Klaus; Wörtche, H J

    2001-01-01

    Results are given on tests of a high-resolution tracking hodoscope based on layers of \\hbox{26-$\\mu$m-bore} glass capillaries filled with organic liquid scintillator (1-methylnaphthalene doped with R39). The detector prototype consisted of three 2-mm-thick parallel layers, with surface areas of $2.1 \\times 21$~cm$^2$. The layers had a centre-to-centre spacing of 6~mm, and were read by an optoelectronic chain comprising two electrostatically focused image intensifiers and an Electron-Bombarded Charge-Coupled Device (EBCCD). Tracks of cosmic-ray particles were recorded and analysed. The observed hit density was 6.6~hits/mm for particles crossing the layers perpendicularly, at a distance of 1~cm from the capillaries' readout end, and 4.2~hits/mm for particles at a distance of 20~cm. A track segment reconstructed in a single layer had an rms residual of $\\sim$~20~$\\mu$m, and allowed determination of the track position in a neighbouring layer with a precision of $\\sim$~170~$\\mu$m. This latter value corresponded to...

  2. Study of the spatial resolution of low-material GEM tracking detectors

    Directory of Open Access Journals (Sweden)

    Kudryavtsev V.N.

    2018-01-01

    Full Text Available The spatial resolution of GEM based tracking detectors has been simulated and measured. The simulation includes the GEANT4 based transport of high energy electrons with careful accounting for atomic relaxation processes including emission of fluorescent photons and Auger electrons and custom post-processing, including accounting for diffusion, gas amplification fluctuations, the distribution of signals on readout electrodes, electronics noise and a particular algorithm of the final coordinate calculation (center of gravity. The simulation demonstrates that a minimum of the spatial resolution of about 10 μm can be achieved with strip pitches from 250 μm to 300 μm. For larger pitches the resolution is quickly degrading reaching 80-100 μm at a pitch of 500 μm. The spatial resolution of low-material triple-GEM detectors for the DEUTRON facility at the VEPP-3 storage ring is measured at the extracted beam facility of the VEPP-4M collider. The amount of material in these detectors is reduced by etching the copper of the GEMs electrodes and using a readout structure on a thin kapton foil rather than on a glass fibre plate. The exact amount of material in one DEUTRON detector is measured by studying multiple scattering of 100 MeV electrons in it. The result of these measurements is X/X0 = 2.4×10−3 corresponding to a thickness of the copper layers of the GEM foils of 3 μm. The spatial resolution of one DEUTRON detector is measured with 500 MeV electrons and the measured value is equal to 35 ± 1 μm for orthogonal tracks.

  3. Study of the spatial resolution of low-material GEM tracking detectors

    Science.gov (United States)

    Kudryavtsev, V. N.; Maltsev, T. V.; Shekhtman, L. I.

    2018-02-01

    The spatial resolution of GEM based tracking detectors has been simulated and measured. The simulation includes the GEANT4 based transport of high energy electrons with careful accounting for atomic relaxation processes including emission of fluorescent photons and Auger electrons and custom post-processing, including accounting for diffusion, gas amplification fluctuations, the distribution of signals on readout electrodes, electronics noise and a particular algorithm of the final coordinate calculation (center of gravity). The simulation demonstrates that a minimum of the spatial resolution of about 10 μm can be achieved with strip pitches from 250 μm to 300 μm. For larger pitches the resolution is quickly degrading reaching 80-100 μm at a pitch of 500 μm. The spatial resolution of low-material triple-GEM detectors for the DEUTRON facility at the VEPP-3 storage ring is measured at the extracted beam facility of the VEPP-4M collider. The amount of material in these detectors is reduced by etching the copper of the GEMs electrodes and using a readout structure on a thin kapton foil rather than on a glass fibre plate. The exact amount of material in one DEUTRON detector is measured by studying multiple scattering of 100 MeV electrons in it. The result of these measurements is X/X0 = 2.4×10-3 corresponding to a thickness of the copper layers of the GEM foils of 3 μm. The spatial resolution of one DEUTRON detector is measured with 500 MeV electrons and the measured value is equal to 35 ± 1 μm for orthogonal tracks.

  4. Tracking Solid Oxide Cell Microstructure Evolution by High Resolution 3D Nano-Tomography

    DEFF Research Database (Denmark)

    De Angelis, Salvatore

    . The degradation processes are mainly attributed to morphological changes occurring within the electrodes microstructure. Therefore, precise tracking of 3D microstructural evolution during operation is considered crucial to understanding the complex relationship between microstructure and performance. In this work......, X-ray ptychographic tomography is applied to SOC materials, demonstrating unprecedented spatial resolution and data quality. The eect of a complete redox cycle on the same Ni-YSZ microstructure is visualized ex-situ in 3D, showing major rearrangement of the nickel network after reduction......, the formation of cracks in the YSZ, and void formation in nickel oxide after oxidation. Capitalizing on the high resolution of ptychography, the eect of nickel coarsening on the Ni-YSZ microstructure evolution is studied ex-situ in three dimensions, while the sample is repeatedly scanned and treated at high...

  5. Comparison of different "along the track" high resolution satellite stereo-pair for DSM extraction

    Science.gov (United States)

    Nikolakopoulos, Konstantinos G.

    2013-10-01

    The possibility to create DEM from stereo pairs is based on the Pythagoras theorem and on the principles of photogrammetry that are applied to aerial photographs stereo pairs for the last seventy years. The application of these principles to digital satellite stereo data was inherent in the first satellite missions. During the last decades the satellite stereo-pairs were acquired across the track in different days (SPOT, ERS etc.). More recently the same-date along the track stereo-data acquisition seems to prevail (Terra ASTER, SPOT5 HRS, Cartosat, ALOS Prism) as it reduces the radiometric image variations (refractive effects, sun illumination, temporal changes) and thus increases the correlation success rate in any image matching.Two of the newest satellite sensors with stereo collection capability is Cartosat and ALOS Prism. Both of them acquire stereopairs along the track with a 2,5m spatial resolution covering areas of 30X30km. In this study we compare two different satellite stereo-pair collected along the track for DSM creation. The first one is created from a Cartosat stereopair and the second one from an ALOS PRISM triplet. The area of study is situated in Chalkidiki Peninsula, Greece. Both DEMs were created using the same ground control points collected with a Differential GPS. After a first control for random or systematic errors a statistical analysis was done. Points of certified elevation have been used to estimate the accuracy of these two DSMs. The elevation difference between the different DEMs was calculated. 2D RMSE, correlation and the percentile value were also computed and the results are presented.

  6. Early Cardiac Involvement Affects Left Ventricular Longitudinal Function in Females Carrying α-Galactosidase A Mutation: Role of Hybrid Positron Emission Tomography and Magnetic Resonance Imaging and Speckle-Tracking Echocardiography.

    Science.gov (United States)

    Spinelli, Letizia; Imbriaco, Massimo; Nappi, Carmela; Nicolai, Emanuele; Giugliano, Giuseppe; Ponsiglione, Andrea; Diomiaiuti, Tommaso Claudio; Riccio, Eleonora; Duro, Giovanni; Pisani, Antonio; Trimarco, Bruno; Cuocolo, Alberto

    2018-04-01

    Hybrid 18 F-fluorodeoxyglucose (FDG) positron emission tomography and magnetic resonance imaging may differentiate mature fibrosis or scar from fibrosis associated to active inflammation in patients with Anderson-Fabry disease, even in nonhypertrophic stage. This study was designed to compare the results of positron emission tomography and magnetic resonance cardiac imaging with those of speckle-tracking echocardiography in heterozygous Anderson-Fabry disease females. Twenty-four heterozygous females carrying α-galactosidase A mutation and without left ventricular hypertrophy underwent cardiac positron emission tomography and magnetic resonance using 18 F-FDG for glucose uptake and 2-dimensional strain echocardiography. 18 F-FDG myocardial uptake was quantified by measuring the coefficient of variation (COV) of the standardized uptake value using a 17-segment model. Focal 18 F-FDG uptake with COV >0.17 was detected in 13 patients, including 2 patients with late gadolinium enhancement at magnetic resonance. COV was 0.30±0.14 in patients with focal 18 F-FDG uptake and 0.12±0.03 in those without ( P 0.17 compared with those with COV ≤0.17 (-18.5±2.7% versus -22.2±1.8%; P =0.024). For predicting COV >0.17, a global longitudinal strain >-19.8% had 77% sensitivity and 91% specificity and a value >2 dysfunctional segments 92% sensitivity and 100% specificity. In females carrying α-galactosidase A mutation, focal 18 F-FDG uptake represents an early sign of disease-related myocardial damage and is associated with impaired left ventricular longitudinal function. These findings support the hypothesis that inflammation plays an important role in glycosphingolipids storage disorders. © 2018 American Heart Association, Inc.

  7. Value of tissue Doppler-derived Tei index and two-dimensional speckle tracking imaging derived longitudinal strain on predicting outcome of patients with light-chain cardiac amyloidosis.

    Science.gov (United States)

    Liu, Dan; Hu, Kai; Herrmann, Sebastian; Cikes, Maja; Ertl, Georg; Weidemann, Frank; Störk, Stefan; Nordbeck, Peter

    2017-06-01

    Prognosis of patients with light-chain cardiac amyloidosis (AL-CA) is poor. Speckle tracking imaging (STI) derived longitudinal deformation parameters and Doppler-derived left ventricular (LV) Tei index are valuable predictors of outcome in patients with AL-CA. We estimated the prognostic utility of Tei index and deformation parameters in 58 comprehensively phenotyped patients with AL-CA after a median follow-up of 365 days (quartiles 121, 365 days). The primary end point was all-cause mortality. 19 (33%) patients died during follow-up. Tei index (0.89 ± 0.29 vs. 0.61 ± 0.16, p < 0.001) and E to global early diastolic strain rate ratio (E/GLSR dias ) were higher while global longitudinal systolic strain (GLS sys ) was lower in non-survivors than in survivors (all p < 0.05). Tei index, NYHA functional class, GLS sys and E/GLSR dias were independent predictors of all-cause mortality risk, and Tei index ≥0.9 (HR 7.01, 95% CI 2.43-20.21, p < 0.001) was the best predictor of poor outcome. Combining Tei index and GLS sys yielded the best results on predicting death within 1 year (100% with Tei index ≥0.9 and GLS sys ≤13%) or survival (95% with Tei index ≤0.9 and GLS sys ≥13%). We conclude that 1-year mortality risk in AL-CA patients can be reliably predicted using Tei index or deformation parameters, with combined analysis offering best performance.

  8. Resting multilayer 2D speckle-tracking TTE for detection of ischemic segments confirmed by invasive FFR part-2, using post-systolic-strain-index and time from aortic-valve-closure to regional peak longitudinal-strain.

    Science.gov (United States)

    Ozawa, Koya; Funabashi, Nobusada; Nishi, Takeshi; Takahara, Masayuki; Fujimoto, Yoshihide; Kamata, Tomoko; Kobayashi, Yoshio

    2016-08-15

    This study evaluated the post-systolic strain index (PSI), and the time interval between aortic valve closure (AVC) and regional peak longitudinal strain (PLS), measured by transthoracic echocardiography (TTE), for detection of left ventricular (LV) myocardial ischemic segments confirmed by invasive fractional flow reserve (FFR). 39 stable patients (32 males; 65.8±11.9years) with 46 coronary arteries at ≥50% stenosis on invasive coronary angiography underwent 2D speckle tracking TTE (Vivid E9, GE Healthcare) and invasive FFR measurements. PSI, AVC and regional PLS in each LV segment were calculated. FFR ≤0.80 was detected in 27 LV segments. There were no significant differences between segments supplied by FFR ≤0.80 and FFR >0.80 vessels in either PSI or the time interval between AVC and regional PLS. To identify LV segments±FFR ≤0.80, the receiver operator characteristic (ROC) curves for PSI, and the time interval between AVC and regional PLS had areas under the curve (AUC) values of 0.58 and 0.57, respectively, with best cut-off points of 12% (sensitivity 70.4%, specificity 57.9%) and 88ms (sensitivity 70.4%, specificity 52.6%), respectively, but the AUCs were not statistically significant. In stable coronary artery disease patients with ≥50% coronary artery stenosis, measurement of PSI, and the time interval between AVC and regional PLS, on resting TTE, enabled the identification of LV segments with FFR ≤0.80 using each appropriate threshold for PSI, and the time interval between AVC and regional PLS, with reasonable diagnostic accuracy. However, the AUC values were not statistically significant. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. Laser speckle imaging based on photothermally driven convection

    Science.gov (United States)

    Regan, Caitlin; Choi, Bernard

    2016-02-01

    Laser speckle imaging (LSI) is an interferometric technique that provides information about the relative speed of moving scatterers in a sample. Photothermal LSI overcomes limitations in depth resolution faced by conventional LSI by incorporating an excitation pulse to target absorption by hemoglobin within the vascular network. Here we present results from experiments designed to determine the mechanism by which photothermal LSI decreases speckle contrast. We measured the impact of mechanical properties on speckle contrast, as well as the spatiotemporal temperature dynamics and bulk convective motion occurring during photothermal LSI. Our collective data strongly support the hypothesis that photothermal LSI achieves a transient reduction in speckle contrast due to bulk motion associated with thermally driven convection. The ability of photothermal LSI to image structures below a scattering medium may have important preclinical and clinical applications.

  10. Focal plane instrumentation: a very high resolution MWPC system for inclined tracks

    International Nuclear Information System (INIS)

    Bertozzi, W.; Hynes, M.V.; Sargent, C.P.; Creswell, C.; Dunn, P.C.; Hirsch, A.; Leitch, M.; Norum, B.; Rad, F.N.; Sasanuma, T.

    1977-01-01

    A focal plane system has been developed for the MIT energy-loss spectrometer. The arrival time information from adjacent wires of one MWPC (s=2mm), is used to trace particle trajectories with a position resolution of 120μm (2sigma) and an angular resolution of less than 17 mrad (2sigma). The tracks are inclined to the MWPC at about 45 0 . The readout uses 3 delay lines connected to successive sense wires in a cyclical pattern. Coarse wire positions are determined by differences and drift times by sums of signal arrival times at the ends of the delays lines. A Cherenkov counter provides a fiducial signal. Interpolation is independent of drift velocity since the drift is normal to the sense plane. A similar readout with a second chamber provides position information perpendicular to momentum plane. This information is used to correct on-line for focal plane curvatures and other spectrometer aberrations. Final momentum resolution is about 10 -4 . (Auth.)

  11. Reducing Earth Topography Resolution for SMAP Mission Ground Tracks Using K-Means Clustering

    Science.gov (United States)

    Rizvi, Farheen

    2013-01-01

    The K-means clustering algorithm is used to reduce Earth topography resolution for the SMAP mission ground tracks. As SMAP propagates in orbit, knowledge of the radar antenna footprints on Earth is required for the antenna misalignment calibration. Each antenna footprint contains a latitude and longitude location pair on the Earth surface. There are 400 pairs in one data set for the calibration model. It is computationally expensive to calculate corresponding Earth elevation for these data pairs. Thus, the antenna footprint resolution is reduced. Similar topographical data pairs are grouped together with the K-means clustering algorithm. The resolution is reduced to the mean of each topographical cluster called the cluster centroid. The corresponding Earth elevation for each cluster centroid is assigned to the entire group. Results show that 400 data points are reduced to 60 while still maintaining algorithm performance and computational efficiency. In this work, sensitivity analysis is also performed to show a trade-off between algorithm performance versus computational efficiency as the number of cluster centroids and algorithm iterations are increased.

  12. A Microscopic Optically Tracking Navigation System That Uses High-resolution 3D Computer Graphics.

    Science.gov (United States)

    Yoshino, Masanori; Saito, Toki; Kin, Taichi; Nakagawa, Daichi; Nakatomi, Hirofumi; Oyama, Hiroshi; Saito, Nobuhito

    2015-01-01

    Three-dimensional (3D) computer graphics (CG) are useful for preoperative planning of neurosurgical operations. However, application of 3D CG to intraoperative navigation is not widespread because existing commercial operative navigation systems do not show 3D CG in sufficient detail. We have developed a microscopic optically tracking navigation system that uses high-resolution 3D CG. This article presents the technical details of our microscopic optically tracking navigation system. Our navigation system consists of three components: the operative microscope, registration, and the image display system. An optical tracker was attached to the microscope to monitor the position and attitude of the microscope in real time; point-pair registration was used to register the operation room coordinate system, and the image coordinate system; and the image display system showed the 3D CG image in the field-of-view of the microscope. Ten neurosurgeons (seven males, two females; mean age 32.9 years) participated in an experiment to assess the accuracy of this system using a phantom model. Accuracy of our system was compared with the commercial system. The 3D CG provided by the navigation system coincided well with the operative scene under the microscope. Target registration error for our system was 2.9 ± 1.9 mm. Our navigation system provides a clear image of the operation position and the surrounding structures. Systems like this may reduce intraoperative complications.

  13. Speckle-modulating optical coherence tomography in living mice and humans

    Science.gov (United States)

    Liba, Orly; Lew, Matthew D.; Sorelle, Elliott D.; Dutta, Rebecca; Sen, Debasish; Moshfeghi, Darius M.; Chu, Steven; de La Zerda, Adam

    2017-06-01

    Optical coherence tomography (OCT) is a powerful biomedical imaging technology that relies on the coherent detection of backscattered light to image tissue morphology in vivo. As a consequence, OCT is susceptible to coherent noise (speckle noise), which imposes significant limitations on its diagnostic capabilities. Here we show speckle-modulating OCT (SM-OCT), a method based purely on light manipulation that virtually eliminates speckle noise originating from a sample. SM-OCT accomplishes this by creating and averaging an unlimited number of scans with uncorrelated speckle patterns without compromising spatial resolution. Using SM-OCT, we reveal small structures in the tissues of living animals, such as the inner stromal structure of a live mouse cornea, the fine structures inside the mouse pinna, and sweat ducts and Meissner's corpuscle in the human fingertip skin--features that are otherwise obscured by speckle noise when using conventional OCT or OCT with current state of the art speckle reduction methods.

  14. Computer vision elastography: speckle adaptive motion estimation for elastography using ultrasound sequences.

    Science.gov (United States)

    Revell, James; Mirmehdi, Majid; McNally, Donal

    2005-06-01

    We present the development and validation of an image based speckle tracking methodology, for determining temporal two-dimensional (2-D) axial and lateral displacement and strain fields from ultrasound video streams. We refine a multiple scale region matching approach incorporating novel solutions to known speckle tracking problems. Key contributions include automatic similarity measure selection to adapt to varying speckle density, quantifying trajectory fields, and spatiotemporal elastograms. Results are validated using tissue mimicking phantoms and in vitro data, before applying them to in vivo musculoskeletal ultrasound sequences. The method presented has the potential to improve clinical knowledge of tendon pathology from carpel tunnel syndrome, inflammation from implants, sport injuries, and many others.

  15. Impact of measuring electron tracks in high-resolution scientific charge-coupled devices within Compton imaging systems

    International Nuclear Information System (INIS)

    Chivers, D.H.; Coffer, A.; Plimley, B.; Vetter, K.

    2011-01-01

    We have implemented benchmarked models to determine the gain in sensitivity of electron-tracking based Compton imaging relative to conventional Compton imaging by the use of high-resolution scientific charge-coupled devices (CCD). These models are based on the recently demonstrated ability of electron-tracking based Compton imaging by using fully depleted scientific CCDs. Here we evaluate the gain in sensitivity by employing Monte Carlo simulations in combination with advanced charge transport models to calculate two-dimensional charge distributions corresponding to experimentally obtained tracks. In order to reconstruct the angle of the incident γ-ray, a trajectory determination algorithm was used on each track and integrated into a back-projection routine utilizing a geodesic-vertex ray tracing technique. Analysis was performed for incident γ-ray energies of 662 keV and results show an increase in sensitivity consistent with tracking of the Compton electron to approximately ±30 o .

  16. Speckle interferometry of asteroids

    International Nuclear Information System (INIS)

    Drummond, J.

    1988-01-01

    By studying the image two-dimensional power spectra or autocorrelations projected by an asteroid as it rotates, it is possible to locate its rotational pole and derive its three axes dimensions through speckle interferometry under certain assumptions of uniform, geometric scattering, and triaxial ellipsoid shape. However, in cases where images can be reconstructed, the need for making the assumptions is obviated. Furthermore, the ultimate goal for speckle interferometry of image reconstruction will lead to mapping albedo features (if they exist) as impact areas or geological units. The first glimpses of the surface of an asteroid were obtained from images of 4 Vesta reconstructed from speckle interferometric observations. These images reveal that Vesta is quite Moon-like in having large hemispheric-scale albedo features. All of its lightcurves can be produced from a simple model developed from the images. Although undoubtedly more intricate than the model, Vesta's lightcurves can be matched by a model with three dark and four bright spots. The dark areas so dominate one hemisphere that a lightcurve minimum occurs when the maximum cross-section area is visible. The triaxial ellipsoid shape derived for Vesta is not consistent with the notion that the asteroid has an equilibrium shape in spite of its having apparently been differentiated

  17. Conflict Resolution in Aceh in Light of Track One and a Half Diplomacy

    Directory of Open Access Journals (Sweden)

    Robert M. Heiling

    2008-01-01

    Full Text Available This paper analyzes the role of mediators in the resolution of the Aceh conflict within the framework of a three-step process. Two separate mediation efforts, one conducted by the Centre for Humanitarian Dialogue from 1999 until 2003 and a second one led by Martti Ahtisaari and his Crisis Management Initiative in 2004/2005, attempted to solve the Aceh confl ict. The author shows that beside contextual factors such as ripeness of the conflict and advantageous relations between and characteristics of the conflict parties, the success of Ahtisaari’s engagement can be further explained by procedural factors. These include mediator behaviour and mediation strategies. Furthermore the mediator’s ability to use contacts with official track one actors was crucial in securing the signing as well as the implementation of the present peace agreement. ----- Der Artikel analysiert die Rolle von Mediatoren in der Lösung des Aceh Konfl ikts mittels eines drei-Phasen Modells von Konfliktlösung. Zwei voneinander unabhängige Mediationsverfahren, jenes des Centre for Humanitarian Dialogue von 1999 bis 2003, und ein weiteres geleitet durch Martti Ahtisaari und seiner Crisis Management Initiative in 2004/2005, zielten darauf ab den Konflikt zu lösen. Der Autor zeigt, dass neben kontextuellen Faktoren wie einer “ripeness” des Konflikts sowie günstigen Veränderungen auf Seite der Konfliktparteien, prozedurale Faktoren für den Erfolg Ahtisaaris entscheidend waren. Diese Faktoren beziehen sich auf das Agieren und die Strategien des Mediators. Die Fähigkeit des Mediators, Kontakte zu offiziellen “track one” Akteuren aktiv während des Mediationsprozesses zu nutzen, bildete einen Schlüsselfaktor darin einen Friedensschluss und im weiteren Verlauf eine weitgehend erfolgreiche Umsetzung des aktuellen Abkommens zwischen den ehemaligen Konfliktparteien zu erreichen.

  18. Diagnosis of spatial resolution for microbeam scanning PIXE using STIM method and CR-39 track detector in PASTA

    International Nuclear Information System (INIS)

    Hamano, T.; Imaseki, H.; Yukawa, M.; Ishikawa, T.; Iso, H.; Matsumoto, K.

    2003-01-01

    In PIXE analysis system and Tandem Accelerator facility (PASTA) of NIRS, we are using Scanning Transmission Ion Microscopy (STIM) method and solid track detector to diagnose the spatial resolution of scanning microbeam PIXE analysis system. These methods are widely used by many microbeam facilities. (author)

  19. Alterations of left ventricular deformation and cardiac sympathetic derangement in patients with systolic heart failure: a 3D speckle tracking echocardiography and cardiac {sup 123}I-MIBG study

    Energy Technology Data Exchange (ETDEWEB)

    Leosco, Dario; Parisi, Valentina; Pagano, Gennaro; Femminella, Grazia Daniela; Bevilacqua, Agnese; Formisano, Roberto; Ferro, Gaetana; De Lucia, Claudio; Ferrara, Nicola [University Federico II, Department of Translational Medical Science, Naples (Italy); Pellegrino, Teresa [Italian National Research Council (CNR), Institute of Biostructure and Bioimaging, Naples (Italy); University Federico II, Department of Advanced Biomedical Science, Naples (Italy); Paolillo, Stefania [University Federico II, Department of Advanced Biomedical Science, Naples (Italy); SDN Foundation, Institute of Diagnostic and Nuclear Development, Naples (Italy); Prastaro, Maria; Filardi, Pasquale Perrone; Cuocolo, Alberto [University Federico II, Department of Advanced Biomedical Science, Naples (Italy); Rengo, Giuseppe [University Federico II, Department of Translational Medical Science, Naples (Italy); Salvatore Maugeri Foundation, IRCCS, Istituto di Telese, Benevento, BN (Italy)

    2015-09-15

    Myocardial contractile function is under the control of cardiac sympathetic activity. Three-dimensional speckle tracking echocardiography (3D-STE) and cardiac imaging with {sup 123}I-metaiodobenzylguanidine ({sup 123}I-MIBG) are two sophisticated techniques for the assessment of left ventricular (LV) deformation and sympathetic innervation, respectively, which offer important prognostic information in patients with heart failure (HF). The purpose of this investigation was to explore, in patients with systolic HF, the relationship between LV deformation assessed by 3D-STE and cardiac sympathetic derangement evaluated by {sup 123}I-MIBG imaging. We prospectively studied 75 patients with systolic HF. All patients underwent a 3D-STE study (longitudinal, circumferential, area and radial) and {sup 123}I-MIBG planar and SPECT cardiac imaging. 3D-STE longitudinal, circumferential and area strain values were correlated with {sup 123}I-MIBG late heart to mediastinum (H/M) ratio and late SPECT total defect score. After stratification of the patients according to ischaemic or nonischaemic HF aetiology, we observed a good correlation of all 3D-STE measurements with late H/M ratio and SPECT data in the ischaemic group, but in patients with HF of nonischaemic aetiology, no correlation was found between LV deformation and cardiac sympathetic activity. At the regional level, the strongest correlation between LV deformation and adrenergic innervation was found for the left anterior descending coronary artery distribution territory for all four 3D-STE values. In multivariate linear regression analyses, including age, gender, LV ejection fraction, NYHA class, body mass index, heart rate and HF aetiology, only 3D-STE area and radial strain values significantly predicted cardiac sympathetic derangement on {sup 123}I-MIBG late SPECT. This study indicated that 3D-STE measurements are correlated with {sup 123}I-MIBG planar and SPECT data. Furthermore, 3D-STE area and radial strain values

  20. A practical approach to optimizing the preparation of speckle patterns for digital-image correlation

    International Nuclear Information System (INIS)

    Lionello, Giacomo; Cristofolini, Luca

    2014-01-01

    The quality of strain measurements by digital image correlation (DIC) strongly depends on the quality of the pattern on the specimen’s surface. An ideal pattern should be highly contrasted, stochastic, and isotropic. In addition, the speckle pattern should have an average size that exceeds the image pixel size by a factor of 3–5. (Smaller speckles cause poor contrast, and larger speckles cause poor spatial resolution.) Finally, the ideal pattern should have a limited scatter in terms of speckle sizes. The aims of this study were: (i) to define the ideal speckle size in relation to the specimen size and acquisition system; (ii) provide practical guidelines to identify the optimal settings of an airbrush gun, in order to produce a pattern that is as close as possible to the desired one while minimizing the scatter of speckle sizes. Patterns of different sizes were produced using two different airbrush guns with different settings of the four most influential factors (dilution, airflow setting, spraying distance, and air pressure). A full-factorial DOE strategy was implemented to explore the four factors at two levels each: 36 specimens were analyzed for each of the 16 combinations. The images were acquired using the digital cameras of a DIC system. The distribution of speckle sizes was analyzed to calculate the average speckle size and the standard deviation of the corresponding truncated Gaussian distribution. A mathematical model was built to enable prediction of the average speckle size in relation to the airbrush gun settings. We showed that it is possible to obtain a pattern with a highly controlled average and a limited scatter of speckle sizes, so as to match the ideal distribution of speckle sizes for DIC. Although the settings identified here apply only to the specific equipment being used, this method can be adapted to any airbrush to produce a desired speckle pattern. (technical design note)

  1. 3-color photometry of a sunspot using speckle masking techniques

    NARCIS (Netherlands)

    Wiehr, E.; Sütterlin, P.

    1998-01-01

    A three-colour photometry is used to deduce the temperature of sunspot fine-structures. Using the Speckle-Masking method for image restoration, the resulting images (one per colour and burst) have a spatial resolution only limited by the telescope's aperture, i.e. 95km (blue), 145 km (red) and

  2. Speckle pattern processing by digital image correlation

    Directory of Open Access Journals (Sweden)

    Gubarev Fedor

    2016-01-01

    Full Text Available Testing the method of speckle pattern processing based on the digital image correlation is carried out in the current work. Three the most widely used formulas of the correlation coefficient are tested. To determine the accuracy of the speckle pattern processing, test speckle patterns with known displacement are used. The optimal size of a speckle pattern template used for determination of correlation and corresponding the speckle pattern displacement is also considered in the work.

  3. Super-resolution imaging and tracking of protein-protein interactions in sub-diffraction cellular space

    Science.gov (United States)

    Liu, Zhen; Xing, Dong; Su, Qian Peter; Zhu, Yun; Zhang, Jiamei; Kong, Xinyu; Xue, Boxin; Wang, Sheng; Sun, Hao; Tao, Yile; Sun, Yujie

    2014-07-01

    Imaging the location and dynamics of individual interacting protein pairs is essential but often difficult because of the fluorescent background from other paired and non-paired molecules, particularly in the sub-diffraction cellular space. Here we develop a new method combining bimolecular fluorescence complementation and photoactivated localization microscopy for super-resolution imaging and single-molecule tracking of specific protein-protein interactions. The method is used to study the interaction of two abundant proteins, MreB and EF-Tu, in Escherichia coli cells. The super-resolution imaging shows interesting distribution and domain sizes of interacting MreB-EF-Tu pairs as a subpopulation of total EF-Tu. The single-molecule tracking of MreB, EF-Tu and MreB-EF-Tu pairs reveals intriguing localization-dependent heterogonous dynamics and provides valuable insights to understanding the roles of MreB-EF-Tu interactions.

  4. Super-resolution imaging and tracking of protein–protein interactions in sub-diffraction cellular space

    Science.gov (United States)

    Liu, Zhen; Xing, Dong; Su, Qian Peter; Zhu, Yun; Zhang, Jiamei; Kong, Xinyu; Xue, Boxin; Wang, Sheng; Sun, Hao; Tao, Yile; Sun, Yujie

    2014-01-01

    Imaging the location and dynamics of individual interacting protein pairs is essential but often difficult because of the fluorescent background from other paired and non-paired molecules, particularly in the sub-diffraction cellular space. Here we develop a new method combining bimolecular fluorescence complementation and photoactivated localization microscopy for super-resolution imaging and single-molecule tracking of specific protein–protein interactions. The method is used to study the interaction of two abundant proteins, MreB and EF-Tu, in Escherichia coli cells. The super-resolution imaging shows interesting distribution and domain sizes of interacting MreB–EF-Tu pairs as a subpopulation of total EF-Tu. The single-molecule tracking of MreB, EF-Tu and MreB–EF-Tu pairs reveals intriguing localization-dependent heterogonous dynamics and provides valuable insights to understanding the roles of MreB–EF-Tu interactions. PMID:25030837

  5. Potential of the McMath-Pierce 1.6-Meter Solar Telescope for Speckle Interferometry

    Science.gov (United States)

    Harshaw, Richard; Jones, Gregory; Wiley, Edward; Boyce, Patrick; Branston, Detrick; Rowe, David; Genet, Russell

    2015-09-01

    We explored the aiming and tracking accuracy of the McMath-Pierce 1.6 m solar telescope at Kitt Peak National Observatory as part of an investigation of using this telescope for speckle interferometry of close visual double stars. Several slews of various lengths looked for hysteresis in the positioning system (we found none of significance) and concluded that the 1.6 m telescope would make a useful telescope for speckle interferometry.

  6. On the spatial errors and resolution of near tracks when parallel tracing by their images on photographs

    International Nuclear Information System (INIS)

    Ehrglis, K.Eh.

    1980-01-01

    Errors in the determination of spatial reference point (SRP) coordinates being reconstructed on the basis of photograph reference points are considered. The width of paths of probable track positions on photographs and the length of intersection zones of these paths with hampering track images are estimated. Conditions for a stable automatic tracing of closely traversing in space tracks are determined. The conclusion is made that of 5-6 SRP are accumulated the method of spatial tracing when shifting local scanning centres on photographs with a corresponding speed permits to trace automatically closely traversing tracks in the middle zone of the Merabel chamber when the angle between them is approximately 1 deg and the distance in space - 3-7 mm. It is emphasized that, when forecasting 8-10 SRP, the spatial or angle track resolution improves 1.5 times more due to the diminution of forecasting errors and corresponding narrowing of sensitivity paths. The described method will be especially effective when processing photographs taken in bubble chambers of a new generation at particle energies being tens-hundreds GeV [ru

  7. Color speckle in laser displays

    Science.gov (United States)

    Kuroda, Kazuo

    2015-07-01

    At the beginning of this century, lighting technology has been shifted from discharge lamps, fluorescent lamps and electric bulbs to solid-state lighting. Current solid-state lighting is based on the light emitting diodes (LED) technology, but the laser lighting technology is developing rapidly, such as, laser cinema projectors, laser TVs, laser head-up displays, laser head mounted displays, and laser headlamps for motor vehicles. One of the main issues of laser displays is the reduction of speckle noise1). For the monochromatic laser light, speckle is random interference pattern on the image plane (retina for human observer). For laser displays, RGB (red-green-blue) lasers form speckle patterns independently, which results in random distribution of chromaticity, called color speckle2).

  8. High Resolution Astrophysical Observations Using Speckle Imaging

    Science.gov (United States)

    1986-04-11

    reserved. Printed in U.S A . A NEW OPTICAL SOURCE ASSOCIATED WITH T TAURI P. NISENSON, R. V. STACHNIK, M. KAROVSKA , AND R. NOYES Harvard-Smithsonian Center...NISENSON, STACHNIK, KAROVSKA . AND NoYEs (see page L18) APPENDIX F ON THE a ORIONIS TRIPLE SYSTEM M. Karovska , P. Nisenson, R. Noyes Harvard-Smithsonian...3.5 and 4.0 at a wavelengtRh of 530 nm. In Addition, Karovska (1984) inferred the possible existence of a second companion from an image recon

  9. Laser Speckle Contrast Imaging: theory, instrumentation and applications.

    Science.gov (United States)

    Senarathna, Janaka; Rege, Abhishek; Li, Nan; Thakor, Nitish V

    2013-01-01

    Laser Speckle Contrast Imaging (LSCI) is a wide field of view, non scanning optical technique for observing blood flow. Speckles are produced when coherent light scattered back from biological tissue is diffracted through the limiting aperture of focusing optics. Mobile scatterers cause the speckle pattern to blur; a model can be constructed by inversely relating the degree of blur, termed speckle contrast to the scatterer speed. In tissue, red blood cells are the main source of moving scatterers. Therefore, blood flow acts as a virtual contrast agent, outlining blood vessels. The spatial resolution (~10 μm) and temporal resolution (10 ms to 10 s) of LSCI can be tailored to the application. Restricted by the penetration depth of light, LSCI can only visualize superficial blood flow. Additionally, due to its non scanning nature, LSCI is unable to provide depth resolved images. The simple setup and non-dependence on exogenous contrast agents have made LSCI a popular tool for studying vascular structure and blood flow dynamics. We discuss the theory and practice of LSCI and critically analyze its merit in major areas of application such as retinal imaging, imaging of skin perfusion as well as imaging of neurophysiology.

  10. Studies on the Belle II L1 CDC track trigger's z-vertex resolution with neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Skambraks, Sebastian; Neuhaus, Sara; Chen, Yang [Technische Universitaet Muenchen (Germany); Abudinen, Fernando; Kiesling, Christian [Max-Planck-Institut fuer Physik, Muenchen (Germany)

    2015-07-01

    We present the use of a neural network ensemble for the first level (L1) track trigger subsystem of Belle II. Our method employs hit and drift time information from the Central Drift Chamber (CDC). Estimating the z-coordinates of the vertex positions improves the signal to background ratio in the recorded data. Especially beam induced background can clearly be rejected, allowing to relax the 2D trigger conditions and thus enhancing the physics gain for low multiplicity events (e.g. tau pair production). Neural networks enable an improvement of the z-vertex resolution compared to linear least squares track fitting. As general function approximators, they are capable of learning nonlinearities solely from a training dataset. We propose a combined setup, integrating the benefits of the linear fit and enriching it with the nonlinear prediction capabilities of the neural networks. The precise z-vertices of single tracks are estimated by an ensemble of local expert neural networks, specialized to sectors in the track parameter phase space. A comparison is presented, demonstrating the differences of the linear fit and the neural network approach.

  11. SU-E-J-197: Investigation of Microsoft Kinect 2.0 Depth Resolution for Patient Motion Tracking

    Energy Technology Data Exchange (ETDEWEB)

    Silverstein, E; Snyder, M [Wayne State University, Detroit, MI (United States)

    2015-06-15

    Purpose: Investigate the use of the Kinect 2.0 for patient motion tracking during radiotherapy by studying spatial and depth resolution capabilities. Methods: Using code written in C#, depth map data was abstracted from the Kinect to create an initial depth map template indicative of the initial position of an object to be compared to the depth map of the object over time. To test this process, simple setup was created in which two objects were imaged: a 40 cm × 40 cm board covered in non reflective material and a 15 cm × 26 cm textbook with a slightly reflective, glossy cover. Each object, imaged and measured separately, was placed on a movable platform with object to camera distance measured. The object was then moved a specified amount to ascertain whether the Kinect’s depth camera would visualize the difference in position of the object. Results: Initial investigations have shown the Kinect depth resolution is dependent on the object to camera distance. Measurements indicate that movements as small as 1 mm can be visualized for objects as close as 50 cm away. This depth resolution decreases linearly with object to camera distance. At 4 m, the depth resolution had decreased to observe a minimum movement of 1 cm. Conclusion: The improved resolution and advanced hardware of the Kinect 2.0 allows for increase of depth resolution over the Kinect 1.0. Although obvious that the depth resolution should decrease with increasing distance from an object given the decrease in number of pixels representing said object, the depth resolution at large distances indicates its usefulness in a clinical setting.

  12. The Magnetic Nanoparticle Movement in Magnetic Fluid Characterized by the Laser Dynamic Speckle Interferometry

    Directory of Open Access Journals (Sweden)

    Xijun Wang

    2014-01-01

    Full Text Available A dual scanning laser speckle interferometry experiment was designed to observe the dynamic behavior of the magnetic fluid actuated by a magnetic field. In order to improve the spatial resolution of the dynamic speckle measurement, the phase delay scanning was used to compensate the additional phase variation which was caused by the transverse scanning. The correlation coefficients corresponding to the temporal dynamic speckle patterns within the same time interval scattering from the nanoparticles were calculated in the experiment on nanoscale magnetic clusters. In the experiment, the speckle of the magnetic nanoparticle fluid movement has been recorded by the lens unmounted CCD within the interferometry strips, although the speckle led to the distinguished annihilation of the light coherence. The results have showed that the nanoparticle fluid dynamic properties appeared synergistically in the fringe speckles. The analyses of the nanoparticle's relative speed and the speckle pattern moving amount in the fringes have proved the nanoparticle’s movement in a laminar flow in the experiment.

  13. Tracking the long-distance dispersal of marine organisms: sensitivity to ocean model resolution

    OpenAIRE

    Putman, Nathan F.; He, Ruoying

    2013-01-01

    Ocean circulation models are widely used to simulate organism transport in the open sea, where challenges of directly tracking organisms across vast spatial and temporal scales are daunting. Many recent studies tout the use of ‘high-resolution’ models, which are forced with atmospheric data on the scale of several hours and integrated with a time step of several minutes or seconds. However, in many cases, the model's outputs that are used to simulate organism movement have been averaged to co...

  14. Dynamical speckles in watery surfaces

    International Nuclear Information System (INIS)

    Llovera-Gonzalez, J.J.; Moreno-Yeras, A.; Garcia-Diaz, M.; Alvarez-Salgado, Y.

    2009-01-01

    Recovery of watery surfaces with monolayer of surfactant substances is of interest in diverse technological applications. The format ion and study of molecular monolayer deposited in these surfaces require the application of measurements techniques that allow evaluating the recovery grade locally without modifying practically the studied surface. In this paper the preliminary results obtained by the authors it plows exposed applying the technique of dynamic speckle interferometry in watery surfaces and their consideration like to possible resource to measure the grade of local recovery of these surfaces on the it bases that the speckles pattern dog reveal the dynamics of evaporation that takes place in the same ones. (Author)

  15. Development of large-volume, high-resolution tracking detectors based on capillaries filled with liquid scintillator

    International Nuclear Information System (INIS)

    Buontempo, S.; Fabre, J.P.; Frenkel, A.; Gregoire, G.; Hoepfner, K.; Konijn, J.; Kozarenko, E.; Kreslo, I.; Kushnirenko, A.; Martellotti, G.; Michel, L.; Mondardini, M.R.; Penso, G.; Siegmund, W.P.; Strack, R.; Tyukov, V.; Vasilchenko, V.; Vilain, P.; Wilquet, G.; Winter, K.; Wong, H.; Zymin, K.

    1995-01-01

    Searches for the decay of short-lived particles require real time, high-resolution tracking in active targets, which in the case of neutrino physics should be of large volume. The possibility of achieving this by using glass capillaries filled with organic liquid scintillator is being investigated in the framework of the CHORUS experiment at CERN. In this paper, after outlining the application foreseen, advances in the tracking technique are discussed and results from tests are reported. An active target of dimensions 180x2x2 cm 3 has been assembled from capillaries with 20 μm diameter pores. The readout scheme currently in operation allows the reading of similar 5x10 5 channels using a single chain of image intensifiers having a resolution of σ similar 20 μm. Following the development of new liquid scintillators and purification methods an attenuation length of similar 3 m has been obtained. This translates into a hit density of 3.5 per mm for a minimum-ionizing particle that crosses the active target at a distance of 1 m from the readout end. (orig.)

  16. The POKEMON Speckle Survey of Nearby M-Dwarfs

    Science.gov (United States)

    van Belle, Gerard; von Braun, Kaspar; Horch, Elliott; Clark, Catherine; DSSI Speckle Team

    2018-01-01

    The POKEMON (Pervasive Overview of Kompanions of Every M-dwarf in Our Neighborhood) survey of nearby M-dwarfs intends to inspect, at diffraction-limited resolution, every low-mass star out to 15pc, along with selected additional objects to 25pc. The primary emphasis of the survey is detection of low-mass companions to these M-dwarfs for refinement of the low-mass star multiplicity rate. The resultant catalog of M-dwarf companions will also guide immediate refinement of transit planet detection results from surveys such as TESS. POKEMON is using Lowell Observatory's 4.3-m Discovery Channel Telescope (DCT) with the Differential Speckle Survey Instrument (DSSI) speckle camera, along with the NN-Explore Exoplanet Stellar Speckle Imager (NESSI) speckle imager on 3.5-m WIYN; the survey takes advantage of the extremely rapid observing cadence rates possible with WIYN and (especially) DCT. The current status and preliminary results from the first 20+ nights of observing will be presented. Gotta observe them all!

  17. Fluorescent Nanodiamond: A Versatile Tool for Long-Term Cell Tracking, Super-Resolution Imaging, and Nanoscale Temperature Sensing.

    Science.gov (United States)

    Hsiao, Wesley Wei-Wen; Hui, Yuen Yung; Tsai, Pei-Chang; Chang, Huan-Cheng

    2016-03-15

    Fluorescent nanodiamond (FND) has recently played a central role in fueling new discoveries in interdisciplinary fields spanning biology, chemistry, physics, and materials sciences. The nanoparticle is unique in that it contains a high density ensemble of negatively charged nitrogen-vacancy (NV(-)) centers as built-in fluorophores. The center possesses a number of outstanding optical and magnetic properties. First, NV(-) has an absorption maximum at ∼550 nm, and when exposed to green-orange light, it emits bright fluorescence at ∼700 nm with a lifetime of longer than 10 ns. These spectroscopic properties are little affected by surface modification but are distinctly different from those of cell autofluorescence and thus enable background-free imaging of FNDs in tissue sections. Such characteristics together with its excellent biocompatibility render FND ideal for long-term cell tracking applications, particularly in stem cell research. Next, as an artificial atom in the solid state, the NV(-) center is perfectly photostable, without photobleaching and blinking. Therefore, the NV-containing FND is suitable as a contrast agent for super-resolution imaging by stimulated emission depletion (STED). An improvement of the spatial resolution by 20-fold is readily achievable by using a high-power STED laser to deplete the NV(-) fluorescence. Such improvement is crucial in revealing the detailed structures of biological complexes and assemblies, including cellular organelles and subcellular compartments. Further enhancement of the resolution for live cell imaging is possible by manipulating the charge states of the NV centers. As the "brightest" member of the nanocarbon family, FND holds great promise and potential for bioimaging with unprecedented resolution and precision. Lastly, the NV(-) center in diamond is an atom-like quantum system with a total electron spin of 1. The ground states of the spins show a crystal field splitting of 2.87 GHz, separating the ms = 0 and

  18. Objective speckle velocimetry for autonomous vehicle odometry.

    Science.gov (United States)

    Francis, D; Charrett, T O H; Waugh, L; Tatam, R P

    2012-06-01

    Speckle velocimetry is investigated as a means of determining odometry data with potential for application on autonomous robotic vehicles. The technique described here relies on the integration of translation measurements made by normalized cross-correlation of speckle patterns to determine the change in position over time. The use of objective (non-imaged) speckle offers a number of advantages over subjective (imaged) speckle, such as a reduction in the number of optical components, reduced modulation of speckles at the edges of the image, and improved light efficiency. The influence of the source/detector configuration on the speckle translation to vehicle translation scaling factor for objective speckle is investigated using a computer model and verified experimentally. Experimental measurements are presented at velocities up to 80  mm s(-1) which show accuracy better than 0.4%.

  19. Speckle dynamics under ergodicity breaking

    Science.gov (United States)

    Sdobnov, Anton; Bykov, Alexander; Molodij, Guillaume; Kalchenko, Vyacheslav; Jarvinen, Topias; Popov, Alexey; Kordas, Krisztian; Meglinski, Igor

    2018-04-01

    Laser speckle contrast imaging (LSCI) is a well-known and versatile approach for the non-invasive visualization of flows and microcirculation localized in turbid scattering media, including biological tissues. In most conventional implementations of LSCI the ergodic regime is typically assumed valid. However, most composite turbid scattering media, especially biological tissues, are non-ergodic, containing a mixture of dynamic and static centers of light scattering. In the current study, we examined the speckle contrast in different dynamic conditions with the aim of assessing limitations in the quantitative interpretation of speckle contrast images. Based on a simple phenomenological approach, we introduced a coefficient of speckle dynamics to quantitatively assess the ratio of the dynamic part of a scattering medium to the static one. The introduced coefficient allows one to distinguish real changes in motion from the mere appearance of static components in the field of view. As examples of systems with static/dynamic transitions, thawing and heating of Intralipid samples were studied by the LSCI approach.

  20. SPECKLE INTERFEROMETRY AT SOAR IN 2014

    International Nuclear Information System (INIS)

    Tokovinin, Andrei; Mason, Brian D.; Hartkopf, William I.; Mendez, Rene A.; Horch, Elliott P.

    2015-01-01

    The results of speckle interferometric observations at the Southern Astrophysical Research Telescope (SOAR) telescope in 2014 are given. A total of 1641 observations were taken, yielding 1636 measurements of 1218 resolved binary and multiple stars and 577 non-resolutions of 441 targets. We resolved for the first time 56 pairs, including some nearby astrometric or spectroscopic binaries and ten new subsystems in previously known visual binaries. The calibration of the data is checked by linear fits to the positions of 41 wide binaries observed at SOAR over several seasons. The typical calibration accuracy is 0.°1 in angle and 0.3% in pixel scale, while the measurement errors are on the order of 3 mas. The new data are used here to compute 194 binary star orbits, 148 of which are improvements on previous orbital solutions and 46 are first-time orbits

  1. Tracking the Resolution of Student Misconceptions about the Central Dogma of Molecular Biology.

    Science.gov (United States)

    Briggs, Amy G; Morgan, Stephanie K; Sanderson, Seth K; Schulting, Molly C; Wieseman, Laramie J

    2016-12-01

    The goal of our study was to track changes in student understanding of the central dogma of molecular biology before and after taking a genetics course. Concept maps require the ability to synthesize new information into existing knowledge frameworks, and so the hypothesis guiding this study was that student performance on concept maps reveals specific central dogma misconceptions gained, lost, and retained by students. Students in a genetics course completed pre- and posttest concept mapping tasks using terms related to the central dogma. Student maps increased in complexity and validity, indicating learning gains in both content and complexity of understanding. Changes in each of the 351 possible connections in the mapping task were tracked for each student. Our students did not retain much about the central dogma from their introductory biology courses, but they did move to more advanced levels of understanding by the end of the genetics course. The information they retained from their introductory courses focused on structural components (e.g., protein is made of amino acids) and not on overall mechanistic components (e.g., DNA comes before RNA, the ribosome makes protein). Students made the greatest gains in connections related to transcription, and they resolved the most prior misconceptions about translation. These concept-mapping tasks revealed that students are able to correct prior misconceptions about the central dogma during an intermediate-level genetics course. From these results, educators can design new classroom interventions to target those aspects of this foundational principle with which students have the most trouble.

  2. 3D high resolution tracking of ice flow using mutli-temporal stereo satellite imagery, Franz Josef Glacier, New Zealand

    Science.gov (United States)

    Leprince, S.; Lin, J.; Ayoub, F.; Herman, F.; Avouac, J.

    2013-12-01

    We present the latest capabilities added to the Co-Registration of Optically Sensed Images and Correlation (COSI-Corr) software, which aim at analyzing time-series of stereoscopic imagery to document 3D variations of the ground surface. We review the processing chain and present the new and improved modules for satellite pushbroom imagery, in particular the N-image bundle block adjustment to jointly optimize the viewing geometry of multiple acquisitions, the improved multi-scale image matching based on Semi-Global Matching (SGM) to extract high resolution topography, and the triangulation of multi-temporal disparity maps to derive 3D ground motion. In particular, processes are optimized to run on a cluster computing environment. This new suite of algorithms is applied to the study of Worldview stereo imagery above the Franz Josef, Fox, and Tasman Glaciers, New Zealand, acquired on 01/30/2013, 02/09/2013, and 02/28/2013. We derive high resolution (1m post-spacing) maps of ice flow in three dimensions, where ice velocities of up to 4 m/day are recorded. Images were collected in early summer during a dry and sunny period, which followed two weeks of unsettled weather with several heavy rainfall events across the Southern Alps. The 3D tracking of ice flow highlights the surface response of the glaciers to changes in effective pressure at the ice-bedrock interface due to heavy rainfall, at an unprecedented spatial resolution.

  3. In-vivo brain blood flow imaging based on laser speckle contrast imaging and synchrotron radiation microangiography

    International Nuclear Information System (INIS)

    Miao, Peng; Feng, Shihan; Zhang, Qi; Lin, Xiaojie; Xie, Bohua; Liu, Chenwei; Yang, Guo-Yuan

    2014-01-01

    Abstract In-vivo imaging of blood flow in the cortex and sub-cortex is still a challenge in biological and pathological studies of cerebral vascular diseases. Laser speckle contrast imaging (LSCI) only provides cortex blood flow information. Traditional synchrotron radiation micro-angiography (SRA) provides sub-cortical vasculature information with high resolution. In this study, a bolus front-tracking method was developed to extract blood flow information based on SRA. Combining LSCI and SRA, arterial blood flow in the ipsilateral cortex and sub-cortex was monitored after experimental intracerebral hemorrhage of mice. At 72 h after injury, a significant blood flow increase was observed in the lenticulostriate artery along with blood flow decrease in cortical branches of the middle cerebral artery. This combined strategy provides a new approach for the investigation of brain vasculature and blood flow changes in preclinical studies. (paper)

  4. Tracking the Resolution of Student Misconceptions about the Central Dogma of Molecular Biology†

    Science.gov (United States)

    Briggs, Amy G.; Morgan, Stephanie K.; Sanderson, Seth K.; Schulting, Molly C.; Wieseman, Laramie J.

    2016-01-01

    The goal of our study was to track changes in student understanding of the central dogma of molecular biology before and after taking a genetics course. Concept maps require the ability to synthesize new information into existing knowledge frameworks, and so the hypothesis guiding this study was that student performance on concept maps reveals specific central dogma misconceptions gained, lost, and retained by students. Students in a genetics course completed pre- and posttest concept mapping tasks using terms related to the central dogma. Student maps increased in complexity and validity, indicating learning gains in both content and complexity of understanding. Changes in each of the 351 possible connections in the mapping task were tracked for each student. Our students did not retain much about the central dogma from their introductory biology courses, but they did move to more advanced levels of understanding by the end of the genetics course. The information they retained from their introductory courses focused on structural components (e.g., protein is made of amino acids) and not on overall mechanistic components (e.g., DNA comes before RNA, the ribosome makes protein). Students made the greatest gains in connections related to transcription, and they resolved the most prior misconceptions about translation. These concept-mapping tasks revealed that students are able to correct prior misconceptions about the central dogma during an intermediate-level genetics course. From these results, educators can design new classroom interventions to target those aspects of this foundational principle with which students have the most trouble. PMID:28101260

  5. Tracking the Resolution of Student Misconceptions about the Central Dogma of Molecular Biology

    Directory of Open Access Journals (Sweden)

    Amy G. Briggs

    2016-12-01

    Full Text Available The goal of our study was to track changes in student understanding of the central dogma of molecular biology before and after taking a genetics course. Concept maps require the ability to synthesize new information into existing knowledge frameworks, and so the hypothesis guiding this study was that student performance on concept maps reveals specific central dogma misconceptions gained, lost, and retained by students. Students in a genetics course completed pre- and posttest concept mapping tasks using terms related to the central dogma. Student maps increased in complexity and validity, indicating learning gains in both content and complexity of understanding. Changes in each of the 351 possible connections in the mapping task were tracked for each student. Our students did not retain much about the central dogma from their introductory biology courses, but they did move to more advanced levels of understanding by the end of the genetics course. The information they retained from their introductory courses focused on structural components (e.g., protein is made of amino acids and not on overall mechanistic components (e.g., DNA comes before RNA, the ribosome makes protein. Students made the greatest gains in connections related to transcription, and they resolved the most prior misconceptions about translation. These concept-mapping tasks revealed that students are able to correct prior misconceptions about the central dogma during an intermediate-level genetics course. From these results, educators can design new classroom interventions to target those aspects of this foundational principle with which students have the most trouble.

  6. Simultaneous dual wavelength eye-tracked ultrahigh resolution retinal and choroidal optical coherence tomography

    DEFF Research Database (Denmark)

    Unterhuber, A.; Povaay, B.; Müller, André

    2013-01-01

    We demonstrate an optical coherence tomography device that simultaneously combines different novel ultrabroad bandwidth light sources centered in the 800 and 1060 nm regions, operating at 66 kHz depth scan rate, and a confocal laser scanning ophthalmoscope-based eye tracker to permit motion......-artifact-free, ultrahigh resolution and high contrast retinal and choroidal imaging. The two wavelengths of the device provide the complementary information needed for diagnosis of subtle retinal changes, while also increasing visibility of deeper-lying layers to image pathologies that include opaque media in the anterior...... eye segment or eyes with increased choroidal thickness....

  7. En face speckle reduction in optical coherence microscopy by frequency compounding.

    Science.gov (United States)

    Magnain, Caroline; Wang, Hui; Sakadžić, Sava; Fischl, Bruce; Boas, David A

    2016-05-01

    We report the use of frequency compounding to significantly reduce speckle noise in optical coherence microscopy, more specifically on the en face images. This method relies on the fact that the speckle patterns recorded from different wavelengths simultaneously are independent; hence their summation yields significant reduction in noise, with only a single acquisition. The results of our experiments with microbeads show that the narrow confocal parameter, due to a high numerical aperture objective, restricts the axial resolution loss that would otherwise theoretically broaden linearly with the number of optical frequency bands used. This speckle reduction scheme preserves the lateral resolution since it is performed on individual A-scans. Finally, we apply this technique to images of fixed human brain tissue, showing significant improvements in contrast-to-noise ratio with only moderate loss of axial resolution, in an effort to improve automatic three-dimensional detection of cells and fibers in the cortex.

  8. High-Resolution Tracking Asymmetric Lithium Insertion and Extraction and Local Structure Ordering in SnS2.

    Science.gov (United States)

    Gao, Peng; Wang, Liping; Zhang, Yu-Yang; Huang, Yuan; Liao, Lei; Sutter, Peter; Liu, Kaihui; Yu, Dapeng; Wang, En-Ge

    2016-09-14

    In the rechargeable lithium ion batteries, the rate capability and energy efficiency are largely governed by the lithium ion transport dynamics and phase transition pathways in electrodes. Real-time and atomic-scale tracking of fully reversible lithium insertion and extraction processes in electrodes, which would ultimately lead to mechanistic understanding of how the electrodes function and why they fail, is highly desirable but very challenging. Here, we track lithium insertion and extraction in the van der Waals interactions dominated SnS2 by in situ high-resolution TEM method. We find that the lithium insertion occurs via a fast two-phase reaction to form expanded and defective LiSnS2, while the lithium extraction initially involves heterogeneous nucleation of intermediate superstructure Li0.5SnS2 domains with a 1-4 nm size. Density functional theory calculations indicate that the Li0.5SnS2 is kinetically favored and structurally stable. The asymmetric reaction pathways may supply enlightening insights into the mechanistic understanding of the underlying electrochemistry in the layered electrode materials and also suggest possible alternatives to the accepted explanation of the origins of voltage hysteresis in the intercalation electrode materials.

  9. Online readout and control unit for high-speed/high resolution readout of silicon tracking detectors

    International Nuclear Information System (INIS)

    Buerger, J.; Hansen, K.; Lange, W.; Nowak, T.; Prell, S.; Zimmermann, W.

    1997-01-01

    We are describing a high speed VME readout and control module developed and presently working at the H1 experiment at DESY in Hamburg. It has the capability to read out 4 x 2048 analogue data channels at sampling rates up to 10 MHz with a dynamic input range of 1 V. The nominal resolution of the A/D converters can be adjusted between 8 and 12 bit. At the latter resolution we obtain signal-to-noise ratio better than 61.4 dB at a conversion rate of 5 MSps. At this data rate all 8192 detector channels can be read out to the internal raw data memory and VME interface within about 410 μs and 510 μs, respectively. The pedestal subtracted signals can be analyzed on-line. At a raw data hit occupation of 10%, the VME readout time is 50 μs per module. Each module provides four complementary CMOS signals to control the front-end electronics and four independent sets of power supplies for analogue and digital voltages (10 V, 100 mA) to drive the front-end electronics and for the bias voltage (100 V, 1.2 mA) to assure the full functionality of the detectors and the readout. (orig.)

  10. Online readout and control unit for high-speed/high resolution readout of silicon tracking detectors

    Science.gov (United States)

    Bürger, J.; Hansen, K.; Lange, W.; Nowak, T.; Prell, S.; Zimmermann, W.

    1997-02-01

    We are describing a high speed VME readout and control module developed and presently working at the H1 experiment at DESY in Hamburg. It has the capability to read out 4 × 2048 analogue data channels at sampling rates up to 10 MHz with a dynamic input range of 1 V. The nominal resolution of the A/D converters can be adjusted between 8 and 12 bit. At the latter resolution we obtain signal-to-noise ratio better than 61.4 dB at a conversion rate of 5 MSps. At this data rate all 8192 detector channels can be read out to the internal raw data memory and VME interface within about 410 μs and 510 μs, respectively. The pedestal subtracted signals can be analyzed on-line. At a raw data hit occupation of 10%, the VME readout time is 50 μs per module. Each module provides four complementary CMOS signals to control the front-end electronics and four independent sets of power supplies for analogue and digital voltages (10 V, 100 mA) to drive the front-end electronics and for the bias voltage (100 V, 1.2 mA) to assure the full functionality of the detectors and the readout.

  11. Online readout and control unit for high-speed / high resolution readout of silicon tracking detectors

    International Nuclear Information System (INIS)

    Buerger, J.; Hansen, K.; Lange, W.; Nowak, T.; Prell, S.; Zimmermann, W.

    1996-09-01

    We are describing a high speed VME readout and control module developed and presently working at the H1 experiment at DESY in Hamburg. It has the capability to read out 4 x 2048 analogue data channels at sampling rates up to 10 MHz with a dynamic input range of 1 V. The nominal resolution of the A/D converters can be adjusted between 8 and 12 bit. At the latter resolution we obtain signal-to-noise ratio better than 61.4 dB at a conversion rate of 5 MSps. At this data rate all 8192 detector channels can be read out to the internal raw data memory and VME interface within about 410 μs and 510 μs, respectively. The pedestal subtracted signals can be analyzed on-line. At a raw data hit occupation of 10%, the VME readout time is 50 μs per module. Each module provides four complementary CMOS signals to control the front-end electronics and four independent sets of power supplies for analogue and digital voltages (10 V, 100 mA) to drive the front-end electronics and for the bias voltage (100 V, 1.2 mA) to assure the full functionality of the detectors and the readout. (orig.)

  12. Resolution of habitat-associated ecogenomic signatures in bacteriophage genomes and application to microbial source tracking.

    Science.gov (United States)

    Ogilvie, Lesley A; Nzakizwanayo, Jonathan; Guppy, Fergus M; Dedi, Cinzia; Diston, David; Taylor, Huw; Ebdon, James; Jones, Brian V

    2018-04-01

    Just as the expansion in genome sequencing has revealed and permitted the exploitation of phylogenetic signals embedded in bacterial genomes, the application of metagenomics has begun to provide similar insights at the ecosystem level for microbial communities. However, little is known regarding this aspect of bacteriophage associated with microbial ecosystems, and if phage encode discernible habitat-associated signals diagnostic of underlying microbiomes. Here we demonstrate that individual phage can encode clear habitat-related 'ecogenomic signatures', based on relative representation of phage-encoded gene homologues in metagenomic data sets. Furthermore, we show the ecogenomic signature encoded by the gut-associated ɸB124-14 can be used to segregate metagenomes according to environmental origin, and distinguish 'contaminated' environmental metagenomes (subject to simulated in silico human faecal pollution) from uncontaminated data sets. This indicates phage-encoded ecological signals likely possess sufficient discriminatory power for use in biotechnological applications, such as development of microbial source tracking tools for monitoring water quality.

  13. Tracking channel bed resiliency in forested mountain catchments using high temporal resolution channel bed movement

    Science.gov (United States)

    Martin, Sarah E.; Conklin, Martha H.

    2018-01-01

    This study uses continuous-recording load cell pressure sensors in four, high-elevation (1500-1800 m), Sierra Nevada headwater streams to collect high-temporal-resolution, bedload-movement data for investigating the channel bed movement patterns within these streams for water years 2012-2014. Data show an annual pattern where channel bed material in the thalweg starts to build up in early fall, peaks around peak snow melt, and scours back to baseline levels during hydrograph drawdown and base flow. This pattern is punctuated by disturbance and recovery of channel bed material associated with short-term storm events. A conceptual model, linking sediment sources at the channel margins to patterns of channel bed fill and scour in the thalweg, is proposed building on the results of Martin et al. (2014). The material in the thalweg represents a balance between sediment supply from the channel margins and sporadic, conveyor-belt-like downstream transport in the thalweg. The conceptual model highlights not only the importance of production and transport rates but also that seasonal connectedness between the margins and thalweg is a key sediment control, determining the accumulation rate of sediment stores at the margins and the redistribution of sediment from margins to thalweg that feeds the conveyor belt. Disturbance and recovery cycles are observed at multiple temporal scales; but long term, the channel beds are stable, suggesting that the beds act as short-term storage for sediment but are in equilibrium interannually. The feasibility of use for these sensors in forested mountain stream environments is tested. Despite a high failure rate (50%), load cell pressure sensors show potential for high-temporal-resolution bedload measurements, allowing for the collection of channel bed movement data to move beyond time-integrated change measurements - where many of the subtleties of bedload movement patterns may be missed - to continuous and/or real-time measurements. This

  14. EEG can track the time course of successful reference resolution in small visual worlds

    Directory of Open Access Journals (Sweden)

    Christian eBrodbeck

    2015-11-01

    Full Text Available Previous research has shown that language comprehenders resolve reference quickly and incrementally, but not much is known about the neural processes and representations that are involved. Studies of visual short-term memory suggest that access to the representation of an item from a previously seen display is associated with a negative evoked potential at posterior electrodes contralateral to the spatial location of that item in the display. In this paper we demonstrate that resolving the reference of a noun phrase in a recently seen visual display is associated with an event-related potential that is analogous to this effect. Our design was adapted from the visual world paradigm: in each trial, participants saw a display containing 3 simple objects, followed by a question about the objects, such as Was the pink fish next to a boat?, presented word by word. Questions differed in whether the color adjective allowed the reader to identify the referent of the noun phrase or not (i.e., whether one or more objects of the named color were present. Consistent with our hypothesis, we observed that reference resolution by the adjective was associated with a negative evoked potential at posterior electrodes contralateral to spatial location of the referent, starting approximately 333 ms after the onset of the adjective. The fact that the laterality of the effect depended upon the location of the referent within the display suggests that reference resolution in visual domains involves, at some level, a modality-specific representation. In addition, the effect gives us an estimate of the time course of processing from perception of the written word to the point at which its meaning is brought into correspondence with the referential domain.

  15. Statistics of spatially integrated speckle intensity difference

    DEFF Research Database (Denmark)

    Hanson, Steen Grüner; Yura, Harold

    2009-01-01

    We consider the statistics of the spatially integrated speckle intensity difference obtained from two separated finite collecting apertures. For fully developed speckle, closed-form analytic solutions for both the probability density function and the cumulative distribution function are derived...... here for both arbitrary values of the mean number of speckles contained within an aperture and the degree of coherence of the optical field. Additionally, closed-form expressions are obtained for the corresponding nth statistical moments....

  16. Position control of ECRH launcher mirrors by laser speckle sensor

    International Nuclear Information System (INIS)

    Michelsen, Poul K.; Bindslev, Henrik; Hansen, Rene Skov; Hanson, Steen G.

    2003-01-01

    necessary to have an independent measuring system for monitoring the angular positioning of this mirror. A microwave or laser produced heat spot on the mirror and on the tiles on the inside of the torus wall can be monitored regularly by an infrared camera. The correct position of the spot can probably be obtained by adjusting the position and the angle of the first mirror on the launcher. The two-dimensional angular displacement of the last mirror may be continuously monitored by the speckle method described. If a laser beam illuminates the backside of the mirror, and the speckle pattern is monitored by a detector (ccd camera or similar), very small angular displacements can be detected. It was recently shown that if the detection plane is close to the object, the resolution may be as low as 5 mrad. For the large tokamak case the detector may have to be placed several meters from the mirror, which may affect the resolution. The main purpose with the present work is to investigate which resolution may be obtainable when the distance between the laser and the object/detector is of the order of several meters. A measuring of an angular displacement requires a calculation of the 2D covariance of the two speckle patterns followed by a peak-finding procedure. The temporal resolution is limited by the time it takes to perform this calculation, and depending on the computer and the numerical procedure it may be of the order a second or less. Measurement of the angular displacement of an object is important in many cases involving controlled mechanical motion. Usually, the way is to apply a coded target or some kind of pick-up probe. In many systems it may be an advantage or even necessary to avoid contact with the moving mechanical object for different reasons. Various systems have been suggested. The measurements show good agreement between applied and measured values of the angular displacement. The method used here results in a bias effect in case the angular displacement of

  17. Speckle photography applied to measure deformations of very large structures

    Science.gov (United States)

    Conley, Edgar; Morgan, Chris K.

    1995-04-01

    Fundamental principles of mechanics have recently been brought to bear on problems concerning very large structures. Fields of study include tectonic plate motion, nuclear waste repository vault closure mechanisms, the flow of glacier and sea ice, and highway bridge damage assessment and residual life prediction. Quantitative observations, appropriate for formulating and verifying models, are still scarce however, so the need to adapt new methods of experimental mechanics is clear. Large dynamic systems often exist in environments subject to rapid change. Therefore, a simple field technique that incorporates short time scales and short gage lengths is required. Further, the measuring methods must yield displacements reliably, and under oft-times adverse field conditions. Fortunately, the advantages conferred by an experimental mechanics technique known as speckle photography nicely fulfill this rather stringent set of performance requirements. Speckle seemed to lend itself nicely to the application since it is robust and relatively inexpensive. Experiment requirements are minimal -- a camera, high resolution film, illumination, and an optically rough surface. Perhaps most important is speckle's distinct advantage over point-by-point methods: It maps the two dimensional displacement vectors of the whole field of interest. And finally, given the method's high spatial resolution, relatively short observation times are necessary. In this paper we discuss speckle, two variations of which were used to gage the deformation of a reinforced concrete bridge structure subjected to bending loads. The measurement technique proved to be easily applied, and yielded the location of the neutral axis self consistently. The research demonstrates the feasibility of using whole field techniques to detect and quantify surface strains of large structures under load.

  18. High-Resolution Microbiome Profiling for Detection and Tracking of Salmonella enterica

    Directory of Open Access Journals (Sweden)

    Christopher J. Grim

    2017-08-01

    Full Text Available 16S rRNA community profiling continues to be a useful tool to study microbiome composition and dynamics, in part due to advances in next generation sequencing technology that translate into reductions in cost. Reliable taxonomic identification to the species-level, however, remains difficult, especially for short-read sequencing platforms, due to incomplete coverage of the 16S rRNA gene. This is especially true for Salmonella enterica, which is often found as a low abundant member of the microbial community, and is often found in combination with several other closely related enteric species. Here, we report on the evaluation and application of Resphera Insight, an ultra-high resolution taxonomic assignment algorithm for 16S rRNA sequences to the species level. The analytical pipeline achieved 99.7% sensitivity to correctly identify S. enterica from WGS datasets extracted from the FDA GenomeTrakr Bioproject, while demonstrating 99.9% specificity over other Enterobacteriaceae members. From low-diversity and low-complexity samples, namely ice cream, the algorithm achieved 100% specificity and sensitivity for Salmonella detection. As demonstrated using cilantro and chili powder, for highly complex and diverse samples, especially those that contain closely related species, the detection threshold will likely have to be adjusted higher to account for misidentifications. We also demonstrate the utility of this approach to detect Salmonella in the clinical setting, in this case, bloodborne infections.

  19. Simulations of x-ray speckle-based dark-field and phase-contrast imaging with a polychromatic beam

    Energy Technology Data Exchange (ETDEWEB)

    Zdora, Marie-Christine, E-mail: marie-christine.zdora@diamond.ac.uk [Lehrstuhl für Biomedizinische Physik, Physik-Department & Institut für Medizintechnik, Technische Universität München, 85748 Garching (Germany); Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE (United Kingdom); Department of Physics & Astronomy, University College London, London WC1E 6BT (United Kingdom); Thibault, Pierre [Department of Physics & Astronomy, University College London, London WC1E 6BT (United Kingdom); Pfeiffer, Franz [Lehrstuhl für Biomedizinische Physik, Physik-Department & Institut für Medizintechnik, Technische Universität München, 85748 Garching (Germany); Zanette, Irene [Lehrstuhl für Biomedizinische Physik, Physik-Department & Institut für Medizintechnik, Technische Universität München, 85748 Garching (Germany); Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE (United Kingdom)

    2015-09-21

    Following the first experimental demonstration of x-ray speckle-based multimodal imaging using a polychromatic beam [I. Zanette et al., Phys. Rev. Lett. 112(25), 253903 (2014)], we present a simulation study on the effects of a polychromatic x-ray spectrum on the performance of this technique. We observe that the contrast of the near-field speckles is only mildly influenced by the bandwidth of the energy spectrum. Moreover, using a homogeneous object with simple geometry, we characterize the beam hardening artifacts in the reconstructed transmission and refraction angle images, and we describe how the beam hardening also affects the dark-field signal provided by speckle tracking. This study is particularly important for further implementations and developments of coherent speckle-based techniques at laboratory x-ray sources.

  20. Geometric Speckle Reduction.

    Science.gov (United States)

    1986-10-01

    F.G 17/9 lolllllllllamm EEEEEEEEEE-iEEEEEEEJWL iLLL/ E Ijill 1 0 L2.2 r3 IIj _ 11111 128 4ROCOPY RESOLUTION TEST CHART MATONAL SUREAU Ot %TANDAa!M 1%3-A...convex combination of the smoothed local maxi- mum and the global maximum G; g(m,n) E . g1 (m + j, n + k)b(j, k) + (1 - B)G, (3) Jii < N Ik < N 9 L...Vol. 43, S.G. Tyan, Berlin, Springer- VeTa , 1981. 14 Ir f.v S--RIM 26. N.C. Gallagher, Jr. and G.L. Wise, "A Theoretical Analysis of the Properties

  1. Development of Speckle Interferometry Algorithm and System

    International Nuclear Information System (INIS)

    Shamsir, A. A. M.; Jafri, M. Z. M.; Lim, H. S.

    2011-01-01

    Electronic speckle pattern interferometry (ESPI) method is a wholefield, non destructive measurement method widely used in the industries such as detection of defects on metal bodies, detection of defects in intergrated circuits in digital electronics components and in the preservation of priceless artwork. In this research field, this method is widely used to develop algorithms and to develop a new laboratory setup for implementing the speckle pattern interferometry. In speckle interferometry, an optically rough test surface is illuminated with an expanded laser beam creating a laser speckle pattern in the space surrounding the illuminated region. The speckle pattern is optically mixed with a second coherent light field that is either another speckle pattern or a smooth light field. This produces an interferometric speckle pattern that will be detected by sensor to count the change of the speckle pattern due to force given. In this project, an experimental setup of ESPI is proposed to analyze a stainless steel plate using 632.8 nm (red) wavelength of lights.

  2. Ectoparasites and intestinal helminths of speckled pigeon ...

    African Journals Online (AJOL)

    Ectoparasites and intestinal helminths of speckled pigeon ( Columba guinea Hartlaub and Finsch 1870) in Zaria, Nigeria. ... Science World Journal ... A total of 30 (20 males and 10 females) Speckled Pigeons trapped from the wild in Zaria and its environs, Nigeria, were examined for ectoparasites and intestinal helminths, ...

  3. The measurement of climate change using data from the Advanced Very High Resolution and Along Track Scanning Radiometers

    Science.gov (United States)

    Lawrence, S. P.; Llewellyn-Jones, D. T.; Smith, S. J.

    2004-08-01

    Global sea-surface temperature is an important indicator of climate change, with the ability to reflect warming/cooling climate trends. The detection of such trends requires rigorous measurements that are global, accurate, and consistent. Space instruments can provide the means to achieve these required attributes in sea-surface temperature data. Analyses of two independent data sets from the Advanced Very High Resolution and Along Track Scanning Radiometers series of space sensors during the period 1985 to 2000 reveal trends of increasing global temperature with magnitudes of 0.09°C and 0.13°C per decade, respectively, closely matching that expected due to current levels of greenhouse gas exchange. In addition, an analysis based upon singular value decomposition, allowing the removal of El Niño in order to examine areas of change other than the tropical Pacific region, indicates that the 1997 El Niño event affected sea-surface temperature globally. The methodology demonstrated here can be applied to other data sets, which cover long time series observations of geophysical observations in order to characterize long-term change. The conclusion is that satellite sea-surface temperature provides an important means to quantify and explore the processes of climate change.

  4. Temperature mapping of sunspots and pores from speckle reconstructed three colour photometry

    NARCIS (Netherlands)

    Sütterlin, P.; Wiehr, E.

    1998-01-01

    The two-dimensional temperature distribution in a highly structured sunspot and in two small umbrae is determined from a three-colour photometry in narrow spectral continua. Disturbing influences from the earth’s atmosphere are removed by speckle masking techniques, yielding a spatial resolution

  5. NESSI and `Alopeke: Two new dual-channel speckle imaging instruments

    Science.gov (United States)

    Scott, Nicholas J.

    2018-01-01

    NESSI and `Alopeke are two new speckle imagers built at NASA's Ames Research Center for community use at the WIYN and Gemini telescopes, respectively. The two instruments are functionally similar and include the capability for wide-field imaging in additional to speckle interferometry. The diffraction-limited imaging available through speckle effectively eliminates distortions due to the presence of Earth's atmosphere by `freezing out' changes in the atmosphere by taking extremely short exposures and combining the resultant speckles in Fourier space. This technique enables angular resolutions equal to the theoretical best possible for a given telescope, effectively giving space-based resolution from the ground. Our instruments provide the highest spatial resolution available today on any single aperture telescope.A primary role of these instruments is exoplanet validation for the Kepler, K2, TESS, and many RV programs. Contrast ratios of 6 or more magnitudes are easily obtained. The instrument uses two emCCD cameras providing simultaneous dual-color observations help to characterize detected companions. High resolution imaging enables the identification of blended binaries that contaminate many exoplanet detections, leading to incorrectly measured radii. In this way small, rocky systems, such as Kepler-186b and the TRAPPIST-1 planet family, may be validated and thus the detected planets radii are correctly measured.

  6. Speckle techniques for determining stresses in moving objects

    Science.gov (United States)

    Murphree, E. A.; Wilson, T. F.; Ranson, W. F.; Swinson, W. F.

    1978-01-01

    Laser speckle interferometry is a relatively new experimental technique which shows promise of alleviating many difficult problems in experimental mechanics. The method utilizes simple high-resolution photographs of the surface which is illuminated by coherent light. The result is a real-time or permanently stored whole-field record of interference fringes which yields a map of displacements in the object. In this thesis, the time-average theory using the Fourier transform is developed to present the application of this technique to measurement of in-plane displacement induced by the vibration of an object.

  7. Integration of image exposure time into a modified laser speckle imaging method

    Energy Technology Data Exchange (ETDEWEB)

    RamIrez-San-Juan, J C; Salazar-Hermenegildo, N; Ramos-Garcia, R; Munoz-Lopez, J [Optics Department, INAOE, Puebla (Mexico); Huang, Y C [Department of Electrical Engineering and Computer Science, University of California, Irvine, CA (United States); Choi, B, E-mail: jcram@inaoep.m [Beckman Laser Institute and Medical Clinic, University of California, Irvine, CA (United States)

    2010-11-21

    Speckle-based methods have been developed to characterize tissue blood flow and perfusion. One such method, called modified laser speckle imaging (mLSI), enables computation of blood flow maps with relatively high spatial resolution. Although it is known that the sensitivity and noise in LSI measurements depend on image exposure time, a fundamental disadvantage of mLSI is that it does not take into account this parameter. In this work, we integrate the exposure time into the mLSI method and provide experimental support of our approach with measurements from an in vitro flow phantom.

  8. Integration of image exposure time into a modified laser speckle imaging method

    International Nuclear Information System (INIS)

    RamIrez-San-Juan, J C; Salazar-Hermenegildo, N; Ramos-Garcia, R; Munoz-Lopez, J; Huang, Y C; Choi, B

    2010-01-01

    Speckle-based methods have been developed to characterize tissue blood flow and perfusion. One such method, called modified laser speckle imaging (mLSI), enables computation of blood flow maps with relatively high spatial resolution. Although it is known that the sensitivity and noise in LSI measurements depend on image exposure time, a fundamental disadvantage of mLSI is that it does not take into account this parameter. In this work, we integrate the exposure time into the mLSI method and provide experimental support of our approach with measurements from an in vitro flow phantom.

  9. Leveraging Earth Observations to Improve Data Resolution and Tracking of Sustainable Development Goals in Water Resources and Public Health

    Science.gov (United States)

    Akanda, A. S.; Nusrat, F.; Hasan, M. A.; Fallatah, O.

    2017-12-01

    Water scarcity affects more than 40 per cent of the world population and is projected to rise substantially, affecting safe water and sanitation access globally. The recently released WHO/UNICEF Joint Monitoring Programme (JMP) 2017 report on global water and sanitation access paints a grim picture across the planet; approximately 30% people worldwide, or 2.1 billion, still lack access to safe, readily available clean water, and 60% people worldwide, or 4.5 billion ppl, lack safely managed sanitation. Meanwhile, demand for water and competition for water resources are sharply rising amid growing uncertainty of climate change and its impacts on water resources. The United Nations Agenda 2030 Sustainable Development Goals (SDGs) call for substantially increasing water-use efficiency across all sectors and ensuring sustainable withdrawals and supply of freshwater to address water scarcity, providing clean water and sanitation for all, increasing international cooperation over transboundary surface and groundwater resources (under Goal 6), as well as ending preventable deaths of newborns and children under 5 years of age, and end the epidemics of neglected tropical and water-borne diseases (under Goal 3). Data availability in developing regions, especially at the appropriate resolution in both space and time, has been a recurring problem for various technological and institutional reasons. Earth observation techniques provide the most cost-effective and encompassing tool to monitor these regions, large transboundary river basins and aquifer systems, and water resources vulnerabilities to climate change around the globe. University of Rhode Island, with US and international collaborators, is using earth observations to develop tools to analyze, monitor and support decision-makers to track their progress towards SDGs with better data resolution and accuracy. Here, we provide case studies on 1) providing safe water and sanitation access South Asia through safe water

  10. Advances in speckle metrology and related techniques

    CERN Document Server

    Kaufmann, Guillermo H

    2010-01-01

    Speckle metrology includes various optical techniques that are based on the speckle fields generated by reflection from a rough surface or by transmission through a rough diffuser. These techniques have proven to be very useful in testing different materials in a non-destructive way. They have changed dramatically during the last years due to the development of modern optical components, with faster and more powerful digital computers, and novel data processing approaches. This most up-to-date overview of the topic describes new techniques developed in the field of speckle metrology over the l

  11. Speckle Interferometry at SOAR in 2014

    Science.gov (United States)

    Tokovinin, Andrei; Mason, Brian D.; Hartkopf, William I.; Mendez, Rene A.; Horch, Elliott P.

    2015-08-01

    The results of speckle interferometric observations at the Southern Astrophysical Research Telescope (SOAR) telescope in 2014 are given. A total of 1641 observations were taken, yielding 1636 measurements of 1218 resolved binary and multiple stars and 577 non-resolutions of 441 targets. We resolved for the first time 56 pairs, including some nearby astrometric or spectroscopic binaries and ten new subsystems in previously known visual binaries. The calibration of the data is checked by linear fits to the positions of 41 wide binaries observed at SOAR over several seasons. The typical calibration accuracy is 0.°1 in angle and 0.3% in pixel scale, while the measurement errors are on the order of 3 mas. The new data are used here to compute 194 binary star orbits, 148 of which are improvements on previous orbital solutions and 46 are first-time orbits. Based on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia, e Inovação (MCTI) da República Federativa do Brasil, the U.S. National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU).

  12. Speckle Interferometry of Red Dwarf Stars

    Science.gov (United States)

    Mason, Brian D.; Hartkopf, William I.; Miles, Korie N.; Subasavage, John P.; Raghavan, Deepak; Henry, Todd J.

    2018-05-01

    We report high-resolution optical speckle observations of 336 M dwarfs, which results in 113 measurements of the relative position of 80 systems and 256 other stars with no indications of duplicity. These are the first measurements for two of the systems. We also present the earliest measurements of relative position for 17 others. We include orbits for six of the systems, two revised and four reported for the first time. For one of the systems with a new orbit, G 161-7, we determine masses of 0.156 ± 0.011 and 0.1175+/- 0.0079 {{ \\mathcal M }}ȯ for the A and B components, respectively. All six of these new calculated orbits have short periods (between five and 38 years) and hold the promise of deriving accurate masses in the near future. For many other pairs we can establish their nature as physical or chance alignment, depending on their relative motion. Of the 80 systems, 32 have calculated orbits, 25 others are physical pairs, four are optical pairs, and 19 are currently unknown.

  13. MATLAB for laser speckle contrast analysis (LASCA): a practice-based approach

    Science.gov (United States)

    Postnikov, Eugene B.; Tsoy, Maria O.; Postnov, Dmitry E.

    2018-04-01

    Laser Speckle Contrast Analysis (LASCA) is one of the most powerful modern methods for revealing blood dynamics. The experimental design and theory for this method are well established, and the computational recipie is often regarded to be trivial. However, the achieved performance and spatial resolution may considerable differ for different implementations. We comprise a minireview of known approaches to the spatial laser speckle contrast data processing and their realization in MATLAB code providing an explicit correspondence to the mathematical representation, a discussion of available implementations. We also present the algorithm based on the 2D Haar wavelet transform, also supplied with the program code. This new method provides an opportunity to introduce horizontal, vertical and diagonal speckle contrasts; it may be used for processing highly anisotropic images of vascular trees. We provide the comparative analysis of the accuracy of vascular pattern detection and the processing times with a special attention to details of the used MATLAB procedures.

  14. Effect of static scatterers in laser speckle contrast imaging: an experimental study on correlation and contrast

    Science.gov (United States)

    Vaz, Pedro G.; Humeau-Heurtier, Anne; Figueiras, Edite; Correia, Carlos; Cardoso, João

    2018-01-01

    Laser speckle contrast imaging (LSCI) is a non-invasive microvascular blood flow assessment technique with good temporal and spatial resolution. Most LSCI systems, including commercial devices, can perform only qualitative blood flow evaluation, which is a major limitation of this technique. There are several factors that prevent the utilization of LSCI as a quantitative technique. Among these factors, we can highlight the effect of static scatterers. The goal of this work was to study the influence of differences in static and dynamic scatterer concentration on laser speckle correlation and contrast. In order to achieve this, a laser speckle prototype was developed and tested using an optical phantom with various concentrations of static and dynamic scatterers. It was found that the laser speckle correlation could be used to estimate the relative concentration of static/dynamic scatterers within a sample. Moreover, the speckle correlation proved to be independent of the dynamic scatterer velocity, which is a fundamental characteristic to be used in contrast correction.

  15. Speckle imaging of active galactic nuclei: NGC 1068 and NGC 4151

    International Nuclear Information System (INIS)

    Ebstein, S.M.

    1987-01-01

    High-resolution images of NGC 1068 and NGC 4151 in the [O III) 5007A line the nearby continuum produced from data taken with the PAPA photon-counting imaging detector using the technique of speckle imaging are presented. The images show an unresolved core of [O III] 5007A emission in the middle of an extended emission region. The extended emission tends to lie alongside the subarcsecond radio structure. In NGC 4151, the extended emission comes from a nearly linear structure extending on both sides of the unresolved core. In NGC 1068, the extended emission is also a linear structure centered on the unresolved core but the emission is concentrated in lobes lying to either side of the major axis. The continuum of NGC 4151 is spatially unresolved. The continuum of NGC 1068 is extended ∼1'' to the SW of the center of the [O III] 5007A emission. Certain aspects of the PAPA detector are discussed, including the variable-threshold discriminators that track the image intensifier pulse height and the camera artifacts. The data processing is described in detail

  16. Two-dimensional tracking of a motile micro-organism allowing high-resolution observation with various imaging techniques

    International Nuclear Information System (INIS)

    Oku, H.; Ogawa, N.; Ishikawa, M.; Hashimoto, K.

    2005-01-01

    In this article, a micro-organism tracking system using a high-speed vision system is reported. This system two dimensionally tracks a freely swimming micro-organism within the field of an optical microscope by moving a chamber of target micro-organisms based on high-speed visual feedback. The system we developed could track a paramecium using various imaging techniques, including bright-field illumination, dark-field illumination, and differential interference contrast, at magnifications of 5 times and 20 times. A maximum tracking duration of 300 s was demonstrated. Also, the system could track an object with a velocity of up to 35 000 μm/s (175 diameters/s), which is significantly faster than swimming micro-organisms

  17. Statistics of polarization speckle: theory versus experiment

    DEFF Research Database (Denmark)

    Wang, Wei; Hanson, Steen Grüner; Takeda, Mitsuo

    2010-01-01

    In this paper, we reviewed our recent work on the statistical properties of polarization speckle, described by stochastic Stokes parameters fluctuating in space. Based on the Gaussian assumption for the random electric field components and polar-interferometer, we investigated theoretically...... and experimentally the statistics of Stokes parameters of polarization speckle, including probability density function of Stokes parameters with the spatial degree of polarization, autocorrelation of Stokes vector and statistics of spatial derivatives for Stokes parameters....

  18. The SKED: speckle knife edge detector

    International Nuclear Information System (INIS)

    Sharpies, S D; Light, R A; Achamfuo-Yeboah, S O; Clark, M; Somekh, M G

    2014-01-01

    The knife edge detector—also known as optical beam deflection—is a simple and robust method of detecting ultrasonic waves using a laser. It is particularly suitable for detection of high frequency surface acoustic waves as the response is proportional to variation of the local tilt of the surface. In the case of a specular reflection of the incident laser beam from a smooth surface, any lateral movement of the reflected beam caused by the ultrasonic waves is easily detected by a pair of photodiodes. The major disadvantage of the knife edge detector is that it does not cope well with optically rough surfaces, those that give a speckled reflection. The optical speckles from a rough surface adversely affect the efficiency of the knife edge detector, because 'dark' speckles move synchronously with 'bright' speckles, and their contributions to the ultrasonic signal cancel each other out. We have developed a new self-adapting sensor which can cope with the optical speckles reflected from a rough surface. It is inelegantly called the SKED—speckle knife edge detector—and like its smooth surface namesake it is simple, cheap, compact, and robust. We describe the theory of its operation, and present preliminary experimental results validating the overall concept and the operation of the prototype device

  19. The SKED: speckle knife edge detector

    Science.gov (United States)

    Sharpies, S. D.; Light, R. A.; Achamfuo-Yeboah, S. O.; Clark, M.; Somekh, M. G.

    2014-06-01

    The knife edge detector—also known as optical beam deflection—is a simple and robust method of detecting ultrasonic waves using a laser. It is particularly suitable for detection of high frequency surface acoustic waves as the response is proportional to variation of the local tilt of the surface. In the case of a specular reflection of the incident laser beam from a smooth surface, any lateral movement of the reflected beam caused by the ultrasonic waves is easily detected by a pair of photodiodes. The major disadvantage of the knife edge detector is that it does not cope well with optically rough surfaces, those that give a speckled reflection. The optical speckles from a rough surface adversely affect the efficiency of the knife edge detector, because 'dark' speckles move synchronously with 'bright' speckles, and their contributions to the ultrasonic signal cancel each other out. We have developed a new self-adapting sensor which can cope with the optical speckles reflected from a rough surface. It is inelegantly called the SKED—speckle knife edge detector—and like its smooth surface namesake it is simple, cheap, compact, and robust. We describe the theory of its operation, and present preliminary experimental results validating the overall concept and the operation of the prototype device.

  20. Speckle interferometry. Data acquisition and control for the SPID instrument.

    Science.gov (United States)

    Altarac, S.; Tallon, M.; Thiebaut, E.; Foy, R.

    1998-08-01

    SPID (SPeckle Imaging by Deconvolution) is a new speckle camera currently under construction at CRAL-Observatoire de Lyon. Its high spectral resolution and high image restoration capabilities open new astrophysical programs. The instrument SPID is composed of four main optical modules which are fully automated and computer controlled by a software written in Tcl/Tk/Tix and C. This software provides an intelligent assistance to the user by choosing observational parameters as a function of atmospheric parameters, computed in real time, and the desired restored image quality. Data acquisition is made by a photon-counting detector (CP40). A VME-based computer under OS9 controls the detector and stocks the data. The intelligent system runs under Linux on a PC. A slave PC under DOS commands the motors. These 3 computers communicate through an Ethernet network. SPID can be considered as a precursor for VLT's (Very Large Telescope, four 8-meter telescopes currently built in Chile by European Southern Observatory) very high spatial resolution camera.

  1. Digital Speckle Photography of Subpixel Displacements of Speckle Structures Based on Analysis of Their Spatial Spectra

    Science.gov (United States)

    Maksimova, L. A.; Ryabukho, P. V.; Mysina, N. Yu.; Lyakin, D. V.; Ryabukho, V. P.

    2018-04-01

    We have investigated the capabilities of the method of digital speckle interferometry for determining subpixel displacements of a speckle structure formed by a displaceable or deformable object with a scattering surface. An analysis of spatial spectra of speckle structures makes it possible to perform measurements with a subpixel accuracy and to extend the lower boundary of the range of measurements of displacements of speckle structures to the range of subpixel values. The method is realized on the basis of digital recording of the images of undisplaced and displaced speckle structures, their spatial frequency analysis using numerically specified constant phase shifts, and correlation analysis of spatial spectra of speckle structures. Transformation into the frequency range makes it possible to obtain quantities to be measured with a subpixel accuracy from the shift of the interference-pattern minimum in the diffraction halo by introducing an additional phase shift into the complex spatial spectrum of the speckle structure or from the slope of the linear plot of the function of accumulated phase difference in the field of the complex spatial spectrum of the displaced speckle structure. The capabilities of the method have been investigated in natural experiment.

  2. IMAGE ENHANCEMENT AND SPECKLE REDUCTION OF FULL POLARIMETRIC SAR DATA BY GAUSSIAN MARKOV RANDOM FIELD

    Directory of Open Access Journals (Sweden)

    M. Mahdian

    2013-09-01

    Full Text Available In recent years, the use of Polarimetric Synthetic Aperture Radar (PolSAR data in different applications dramatically has been increased. In SAR imagery an interference phenomenon with random behavior exists which is called speckle noise. The interpretation of data encounters some troubles due to the presence of speckle which can be considered as a multiplicative noise affecting all coherent imaging systems. Indeed, speckle degrade radiometric resolution of PolSAR images, therefore it is needful to perform speckle filtering on the SAR data type. Markov Random Field (MRF has proven to be a powerful method for drawing out eliciting contextual information from remotely sensed images. In the present paper, a probability density function (PDF, which is fitted well with the PolSAR data based on the goodness-of-fit test, is first obtained for the pixel-wise analysis. Then the contextual smoothing is achieved with the MRF method. This novel speckle reduction method combines an advanced statistical distribution with spatial contextual information for PolSAR data. These two parts of information are combined based on weighted summation of pixel-wise and contextual models. This approach not only preserves edge information in the images, but also improves signal-to-noise ratio of the results. The method maintains the mean value of original signal in the homogenous areas and preserves the edges of features in the heterogeneous regions. Experiments on real medium resolution ALOS data from Tehran, and also high resolution full polarimetric SAR data over the Oberpfaffenhofen test-site in Germany, demonstrate the effectiveness of the algorithm compared with well-known despeckling methods.

  3. Storm Identification, Tracking and Forecasting Using High-Resolution Images of Short-Range X-Band Radar

    Directory of Open Access Journals (Sweden)

    Sajid Shah

    2015-05-01

    Full Text Available Rain nowcasting is an essential part of weather monitoring. It plays a vital role in human life, ranging from advanced warning systems to scheduling open air events and tourism. A nowcasting system can be divided into three fundamental steps, i.e., storm identification, tracking and nowcasting. The main contribution of this work is to propose procedures for each step of the rain nowcasting tool and to objectively evaluate the performances of every step, focusing on two-dimension data collected from short-range X-band radars installed in different parts of Italy. This work presents the solution of previously unsolved problems in storm identification: first, the selection of suitable thresholds for storm identification; second, the isolation of false merger (loosely-connected storms; and third, the identification of a high reflectivity sub-storm within a large storm. The storm tracking step of the existing tools, such as TITANand SCIT, use only up to two storm attributes, i.e., center of mass and area. It is possible to use more attributes for tracking. Furthermore, the contribution of each attribute in storm tracking is yet to be investigated. This paper presents a novel procedure called SALdEdA (structure, amplitude, location, eccentricity difference and areal difference for storm tracking. This work also presents the contribution of each component of SALdEdA in storm tracking. The second order exponential smoothing strategy is used for storm nowcasting, where the growth and decay of each variable of interest is considered to be linear. We evaluated the major steps of our method. The adopted techniques for automatic threshold calculation are assessed with a 97% goodness. False merger and sub-storms within a cluster of storms are successfully handled. Furthermore, the storm tracking procedure produced good results with an accuracy of 99.34% for convective events and 100% for stratiform events.

  4. Speckle Filtering of GF-3 Polarimetric SAR Data with Joint Restriction Principle.

    Science.gov (United States)

    Xie, Jinwei; Li, Zhenfang; Zhou, Chaowei; Fang, Yuyuan; Zhang, Qingjun

    2018-05-12

    Polarimetric SAR (PolSAR) scattering characteristics of imagery are always obtained from the second order moments estimation of multi-polarization data, that is, the estimation of covariance or coherency matrices. Due to the extra-paths that signal reflected from separate scatterers within the resolution cell has to travel, speckle noise always exists in SAR images and has a severe impact on the scattering performance, especially on single look complex images. In order to achieve high accuracy in estimating covariance or coherency matrices, three aspects are taken into consideration: (1) the edges and texture of the scene are distinct after speckle filtering; (2) the statistical characteristic should be similar to the object pixel; and (3) the polarimetric scattering signature should be preserved, in addition to speckle reduction. In this paper, a joint restriction principle is proposed to meet the requirement. Three different restriction principles are introduced to the processing of speckle filtering. First, a new template, which is more suitable for the point or line targets, is designed to ensure the morphological consistency. Then, the extent sigma filter is used to restrict the pixels in the template aforementioned to have an identical statistic characteristic. At last, a polarimetric similarity factor is applied to the same pixels above, to guarantee the similar polarimetric features amongst the optional pixels. This processing procedure is named as speckle filtering with joint restriction principle and the approach is applied to GF-3 polarimetric SAR data acquired in San Francisco, CA, USA. Its effectiveness of keeping the image sharpness and preserving the scattering mechanism as well as speckle reduction is validated by the comparison with boxcar filters and refined Lee filter.

  5. WE-G-17A-01: Improving Tracking Image Spatial Resolution for Onboard MR Image Guided Radiation Therapy Using the WHISKEE Technique

    International Nuclear Information System (INIS)

    Hu, Y; Mutic, S; Du, D; Green, O; Zeng, Q; Nana, R; Patrick, J; Shvartsman, S; Dempsey, J

    2014-01-01

    Purpose: To evaluate the feasibility of using the weighted hybrid iterative spiral k-space encoded estimation (WHISKEE) technique to improve spatial resolution of tracking images for onboard MR image guided radiation therapy (MR-IGRT). Methods: MR tracking images of abdomen and pelvis had been acquired from healthy volunteers using the ViewRay onboard MRIGRT system (ViewRay Inc. Oakwood Village, OH) at a spatial resolution of 2.0mm*2.0mm*5.0mm. The tracking MR images were acquired using the TrueFISP sequence. The temporal resolution had to be traded off to 2 frames per second (FPS) to achieve the 2.0mm in-plane spatial resolution. All MR images were imported into the MATLAB software. K-space data were synthesized through the Fourier Transform of the MR images. A mask was created to selected k-space points that corresponded to the under-sampled spiral k-space trajectory with an acceleration (or undersampling) factor of 3. The mask was applied to the fully sampled k-space data to synthesize the undersampled k-space data. The WHISKEE method was applied to the synthesized undersampled k-space data to reconstructed tracking MR images at 6 FPS. As a comparison, the undersampled k-space data were also reconstructed using the zero-padding technique. The reconstructed images were compared to the original image. The relatively reconstruction error was evaluated using the percentage of the norm of the differential image over the norm of the original image. Results: Compared to the zero-padding technique, the WHISKEE method was able to reconstruct MR images with better image quality. It significantly reduced the relative reconstruction error from 39.5% to 3.1% for the pelvis image and from 41.5% to 4.6% for the abdomen image at an acceleration factor of 3. Conclusion: We demonstrated that it was possible to use the WHISKEE method to expedite MR image acquisition for onboard MR-IGRT systems to achieve good spatial and temporal resolutions simultaneously. Y. Hu and O. green

  6. WE-G-17A-01: Improving Tracking Image Spatial Resolution for Onboard MR Image Guided Radiation Therapy Using the WHISKEE Technique

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Y; Mutic, S; Du, D; Green, O [Washington University School of Medicine, Saint Louis, MO (United States); Zeng, Q; Nana, R; Patrick, J; Shvartsman, S; Dempsey, J [ViewRay Incorporated, Oakwood Village, OH (United States)

    2014-06-15

    Purpose: To evaluate the feasibility of using the weighted hybrid iterative spiral k-space encoded estimation (WHISKEE) technique to improve spatial resolution of tracking images for onboard MR image guided radiation therapy (MR-IGRT). Methods: MR tracking images of abdomen and pelvis had been acquired from healthy volunteers using the ViewRay onboard MRIGRT system (ViewRay Inc. Oakwood Village, OH) at a spatial resolution of 2.0mm*2.0mm*5.0mm. The tracking MR images were acquired using the TrueFISP sequence. The temporal resolution had to be traded off to 2 frames per second (FPS) to achieve the 2.0mm in-plane spatial resolution. All MR images were imported into the MATLAB software. K-space data were synthesized through the Fourier Transform of the MR images. A mask was created to selected k-space points that corresponded to the under-sampled spiral k-space trajectory with an acceleration (or undersampling) factor of 3. The mask was applied to the fully sampled k-space data to synthesize the undersampled k-space data. The WHISKEE method was applied to the synthesized undersampled k-space data to reconstructed tracking MR images at 6 FPS. As a comparison, the undersampled k-space data were also reconstructed using the zero-padding technique. The reconstructed images were compared to the original image. The relatively reconstruction error was evaluated using the percentage of the norm of the differential image over the norm of the original image. Results: Compared to the zero-padding technique, the WHISKEE method was able to reconstruct MR images with better image quality. It significantly reduced the relative reconstruction error from 39.5% to 3.1% for the pelvis image and from 41.5% to 4.6% for the abdomen image at an acceleration factor of 3. Conclusion: We demonstrated that it was possible to use the WHISKEE method to expedite MR image acquisition for onboard MR-IGRT systems to achieve good spatial and temporal resolutions simultaneously. Y. Hu and O. green

  7. Rapid, topology-based particle tracking for high-resolution measurements of large complex 3D motion fields.

    Science.gov (United States)

    Patel, Mohak; Leggett, Susan E; Landauer, Alexander K; Wong, Ian Y; Franck, Christian

    2018-04-03

    Spatiotemporal tracking of tracer particles or objects of interest can reveal localized behaviors in biological and physical systems. However, existing tracking algorithms are most effective for relatively low numbers of particles that undergo displacements smaller than their typical interparticle separation distance. Here, we demonstrate a single particle tracking algorithm to reconstruct large complex motion fields with large particle numbers, orders of magnitude larger than previously tractably resolvable, thus opening the door for attaining very high Nyquist spatial frequency motion recovery in the images. Our key innovations are feature vectors that encode nearest neighbor positions, a rigorous outlier removal scheme, and an iterative deformation warping scheme. We test this technique for its accuracy and computational efficacy using synthetically and experimentally generated 3D particle images, including non-affine deformation fields in soft materials, complex fluid flows, and cell-generated deformations. We augment this algorithm with additional particle information (e.g., color, size, or shape) to further enhance tracking accuracy for high gradient and large displacement fields. These applications demonstrate that this versatile technique can rapidly track unprecedented numbers of particles to resolve large and complex motion fields in 2D and 3D images, particularly when spatial correlations exist.

  8. Speckle perception and disturbance limit in laser based projectors

    Science.gov (United States)

    Verschaffelt, Guy; Roelandt, Stijn; Meuret, Youri; Van den Broeck, Wendy; Kilpi, Katriina; Lievens, Bram; Jacobs, An; Janssens, Peter; Thienpont, Hugo

    2016-04-01

    We investigate the level of speckle that can be tolerated in a laser cinema projector. For this purpose, we equipped a movie theatre room with a prototype laser projector. A group of 186 participants was gathered to evaluate the speckle perception of several, short movie trailers in a subjective `Quality of Experience' experiment. This study is important as the introduction of lasers in projection systems has been hampered by the presence of speckle in projected images. We identify a speckle disturbance threshold by statistically analyzing the observers' responses for different values of the amount of speckle, which was monitored using a well-defined speckle measurement method. The analysis shows that the speckle perception of a human observer is not only dependent on the objectively measured amount of speckle, but it is also strongly influenced by the image content. As is also discussed in [Verschaffelt et al., Scientific Reports 5, art. nr. 14105, 2015] we find that, for moving images, the speckle becomes disturbing if the speckle contrast becomes larger than 6.9% for the red, 6.0% for the green, and 4.8% for the blue primary colors of the projector, whereas for still images the speckle detection threshold is about 3%. As we could not independently tune the speckle contrast of each of the primary colors, this speckle disturbance limit seems to be determined by the 6.9% speckle contrast of the red color as this primary color contains the largest amount of speckle. The speckle disturbance limit for movies thus turns out to be substantially larger than that for still images, and hence is easier to attain.

  9. Speckle-learning-based object recognition through scattering media.

    Science.gov (United States)

    Ando, Takamasa; Horisaki, Ryoichi; Tanida, Jun

    2015-12-28

    We experimentally demonstrated object recognition through scattering media based on direct machine learning of a number of speckle intensity images. In the experiments, speckle intensity images of amplitude or phase objects on a spatial light modulator between scattering plates were captured by a camera. We used the support vector machine for binary classification of the captured speckle intensity images of face and non-face data. The experimental results showed that speckles are sufficient for machine learning.

  10. Measuring Temporal Resolution (Release of Masking) with a Hughson-Westlake Up-Down Instead of a Békèsy-Tracking Procedure.

    Science.gov (United States)

    Rhebergen, Koenraad S; van Esch, Thamar E M; Dreschler, Wouter A

    2015-06-01

    A temporal resolution test in addition to the pure-tone audiogram may be of great clinical interest because of its relevance in speech perception and expected relevance in hearing aid fitting. Larsby and Arlinger developed an appropriate clinical test, but this test uses a Békèsy-tracking procedure for estimating masked thresholds in stationary and interrupted noise to assess release of masking (RoM) for temporal resolution. Generally the Hughson-Westlake up-down procedure is used in the clinic to measure the pure-tone thresholds in quiet. A uniform approach will facilitate clinical application and might be appropriate for RoM measurements as well. Because there is no golden standard for measuring the RoM in the clinic, we examine in the present study the Hughson-Westlake up-down procedure to measure the RoM and compare the results with the Békèsy-tracking procedure. The purpose of the current study was to examine the differences between a Békèsy-tracking procedure and the Hughson-Westlake up-down procedure for estimating masked thresholds in stationary and interrupted noise to assess RoM. RoM is assessed in eight normal-hearing (NH) and ten hearing-impaired (HI) listeners through both methods. Results from both methods are compared with each other and with predicted thresholds from a model. Wilcoxon signed-rank tests, paired t tests. Some differences between the two methods were found. We used a model to quantify the results of the two measurement procedures. The results of the Hughson-Westlake procedure were clearly better in agreement with the model than the results of the Békèsy-tracking procedure. Furthermore, the Békèsy-tracking procedure showed more spread in the results of the NH listeners than the Hughson-Westlake procedure. The Hughson-Westlake procedure seems to be an applicable alternative for measuring RoM for temporal resolution in the clinical audiological practice. American Academy of Audiology.

  11. Finding small displacements of recorded speckle patterns: revisited

    DEFF Research Database (Denmark)

    Hanson, Steen Grüner; Jakobsen, Michael Linde; Chakrabarti, Maumita

    2015-01-01

    An analytical expression for the bias effect in digital speckle correlation is derived based on a Gaussian approximation of the spatial pixel size and array extent. The evaluation is carried out having assumed an incident speckle field. The analysis is focused on speckle displacements in the order...

  12. Statistical Image Recovery From Laser Speckle Patterns With Polarization Diversity

    Science.gov (United States)

    2010-09-01

    several techniques for speckle suppression in optical imaging [19]. However, averaging nonimaged laser speckle patterns does not yield the same result...Comparison”. Applied Optics , 21(15):2758–2769, August 1982. 13. Fienup, James R. “Image Formation from Nonimaged Laser Speckle Patterns”. S. R. Robinson...6 ν Optical Frequency . . . . . . . . . . . . . . . . . . . . . . 6 t Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 ϕ

  13. ISED: Constructing a high-resolution elevation road dataset from massive, low-quality in-situ observations derived from geosocial fitness tracking data.

    Directory of Open Access Journals (Sweden)

    Grant McKenzie

    Full Text Available Gaining access to inexpensive, high-resolution, up-to-date, three-dimensional road network data is a top priority beyond research, as such data would fuel applications in industry, governments, and the broader public alike. Road network data are openly available via user-generated content such as OpenStreetMap (OSM but lack the resolution required for many tasks, e.g., emergency management. More importantly, however, few publicly available data offer information on elevation and slope. For most parts of the world, up-to-date digital elevation products with a resolution of less than 10 meters are a distant dream and, if available, those datasets have to be matched to the road network through an error-prone process. In this paper we present a radically different approach by deriving road network elevation data from massive amounts of in-situ observations extracted from user-contributed data from an online social fitness tracking application. While each individual observation may be of low-quality in terms of resolution and accuracy, taken together they form an accurate, high-resolution, up-to-date, three-dimensional road network that excels where other technologies such as LiDAR fail, e.g., in case of overpasses, overhangs, and so forth. In fact, the 1m spatial resolution dataset created in this research based on 350 million individual 3D location fixes has an RMSE of approximately 3.11m compared to a LiDAR-based ground-truth and can be used to enhance existing road network datasets where individual elevation fixes differ by up to 60m. In contrast, using interpolated data from the National Elevation Dataset (NED results in 4.75m RMSE compared to the base line. We utilize Linked Data technologies to integrate the proposed high-resolution dataset with OpenStreetMap road geometries without requiring any changes to the OSM data model.

  14. ISED: Constructing a high-resolution elevation road dataset from massive, low-quality in-situ observations derived from geosocial fitness tracking data.

    Science.gov (United States)

    McKenzie, Grant; Janowicz, Krzysztof

    2017-01-01

    Gaining access to inexpensive, high-resolution, up-to-date, three-dimensional road network data is a top priority beyond research, as such data would fuel applications in industry, governments, and the broader public alike. Road network data are openly available via user-generated content such as OpenStreetMap (OSM) but lack the resolution required for many tasks, e.g., emergency management. More importantly, however, few publicly available data offer information on elevation and slope. For most parts of the world, up-to-date digital elevation products with a resolution of less than 10 meters are a distant dream and, if available, those datasets have to be matched to the road network through an error-prone process. In this paper we present a radically different approach by deriving road network elevation data from massive amounts of in-situ observations extracted from user-contributed data from an online social fitness tracking application. While each individual observation may be of low-quality in terms of resolution and accuracy, taken together they form an accurate, high-resolution, up-to-date, three-dimensional road network that excels where other technologies such as LiDAR fail, e.g., in case of overpasses, overhangs, and so forth. In fact, the 1m spatial resolution dataset created in this research based on 350 million individual 3D location fixes has an RMSE of approximately 3.11m compared to a LiDAR-based ground-truth and can be used to enhance existing road network datasets where individual elevation fixes differ by up to 60m. In contrast, using interpolated data from the National Elevation Dataset (NED) results in 4.75m RMSE compared to the base line. We utilize Linked Data technologies to integrate the proposed high-resolution dataset with OpenStreetMap road geometries without requiring any changes to the OSM data model.

  15. A 18 m 2 cylindrical tracking detector made of 2.6 m long, stereo mylar straw tubes with 100 μm resolution

    Science.gov (United States)

    Benussi, L.; Bertani, M.; Bianco, S.; Fabbri, F. L.; Gianotti, P.; Giardoni, M.; Ghezzo, A.; Guaraldo, C.; Lanaro, A.; Locchi, P.; Lu, J.; Lucherini, V.; Mecozzi, A.; Pace, E.; Passamonti, L.; Qaisar, N.; Ricciardi, A.; Sarwar, S.; Serdyouk, V.; Trasatti, L.; Volkov, A.; Zia, A.

    1998-12-01

    An array of 2424 2.6 m-long, 15 mm-diameter mylar straw tubes, arranged in two axial and four stereo layers, has been assembled. The array covers a cylindrical tracking surface of 18 m 2 and provides coordinate measurement in the drift direction and along the wire. A correction of the systematic effects which are introduced by gravitational sag and electrostatics, thus dominating the detector performance especially with long straws, allows to determine wire position from drift-time distribution. The correction has been applied to reach a space resolution of 40 μm with DME, 100 μm with Ar+C 2H 6, and 100-200 μm with CO 2. Such a resolution is the best ever obtained for straws of these dimensions. A study of the gas leakage for the straw system has been performed, and results are reported. The array is being commissioned as a subdetector of the FINUDA spectrometer, and tracking performances are being studied with cosmic rays.

  16. A 18 m2 cylindrical tracking detector made of 2,6 m long, stereo mylar straw tubes with 100 μm resolution

    International Nuclear Information System (INIS)

    Benussi, L.; Bertani, M.; Bianco, S.; Fabbri, F.L.; Gianotti, P.; Giardoni, M.; Ghezzo, A.; Guaraldo, C.; Lanaro, A.; Locchi, P.; Lu, J.; Lucherini, V.; Mecozzi, A.; Pace, E.; Passamonti, L.; Qaisar, N.; Ricciardi, A.; Sarwar, S.; Serdyouk, V.; Trasatti, L.; Volkov, A.; Zia, A.

    1998-01-01

    An array of 2424 2.6 m-long, 15 mm-diameter mylar straw tubes, arranged in two axial and four stereo layers, has been assembled. The array covers a cylindrical tracking surface of 18 m 2 and provides coordinate measurement in the drift direction and along the wire. An under-standing of the systematic effects which are introduced by gravitational sag and electrostatics, thus dominating the detector performance especially with long straws, allows to determine wire position from drift-time distribution. The correction has been applied to reach a space resolution of 40 μm with DME, 100 μm with Ar + C 2 H 6 , and 100-200 μm with CO 2 . Such a resolution is the best ever obtained for straws of these dimensions. A study of the gas leakage for the straw system has been performed, and results are reported. The array is being commissioned as a subdetector of the FINUDA spectrometer, and tracking performances are being studied with cosmic rays. (author)

  17. Laser speckle imaging identification of increases in cortical microcirculatory blood flow induced by motor activity during awake craniotomy ; Clinical article

    NARCIS (Netherlands)

    E. Klijn (Elko); M.E.J.L. Hulscher (Marlies); R.K. Balvers (Rutger); W.P.J. Holland (Wim); J. Bakker (Jan); A.J.P.E. Vincent (Arnoud); C.M.F. Dirven (Clemens); C. Ince (Can)

    2013-01-01

    textabstractObject. The goal of awake neurosurgery is to maximize resection of brain lesions with minimal injury to functional brain areas. Laser speckle imaging (LSI) is a noninvasive macroscopic technique with high spatial and temporal resolution used to monitor changes in capillary perfusion. In

  18. Laser speckle imaging identification of increases in cortical microcirculatory blood flow induced by motor activity during awake craniotomy

    NARCIS (Netherlands)

    Klijn, Eva; Hulscher, Hester C.; Balvers, Rutger K.; Holland, Wim P. J.; Bakker, Jan; Vincent, Arnaud J. P. E.; Dirven, Clemens M. F.; Ince, Can

    2013-01-01

    The goal of awake neurosurgery is to maximize resection of brain lesions with minimal injury to functional brain areas. Laser speckle imaging (LSI) is a noninvasive macroscopic technique with high spatial and temporal resolution used to monitor changes in capillary perfusion. In this study, the

  19. Speckle disturbance limit in laser-based cinema projection systems

    Science.gov (United States)

    Verschaffelt, Guy; Roelandt, Stijn; Meuret, Youri; van den Broeck, Wendy; Kilpi, Katriina; Lievens, Bram; Jacobs, An; Janssens, Peter; Thienpont, Hugo

    2015-09-01

    In a multi-disciplinary effort, we investigate the level of speckle that can be tolerated in a laser cinema projector based on a quality of experience experiment with movie clips shown to a test audience in a real-life movie theatre setting. We identify a speckle disturbance threshold by statistically analyzing the observers’ responses for different values of the amount of speckle, which was monitored using a well-defined speckle measurement method. The analysis shows that the speckle perception of a human observer is not only dependent on the objectively measured amount of speckle, but it is also strongly influenced by the image content. The speckle disturbance limit for movies turns out to be substantially larger than that for still images, and hence is easier to attain.

  20. Ice Velocity Mapping Using TOPS SAR Data and Offset Tracking

    DEFF Research Database (Denmark)

    Dall, Jørgen; Kusk, Anders; Nielsen, Ulrik

    2015-01-01

    Feature tracking and speckle tracking, are robust techniques to measure the velocity of glaciers and ice sheets. Displacement maps based on TOPS data may have small gaps if the bursts are not handled properly. Ice moving from one burst to a consecutive burst between two observations is not observ...

  1. SPECKLE IMAGING EXCLUDES LOW-MASS COMPANIONS ORBITING THE EXOPLANET HOST STAR TRAPPIST-1

    Energy Technology Data Exchange (ETDEWEB)

    Howell, Steve B.; Scott, Nicholas J. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Everett, Mark E. [National Optical Astronomy Observatory, 950 N. Cherry Avenue, Tucson, AZ 85719 (United States); Horch, Elliott P. [Department of Physics, Southern Connecticut State University, 501 Crescent Street, New Haven, CT, 06515 (United States); Winters, Jennifer G. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, 02138 (United States); Hirsch, Lea [Astronomy Department, University of California, Berkeley, 510 Campbell Hall, Berkeley, CA, 94720 (United States); Nusdeo, Dan [Department of Physics and Astronomy, Georgia State University, P.O. Box 5060, Atlanta, GA 30302 (United States)

    2016-09-20

    We have obtained the highest-resolution images available of TRAPPIST-1 using the Gemini-South telescope and our speckle imaging camera. Observing at 692 and 883 nm, we reached the diffraction limit of the telescope providing a best resolution of 27 mas or, at the distance of TRAPPIST-1, a spatial resolution of 0.32 au. Our imaging of the star extends from 0.32 to 14.5 au. We show that to a high confidence level, we can exclude all possible stellar and brown dwarf companions, indicating that TRAPPIST-1 is a single star.

  2. SPECKLE IMAGING EXCLUDES LOW-MASS COMPANIONS ORBITING THE EXOPLANET HOST STAR TRAPPIST-1

    International Nuclear Information System (INIS)

    Howell, Steve B.; Scott, Nicholas J.; Everett, Mark E.; Horch, Elliott P.; Winters, Jennifer G.; Hirsch, Lea; Nusdeo, Dan

    2016-01-01

    We have obtained the highest-resolution images available of TRAPPIST-1 using the Gemini-South telescope and our speckle imaging camera. Observing at 692 and 883 nm, we reached the diffraction limit of the telescope providing a best resolution of 27 mas or, at the distance of TRAPPIST-1, a spatial resolution of 0.32 au. Our imaging of the star extends from 0.32 to 14.5 au. We show that to a high confidence level, we can exclude all possible stellar and brown dwarf companions, indicating that TRAPPIST-1 is a single star.

  3. 77 FR 67348 - Privacy Act of 1974; System of Records-Alternative Dispute Resolution (ADR) Center Case Tracking...

    Science.gov (United States)

    2012-11-09

    ....S.C. 791 et seq.; the Equal Pay Act, 29 U.S.C. 206(d); the Genetic Information Nondiscrimination Act... DEPARTMENT OF EDUCATION Privacy Act of 1974; System of Records--Alternative Dispute Resolution... with the Privacy Act of 1974, as amended, 5 U.S.C. 552a (Privacy Act), the Department of Education...

  4. Multimode waveguide speckle patterns for compressive sensing.

    Science.gov (United States)

    Valley, George C; Sefler, George A; Justin Shaw, T

    2016-06-01

    Compressive sensing (CS) of sparse gigahertz-band RF signals using microwave photonics may achieve better performances with smaller size, weight, and power than electronic CS or conventional Nyquist rate sampling. The critical element in a CS system is the device that produces the CS measurement matrix (MM). We show that passive speckle patterns in multimode waveguides potentially provide excellent MMs for CS. We measure and calculate the MM for a multimode fiber and perform simulations using this MM in a CS system. We show that the speckle MM exhibits the sharp phase transition and coherence properties needed for CS and that these properties are similar to those of a sub-Gaussian MM with the same mean and standard deviation. We calculate the MM for a multimode planar waveguide and find dimensions of the planar guide that give a speckle MM with a performance similar to that of the multimode fiber. The CS simulations show that all measured and calculated speckle MMs exhibit a robust performance with equal amplitude signals that are sparse in time, in frequency, and in wavelets (Haar wavelet transform). The planar waveguide results indicate a path to a microwave photonic integrated circuit for measuring sparse gigahertz-band RF signals using CS.

  5. Speckle reduction techniques in digital holography

    Energy Technology Data Exchange (ETDEWEB)

    Monaghan, David; Kelly, Damien; Hennelly, Bryan [Department of Computer Science, National University of Ireland, Maynooth, Co. Kildare (Ireland); Javidi, Bahram, E-mail: bryanh@cs.nuim.i [University of Connecticut Electrical and Computer Engineering Department 371 Fairfield Road, Unit 2157 Storrs, CT 06269-2157 (United States)

    2010-02-01

    We have studied several speckle reduction techniques, applicable to digital holography. These include the use of optical diffusers, wavelet filtering, simulating temporal incoherence and filtering in the Fourier domain. The Digital Holograms (DHs) used in this study are captured using a Phase Shift Interferometric (PSI) in-line setup and subsequently reconstructed numerically.

  6. Exploring sex differences in the adult zebra finch brain: In vivo diffusion tensor imaging and ex vivo super-resolution track density imaging.

    Science.gov (United States)

    Hamaide, Julie; De Groof, Geert; Van Steenkiste, Gwendolyn; Jeurissen, Ben; Van Audekerke, Johan; Naeyaert, Maarten; Van Ruijssevelt, Lisbeth; Cornil, Charlotte; Sijbers, Jan; Verhoye, Marleen; Van der Linden, Annemie

    2017-02-01

    Zebra finches are an excellent model to study the process of vocal learning, a complex socially-learned tool of communication that forms the basis of spoken human language. So far, structural investigation of the zebra finch brain has been performed ex vivo using invasive methods such as histology. These methods are highly specific, however, they strongly interfere with performing whole-brain analyses and exclude longitudinal studies aimed at establishing causal correlations between neuroplastic events and specific behavioral performances. Therefore, the aim of the current study was to implement an in vivo Diffusion Tensor Imaging (DTI) protocol sensitive enough to detect structural sex differences in the adult zebra finch brain. Voxel-wise comparison of male and female DTI parameter maps shows clear differences in several components of the song control system (i.e. Area X surroundings, the high vocal center (HVC) and the lateral magnocellular nucleus of the anterior nidopallium (LMAN)), which corroborate previous findings and are in line with the clear behavioral difference as only males sing. Furthermore, to obtain additional insights into the 3-dimensional organization of the zebra finch brain and clarify findings obtained by the in vivo study, ex vivo DTI data of the male and female brain were acquired as well, using a recently established super-resolution reconstruction (SRR) imaging strategy. Interestingly, the SRR-DTI approach led to a marked reduction in acquisition time without interfering with the (spatial and angular) resolution and SNR which enabled to acquire a data set characterized by a 78μm isotropic resolution including 90 diffusion gradient directions within 44h of scanning time. Based on the reconstructed SRR-DTI maps, whole brain probabilistic Track Density Imaging (TDI) was performed for the purpose of super resolved track density imaging, further pushing the resolution up to 40μm isotropic. The DTI and TDI maps realized atlas

  7. Track parameter resolution study of a pixel only detector for LHC geometry and future high rate experiments

    Energy Technology Data Exchange (ETDEWEB)

    Blago, Michele Piero; Kar, Tamasi Rameshchandra; Schoening, Andre [Physikalisches Institut, Universitaet Heidelberg (Germany)

    2016-07-01

    Recent progress in pixel detector technology, for example using High Voltage-Monolithic Pixel Sensors (HV-MAPS), makes it feasible to construct an all-silicon pixel detector for large scale particle experiments like ATLAS and CMS or other future collider experiments. Preliminary studies have shown that nine layers of pixel sensors are sufficient to reliably reconstruct particle trajectories. The performance of such an all-pixel detector is studied based on a full GEANT simulation for high luminosity conditions at the upgraded LHC. Furthermore, the ability of an all-pixel detector to form trigger decisions using a special triplet pixel layer design is studied. Such a design could be used to reconstruct all tracks originating from the proton-proton interaction at the first hardware level at 40 MHz collision frequency.

  8. The journey of integrins and partners in a complex interactions landscape studied by super-resolution microscopy and single protein tracking

    International Nuclear Information System (INIS)

    Rossier, Olivier; Giannone, Grégory

    2016-01-01

    Cells adjust their adhesive and cytoskeletal organizations according to changes in the biochemical and physical nature of their surroundings. In return, by adhering and generating forces on the extracellular matrix (ECM) cells organize their microenvironment. Integrin-dependent focal adhesions (FAs) are the converging zones integrating biochemical and biomechanical signals arising from the ECM and the actin cytoskeleton. Thus, integrin-mediated adhesion and mechanotransduction, the conversion of mechanical forces into biochemical signals, are involved in critical cellular functions such as migration, proliferation and differentiation, and their deregulation contributes to pathologies including cancer. A challenging problem is to decipher how stochastic protein movements and interactions lead to formation of dynamic architecture such as integrin-dependent adhesive structures. In this review, we will describe recent advances made possible by super-resolution microscopies and single molecule tracking approaches that provided new understanding on the organization and the dynamics of integrins and intracellular regulators at the nanoscale in living cells.

  9. The journey of integrins and partners in a complex interactions landscape studied by super-resolution microscopy and single protein tracking

    Energy Technology Data Exchange (ETDEWEB)

    Rossier, Olivier; Giannone, Grégory [Univ. Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, F-33000 Bordeaux (France); CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, F-33000 Bordeaux (France)

    2016-04-10

    Cells adjust their adhesive and cytoskeletal organizations according to changes in the biochemical and physical nature of their surroundings. In return, by adhering and generating forces on the extracellular matrix (ECM) cells organize their microenvironment. Integrin-dependent focal adhesions (FAs) are the converging zones integrating biochemical and biomechanical signals arising from the ECM and the actin cytoskeleton. Thus, integrin-mediated adhesion and mechanotransduction, the conversion of mechanical forces into biochemical signals, are involved in critical cellular functions such as migration, proliferation and differentiation, and their deregulation contributes to pathologies including cancer. A challenging problem is to decipher how stochastic protein movements and interactions lead to formation of dynamic architecture such as integrin-dependent adhesive structures. In this review, we will describe recent advances made possible by super-resolution microscopies and single molecule tracking approaches that provided new understanding on the organization and the dynamics of integrins and intracellular regulators at the nanoscale in living cells.

  10. Ex-situ tracking solid oxide cell electrode microstructural evolution in a redox cycle by high resolution ptychographic nanotomography

    DEFF Research Database (Denmark)

    De Angelis, Salvatore; Jørgensen, Peter Stanley; Esposito, Vincenzo

    2017-01-01

    , the nickel and pore networks undergo major reorganization and the formation of internal voids is observed in the nickel-oxide particles after the oxidation. These observations are discussed in terms of reaction kinetics, electrode mechanical stress and the consequences of redox cycling on electrode...... towards this aim by visualizing a complete redox cycle in a solid oxide cell (SOC) electrode. The experiment demonstrates synchrotron-based ptychography as a method of imaging SOC electrodes, providing an unprecedented combination of 3D image quality and spatial resolution among non-destructive imaging...

  11. Highly porous nanoberyllium for X-ray beam speckle suppression

    Energy Technology Data Exchange (ETDEWEB)

    Goikhman, Alexander, E-mail: agoikhman@ymail.com; Lyatun, Ivan; Ershov, Petr [Immanuel Kant Baltic Federal University, Nevskogo str. 14, Kaliningrad 236041 (Russian Federation); Snigireva, Irina [European Synchrotron Radiation Facility, BP 220, 38043 Grenoble (France); Wojda, Pawel [Immanuel Kant Baltic Federal University, Nevskogo str. 14, Kaliningrad 236041 (Russian Federation); Gdańsk University of Technology, 11/12 G. Narutowicza, Gdańsk 80-233 (Poland); Gorlevsky, Vladimir; Semenov, Alexander; Sheverdyaev, Maksim; Koletskiy, Viktor [A. A. Bochvar High-Technology Scientific Research Institute for Inorganic Materials, Rogova str. 5a, Moscow 123098 (Russian Federation); Snigirev, Anatoly [Immanuel Kant Baltic Federal University, Nevskogo str. 14, Kaliningrad 236041 (Russian Federation); European Synchrotron Radiation Facility, BP 220, 38043 Grenoble (France)

    2015-04-09

    A speckle suppression device containing highly porous nanoberyllium is proposed for manipulating the spatial coherence length and removing undesirable speckle structure during imaging experiments. This paper reports a special device called a ‘speckle suppressor’, which contains a highly porous nanoberyllium plate squeezed between two beryllium windows. The insertion of the speckle suppressor in an X-ray beam allows manipulation of the spatial coherence length, thus changing the effective source size and removing the undesirable speckle structure in X-ray imaging experiments almost without beam attenuation. The absorption of the nanoberyllium plate is below 1% for 1 mm thickness at 12 keV. The speckle suppressor was tested on the ID06 ESRF beamline with X-rays in the energy range from 9 to 15 keV. It was applied for the transformation of the phase–amplitude contrast to the pure amplitude contrast in full-field microscopy.

  12. Highly porous nanoberyllium for X-ray beam speckle suppression

    International Nuclear Information System (INIS)

    Goikhman, Alexander; Lyatun, Ivan; Ershov, Petr; Snigireva, Irina; Wojda, Pawel; Gorlevsky, Vladimir; Semenov, Alexander; Sheverdyaev, Maksim; Koletskiy, Viktor; Snigirev, Anatoly

    2015-01-01

    A speckle suppression device containing highly porous nanoberyllium is proposed for manipulating the spatial coherence length and removing undesirable speckle structure during imaging experiments. This paper reports a special device called a ‘speckle suppressor’, which contains a highly porous nanoberyllium plate squeezed between two beryllium windows. The insertion of the speckle suppressor in an X-ray beam allows manipulation of the spatial coherence length, thus changing the effective source size and removing the undesirable speckle structure in X-ray imaging experiments almost without beam attenuation. The absorption of the nanoberyllium plate is below 1% for 1 mm thickness at 12 keV. The speckle suppressor was tested on the ID06 ESRF beamline with X-rays in the energy range from 9 to 15 keV. It was applied for the transformation of the phase–amplitude contrast to the pure amplitude contrast in full-field microscopy

  13. High-resolution recording of particle tracks with in-line holography in a large cryogenic bubble chamber

    CERN Document Server

    Harigel, G G

    2000-01-01

    Holography has been used successfully in combination with conventional optics for the first time in a large cryogenic bubble chamber, the 15-Foot Bubble Chamber at the Fermi National Accelerator Laboratory (FNAL), during a physics run in a high-energy neutrino beam. The innovative system combined the reference beam with the object beam, irradiating a conical volume of ~1.5 m/sup 3/. Bubble tracks from neutrino interactions with a width of ~120 mu m have been recorded with good contrast. The ratio of intensities of the object light to the reference light striking the film is called the beam branching ratio (BBR). We obtained in our experiment an exceedingly small minimum-observable ratio of BBR=(0.54/0.21)*10/sup -7/. The technology has the potential for a wide range of applications. This paper describes the various difficulties in achieving the success. It required the development of laser pulse stretching via enhanced closed loop control with slow Q-switching, to overcome excessive heating of the cryogenic l...

  14. The Track of Brain Activity during the Observation of TV Commercials with the High-Resolution EEG Technology

    Directory of Open Access Journals (Sweden)

    Laura Astolfi

    2009-01-01

    Full Text Available We estimate cortical activity in normal subjects during the observation of TV commercials inserted within a movie by using high-resolution EEG techniques. The brain activity was evaluated in both time and frequency domains by solving the associate inverse problem of EEG with the use of realistic head models. In particular, we recover statistically significant information about cortical areas engaged by particular scenes inserted within the TV commercial proposed with respect to the brain activity estimated while watching a documentary. Results obtained in the population investigated suggest that the statistically significant brain activity during the observation of the TV commercial was mainly concentrated in frontoparietal cortical areas, roughly coincident with the Brodmann areas 8, 9, and 7, in the analyzed population.

  15. Real time processor for array speckle interferometry

    International Nuclear Information System (INIS)

    Chin, G.; Florez, J.; Borelli, R.; Fong, W.; Miko, J.; Trujillo, C.

    1989-01-01

    With the construction of several new large aperture telescopes and the development of large format array detectors in the near IR, the ability to obtain diffraction limited seeing via IR array speckle interferometry offers a powerful tool. We are constructing a real-time processor to acquire image frames, perform array flat-fielding, execute a 64 x 64 element 2D complex FFT, and to average the power spectrum all within the 25 msec coherence time for speckles at near IR wavelength. The processor is a compact unit controlled by a PC with real time display and data storage capability. It provides the ability to optimize observations and obtain results on the telescope rather than waiting several weeks before the data can be analyzed and viewed with off-line methods

  16. Twisted speckle entities inside wave-front reversal mirrors

    International Nuclear Information System (INIS)

    Okulov, A. Yu

    2009-01-01

    The previously unknown property of the optical speckle pattern reported. The interference of a speckle with the counterpropagating phase-conjugated (PC) speckle wave produces a randomly distributed ensemble of a twisted entities (ropes) surrounding optical vortex lines. These entities appear in a wide range of a randomly chosen speckle parameters inside the phase-conjugating mirrors regardless to an internal physical mechanism of the wave-front reversal. These numerically generated interference patterns are relevant to the Brillouin PC mirrors and to a four-wave mixing PC mirrors based upon laser trapped ultracold atomic cloud.

  17. Static speckle experiments using white synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sant, Tushar; Panzner, Tobias; Pietsch, Ullrich [Solid State Physics Group, University of Siegen (Germany)

    2008-07-01

    Static speckle experiments were performed using coherent white X-ray radiation from a bending magnet at BESSYII. Semiconductor and polymer surfaces were investigated under incidence condition smaller than the critical angle of total external reflection. The scattering pattern of the sample results from the illumination function modified by the surface undulations. The periodic oscillations are caused by the illumination function whereas other irregular features are associated with sample surface. The speckle map of reflection from a laterally periodic structure like GaAs grating is studied. Under coherent illumination the grating peaks split into speckles because of fluctuations on the sample surface. It is important to understand which length scales on the sample surface are responsible for the oscillations in reflectivity map. To investigate this experiments are done with a triangular shaped sample. Different parts of the sample are illuminated with the footprint on the sample larger or smaller than the actual sample length. This gives prior information about total illuminated area on the sample. Using this additional information a detailed surface profile of the sample is reconstructed.

  18. Early detection and treatment of Speckled leukoplakia

    Directory of Open Access Journals (Sweden)

    Selviana Tampoma

    2016-12-01

    Full Text Available Background: Leukoplakia is one of potentially malignant disorders that can be found on oral mucosa. Speckled leukoplakia is a rare type of leukoplakia with a very high risk of premalignant growth. Approximately 3 % of worldwide population has suffered from leukoplakia, 5-25% of which tend to be malignant leukoplakia. Purpose: This case report was aimed to discuss about early detection of speckled leukoplakia as one of potentially malignant disorders. Case: A 62 year old male patient came with chief complaint of bald and painful tongue since one month ago. The patient has a history of allergic reaction, hypertension, uric acid, and hepatitis B. He had been a heavy smoker since young until 10 years ago. Intra oral examination showed a firm, rough, non scrapable white plaque lesion with a size of 1 x 1.5 cm, surrounded by painful erosion with diffuse boundary. Case Management: Based on cytology examination, the patient was reffered to oncologist to get an excisional biopsy. Next, the patient succesfully underwent the excisional biopsy and came for control. The results showed the healing process of the lesion with a minimal complaint of bald tongue, especially when eating spicy or hot meal. To improve healing process, the patient then was given an antibacterial mouth rinse containing zinc and mulvitamin. Conclusion: Speckled leukoplakia could show high malignant transformation rate, therefore, early detection and treatment are necessary.

  19. High-resolution magnetic resonance imaging tracks changes in organ and tissue mass in obese and aging rats.

    Science.gov (United States)

    Tang, Haiying; Vasselli, Joseph R; Wu, Ed X; Boozer, Carol N; Gallagher, Dympna

    2002-03-01

    Magnetic resonance imaging (MRI) has the ability to discriminate between various soft tissues in vivo. Whole body, specific organ, total adipose tissue (TAT), intra-abdominal adipose tissue (IAAT), and skeletal muscle (SM) weights determined by MRI were compared with weights determined by dissection and chemical analysis in two studies with male Sprague-Dawley rats. A 4.2-T MRI machine acquired high-resolution, in vivo, longitudinal whole body images of rats as they developed obesity or aged. Weights of the whole body and specific tissues were determined using computer image analysis software, including semiautomatic segmentation algorithms for volume calculations. High correlations were found for body weight (r = 0.98), TAT (r = 0.99), and IAAT (r = 0.98) between MRI and dissection and chemical analyses. MRI estimated the weight of the brain, kidneys, and spleen with high accuracy (r > 0.9), but overestimated IAAT, SM, and liver volumes. No differences were detected in organ weights using MRI and dissection measurements. Longitudinal MRI measurements made during the development of obesity and aging accurately represented changes in organ and tissue mass.

  20. THE DUAL-TRACK APPROACH OF THE PRC TO THE RESOLUTION OF DISPUTES IN THE SOUTH CHINA SEA

    Directory of Open Access Journals (Sweden)

    Т И Понька

    2017-12-01

    Full Text Available The Asia-Pacific region is becoming one of the centers of global economic and political development. Countries of the region actively develop their economy, implement democratic reforms, and are also interested in peace and security in the region. A serious destabilizing factor in the Asia-Pacific region is territorial disputes between China and a number of countries in the region. China is taking the lead in the region and resolutely defends its interests, including territorial ones. The growing economic and military strength of China bothers other countries of Asia-Pacific region. Japan, Vietnam, South Korea, Indonesia also claim regional leadership. They also demonstrate determination in their territorial claims. Confrontation with China encourages the countries of the region to seek political and military support from the US, that could lead to the aggravation of the situation in the region in future. Meanwhile, China is also interested in good relations with neighbors, that’s why it changes approaches of solving its territorial issues. The objective of the research is to define China’s approach to territorial disputes in Asia-Pacific region. For this purpose, the authors set some tasks: first, to point out the main territorial disputes between China and Asia-Pacific countries, second, to consider how the problem of territorial disputes in Asia-Pacific region first appeared and developed, and how the Chinese government reacted to it, and finally, to analyze the role of international organizations, such as the UN and ASEAN in settling disputes in Asia-Pacific region. Summarizing the results of their research, the authors make the important conclusion that China’s stance on disputed territories remains unchanged, and at the same time, Chinese government seeks to solve the existing territorial problems peacefully, without using military force.

  1. Compound speckles and their statistical and dynamical properties

    DEFF Research Database (Denmark)

    Hanson, Steen Grüner; Jakobsen, Michael Linde; Skov Hansen, Rene

    2008-01-01

    Two issues will be treated in this presentation, both focusing on gaining a deeper understanding of dynamic speckles, aiming at the use for probing dynamical properties of scattering structures. The first issue to be addressed is the dynamics of speckles arising from illuminating a solid surface...

  2. Correlation of Spatially Filtered Dynamic Speckles in Distance Measurement Application

    International Nuclear Information System (INIS)

    Semenov, Dmitry V.; Nippolainen, Ervin; Kamshilin, Alexei A.; Miridonov, Serguei V.

    2008-01-01

    In this paper statistical properties of spatially filtered dynamic speckles are considered. This phenomenon was not sufficiently studied yet while spatial filtering is an important instrument for speckles velocity measurements. In case of spatial filtering speckle velocity information is derived from the modulation frequency of filtered light power which is measured by photodetector. Typical photodetector output is represented by a narrow-band random noise signal which includes non-informative intervals. Therefore more or less precious frequency measurement requires averaging. In its turn averaging implies uncorrelated samples. However, conducting research we found that correlation is typical property not only of dynamic speckle patterns but also of spatially filtered speckles. Using spatial filtering the correlation is observed as a response of measurements provided to the same part of the object surface or in case of simultaneously using several adjacent photodetectors. Found correlations can not be explained using just properties of unfiltered dynamic speckles. As we demonstrate the subject of this paper is important not only from pure theoretical point but also from the point of applied speckle metrology. E.g. using single spatial filter and an array of photodetector can greatly improve accuracy of speckle velocity measurements

  3. Speckle-based at-wavelength metrology of x-ray optics at Diamond Light Source

    Science.gov (United States)

    Wang, Hongchang; Zhou, Tunhe; Kashyap, Yogesh; Sawhney, Kawal

    2017-08-01

    To achieve high resolution and sensitivity on the nanometer scale, further development of X-ray optics is required. Although ex-situ metrology provides valuable information about X-ray optics, the ultimate performance of X-ray optics is critically dependent on the exact nature of the working conditions. Therefore, it is equally important to perform in-situ metrology at the optics' operating wavelength (`at-wavelength' metrology) to optimize the performance of X-ray optics and correct and minimize the collective distortions of the upstream beamline optics, e.g. monochromator, windows, etc. Speckle-based technique has been implemented and further improved at Diamond Light Source. We have demonstrated that the angular sensitivity for measuring the slope error of an optical surface can reach an accuracy of two nanoradians. The recent development of the speckle-based at-wavelength metrology techniques will be presented. Representative examples of the applications of the speckle-based technique will also be given - including optimization of X-ray mirrors and characterization of compound refraction lenses. Such a high-precision metrology technique will be extremely beneficial for the manufacture and in-situ alignment/optimization of X-ray mirrors for next-generation synchrotron beamlines.

  4. Speckle noise reduction for optical coherence tomography based on adaptive 2D dictionary

    Science.gov (United States)

    Lv, Hongli; Fu, Shujun; Zhang, Caiming; Zhai, Lin

    2018-05-01

    As a high-resolution biomedical imaging modality, optical coherence tomography (OCT) is widely used in medical sciences. However, OCT images often suffer from speckle noise, which can mask some important image information, and thus reduce the accuracy of clinical diagnosis. Taking full advantage of nonlocal self-similarity and adaptive 2D-dictionary-based sparse representation, in this work, a speckle noise reduction algorithm is proposed for despeckling OCT images. To reduce speckle noise while preserving local image features, similar nonlocal patches are first extracted from the noisy image and put into groups using a gamma- distribution-based block matching method. An adaptive 2D dictionary is then learned for each patch group. Unlike traditional vector-based sparse coding, we express each image patch by the linear combination of a few matrices. This image-to-matrix method can exploit the local correlation between pixels. Since each image patch might belong to several groups, the despeckled OCT image is finally obtained by aggregating all filtered image patches. The experimental results demonstrate the superior performance of the proposed method over other state-of-the-art despeckling methods, in terms of objective metrics and visual inspection.

  5. Laser speckle imaging of rat retinal blood flow with hybrid temporal and spatial analysis method

    Science.gov (United States)

    Cheng, Haiying; Yan, Yumei; Duong, Timothy Q.

    2009-02-01

    Noninvasive monitoring of blood flow in retinal circulation will reveal the progression and treatment of ocular disorders, such as diabetic retinopathy, age-related macular degeneration and glaucoma. A non-invasive and direct BF measurement technique with high spatial-temporal resolution is needed for retinal imaging. Laser speckle imaging (LSI) is such a method. Currently, there are two analysis methods for LSI: spatial statistics LSI (SS-LSI) and temporal statistical LSI (TS-LSI). Comparing these two analysis methods, SS-LSI has higher signal to noise ratio (SNR) and TSLSI is less susceptible to artifacts from stationary speckle. We proposed a hybrid temporal and spatial analysis method (HTS-LSI) to measure the retinal blood flow. Gas challenge experiment was performed and images were analyzed by HTS-LSI. Results showed that HTS-LSI can not only remove the stationary speckle but also increase the SNR. Under 100% O2, retinal BF decreased by 20-30%. This was consistent with the results observed with laser Doppler technique. As retinal blood flow is a critical physiological parameter and its perturbation has been implicated in the early stages of many retinal diseases, HTS-LSI will be an efficient method in early detection of retina diseases.

  6. Tracking and evolution of irrigation triggered active landslides by multi-source high resolution DEM: The Jiaojiacun landslide group of Heifangtai (Northwest of China)

    Science.gov (United States)

    Zeng, Runqiang; Meng, Xingmin; Wang, Siyuan; Chen, Guan; Lee, Yajun; Zhang, Yi

    2014-05-01

    The construction of three large hydropower stations, i.e. Liujia, Yanguo and Bapan, resulted in the immigration of the impacted people to Heifangtai from 1960s. To support the living and farming of the immigrated people, a large amount of water has been pumped from the Yellow River to Heifangtai, which has changed the former underground water budget and led to 111 landslides from 1968 in this area. To reveal the deformation process of landslides in Heifangtai, a quantitative deformation analysis model of landslide based on multi-source DEM data is established using four periods of topographic maps obtained in 1970, 2001, 2010 and 2013 respectively, including two 1:10000 topographic maps and two 1:1000 data acquired from 3D Laser Scanner. The whole study area was divided into two sections based on the two distinct kinds of landslide patterns. The selected morphometric parameters, residual topographic surface and surface roughness, extracted from three typical landslides, and the statistical analysis (Box-plot diagrams) of the temporal variations of these parameters, allowed the reconstruction and tracking of these landslides. We monitored the changing of landslide boundaries, average vertical and horizontal displacement rates and zones of uplift and subsidence. The volumes of removed and/or accumulated material were estimated as well. We can then demonstrate the kinematics of landslides based on information from high-resolution DEM, and the changing table of underground water, ring-shear test and soil-water characteristic curve referenced from other researchers. The results provide a new insight on the use of multi-source high resolution DEM in the monitoring of irrigation-triggered landslides.

  7. Incoherent improvement of the spatial resolution in digital holography

    International Nuclear Information System (INIS)

    Garcia-Sucerquia, J.; Herrera-Ramirez, J.; Castaneda, R.

    2005-10-01

    We report on a technique for increasing the spatial resolution of digitally recorded and reconstructed holograms of macroscopic objects, via the reduction of the contrast of the speckle noise present in the coherent imaging techniques. The contrast of the speckle noise is reduced through the superposition on an intensity basis of digitally reconstructed holograms of the same static scene. The reconstruction of a very poor contrasted object illustrates the performance of the technique. (author)

  8. Rapid Linguistic Ambiguity Resolution in Young Children with Autism Spectrum Disorder: Eye Tracking Evidence for the Limits of Weak Central Coherence.

    Science.gov (United States)

    Hahn, Noemi; Snedeker, Jesse; Rabagliati, Hugh

    2015-12-01

    Individuals with autism spectrum disorders (ASD) have often been reported to have difficulty integrating information into its broader context, which has motivated the Weak Central Coherence theory of ASD. In the linguistic domain, evidence for this difficulty comes from reports of impaired use of linguistic context to resolve ambiguous words. However, recent work has suggested that impaired use of linguistic context may not be characteristic of ASD, and is instead better explained by co-occurring language impairments. Here, we provide a strong test of these claims, using the visual world eye tracking paradigm to examine the online mechanisms by which children with autism resolve linguistic ambiguity. To address concerns about both language impairments and compensatory strategies, we used a sample whose verbal skills were strong and whose average age (7; 6) was lower than previous work on lexical ambiguity resolution in ASD. Participants (40 with autism and 40 controls) heard sentences with ambiguous words in contexts that either strongly supported one reading or were consistent with both (John fed/saw the bat). We measured activation of the unintended meaning through implicit semantic priming of an associate (looks to a depicted baseball glove). Contrary to the predictions of weak central coherence, children with ASD, like controls, quickly used context to resolve ambiguity, selecting appropriate meanings within a second. We discuss how these results constrain the generality of weak central coherence. © 2015 International Society for Autism Research, Wiley Periodicals, Inc.

  9. The journey of integrins and partners in a complex interactions landscape studied by super-resolution microscopy and single protein tracking.

    Science.gov (United States)

    Rossier, Olivier; Giannone, Grégory

    2016-04-10

    Cells adjust their adhesive and cytoskeletal organizations according to changes in the biochemical and physical nature of their surroundings. In return, by adhering and generating forces on the extracellular matrix (ECM) cells organize their microenvironment. Integrin-dependent focal adhesions (FAs) are the converging zones integrating biochemical and biomechanical signals arising from the ECM and the actin cytoskeleton. Thus, integrin-mediated adhesion and mechanotransduction, the conversion of mechanical forces into biochemical signals, are involved in critical cellular functions such as migration, proliferation and differentiation, and their deregulation contributes to pathologies including cancer. A challenging problem is to decipher how stochastic protein movements and interactions lead to formation of dynamic architecture such as integrin-dependent adhesive structures. In this review, we will describe recent advances made possible by super-resolution microscopies and single molecule tracking approaches that provided new understanding on the organization and the dynamics of integrins and intracellular regulators at the nanoscale in living cells. Copyright © 2015. Published by Elsevier Inc.

  10. Use of high resolution satellite images for tracking of changes in the lineament structure, caused by earthquakes, situated nearly the Pacific coast of the North and South America.

    Science.gov (United States)

    Arellano-Baeza, A. A.; Garcia, R. V.; Trejo-Soto, M.

    The Pacific coast of the North and South America is one of the most seismically and volcanically active regions in the world forming part of the so-called Ring of Fire More than 10 earthquakes with the Richter scale magnitude 4 5 were analyzed They were located in the regions with small seasonal variations and limited vegetation to facilitate the tracking of features associated with the seismic activity only High resolution Aster satellite images were used to extract the principal lineaments using The Lineament Extraction and Stripes Statistic Analysis LESSA software package It was found that the number and orientation of lineaments changed significantly about one month before an earthquake approximately and a few months later the system returns to its initial state This effect increases with the earthquake magnitude and it is much more easily detectable in case of convergent plate boundaries for example Nasca and South American plates The results obtained open the possibility to develop a methodology able to evaluate the seismic risk in the regions with similar geological conditions

  11. Photon event distribution sampling: an image formation technique for scanning microscopes that permits tracking of sub-diffraction particles with high spatial and temporal resolutions.

    Science.gov (United States)

    Larkin, J D; Publicover, N G; Sutko, J L

    2011-01-01

    In photon event distribution sampling, an image formation technique for scanning microscopes, the maximum likelihood position of origin of each detected photon is acquired as a data set rather than binning photons in pixels. Subsequently, an intensity-related probability density function describing the uncertainty associated with the photon position measurement is applied to each position and individual photon intensity distributions are summed to form an image. Compared to pixel-based images, photon event distribution sampling images exhibit increased signal-to-noise and comparable spatial resolution. Photon event distribution sampling is superior to pixel-based image formation in recognizing the presence of structured (non-random) photon distributions at low photon counts and permits use of non-raster scanning patterns. A photon event distribution sampling based method for localizing single particles derived from a multi-variate normal distribution is more precise than statistical (Gaussian) fitting to pixel-based images. Using the multi-variate normal distribution method, non-raster scanning and a typical confocal microscope, localizations with 8 nm precision were achieved at 10 ms sampling rates with acquisition of ~200 photons per frame. Single nanometre precision was obtained with a greater number of photons per frame. In summary, photon event distribution sampling provides an efficient way to form images when low numbers of photons are involved and permits particle tracking with confocal point-scanning microscopes with nanometre precision deep within specimens. © 2010 The Authors Journal of Microscopy © 2010 The Royal Microscopical Society.

  12. Measurement of natural convection by speckle photography

    International Nuclear Information System (INIS)

    Wernekinck, U.; Merzkirch, W.

    1986-01-01

    The principle of speckle photography can be applied to the measurement of density variations in fluids. A modification of existing experimental arrangements allows for the measurement of large values of the light deflection angles as they may occur in heat and mass transfer situations. The method is demonstrated for the case of a helium jet exhausting into still air and the natural convective flow along a heated plate. The obtained data are compared with results measured with classical optical interferometers, and good agreement is found. The advantages of the new technique over the classical optical methods are briefly discussed. 11 references

  13. Observations of binary stars by speckle interferometry

    International Nuclear Information System (INIS)

    Morgan, B.L.; Beckmann, G.K.; Scaddan, R.J.

    1980-01-01

    This is the second paper in a series describing observations of binary stars using the technique of speckle interferometry. Observations were made using the 2.5-m Isaac Newton Telescope and the 1-m telescope of the Royal Greenwich Observatory and the 1.9-m telescope of the South African Astronomical Observatory. The classical Rayleigh diffraction limits are 0.050 arcsec for the 2.5-m telescope, 0.065 arcsec for the 1.9-m telescope and 0.125 arcsec for the 1-m telescope, at a wavelength of 500 nm. The results of 29 measurements of 26 objects are presented. The objects include long period spectroscopic binaries from the 6th Catalogue of Batten, close visual binary systems from the 3rd Catalogue of Finsen and Worley and variable stars. Nine of the objects have not been previously resolved by speckle interferometry. New members are detected in the systems β Cep, p Vel and iota UMa. (author)

  14. Lagrangian speckle model and tissue-motion estimation--theory.

    Science.gov (United States)

    Maurice, R L; Bertrand, M

    1999-07-01

    It is known that when a tissue is subjected to movements such as rotation, shearing, scaling, etc., changes in speckle patterns that result act as a noise source, often responsible for most of the displacement-estimate variance. From a modeling point of view, these changes can be thought of as resulting from two mechanisms: one is the motion of the speckles and the other, the alterations of their morphology. In this paper, we propose a new tissue-motion estimator to counteract these speckle decorrelation effects. The estimator is based on a Lagrangian description of the speckle motion. This description allows us to follow local characteristics of the speckle field as if they were a material property. This method leads to an analytical description of the decorrelation in a way which enables the derivation of an appropriate inverse filter for speckle restoration. The filter is appropriate for linear geometrical transformation of the scattering function (LT), i.e., a constant-strain region of interest (ROI). As the LT itself is a parameter of the filter, a tissue-motion estimator can be formulated as a nonlinear minimization problem, seeking the best match between the pre-tissue-motion image and a restored-speckle post-motion image. The method is tested, using simulated radio-frequency (RF) images of tissue undergoing axial shear.

  15. 斑点追踪技术检测乳腺癌术后化疗药物对心肌的毒性作用%The role of speckle tracking echocardiography in identifying postoperative chemotherapeutic cardiotoxicity in patients with breast cancer

    Institute of Scientific and Technical Information of China (English)

    韩勇; 陈明; 曲俊朴; 夏良华; 董云; 徐旻

    2014-01-01

    前基础状态比较:t=5.33、13.94,同健康对照组比较:t=4.97、4.46、7.18,P均<0.05);(5)MCI曲线下面积为0.894,MCI以-265.7(%×度)为乳腺癌化疗患者的截断值时,其敏感度为82.6%,特异度为78.7%。结论采用STE技术检测乳腺癌化疗患者所获得的MCI,将心肌应变和心脏扭转结合起来,对早期检测化疗药物的心脏毒性作用具有较高的临床参考价值。%Objective To assess the potential clinical signiifcance of myocardial composite index (MCI) in the evaluation of left ventricular myocardial function in breast cancer patients with postoperative chemotherapy by speckle tracking echocardiography (STE). Methods A total of 33 consecutive breast cancer patients with postoperative chemotherapy were prospectively enrolled in Shanghai East Hospital, Tongji University, from February 2012 to February 2013. Thirty-six female healthy volunteers were enrolled as the controls. Routine echocardiographic parameters [left ventricular end diastolic volume (EDV), end systolic volume (ESV), interventricular septum thickness at diastole (IVSTd), left ventricular posterior wall thickness (PWTd) and left ventricular ejection fraction (LVEF)] were obtained. EDV and ESV were corrected for body surface area, and then end diastolic volume index (EDVI) and end-systolic volume index (ESVI) were calculated. STE-derived parameters [left ventricular global longitudinal strain (GLS), global radial strain (GRS), left ventricular twist (LVtw) and myocardial composite index (MCI)] were evaluated. All above data were obtained after 5 anthracycline-based chemotherapeutic cycles and compared with baseline measurements in controls respectively. Receiver operating characteristic (ROC) curves were constructed to determine optimal sensitivity and specificity of continuous variables for the prediction of future cardiotoxicity. Results (1)Changes in EDV, ESV, IVSTd, PWTd and LVEF showed no significant decreases compared with baseline and

  16. A SIMPLE HETERODYNE TEMPORAL SPECKLE-PATTERN INTERFEROMETER

    International Nuclear Information System (INIS)

    Wong, W. O.; Gao, Z.; Lu, J.

    2010-01-01

    A common light path design of heterodyne speckle pattern interferometer based on temporal speckle pattern interferometry is proposed for non-contact, full-field and real-time continuous displacement measurement. Double frequency laser is produced by rotating a half wave plate. An experiment was carried out to measure the dynamic displacement of a cantilever plate for testing the proposed common path heterodyne speckle pattern interferometer. The accuracy of displacement measurement was checked by measuring the motion at the mid-point of the plate with a point displacement sensor.

  17. Enhanced deterministic phase retrieval using a partially developed speckle field

    DEFF Research Database (Denmark)

    Almoro, Percival F.; Waller, Laura; Agour, Mostafa

    2012-01-01

    A technique for enhanced deterministic phase retrieval using a partially developed speckle field (PDSF) and a spatial light modulator (SLM) is demonstrated experimentally. A smooth test wavefront impinges on a phase diffuser, forming a PDSF that is directed to a 4f setup. Two defocused speckle...... intensity measurements are recorded at the output plane corresponding to axially-propagated representations of the PDSF in the input plane. The speckle intensity measurements are then used in a conventional transport of intensity equation (TIE) to reconstruct directly the test wavefront. The PDSF in our...

  18. Quantization analysis of speckle intensity measurements for phase retrieval

    DEFF Research Database (Denmark)

    Maallo, Anne Margarette S.; Almoro, Percival F.; Hanson, Steen Grüner

    2010-01-01

    Speckle intensity measurements utilized for phase retrieval (PR) are sequentially taken with a digital camera, which introduces quantization error that diminishes the signal quality. Influences of quantization on the speckle intensity distribution and PR are investigated numerically...... and experimentally in the static wavefront sensing setup. Resultsshowthat 3 to 4 bits are adequate to represent the speckle intensities and yield acceptable reconstructions at relatively fast convergence rates. Computer memory requirements may be eased down by 2.4 times if a 4 bit instead of an 8 bit camera is used...

  19. Analyzing speckle contrast for HiLo microscopy optimization

    Science.gov (United States)

    Mazzaferri, J.; Kunik, D.; Belisle, J. M.; Singh, K.; Lefrançois, S.; Costantino, S.

    2011-07-01

    HiLo microscopy is a recently developed technique that provides both optical sectioning and fast imaging with a simple implementation and at a very low cost. The methodology combines widefield and speckled illumination images to obtain one optically sectioned image. Hence, the characteristics of such speckle illumination ultimately determine the quality of HiLo images and the overall performance of the method. In this work, we study how speckle contrast influence local variations of fluorescence intensity and brightness profiles of thick samples. We present this article as a guide to adjust the parameters of the system for optimizing the capabilities of this novel technology.

  20. Prosthetic clone and natural human tooth comparison by speckle interferometry

    Science.gov (United States)

    Slangen, Pierre; Corn, Stephane; Fages, Michel; Raynal, Jacques; Cuisinier, Frederic J. G.

    2010-09-01

    New trends in dental prosthodontic interventions tend to preserve the maximum of "body" structure. With the evolution of CAD-CAM techniques, it is now possible to measure "in mouth" the remaining dental tissues. The prosthetic crown is then designed using this shape on which it will be glued on, and also by taking into account the contact surface of the opposite jaw tooth. Several theories discuss on the glue thickness and formulation, but also on the way to evolve to a more biocompatible crown and also new biomechanical concepts. In order to validate these new concepts and materials, and to study the mechanical properties and mechanical integrity of the prosthesis, high resolution optical measurements of the deformations of the glue and the crown are needed. Samples are two intact premolars extracted for orthodontics reasons. The reference sample has no modifications on the tooth while the second sample tooth is shaped to receive a feldspathic ceramic monoblock crown which will be glued. This crown was manufactured with a chairside CAD-CAM system from an intra-oral optical print. The software allows to realize a nearly perfect clone of the reference sample. The necessary space for the glue is also entered with ideal values. This duplication process yields to obtain two samples with identical anatomy for further processing. The glue joint thickness can also be modified if required. The purpose is to compare the behaviour of a natural tooth and its prosthetic clone manufactured with "biomechanical" concepts. Vertical cut samples have been used to deal with planar object observation, and also to look "inside" the tooth. We have developed a complete apparatus enabling the study of the compressive mechanical behaviour of the concerned tooth by speckle interferometry. Because in plane displacements are of great interest for orthodontic measurements1, an optical fiber in-plane sensitive interferometer has been designed. The fibers are wrapped around piezoelectric

  1. Application of laser speckle to randomized numerical linear algebra

    Science.gov (United States)

    Valley, George C.; Shaw, Thomas J.; Stapleton, Andrew D.; Scofield, Adam C.; Sefler, George A.; Johannson, Leif

    2018-02-01

    We propose and simulate integrated optical devices for accelerating numerical linear algebra (NLA) calculations. Data is modulated on chirped optical pulses and these propagate through a multimode waveguide where speckle provides the random projections needed for NLA dimensionality reduction.

  2. The Study Of Optometry Apparatus Of Laser Speckles

    Science.gov (United States)

    Bao-cheng, Wang; Kun, Yao; Xiu-qing, Wu; Chang-ying, Long; Jia-qi, Shi; Shi-zhong, Shi

    1988-01-01

    Based on the regularity of laser speckles movement the method of exam the uncorrected eyes is determined. The apparatus with micro-computer and optical transformation is made. Its practical function is excellent.

  3. A decade of innovation with laser speckle metrology

    Science.gov (United States)

    Ettemeyer, Andreas

    2003-05-01

    Speckle Pattern Interferometry has emerged from the experimental substitution of holographic interferometry to become a powerful problem solving tool in research and industry. The rapid development of computer and digital imaging techniques in combination with minaturization of the optical equipment led to new applications which had not been anticipated before. While classical holographic interferometry had always required careful consideration of the environmental conditions such as vibration, noise, light, etc. and could generally only be performed in the optical laboratory, it is now state of the art, to handle portable speckle measuring equipment at almost any place. During the last decade, the change in design and technique has dramatically influenced the range of applications of speckle metrology and opened new markets. The integration of recent research results into speckle measuring equipment has led to handy equipment, simplified the operation and created high quality data output.

  4. Differential expression of speckled POZ protein, SPOP: Putative ...

    Indian Academy of Sciences (India)

    2014-05-01

    May 1, 2014 ... In other mouse tissues and human cancer cell lines analysed, only low SPOP ... speckled POZ protein; SRC-3, steroid receptor co-activator-3; TNF, tumour necrosis factor; ...... complexity of primary human prostate cancer.

  5. Real time processor for array speckle interferometry

    Science.gov (United States)

    Chin, Gordon; Florez, Jose; Borelli, Renan; Fong, Wai; Miko, Joseph; Trujillo, Carlos

    1989-02-01

    The authors are constructing a real-time processor to acquire image frames, perform array flat-fielding, execute a 64 x 64 element two-dimensional complex FFT (fast Fourier transform) and average the power spectrum, all within the 25 ms coherence time for speckles at near-IR (infrared) wavelength. The processor will be a compact unit controlled by a PC with real-time display and data storage capability. This will provide the ability to optimize observations and obtain results on the telescope rather than waiting several weeks before the data can be analyzed and viewed with offline methods. The image acquisition and processing, design criteria, and processor architecture are described.

  6. Simple educational tool for digital speckle shearography

    International Nuclear Information System (INIS)

    Schirripa Spagnolo, Giuseppe; Martocchia, Andrea; Papalillo, Donato; Cozzella, Lorenzo

    2012-01-01

    In this study, an educational tool has been prepared for obtaining short-term and more economic training on digital speckle shearography (DSS). Shearography non-destructive testing (NDT) has gained wide acceptance over the last decade, providing a number of important and exciting inspection solutions in aerospace, electronics and medical device manufacturing. For exploring these motivations, it is important to develop didactic tools to understand the potential of digital shearography through training and didactic courses in the field of NDT. In this paper we describe a simple tool for making one familiar with the potential of DSS in the area of education and training. The system is realized with a simple and economic optical setup and a virtual instrument based on the LabVIEW™ and DAQ. (paper)

  7. Laser speckle velocimetry for robot manufacturing

    Science.gov (United States)

    Charrett, Thomas O. H.; Bandari, Yashwanth K.; Michel, Florent; Ding, Jialuo; Williams, Stewart W.; Tatam, Ralph P.

    2017-06-01

    A non-contact speckle correlation sensor for the measurement of robotic tool speed is presented for use in robotic manufacturing and is capable of measuring the in-plane relative velocities between a robot end-effector and the workpiece or other surface. The sensor performance was assessed in the laboratory with the sensor accuracies found to be better than 0:01 mm/s over a 70 mm/s velocity range. Finally an example of the sensors application to robotic manufacturing is presented where the sensor was applied to tool speed measurement for path planning in the wire and arc additive manufacturing process using a KUKA KR150 L110/2 industrial robot.

  8. Dynamic Corneal Surface Mapping with Electronic Speckle Pattern Interferometry

    Science.gov (United States)

    Iqbal, S.; Gualini, M. M. S.

    2013-06-01

    In view of the fast advancement in ophthalmic technology and corneal surgery, there is a strong need for the comprehensive mapping and characterization techniques for corneal surface. Optical methods with precision non-contact approaches have been found to be very useful for such bio measurements. Along with the normal mapping approaches, elasticity of corneal surface has an important role in its characterization and needs to be appropriately measured or estimated for broader diagnostics and better prospective surgical results, as it has important role in the post-op corneal surface reconstruction process. Use of normal corneal topographic devices is insufficient for any intricate analysis since these devices operate at relatively moderate resolution. In the given experiment, Pulsed Electronic Speckle Pattern Interferometry has been utilized along with an excitation mechanism to measure the dynamic response of the sample cornea. A Pulsed ESPI device has been chosen for the study because of its micron-level resolution and other advantages in real-time deformation analysis. A bovine cornea has been used as a sample in the subject experiment. The dynamic response has been taken on a chart recorder and it is observed that it does show a marked deformation at a specific excitation frequency, which may be taken as a characteristic elasticity parameter for the surface of that corneal sample. It was seen that outside resonance conditions the bovine cornea was not that much deformed. Through this study, the resonance frequency and the corresponding corneal deformations are mapped and plotted in real time. In these experiments, data was acquired and processed by FRAMES plus computer analysis system. With some analysis of the results, this technique can help us to refine a more detailed corneal surface mathematical model and some preliminary work was done on this. Such modelling enhancements may be useful for finer ablative surgery planning. After further experimentation

  9. Large scale tracking algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Ross L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Love, Joshua Alan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Melgaard, David Kennett [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Karelitz, David B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Pitts, Todd Alan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Zollweg, Joshua David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Anderson, Dylan Z. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Nandy, Prabal [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Whitlow, Gary L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bender, Daniel A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Byrne, Raymond Harry [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-01-01

    Low signal-to-noise data processing algorithms for improved detection, tracking, discrimination and situational threat assessment are a key research challenge. As sensor technologies progress, the number of pixels will increase signi cantly. This will result in increased resolution, which could improve object discrimination, but unfortunately, will also result in a significant increase in the number of potential targets to track. Many tracking techniques, like multi-hypothesis trackers, suffer from a combinatorial explosion as the number of potential targets increase. As the resolution increases, the phenomenology applied towards detection algorithms also changes. For low resolution sensors, "blob" tracking is the norm. For higher resolution data, additional information may be employed in the detection and classfication steps. The most challenging scenarios are those where the targets cannot be fully resolved, yet must be tracked and distinguished for neighboring closely spaced objects. Tracking vehicles in an urban environment is an example of such a challenging scenario. This report evaluates several potential tracking algorithms for large-scale tracking in an urban environment.

  10. Speckle imaging using the principle value decomposition method

    International Nuclear Information System (INIS)

    Sherman, J.W.

    1978-01-01

    Obtaining diffraction-limited images in the presence of atmospheric turbulence is a topic of current interest. Two types of approaches have evolved: real-time correction and speckle imaging. A speckle imaging reconstruction method was developed by use of an ''optimal'' filtering approach. This method is based on a nonlinear integral equation which is solved by principle value decomposition. The method was implemented on a CDC 7600 for study. The restoration algorithm is discussed and its performance is illustrated. 7 figures

  11. Statistical characterization of speckle noise in coherent imaging systems

    Science.gov (United States)

    Yaroslavsky, Leonid; Shefler, A.

    2003-05-01

    Speckle noise imposes fundamental limitation on image quality in coherent radiation based imaging and optical metrology systems. Speckle noise phenomena are associated with properties of objects to diffusely scatter irradiation and with the fact that in recording the wave field, a number of signal distortions inevitably occur due to technical limitations inherent to hologram sensors. The statistical theory of speckle noise was developed with regard to only limited resolving power of coherent imaging devices. It is valid only asymptotically as much as the central limit theorem of the probability theory can be applied. In applications this assumption is not always applicable. Moreover, in treating speckle noise problem one should also consider other sources of the hologram deterioration. In the paper, statistical properties of speckle due to the limitation of hologram size, dynamic range and hologram signal quantization are studied by Monte-Carlo simulation for holograms recorded in near and far diffraction zones. The simulation experiments have shown that, for limited resolving power of the imaging system, widely accepted opinion that speckle contrast is equal to one holds only for rather severe level of the hologram size limitation. For moderate limitations, speckle contrast changes gradually from zero for no limitation to one for limitation to less than about 20% of hologram size. The results obtained for the limitation of the hologram sensor"s dynamic range and hologram signal quantization reveal that speckle noise due to these hologram signal distortions is not multiplicative and is directly associated with the severity of the limitation and quantization. On the base of the simulation results, analytical models are suggested.

  12. Large angle tracking and high discriminating tracking in nuclear emulsion

    International Nuclear Information System (INIS)

    Matsuo, Tomokazu; Shibuya, Hiroshi; Ogawa, Satoru; Fukuda, Tsutomu; Mikado, Shoji

    2015-01-01

    Nuclear emulsion is a high resolution and re-analyzable detector. Conventional “Track Selector” which have angle acceptance |tan θ|<0.6 are widely used to find tracks in emulsion. We made a new track selector “Fine Track Selector” (FTS) which has large angle acceptance and high discriminating ability. The FTS reduces fake tracks using new algorithms, navigation etc. FTS also keeps finding efficiency of tracks around 90% in an angle range of |tan θ| < 3.5. FTS was applied to the τ candidate in OPERA and no additional tracks found. FTS will be useful to our new J-PARC emulsion experiment.

  13. Laser-induced speckle scatter patterns in Bacillus colonies

    Directory of Open Access Journals (Sweden)

    Huisung eKim

    2014-10-01

    Full Text Available Label-free bacterial colony phenotyping technology called BARDOT (BActerial Rapid Detection using Optical scattering Technology provided successful classification of several different bacteria at the genus, species, and serovar level. Recent experiments with colonies of Bacillus species provided strikingly different characteristics of elastic light scatter (ELS patterns, which were comprised of random speckles compared to other bacteria, which are dominated by concentric rings and spokes. Since this laser-based optical sensor interrogates the whole volume of the colony, 3-D information of micro- and macro-structures are all encoded in the far-field scatter patterns. Here, we present a theoretical model explaining the underlying mechanism of the speckle formation by the colonies from Bacillus species. Except for Bacillus polymyxa, all Bacillus spp. produced random bright spots on the imaging plane, which presumably dependent on the cellular and molecular organization and content within the colony. Our scatter model-based analysis revealed that colony spread resulting in variable surface roughness can modify the wavefront of the scatter field. As the center diameter of the Bacillus spp. colony grew from 500 μm to 900 μm, average speckles area decreased 2-fold and the number of small speckles increased 7-fold. In conclusion, as Bacillus colony grows, the average speckle size in the scatter pattern decreases and the number of smaller speckle increases due to the swarming growth characteristics of bacteria within the colony.

  14. Speckle noise reduction for computer generated holograms of objects with diffuse surfaces

    Science.gov (United States)

    Symeonidou, Athanasia; Blinder, David; Ahar, Ayyoub; Schretter, Colas; Munteanu, Adrian; Schelkens, Peter

    2016-04-01

    Digital holography is mainly used today for metrology and microscopic imaging and is emerging as an important potential technology for future holographic television. To generate the holographic content, computer-generated holography (CGH) techniques convert geometric descriptions of a 3D scene content. To model different surface types, an accurate model of light propagation has to be considered, including for example, specular and diffuse reflection. In previous work, we proposed a fast CGH method for point cloud data using multiple wavefront recording planes, look-up tables (LUTs) and occlusion processing. This work extends our method to account for diffuse reflections, enabling rendering of deep 3D scenes in high resolution with wide viewing angle support. This is achieved by modifying the spectral response of the light propagation kernels contained by the look-up tables. However, holograms encoding diffuse reflective surfaces depict significant amounts of speckle noise, a problem inherent to holography. Hence, techniques to improve the reduce speckle noise are evaluated in this paper. Moreover, we propose as well a technique to suppress the aperture diffraction during numerical, viewdependent rendering by apodizing the hologram. Results are compared visually and in terms of their respective computational efficiency. The experiments show that by modelling diffuse reflection in the LUTs, a more realistic yet computationally efficient framework for generating high-resolution CGH is achieved.

  15. Real-time acquisition and display of flow contrast using speckle variance optical coherence tomography in a graphics processing unit.

    Science.gov (United States)

    Xu, Jing; Wong, Kevin; Jian, Yifan; Sarunic, Marinko V

    2014-02-01

    In this report, we describe a graphics processing unit (GPU)-accelerated processing platform for real-time acquisition and display of flow contrast images with Fourier domain optical coherence tomography (FDOCT) in mouse and human eyes in vivo. Motion contrast from blood flow is processed using the speckle variance OCT (svOCT) technique, which relies on the acquisition of multiple B-scan frames at the same location and tracking the change of the speckle pattern. Real-time mouse and human retinal imaging using two different custom-built OCT systems with processing and display performed on GPU are presented with an in-depth analysis of performance metrics. The display output included structural OCT data, en face projections of the intensity data, and the svOCT en face projections of retinal microvasculature; these results compare projections with and without speckle variance in the different retinal layers to reveal significant contrast improvements. As a demonstration, videos of real-time svOCT for in vivo human and mouse retinal imaging are included in our results. The capability of performing real-time svOCT imaging of the retinal vasculature may be a useful tool in a clinical environment for monitoring disease-related pathological changes in the microcirculation such as diabetic retinopathy.

  16. Analysis of laser speckle patterns from fingertips

    DEFF Research Database (Denmark)

    Iversen, Theis Faber Quist; Hanson, Steen Grüner

    2010-01-01

    The trend in human-machine interface technology is heading towards optical solutions for tracking and movement detection. Especially, interactive touch screens and pads, in which the movement of the user’s fingertips is detected and tracked, are of great commercial interest. The applications rang...... of an intermediate optically flat interface, between the fingertip and the illuminating light source....

  17. Momentum transfer Monte Carlo for the simulation of laser speckle imaging and its application in the skin.

    Science.gov (United States)

    Regan, Caitlin; Hayakawa, Carole; Choi, Bernard

    2017-12-01

    Due to its simplicity and low cost, laser speckle imaging (LSI) has achieved widespread use in biomedical applications. However, interpretation of the blood-flow maps remains ambiguous, as LSI enables only limited visualization of vasculature below scattering layers such as the epidermis and skull. Here, we describe a computational model that enables flexible in-silico study of the impact of these factors on LSI measurements. The model uses Monte Carlo methods to simulate light and momentum transport in a heterogeneous tissue geometry. The virtual detectors of the model track several important characteristics of light. This model enables study of LSI aspects that may be difficult or unwieldy to address in an experimental setting, and enables detailed study of the fundamental origins of speckle contrast modulation in tissue-specific geometries. We applied the model to an in-depth exploration of the spectral dependence of speckle contrast signal in the skin, the effects of epidermal melanin content on LSI, and the depth-dependent origins of our signal. We found that LSI of transmitted light allows for a more homogeneous integration of the signal from the entire bulk of the tissue, whereas epi-illumination measurements of contrast are limited to a fraction of the light penetration depth. We quantified the spectral depth dependence of our contrast signal in the skin, and did not observe a statistically significant effect of epidermal melanin on speckle contrast. Finally, we corroborated these simulated results with experimental LSI measurements of flow beneath a thin absorbing layer. The results of this study suggest the use of LSI in the clinic to monitor perfusion in patients with different skin types, or inhomogeneous epidermal melanin distributions.

  18. Speckle Reduction for Ultrasonic Imaging Using Frequency Compounding and Despeckling Filters along with Coded Excitation and Pulse Compression

    Directory of Open Access Journals (Sweden)

    Joshua S. Ullom

    2012-01-01

    Full Text Available A method for improving the contrast-to-noise ratio (CNR while maintaining the −6 dB axial resolution of ultrasonic B-mode images is proposed. The technique proposed is known as eREC-FC, which enhances a recently developed REC-FC technique. REC-FC is a combination of the coded excitation technique known as resolution enhancement compression (REC and the speckle-reduction technique frequency compounding (FC. In REC-FC, image CNR is improved but at the expense of a reduction in axial resolution. However, by compounding various REC-FC images made from various subband widths, the tradeoff between axial resolution and CNR enhancement can be extended. Further improvements in CNR can be obtained by applying postprocessing despeckling filters to the eREC-FC B-mode images. The despeckling filters evaluated were the following: median, Lee, homogeneous mask area, geometric, and speckle-reducing anisotropic diffusion (SRAD. Simulations and experimental measurements were conducted with a single-element transducer (f/2.66 having a center frequency of 2.25 MHz and a −3 dB bandwidth of 50%. In simulations and experiments, the eREC-FC technique resulted in the same axial resolution that would be typically observed with conventional excitation with a pulse. Moreover, increases in CNR of 348% were obtained in experiments when comparing eREC-FC with a Lee filter to conventional pulsing methods.

  19. Deformation measurements of materials at low temperatures using laser speckle photography method

    International Nuclear Information System (INIS)

    Sumio Nakahara; Yukihide Maeda; Kazunori Matsumura; Shigeyoshi Hisada; Takeyoshi Fujita; Kiyoshi Sugihara

    1992-01-01

    The authors observed deformations of several materials during cooling down process from room temperature to liquid nitrogen temperature using the laser speckle photography method. The in-plane displacements were measured by the image plane speckle photography and the out-of-plane displacement gradients by the defocused speckle photography. The results of measurements of in-plane displacement are compared with those of FEM analysis. The applicability of laser speckle photography method to cryogenic engineering are also discussed

  20. Laser speckle decorrelation for fingerprint acquisition

    International Nuclear Information System (INIS)

    Schirripa Spagnolo, Giuseppe; Cozzella, Lorenzo

    2012-01-01

    Biometry is gaining popularity as a physical security approach in situations where a high level of security is necessary. Currently, biometric solutions are embedded in a very large and heterogeneous group of applications. One of the most sensible is for airport security access to boarding gates. More airports are introducing biometric solutions based on face, fingerprint or iris recognition for passenger identification. In particular, fingerprints are the most widely used biometric, and they are mandatorily included in electronic identification documents. One important issue, which is difficult to address in traditional fingerprint acquisition systems, is preventing contact between subsequent users; sebum, which can be a potential vector for contagious diseases. Currently, non-contact devices are used to overcome this problem. In this paper, a new contact device based on laser speckle decorrelation is presented. Our system has the advantage of being compact and low-cost compared with an actual contactless system, allowing enhancement of the sebum pattern imaging contrast in a simple and low-cost way. Furthermore, it avoids the spreading of contagious diseases. (paper)

  1. Speckle Imaging of Binary Stars with Large-Format CCDs

    Science.gov (United States)

    Horch, E.; Ninkov, Z.; Slawson, R. W.; van Altena, W. F.; Meyer, R. D.; Girard, T. M.

    1997-12-01

    In the past, bare (unintensified) CCDs have not been widely used in speckle imaging for two main reasons: 1) the readout rate of most scientific-grade CCDs is too slow to be able to observe at the high frame rates necessary to capture speckle patterns efficiently, and 2) the read noise of CCDs limits the detectability of fainter objects where it becomes difficult to distinguish between speckles and noise peaks in the image. These facts have led to the current supremacy of intensified imaging systems (such as intensified-CCDs) in this field, which can typically be read out at video rates or faster. We have developed a new approach that uses a large format CCD not only to detect the incident photons but also to record many speckle patterns before the chip is read out. This approach effectively uses the large area of the CCD as a physical ``memory cache'' of previous speckle data frames. The method is described, and binary star observations from the University of Toronto Southern Observatory 60-cm telescope and the Wisconsin-Indiana-Yale-NOAO (WIYN) 3.5-m telescope are presented. Plans for future observing and instrumentation improvements are also outlined.

  2. Applications of polarization speckle in skin cancer detection and monitoring

    Science.gov (United States)

    Lee, Tim K.; Tchvialeva, Lioudmila; Phillips, Jamie; Louie, Daniel C.; Zhao, Jianhua; Wang, Wei; Lui, Harvey; Kalia, Sunil

    2018-01-01

    Polarization speckle is a rapidly developed field. Unlike laser speckle, polarization speckle consists of stochastic interference patterns with spatially random polarizations, amplitudes and phases. We have been working in this exciting research field, developing techniques to generate polarization patterns from skin. We hypothesize that polarization speckle patterns could be used in biomedical applications, especially, for detecting and monitoring skin cancers, the most common neoplasmas for white populations around the world. This paper describes our effort in developing two polarization speckle devices. One of them captures the Stokes parameters So and S1 simultaneously, and another one captures all four Stokes parameters So, S1, S2, and S3 in one-shot, within milliseconds. Hence these two devices could be used in medical clinics and assessed skin conditions in-vivo. In order to validate our hypothesis, we conducted a series of three clinical studies. These are early pilot studies, and the results suggest that the devices have potential to detect and monitor skin cancers.

  3. Speckle reduction methods in laser-based picture projectors

    Science.gov (United States)

    Akram, M. Nadeem; Chen, Xuyuan

    2016-02-01

    Laser sources have been promised for many years to be better light sources as compared to traditional lamps or light-emitting diodes (LEDs) for projectors, which enable projectors having wide colour gamut for vivid image, super brightness and high contrast for the best picture quality, long lifetime for maintain free operation, mercury free, and low power consumption for green environment. A major technology obstacle in using lasers for projection has been the speckle noise caused by to the coherent nature of the lasers. For speckle reduction, current state of the art solutions apply moving parts with large physical space demand. Solutions beyond the state of the art need to be developed such as integrated optical components, hybrid MOEMS devices, and active phase modulators for compact speckle reduction. In this article, major methods reported in the literature for the speckle reduction in laser projectors are presented and explained. With the advancement in semiconductor lasers with largely reduced cost for the red, green and the blue primary colours, and the developed methods for their speckle reduction, it is hoped that the lasers will be widely utilized in different projector applications in the near future.

  4. Identification of a chemical inhibitor for nuclear speckle formation: Implications for the function of nuclear speckles in regulation of alternative pre-mRNA splicing

    Energy Technology Data Exchange (ETDEWEB)

    Kurogi, Yutaro; Matsuo, Yota; Mihara, Yuki; Yagi, Hiroaki; Shigaki-Miyamoto, Kaya; Toyota, Syukichi; Azuma, Yuko [Department of Biological Sciences, Graduate School of Science and Technology, Kumamoto University, Chuo-ku, Kumamoto 860-8555 (Japan); Igarashi, Masayuki [Laboratory of Disease Biology, Institute of Microbial Chemistry, Shinagawa-ku, Tokyo 141-0021 (Japan); Tani, Tokio, E-mail: ttani@sci.kumamoto-u.ac.jp [Department of Biological Sciences, Graduate School of Science and Technology, Kumamoto University, Chuo-ku, Kumamoto 860-8555 (Japan)

    2014-03-28

    Highlights: • We identified tubercidin as a compound inducing aberrant formation of the speckles. • Tubercidin causes delocalization of poly (A){sup +}RNAs from nuclear speckles. • Tubercidin induces dispersion of splicing factors from nuclear speckles. • Tubercidin affects alternative pre-mRNA splicing. • Nuclear speckles play a role in regulation of alternative pre-mRNA splicing. - Abstract: Nuclear speckles are subnuclear structures enriched with RNA processing factors and poly (A){sup +} RNAs comprising mRNAs and poly (A){sup +} non-coding RNAs (ncRNAs). Nuclear speckles are thought to be involved in post-transcriptional regulation of gene expression, such as pre-mRNA splicing. By screening 3585 culture extracts of actinomycetes with in situ hybridization using an oligo dT probe, we identified tubercidin, an analogue of adenosine, as an inhibitor of speckle formation, which induces the delocalization of poly (A){sup +} RNA and dispersion of splicing factor SRSF1/SF2 from nuclear speckles in HeLa cells. Treatment with tubercidin also decreased steady-state MALAT1 long ncRNA, thought to be involved in the retention of SRSF1/SF2 in nuclear speckles. In addition, we found that tubercidin treatment promoted exon skipping in the alternative splicing of Clk1 pre-mRNA. These results suggest that nuclear speckles play a role in modulating the concentration of splicing factors in the nucleoplasm to regulate alternative pre-mRNA splicing.

  5. Texture analysis of speckle in optical coherence tomography images of tissue phantoms

    International Nuclear Information System (INIS)

    Gossage, Kirk W; Smith, Cynthia M; Kanter, Elizabeth M; Hariri, Lida P; Stone, Alice L; Rodriguez, Jeffrey J; Williams, Stuart K; Barton, Jennifer K

    2006-01-01

    Optical coherence tomography (OCT) is an imaging modality capable of acquiring cross-sectional images of tissue using back-reflected light. Conventional OCT images have a resolution of 10-15 μm, and are thus best suited for visualizing tissue layers and structures. OCT images of collagen (with and without endothelial cells) have no resolvable features and may appear to simply show an exponential decrease in intensity with depth. However, examination of these images reveals that they display a characteristic repetitive structure due to speckle.The purpose of this study is to evaluate the application of statistical and spectral texture analysis techniques for differentiating living and non-living tissue phantoms containing various sizes and distributions of scatterers based on speckle content in OCT images. Statistically significant differences between texture parameters and excellent classification rates were obtained when comparing various endothelial cell concentrations ranging from 0 cells/ml to 25 million cells/ml. Statistically significant results and excellent classification rates were also obtained using various sizes of microspheres with concentrations ranging from 0 microspheres/ml to 500 million microspheres/ml. This study has shown that texture analysis of OCT images may be capable of differentiating tissue phantoms containing various sizes and distributions of scatterers

  6. Noncontact 3-D Speckle Contrast Diffuse Correlation Tomography of Tissue Blood Flow Distribution.

    Science.gov (United States)

    Huang, Chong; Irwin, Daniel; Zhao, Mingjun; Shang, Yu; Agochukwu, Nneamaka; Wong, Lesley; Yu, Guoqiang

    2017-10-01

    Recent advancements in near-infrared diffuse correlation techniques and instrumentation have opened the path for versatile deep tissue microvasculature blood flow imaging systems. Despite this progress there remains a need for a completely noncontact, noninvasive device with high translatability from small/testing (animal) to large/target (human) subjects with trivial application on both. Accordingly, we discuss our newly developed setup which meets this demand, termed noncontact speckle contrast diffuse correlation tomography (nc_scDCT). The nc_scDCT provides fast, continuous, portable, noninvasive, and inexpensive acquisition of 3-D tomographic deep (up to 10 mm) tissue blood flow distributions with straightforward design and customization. The features presented include a finite-element-method implementation for incorporating complex tissue boundaries, fully noncontact hardware for avoiding tissue compression and interactions, rapid data collection with a diffuse speckle contrast method, reflectance-based design promoting experimental translation, extensibility to related techniques, and robust adjustable source and detector patterns and density for high resolution measurement with flexible regions of interest enabling unique application-specific setups. Validation is shown in the detection and characterization of both high and low contrasts in flow relative to the background using tissue phantoms with a pump-connected tube (high) and phantom spheres (low). Furthermore, in vivo validation of extracting spatiotemporal 3-D blood flow distributions and hyperemic response during forearm cuff occlusion is demonstrated. Finally, the success of instrument feasibility in clinical use is examined through the intraoperative imaging of mastectomy skin flap.

  7. Basic Technology and Clinical Applications of the Updated Model of Laser Speckle Flowgraphy to Ocular Diseases

    Directory of Open Access Journals (Sweden)

    Tetsuya Sugiyama

    2014-08-01

    Full Text Available Laser speckle flowgraphy (LSFG allows for quantitative estimation of blood flow in the optic nerve head (ONH, choroid and retina, utilizing the laser speckle phenomenon. The basic technology and clinical applications of LSFG-NAVI, the updated model of LSFG, are summarized in this review. For developing a commercial version of LSFG, the special area sensor was replaced by the ordinary charge-coupled device camera. In LSFG-NAVI, the mean blur rate (MBR has been introduced as a new parameter. Compared to the original LSFG model, LSFG-NAVI demonstrates a better spatial resolution of the blood flow map of human ocular fundus. The observation area is 24 times larger than the original system. The analysis software can separately calculate MBRs in the blood vessels and tissues (capillaries of an entire ONH and the measurements have good reproducibility. The absolute values of MBR in the ONH have been shown to linearly correlate with the capillary blood flow. The Analysis of MBR pulse waveform provides parameters including skew, blowout score, blowout time, rising and falling rates, flow acceleration index, acceleration time index, and resistivity index for comparing different eyes. Recently, there have been an increasing number of reports on the clinical applications of LSFG-NAVI to ocular diseases, including glaucoma, retinal and choroidal diseases.

  8. High resolution vertical profiles of wind, temperature and humidity obtained by computer processing and digital filtering of radiosonde and radar tracking data from the ITCZ experiment of 1977

    Science.gov (United States)

    Danielson, E. F.; Hipskind, R. S.; Gaines, S. E.

    1980-01-01

    Results are presented from computer processing and digital filtering of radiosonde and radar tracking data obtained during the ITCZ experiment when coordinated measurements were taken daily over a 16 day period across the Panama Canal Zone. The temperature relative humidity and wind velocity profiles are discussed.

  9. Speckles generated by skewed, short-coherence light beams

    International Nuclear Information System (INIS)

    Brogioli, D; Salerno, D; Ziano, R; Mantegazza, F; Croccolo, F

    2011-01-01

    When a coherent laser beam impinges on a random sample (e.g. a colloidal suspension), the scattered light exhibits characteristic speckles. If the temporal coherence of the light source is too short, then the speckles disappear, along with the possibility of performing homodyne or heterodyne scattering detection or photon correlation spectroscopy. Here we investigate the scattering of a so-called ‘skewed coherence beam’, i.e. a short-coherence beam modified such that the field is coherent within slabs that are skewed with respect to the wave fronts. We show that such a beam generates speckles and can be used for heterodyne scattering detection, despite its short temporal coherence. Moreover, we show that the heterodyne signal is not affected by multiple scattering. We suggest that the phenomenon presented here can be used as a means of carrying out heterodyne scattering measurement with any short-coherence radiation, including x-rays. (paper)

  10. Simulation of speckle patterns with pre-defined correlation distributions

    Science.gov (United States)

    Song, Lipei; Zhou, Zhen; Wang, Xueyan; Zhao, Xing; Elson, Daniel S.

    2016-01-01

    We put forward a method to easily generate a single or a sequence of fully developed speckle patterns with pre-defined correlation distribution by utilizing the principle of coherent imaging. The few-to-one mapping between the input correlation matrix and the correlation distribution between simulated speckle patterns is realized and there is a simple square relationship between the values of these two correlation coefficient sets. This method is demonstrated both theoretically and experimentally. The square relationship enables easy conversion from any desired correlation distribution. Since the input correlation distribution can be defined by a digital matrix or a gray-scale image acquired experimentally, this method provides a convenient way to simulate real speckle-related experiments and to evaluate data processing techniques. PMID:27231589

  11. Effect of track etch rate on geometric track characteristics for polymeric track detectors

    International Nuclear Information System (INIS)

    Abdel-Naby, A.A.; El-Akkad, F.A.

    2001-01-01

    Analysis of the variable track etch rate on geometric track characteristic for polymeric track detectors has been applied to the case of LR-155 II SSNTD. Spectrometric characteristics of low energy alpha particles response by the polymeric detector have been obtained. The track etching kinematics theory of development of minor diameter of the etched tracks has been applied. The calculations show that, for this type of detector, the energy dependence of the minor track diameter d is linear for small-etched removal layer h. The energy resolution gets better for higher etched removal layer

  12. Multiple rotation assessment through isothetic fringes in speckle photography

    International Nuclear Information System (INIS)

    Angel, Luciano; Tebaldi, Myrian; Bolognini, Nestor

    2007-01-01

    The use of different pupils for storing each speckled image in speckle photography is employed to determine multiple in-plane rotations. The method consists of recording a four-exposure specklegram where the rotations are done between exposures. This specklegram is then optically processed in a whole field approach rendering isothetic fringes, which give detailed information about the multiple rotations. It is experimentally demonstrated that the proposed arrangement permits the depiction of six isothetics in order to measure either six different angles or three nonparallel components for two local general in-plane displacements

  13. Speckle Interferometry with the OCA Kuhn 22" Telescope

    Science.gov (United States)

    Wasson, Rick

    2018-04-01

    Speckle interferometry measurements of double stars were made in 2015 and 2016, using the Kuhn 22-inch classical Cassegrain telescope of the Orange County Astronomers, a Point Grey Blackfly CMOS camera, and three interference filters. 272 observations are reported for 177 systems, with separations ranging from 0.29" to 2.9". Data reduction was by means of the REDUC and Speckle Tool Box programs. Equipment, observing procedures, calibration, data reduction, and analysis are described, and unusual results for 11 stars are discussed in detail.

  14. Detection of fungi colony growth on bones by dynamic speckle

    Science.gov (United States)

    Vincitorio, F. M.; Budini, N.; Mulone, C.; Spector, M.; Freyre, C.; López Díaz, A. J.; Ramil, A.

    2013-11-01

    In this work we have studied the dynamic speckle patterns of mucor fungi colonies, which were inoculated on different samples. We were interested in analyzing the development of fungi colonies in bones, since during the last two years, a series of infections by mucor fungi have been reported on patients from different hospitals in Argentina. Coincidentally, all of these infections appeared on patients that were subjected to a surgical intervention for implantation of a titanium prosthesis. Apparently, the reason of the infection was a deficient sterilization process in conjunction with an accidental contamination. We observed that fungi growth, activity and death can be distinguished by means of the dynamic speckle technique.

  15. Spatially resolved speckle-correlometry of sol-gel transition

    Science.gov (United States)

    Isaeva, A. A.; Isaeva, E. A.; Pantyukov, A. V.; Zimnyakov, D. A.

    2018-04-01

    Sol-gel transition was studied using the speckle correlometry method with a localized light source and spatial filtering of backscattered radiation. Water solutions of technical or food gelatin with added TiO2 nanoparticles were used as studied objects. Structural transformation of "sol-gel" system was studied at various temperatures from 25°C to 50°C using analysis of the correlation and structure functions of speckle intensity fluctuations. The characteristic temperatures of "sol - gel" transition were evaluated for studied systems. Obtained results can be used for various applications in biomedicine and food industry.

  16. Density of states in an optical speckle potential

    International Nuclear Information System (INIS)

    Falco, G. M.; Fedorenko, A. A.; Giacomelli, J.; Modugno, M.

    2010-01-01

    We study the single-particle density of states of a one-dimensional speckle potential, which is correlated and non-Gaussian. We consider both the repulsive and the attractive cases. The system is controlled by a single dimensionless parameter determined by the mass of the particle, the correlation length, and the average intensity of the field. Depending on the value of this parameter, the system exhibits different regimes, characterized by the localization properties of the eigenfunctions. We calculate the corresponding density of states using the statistical properties of the speckle potential. We find good agreement with the results of numerical simulations.

  17. Speckle-scale focusing in the diffusive regime with time reversal of variance-encoded light (TROVE)

    Science.gov (United States)

    Judkewitz, Benjamin; Wang, Ying Min; Horstmeyer, Roarke; Mathy, Alexandre; Yang, Changhuei

    2013-04-01

    Focusing of light in the diffusive regime inside scattering media has long been considered impossible. Recently, this limitation has been overcome with time reversal of ultrasound-encoded light (TRUE), but the resolution of this approach is fundamentally limited by the large number of optical modes within the ultrasound focus. Here, we introduce a new approach, time reversal of variance-encoded light (TROVE), which demixes these spatial modes by variance encoding to break the resolution barrier imposed by the ultrasound. By encoding individual spatial modes inside the scattering sample with unique variances, we effectively uncouple the system resolution from the size of the ultrasound focus. This enables us to demonstrate optical focusing and imaging with diffuse light at an unprecedented, speckle-scale lateral resolution of ~5 µm.

  18. Speckle-scale focusing in the diffusive regime with time-reversal of variance-encoded light (TROVE).

    Science.gov (United States)

    Judkewitz, Benjamin; Wang, Ying Min; Horstmeyer, Roarke; Mathy, Alexandre; Yang, Changhuei

    2013-04-01

    Focusing of light in the diffusive regime inside scattering media has long been considered impossible. Recently, this limitation has been overcome with time reversal of ultrasound-encoded light (TRUE), but the resolution of this approach is fundamentally limited by the large number of optical modes within the ultrasound focus. Here, we introduce a new approach, time reversal of variance-encoded light (TROVE), which demixes these spatial modes by variance-encoding to break the resolution barrier imposed by the ultrasound. By encoding individual spatial modes inside the scattering sample with unique variances, we effectively uncouple the system resolution from the size of the ultrasound focus. This enables us to demonstrate optical focusing and imaging with diffuse light at unprecedented, speckle-scale lateral resolution of ~ 5 μm.

  19. Evaluation of the discovery potential of an underwater Mediterranean neutrino telescope taking into account the estimated directional resolution and energy of the reconstructed tracks

    International Nuclear Information System (INIS)

    Leisos, A.; Tsirigotis, A.G.; Tzamarias, S.E.

    2013-01-01

    We report on the development of search methods for point-like and extended neutrino sources, utilizing the tracking and energy estimation capabilities of an underwater, Very Large Volume Neutrino Telescope (VLVnT). We demonstrate that the developed techniques offer a significant improvement on the telescope's discovery potential. We also present results on the potential of the Mediterranean KM3NeT to discover galactic neutrino sources

  20. Ultrasound speckle reduction based on fractional order differentiation.

    Science.gov (United States)

    Shao, Dangguo; Zhou, Ting; Liu, Fan; Yi, Sanli; Xiang, Yan; Ma, Lei; Xiong, Xin; He, Jianfeng

    2017-07-01

    Ultrasound images show a granular pattern of noise known as speckle that diminishes their quality and results in difficulties in diagnosis. To preserve edges and features, this paper proposes a fractional differentiation-based image operator to reduce speckle in ultrasound. An image de-noising model based on fractional partial differential equations with balance relation between k (gradient modulus threshold that controls the conduction) and v (the order of fractional differentiation) was constructed by the effective combination of fractional calculus theory and a partial differential equation, and the numerical algorithm of it was achieved using a fractional differential mask operator. The proposed algorithm has better speckle reduction and structure preservation than the three existing methods [P-M model, the speckle reducing anisotropic diffusion (SRAD) technique, and the detail preserving anisotropic diffusion (DPAD) technique]. And it is significantly faster than bilateral filtering (BF) in producing virtually the same experimental results. Ultrasound phantom testing and in vivo imaging show that the proposed method can improve the quality of an ultrasound image in terms of tissue SNR, CNR, and FOM values.

  1. Speckle Suppression by Weighted Euclidean Distance Anisotropic Diffusion

    Directory of Open Access Journals (Sweden)

    Fengcheng Guo

    2018-05-01

    Full Text Available To better reduce image speckle noise while also maintaining edge information in synthetic aperture radar (SAR images, we propose a novel anisotropic diffusion algorithm using weighted Euclidean distance (WEDAD. Presented here is a modified speckle reducing anisotropic diffusion (SRAD method, which constructs a new edge detection operator using weighted Euclidean distances. The new edge detection operator can adaptively distinguish between homogenous and heterogeneous image regions, effectively generate anisotropic diffusion coefficients for each image pixel, and filter each pixel at different scales. Additionally, the effects of two different weighting methods (Gaussian weighting and non-linear weighting of de-noising were analyzed. The effect of different adjustment coefficient settings on speckle suppression was also explored. A series of experiments were conducted using an added noise image, GF-3 SAR image, and YG-29 SAR image. The experimental results demonstrate that the proposed method can not only significantly suppress speckle, thus improving the visual effects, but also better preserve the edge information of images.

  2. Spatial Behaviour of Singularities in Fractal- and Gaussian Speckle Fields

    DEFF Research Database (Denmark)

    Angelsky, Oleg V.; Maksimyak, Alexander P.; Maksimyak, Peter P.

    2009-01-01

    Peculiarities of the spatial behaviour of the dislocation lines resulting from scattering of coherent radiation from random and fractal rough surfaces are studied. The technique of optical correlation is proposed for diagnostics of phase singularities in a complex speckle field by comparing...

  3. Thermoregulation under semi-natural conditions in speckled ...

    African Journals Online (AJOL)

    We recorded body temperature (Tb) in speckled mousebirds (Colius striatus) under semi-natural conditions in outdoor aviaries, and examined interactions between behavioural and metabolic thermoregulation by experimentally manipulating food availability and communal roosting behaviour. When food was available ad ...

  4. Review of speckle observations of Supernova 1987A

    International Nuclear Information System (INIS)

    Meikle, W.P.S.

    1988-01-01

    SN 1987A is sufficiently close to allow a unique examination of the morphology of a supernova, using speckle interferometry. Several groups [Center for Astrophysics (CfA); Imperial College (IC); Mount Stromlo and Siding Spring Observatories/Anglo-Australian Observatory (M/A)] have reported optical speckle observations. At Hα, both CfA and M/A have determined the angular extent of the emission, and reasonable agreement is obtained. The speckle-derived values are consistent with those obtained from line profiles. IC has also succeeded in resolving the supernova at Hα. At wavelengths other than Hα, at early epochs, angular diameters obtained by CfA are larger than those derived from photometric and spectroscopic measurements, possibly due to scattering effects. At later epochs, the diameters exhibit little variation between the wavelengths examined. CfA reports significant asymmetry in the late epoch data. Several attempts have been made to re-observe (at optical wavelengths) the companion object, but none have succeeded. The nature of this phenomenon is still controversial, but the evidence indicates that the companion was real, with emission from dust apparently being the least problematic explanation. Support for this may lie in IR speckle observations (Haute Provence/Lyon) which, on about day 115, indicated the presence of one or more resolved components at an angular displacement comparable to that of the optical companion. 39 refs., 1 fig., 1 tab

  5. Application of speckle decorrelation method for small translation measurements

    Czech Academy of Sciences Publication Activity Database

    Horváth, Pavel; Hrabovský, Miroslav; Šmíd, Petr

    2004-01-01

    Roč. 34, č. 2 (2004), s. 203-218 ISSN 0078-5466 R&D Projects: GA MŠk LN00A015 Institutional research plan: CEZ:AV0Z1010921 Keywords : speckle * decorrelation * in-plane and normal translation Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.308, year: 2004

  6. Granulometry use for the study of dynamics speckles patterns

    International Nuclear Information System (INIS)

    Mavilioa, Adriana; Fernandez, Margarita; Trivi, Marcelo; Rabal, Hector; Arizaga, Ricardo

    2009-01-01

    Dynamic speckle patterns are generated by laser light scattering on surfaces that exhibit some kind of activity, due to physical or biological processes that take place in the illuminated object. The characterization of this dynamic process is carried out by studying the texture changes of auxiliary images: temporal history of the speckle pattern (THSP) obtained from this speckles patterns. The drying process of water borne paint is studied through a method based on mathematical morphology applied to the THSP image processing. It is based on obtaining the granulometry of these images and their characteristic granulometric spectrum. From the granulometric size distribution of each THSP image four parameters are obtained: mean length, standard deviation, asymmetry and kurtosis. These parameters are found to be suitable as texture features. The Mahalanobis distance is calculated between the texture features of the THSP images representative of the temporary stages of the drying process and the features of the final stage or pattern texture. The behavior of the distance function describes satisfactorily the drying process of the water borne paint. Finally, these results are compared with the obtained by other methods. Compared with others, the granulometric method reported in this work distinguished by its simplicity and easy implementation and can be used to characterize the evolution of any process recorded through dynamic speckles. (Author)

  7. Estudio de técnicas speckle opto-digitales

    OpenAIRE

    Henao Henao, Rodrigo de Jesús

    1997-01-01

    El presente Trabajo de Tesis se dirigió a la investigación, creación, desarrollo e implementación de técnicas que hacen uso del speckle y de su correlación digital, siendo su representante mas exitoso el DPSI. Doctor en Física(Facultad de Ciencias Exactas)

  8. Laser speckle imaging: a novel method for detecting dental erosion.

    Directory of Open Access Journals (Sweden)

    Nelson H Koshoji

    Full Text Available Erosion is a highly prevalent condition known as a non-carious lesion that causes progressive tooth wear due to chemical processes that do not involve the action of bacteria. Speckle images proved sensitive to even minimal mineral loss from the enamel. The aim of the present study was to investigate the use of laser speckle imaging analysis in the spatial domain to quantify shifts in the microstructure of the tooth surface in an erosion model. 32 fragments of the vestibular surface of bovine incisors were divided in for groups (10 min, 20 min. 30 min and 40 min of acid etching immersed in a cola-based beverage (pH approximately 2.5 twice a day during 7 days to create an artificial erosion. By analyzing the laser speckle contrast map (LASCA in the eroded region compared to the sound it was observed that the LASCA map shifts, proportionally to the acid each duration, by: 18%; 23%; 39% and 44% for the 10 min; 20 min; 30 min and 40 min groups, respectively. To the best of our knowledge, this is the first study to demonstrate the correlation between speckle patterns and erosion progression.

  9. Checking in on the Neighbors: Speckle Interferometry of Red Dwarf Stars

    Science.gov (United States)

    Mason, Brian; Hartkopf, William; Miles, Korie; Subasavage, John P.; Raghavan, Deepak; Henry, Todd

    2018-01-01

    High resolution optical speckle observations of M dwarf stars are reported which result in 113 resolved measurements of 80 systems and 256 other stars with no indications of duplicity. Nineteen of these had their first measures here, although all but two of those have later measures reported elsewhere. Included are six orbits, two revised and four reported for the first time. For one of the systems with a new orbit, G 161-7, we determine masses of 0.127+/-0.011 and 0.0961+/-0.0085 \\msun ~ for A and B, respectively. All of the orbit pairs have short periods of between five and thirty-eight years and hold the promise of accurate masses in the near future. For many other pairs we can establish their nature as physical or not depending on their relative motion. Of the 80 systems, 32 have orbits, 25 others are physical, 4 are optical and 19 are currently unknown.

  10. Dye laser light for high-resolution classical photography

    International Nuclear Information System (INIS)

    Geissler, K.K.

    1982-01-01

    The test run with the bubble chamber HOLEBC in October 1981 offered the opportunity of checking the usefulness of de-speckled dye laser light for illumination purposes in high-resolution classical dark field photography of small bubble chambers. (orig./HSI)

  11. Measuring Temporal Resolution (Release of Masking) with a Hughson-Westlake Up-Down Instead of a Bekesy-Tracking Procedure

    NARCIS (Netherlands)

    Rhebergen, Koenraad S.; van Esch, Thamar E. M.; Dreschler, Wouter A.

    2015-01-01

    Background: A temporal resolution test in addition to the pure-tone audiogram may be of great clinical interest because of its relevance in speech perception and expected relevance in hearing aid fitting. Larsby and Arlinger developed an appropriate clinical test, but this test uses a

  12. Nanoscale measurements of proton tracks using fluorescent nuclear track detectors

    Energy Technology Data Exchange (ETDEWEB)

    Sawakuchi, Gabriel O., E-mail: gsawakuchi@mdanderson.org; Sahoo, Narayan [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and Graduate School of Biomedical Sciences, The University of Texas, Houston, Texas 77030 (United States); Ferreira, Felisberto A. [Department of Nuclear Physics, University of Sao Paulo, SP 05508-090 (Brazil); McFadden, Conor H. [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Hallacy, Timothy M. [Biophysics Program, Harvard University, Cambridge, Massachusetts 02138 (United States); Granville, Dal A. [Department of Medical Physics, The Ottawa Hospital Cancer Centre, Ottawa, Ontario K1H 8L6 (Canada); Akselrod, Mark S. [Crystal Growth Division, Landauer, Inc., Stillwater, Oklahoma 74074 (United States)

    2016-05-15

    Purpose: The authors describe a method in which fluorescence nuclear track detectors (FNTDs), novel track detectors with nanoscale spatial resolution, are used to determine the linear energy transfer (LET) of individual proton tracks from proton therapy beams by allowing visualization and 3D reconstruction of such tracks. Methods: FNTDs were exposed to proton therapy beams with nominal energies ranging from 100 to 250 MeV. Proton track images were then recorded by confocal microscopy of the FNTDs. Proton tracks in the FNTD images were fit by using a Gaussian function to extract fluorescence amplitudes. Histograms of fluorescence amplitudes were then compared with LET spectra. Results: The authors successfully used FNTDs to register individual proton tracks from high-energy proton therapy beams, allowing reconstruction of 3D images of proton tracks along with delta rays. The track amplitudes from FNTDs could be used to parameterize LET spectra, allowing the LET of individual proton tracks from therapeutic proton beams to be determined. Conclusions: FNTDs can be used to directly visualize proton tracks and their delta rays at the nanoscale level. Because the track intensities in the FNTDs correlate with LET, they could be used further to measure LET of individual proton tracks. This method may be useful for measuring nanoscale radiation quantities and for measuring the LET of individual proton tracks in radiation biology experiments.

  13. Correcting for motion artifact in handheld laser speckle images

    Science.gov (United States)

    Lertsakdadet, Ben; Yang, Bruce Y.; Dunn, Cody E.; Ponticorvo, Adrien; Crouzet, Christian; Bernal, Nicole; Durkin, Anthony J.; Choi, Bernard

    2018-03-01

    Laser speckle imaging (LSI) is a wide-field optical technique that enables superficial blood flow quantification. LSI is normally performed in a mounted configuration to decrease the likelihood of motion artifact. However, mounted LSI systems are cumbersome and difficult to transport quickly in a clinical setting for which portability is essential in providing bedside patient care. To address this issue, we created a handheld LSI device using scientific grade components. To account for motion artifact of the LSI device used in a handheld setup, we incorporated a fiducial marker (FM) into our imaging protocol and determined the difference between highest and lowest speckle contrast values for the FM within each data set (Kbest and Kworst). The difference between Kbest and Kworst in mounted and handheld setups was 8% and 52%, respectively, thereby reinforcing the need for motion artifact quantification. When using a threshold FM speckle contrast value (KFM) to identify a subset of images with an acceptable level of motion artifact, mounted and handheld LSI measurements of speckle contrast of a flow region (KFLOW) in in vitro flow phantom experiments differed by 8%. Without the use of the FM, mounted and handheld KFLOW values differed by 20%. To further validate our handheld LSI device, we compared mounted and handheld data from an in vivo porcine burn model of superficial and full thickness burns. The speckle contrast within the burn region (KBURN) of the mounted and handheld LSI data differed by burns. Collectively, our results suggest the potential of handheld LSI with an FM as a suitable alternative to mounted LSI, especially in challenging clinical settings with space limitations such as the intensive care unit.

  14. Understanding the exposure-time effect on speckle contrast measurements for laser displays

    Science.gov (United States)

    Suzuki, Koji; Kubota, Shigeo

    2018-02-01

    To evaluate the influence of exposure time on speckle noise for laser displays, speckle contrast measurement method was developed observable at a human eye response time using a high-sensitivity camera which has a signal multiplying function. The nonlinearity of camera light sensitivity was calibrated to measure accurate speckle contrasts, and the measuring lower limit noise of speckle contrast was improved by applying spatial-frequency low pass filter to the captured images. Three commercially available laser displays were measured over a wide range of exposure times from tens of milliseconds to several seconds without adjusting the brightness of laser displays. The speckle contrast of raster-scanned mobile projector without any speckle-reduction device was nearly constant over various exposure times. On the contrary to this, in full-frame projection type laser displays equipped with a temporally-averaging speckle-reduction device, some of their speckle contrasts close to the lower limits noise were slightly increased at the shorter exposure time due to the noise. As a result, the exposure-time effect of speckle contrast could not be observed in our measurements, although it is more reasonable to think that the speckle contrasts of laser displays, which are equipped with the temporally-averaging speckle-reduction device, are dependent on the exposure time. This discrepancy may be attributed to the underestimation of temporal averaging factor. We expected that this method is useful for evaluating various laser displays and clarify the relationship between the speckle noise and the exposure time for a further verification of speckle reduction.

  15. Analysis of statistical properties of laser speckles, forming in skin and mucous of colon: potential application in laser surgery

    Science.gov (United States)

    Rubtsov, Vladimir; Kapralov, Sergey; Chalyk, Iuri; Ulianova, Onega; Ulyanov, Sergey

    2013-02-01

    Statistical properties of laser speckles, formed in skin and mucous of colon have been analyzed and compared. It has been demonstrated that first and second order statistics of "skin" speckles and "mucous" speckles are quite different. It is shown that speckles, formed in mucous, are not Gaussian one. Layered structure of colon mucous causes formation of speckled biospeckles. First- and second- order statistics of speckled speckles have been reviewed in this paper. Statistical properties of Fresnel and Fraunhofer doubly scattered and cascade speckles are described. Non-gaussian statistics of biospeckles may lead to high localization of intensity of coherent light in human tissue during the laser surgery. Way of suppression of highly localized non-gaussian speckles is suggested.

  16. Gigavision - A weatherproof, multibillion pixel resolution time-lapse camera system for recording and tracking phenology in every plant in a landscape

    Science.gov (United States)

    Brown, T.; Borevitz, J. O.; Zimmermann, C.

    2010-12-01

    We have a developed a camera system that can record hourly, gigapixel (multi-billion pixel) scale images of an ecosystem in a 360x90 degree panorama. The “Gigavision” camera system is solar-powered and can wirelessly stream data to a server. Quantitative data collection from multiyear timelapse gigapixel images is facilitated through an innovative web-based toolkit for recording time-series data on developmental stages (phenology) from any plant in the camera’s field of view. Gigapixel images enable time-series recording of entire landscapes with a resolution sufficient to record phenology from a majority of individuals in entire populations of plants. When coupled with next generation sequencing, quantitative population genomics can be performed in a landscape context linking ecology and evolution in situ and in real time. The Gigavision camera system achieves gigapixel image resolution by recording rows and columns of overlapping megapixel images. These images are stitched together into a single gigapixel resolution image using commercially available panorama software. Hardware consists of a 5-18 megapixel resolution DSLR or Network IP camera mounted on a pair of heavy-duty servo motors that provide pan-tilt capabilities. The servos and camera are controlled with a low-power Windows PC. Servo movement, power switching, and system status monitoring are enabled with Phidgets-brand sensor boards. System temperature, humidity, power usage, and battery voltage are all monitored at 5 minute intervals. All sensor data is uploaded via cellular or 802.11 wireless to an interactive online interface for easy remote monitoring of system status. Systems with direct internet connections upload the full sized images directly to our automated stitching server where they are stitched and available online for viewing within an hour of capture. Systems with cellular wireless upload an 80 megapixel “thumbnail” of each larger panorama and full-sized images are manually

  17. D0 central tracking chamber performance studies

    International Nuclear Information System (INIS)

    Pizzuto, D.

    1991-12-01

    The performance of the completed DO central tracking chamber was studied using cosmic rays at the State University of New York at Stony Brook. Also studied was a prototype tracking chamber identical in design to the completed DO tracking chamber. The prototype chamber was exposed to a collimated beam of 150 GeV pions at the Fermilab NWA test facility. Results indicate an RΦ tracking resolution compatible with the limitations imposed by physical considerations, excellent 2 track resolution, and a high track reconstruction efficiency along with a good rejection power against γ → e + e - events

  18. New developments in NDT through electronic speckle pattern interferometry

    International Nuclear Information System (INIS)

    Mohan, S.; Murugesan, P; Mas, R.H.

    2007-01-01

    Full text: Optical holography and speckle interferometry are the emerging optical techniques that can be used for the measurements of microscopic parameters such as displacement, strain, stress and slope. These techniques are applied in various fields such as surface studies, non destructive testing, speckle metrology and steller interferometry. Even though many new NDT methods are available, the suitability for a specific application is based on the material property, nature of defects and sensitivity of detection. Difficulty in radiographic technique is that it fails in detecting tight cracks, planar defects and debonds. Microwave techniques has limited sensitivity for the defect detection and it is not suitable for the objects with metallic cases since the metals are perfect reflectors for the microwaves. Low modulus material attenuates the acoustic energy completely, making ultrasonic testing techniques not feasible. The recently evolved optoelectronic technique namely Electronic Speckle Pattern interferometry (ESPI) is a fast developing optical technique widely used for measuring displacement components, their derivatives, surface roughness, surface contours, shape and others. Due to non contact nature and high sensitivity, this technique has been used as a powerful on line inspection tool for non destructive pattern of materials in industrial environment. The salient feature of ESPI is its capability to display the correlation fringes in a real time on a monitor without the need of photographic processing or optical filtering. ESPI is an alternate non destructive technique suitable for propellant grains and other low modulus materials used in space vehicle systems. The optoelectronic technique can be used to detect cracks, voids and residual stresses etc.., in the components in the industrial environment. In the present investigation, speckle non destructive testing has been carried out on some selected low modulus materials used in space vehicles. The

  19. Unique Microstructural Changes in the Brain Associated with Urological Chronic Pelvic Pain Syndrome (UCPPS Revealed by Diffusion Tensor MRI, Super-Resolution Track Density Imaging, and Statistical Parameter Mapping: A MAPP Network Neuroimaging Study.

    Directory of Open Access Journals (Sweden)

    Davis Woodworth

    Full Text Available Studies have suggested chronic pain syndromes are associated with neural reorganization in specific regions associated with perception, processing, and integration of pain. Urological chronic pelvic pain syndrome (UCPPS represents a collection of pain syndromes characterized by pelvic pain, namely Chronic Prostatitis/Chronic Pelvic Pain Syndrome (CP/CPPS and Interstitial Cystitis/Painful Bladder Syndrome (IC/PBS, that are both poorly understood in their pathophysiology, and treated ineffectively. We hypothesized patients with UCPPS may have microstructural differences in the brain compared with healthy control subjects (HCs, as well as patients with irritable bowel syndrome (IBS, a common gastrointestinal pain disorder. In the current study we performed population-based voxel-wise DTI and super-resolution track density imaging (TDI in a large, two-center sample of phenotyped patients from the multicenter cohort with UCPPS (N = 45, IBS (N = 39, and HCs (N = 56 as part of the MAPP Research Network. Compared with HCs, UCPPS patients had lower fractional anisotropy (FA, lower generalized anisotropy (GA, lower track density, and higher mean diffusivity (MD in brain regions commonly associated with perception and integration of pain information. Results also showed significant differences in specific anatomical regions in UCPPS patients when compared with IBS patients, consistent with microstructural alterations specific to UCPPS. While IBS patients showed clear sex related differences in FA, MD, GA, and track density consistent with previous reports, few such differences were observed in UCPPS patients. Heat maps illustrating the correlation between specific regions of interest and various pain and urinary symptom scores showed clustering of significant associations along the cortico-basal ganglia-thalamic-cortical loop associated with pain integration, modulation, and perception. Together, results suggest patients with UCPPS have extensive

  20. Statistical spatial properties of speckle patterns generated by multiple laser beams

    International Nuclear Information System (INIS)

    Le Cain, A.; Sajer, J. M.; Riazuelo, G.

    2011-01-01

    This paper investigates hot spot characteristics generated by the superposition of multiple laser beams. First, properties of speckle statistics are studied in the context of only one laser beam by computing the autocorrelation function. The case of multiple laser beams is then considered. In certain conditions, it is shown that speckles have an ellipsoidal shape. Analytical expressions of hot spot radii generated by multiple laser beams are derived and compared to numerical estimates made from the autocorrelation function. They are also compared to numerical simulations performed within the paraxial approximation. Excellent agreement is found for the speckle width as well as for the speckle length. Application to the speckle patterns generated in the Laser MegaJoule configuration in the zone where all the beams overlap is presented. Influence of polarization on the size of the speckles as well as on their abundance is studied.

  1. Spiking cortical model-based nonlocal means method for speckle reduction in optical coherence tomography images

    Science.gov (United States)

    Zhang, Xuming; Li, Liu; Zhu, Fei; Hou, Wenguang; Chen, Xinjian

    2014-06-01

    Optical coherence tomography (OCT) images are usually degraded by significant speckle noise, which will strongly hamper their quantitative analysis. However, speckle noise reduction in OCT images is particularly challenging because of the difficulty in differentiating between noise and the information components of the speckle pattern. To address this problem, the spiking cortical model (SCM)-based nonlocal means method is presented. The proposed method explores self-similarities of OCT images based on rotation-invariant features of image patches extracted by SCM and then restores the speckled images by averaging the similar patches. This method can provide sufficient speckle reduction while preserving image details very well due to its effectiveness in finding reliable similar patches under high speckle noise contamination. When applied to the retinal OCT image, this method provides signal-to-noise ratio improvements of >16 dB with a small 5.4% loss of similarity.

  2. Track counting in radon dosimetry

    International Nuclear Information System (INIS)

    Fesenbeck, Ingo; Koehler, Bernd; Reichert, Klaus-Martin

    2013-01-01

    The newly developed, computer-controlled track counting system is capable of imaging and analyzing the entire area of nuclear track detectors. The high optical resolution allows a new analysis approach for the process of automated counting using digital image processing technologies. This way, higher exposed detectors can be evaluated reliably by an automated process as well. (orig.)

  3. OBSERVATIONS OF BINARY STARS WITH THE DIFFERENTIAL SPECKLE SURVEY INSTRUMENT. IV. OBSERVATIONS OF KEPLER, CoRoT, AND HIPPARCOS STARS FROM THE GEMINI NORTH TELESCOPE

    International Nuclear Information System (INIS)

    Horch, Elliott P.; Howell, Steve B.; Everett, Mark E.; Ciardi, David R.

    2012-01-01

    We present the results of 71 speckle observations of binary and unresolved stars, most of which were observed with the DSSI speckle camera at the Gemini North Telescope in 2012 July. The main purpose of the run was to obtain diffraction-limited images of high-priority targets for the Kepler and CoRoT missions, but in addition, we observed a number of close binary stars where the resolution limit of Gemini was used to better determine orbital parameters and/or confirm results obtained at or below the diffraction limit of smaller telescopes. Five new binaries and one triple system were discovered, and first orbits are calculated for other two systems. Several systems are discussed in detail.

  4. Predicting Human Mobility Patterns in Marine Ecosystems: Entropy and Home Range Calculations Based on High-Resolution Fishing Vessel Tracking Data

    Science.gov (United States)

    Murawski, S. A.

    2016-02-01

    A number of recent studies have developed metrics of human mobility patterns based on georeferenced cell phone records. The studies generally indicate a high degree of predictability in human location and relatively narrow home ranges for most people. In marine ecosystems there are a number of important uses for such calculations including marine spatial planning and predicting the impacts of marine management options such as establishing marine protected areas (MPAs). In this study we use individual fishing vessel satellite tracking (VMS) records ( 30 million records) obtained from commercial reef fish fishing vessels in the Gulf of Mexico during 2006-2014. This period witnessed the establishment of a variety of new regulations including individual fishing quotas (IFQs) for snapper, grouper, and tilefish, establishment of spatial-area closures, and the temporary closure of as much as 85,000 nautical miles of productive fishing grounds associated with the Deepwater Horizon oil spill accident. Vessel positions were obtained, with a location frequency of one hour. From these VMS data we calculated three measures of entropy (degree of repeatability in spatial use), as well as calculated the axis of gyration (home range) for each vessel in the data set. These calculations were related to a variety of descriptor variables including vessel size, distance from home port to predominant fishing grounds, revenue generated on fishing trips, and fishing regulations. The applicability of these calculations to marine resource management applications is discussed.

  5. Evaluation of High-Temporal-Resolution Bedload Sensors for Tracking Channel Bed Movement and Transport Thresholds in Forested Mountain Headwater Catchments.

    Science.gov (United States)

    Martin, S.; Conklin, M. H.; Bales, R. C.

    2014-12-01

    High temporal resolution data is required to take channel bed movement data beyond time integrated changes between measurements where many of the subtleties of bedload movement patterns are often missed. This study used continuous bedload scour sensors (flexible, fluid-filled pans connected to a pressure transducer) to collect high temporal resolution, long term bedload movement data for 4 high elevation (1500-1800 m) Sierra Nevada headwater streams draining 1 km2 catchments and to investigate the physical channel characteristics under which they perform best. Data collected by the scour sensors were used to investigate the disturbance and recovery patterns of these streams, to relate the observed patterns to channel bed stability, and to evaluate whether the channel bed is acting as a sediment source, sink, or storage across various temporal scales. Finally, attempts are made to identify discharge thresholds for bed movement from scour sensor and discharge data and to compare these threshold values to observed changes in the channel bed. Bedload scour data, turbidity data, and stream discharge data were collected at 15 minute intervals for (WY 2011 to WY 2014), including both above average (2011) and below average (2012, 2013, 2014) water years. Bedload scour sensors were found to have a relatively high (60%) failure rate in these systems. In addition, they required in situ calibrations as the factory and laboratory calibrations did not translate well to the field deployments. Data from the working sensors, showed patterns of abrupt channel bed disturbance (scour and/or fill) on an hour to day temporal scale followed by gradual recovery on a day to month scale back to a stable equilibrium bed surface elevation. These observed patterns suggest the bed acts as a short term source or sink for sediment, but is roughly sediment neutral over longer time periods implying the changes in bed elevation are reflective of fluctuations in storage rather than a true source or

  6. Measurement of deformation field in CT specimen using laser speckle

    International Nuclear Information System (INIS)

    Jeon, Moon Chang; Kang, Ki Ju

    2001-01-01

    To obtain A 2 experimentally in the J-A 2 theory, deformation field on the lateral surface of a CT specimen was to be determined using laser speckle method. The crack growth was measured using direct current potential drop method and most procedure of experimental and data reduction was performed according to ASTM Standard E1737-96. Laser speckle images during crack propagation were monitored by two CCD cameras to cancel the effect of rotation and translation of the specimen. An algorithm to pursue displacement of a point from each image was developed and successfully used to measure A 2 continuously as the crack tip was propagated. The effects of specimen thickness on J-R curve and A 2 were explored

  7. Polarization speckles and generalized Stokes vector wave: a review [invited

    DEFF Research Database (Denmark)

    Takeda, Mitsuo; Wang, Wei; Hanson, Steen Grüner

    2010-01-01

    We review some of the statistical properties of polarization-related speckle phenomena, with an introduction of a less known concept of polarization speckles and their spatial degree of polarization. As a useful means to characterize twopoint vector field correlations, we review the generalized...... Stokes parameters proposed by Korotkova and Wolf, and introduce its time-domain representation to describe the space-time evolution of the correlation between random electric vector fields at two different space-time points. This time-domain generalized Stokes vector, with components similar to those...... of the beam coherence polarization matrix proposed by Gori, is shown to obey the wave equation in exact analogy to a coherence function of scalar fields. Because of this wave nature, the time-domain generalized Stokes vector is referred to as generalized Stokes vector wave in this paper....

  8. Sensitivity evaluation of dynamic speckle activity measurements using clustering methods

    International Nuclear Information System (INIS)

    Etchepareborda, Pablo; Federico, Alejandro; Kaufmann, Guillermo H.

    2010-01-01

    We evaluate and compare the use of competitive neural networks, self-organizing maps, the expectation-maximization algorithm, K-means, and fuzzy C-means techniques as partitional clustering methods, when the sensitivity of the activity measurement of dynamic speckle images needs to be improved. The temporal history of the acquired intensity generated by each pixel is analyzed in a wavelet decomposition framework, and it is shown that the mean energy of its corresponding wavelet coefficients provides a suited feature space for clustering purposes. The sensitivity obtained by using the evaluated clustering techniques is also compared with the well-known methods of Konishi-Fujii, weighted generalized differences, and wavelet entropy. The performance of the partitional clustering approach is evaluated using simulated dynamic speckle patterns and also experimental data.

  9. Optical design of the comet Shoemaker-Levy speckle camera

    Energy Technology Data Exchange (ETDEWEB)

    Bissinger, H. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    An optical design is presented in which the Lick 3 meter telescope and a bare CCD speckle camera system was used to image the collision sites of the Shoemaker-Levy 9 comet with the Planet Jupiter. The brief overview includes of the optical constraints and system layout. The choice of a Risley prism combination to compensate for the time dependent atmospheric chromatic changes are described. Plate scale and signal-to-noise ratio curves resulting from imaging reference stars are compared with theory. Comparisons between un-corrected and reconstructed images of Jupiter`s impact sites. The results confirm that speckle imaging techniques can be used over an extended time period to provide a method to image large extended objects.

  10. Spatial filtering velocimetry of objective speckles for measuring out-of-plane motion

    DEFF Research Database (Denmark)

    Jakobsen, Michael Linde; Yura, H. T.; Hanson, Steen Grüner

    2012-01-01

    This paper analyzes the dynamics of objective laser speckles as the distance between the object and the observation plane continuously changes. With the purpose of applying optical spatial filtering velocimetry to the speckle dynamics, in order to measure out-of-plane motion in real time......, a rotational symmetric spatial filter is designed. The spatial filter converts the speckle dynamics into a photocurrent with a quasi-sinusoidal response to the out-of-plane motion. The spatial filter is here emulated with a CCD camera, and is tested on speckles arising from a real application. The analysis...

  11. Analysis of the speckle properties in a laser projection system based on a human eye model.

    Science.gov (United States)

    Cui, Zhe; Wang, Anting; Ma, Qianli; Ming, Hai

    2014-03-01

    In this paper, the properties of the speckle that is observed by humans in laser projection systems are theoretically analyzed. The speckle pattern on the fovea of the human retina is numerically simulated by introducing a chromatic human eye model. The results show that the speckle contrast experienced by humans is affected by the light intensity of the projected images and the wavelength of the laser source when considering the paracentral vision. Furthermore, the image quality is also affected by these two parameters. We believe that these results are useful for evaluating the speckle noise in laser projection systems.

  12. Laser speckle velocimetry applied to Rayleigh-Benard convection

    International Nuclear Information System (INIS)

    Arroyo, M.P.; Yonte, T.; Quintanilla, M.; Saviron, J.M.

    1986-01-01

    An application of speckle velocimetry technique to Rayleigh-Benard convection is presented. A 5-mW He-Ne laser allows precise determination of the two-dimensional velocity flow field, up to several mm/sec. The digital techniques used to analyze automatically the multiexposed photographs and to generate velocity and vorticity fields are described. The obtained results are in good agreement with previously reported data. The ability of the technique to cover other experimental conditions is discussed. 14 references

  13. Speckle imaging with the PAPA detector. [Precision Analog Photon Address

    Science.gov (United States)

    Papaliolios, C.; Nisenson, P.; Ebstein, S.

    1985-01-01

    A new 2-D photon-counting camera, the PAPA (precision analog photon address) detector has been built, tested, and used successfully for the acquisition of speckle imaging data. The camera has 512 x 512 pixels and operates at count rates of at least 200,000/sec. In this paper, technical details on the camera are presented and some of the laboratory and astronomical results are included which demonstrate the detector's capabilities.

  14. Speckle contrast diffuse correlation tomography of complex turbid medium flow

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Chong; Irwin, Daniel; Lin, Yu; Shang, Yu; He, Lian; Kong, Weikai; Yu, Guoqiang [Department of Biomedical Engineering, University of Kentucky, Lexington, Kentucky 40506 (United States); Luo, Jia [Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, Kentucky 40506 (United States)

    2015-07-15

    Purpose: Developed herein is a three-dimensional (3D) flow contrast imaging system leveraging advancements in the extension of laser speckle contrast imaging theories to deep tissues along with our recently developed finite-element diffuse correlation tomography (DCT) reconstruction scheme. This technique, termed speckle contrast diffuse correlation tomography (scDCT), enables incorporation of complex optical property heterogeneities and sample boundaries. When combined with a reflectance-based design, this system facilitates a rapid segue into flow contrast imaging of larger, in vivo applications such as humans. Methods: A highly sensitive CCD camera was integrated into a reflectance-based optical system. Four long-coherence laser source positions were coupled to an optical switch for sequencing of tomographic data acquisition providing multiple projections through the sample. This system was investigated through incorporation of liquid and solid tissue-like phantoms exhibiting optical properties and flow characteristics typical of human tissues. Computer simulations were also performed for comparisons. A uniquely encountered smear correction algorithm was employed to correct point-source illumination contributions during image capture with the frame-transfer CCD and reflectance setup. Results: Measurements with scDCT on a homogeneous liquid phantom showed that speckle contrast-based deep flow indices were within 12% of those from standard DCT. Inclusion of a solid phantom submerged below the liquid phantom surface allowed for heterogeneity detection and validation. The heterogeneity was identified successfully by reconstructed 3D flow contrast tomography with scDCT. The heterogeneity center and dimensions and averaged relative flow (within 3%) and localization were in agreement with actuality and computer simulations, respectively. Conclusions: A custom cost-effective CCD-based reflectance 3D flow imaging system demonstrated rapid acquisition of dense boundary

  15. A Portable Dynamic Laser Speckle System for Sensing Long-Term Changes Caused by Treatments in Painting Conservation.

    Science.gov (United States)

    Pérez, Alberto J; González-Peña, Rolando J; Braga, Roberto; Perles, Ángel; Pérez-Marín, Eva; García-Diego, Fernando J

    2018-01-11

    Dynamic laser speckle (DLS) is used as a reliable sensor of activity for all types of materials. Traditional applications are based on high-rate captures (usually greater than 10 frames-per-second, fps). Even for drying processes in conservation treatments, where there is a high level of activity in the first moments after the application and slower activity after some minutes or hours, the process is based on the acquisition of images at a time rate that is the same in moments of high and low activity. In this work, we present an alternative approach to track the drying process of protective layers and other painting conservation processes that take a long time to reduce their levels of activity. We illuminate, using three different wavelength lasers, a temporary protector (cyclododecane) and a varnish, and monitor them using a low fps rate during long-term drying. The results are compared to the traditional method. This work also presents a monitoring method that uses portable equipment. The results present the feasibility of using the portable device and show the improved sensitivity of the dynamic laser speckle when sensing the long-term process for drying cyclododecane and varnish in conservation.

  16. A Portable Dynamic Laser Speckle System for Sensing Long-Term Changes Caused by Treatments in Painting Conservation

    Science.gov (United States)

    Pérez, Alberto J.; Braga, Roberto; Perles, Ángel; Pérez–Marín, Eva; García-Diego, Fernando J.

    2018-01-01

    Dynamic laser speckle (DLS) is used as a reliable sensor of activity for all types of materials. Traditional applications are based on high-rate captures (usually greater than 10 frames-per-second, fps). Even for drying processes in conservation treatments, where there is a high level of activity in the first moments after the application and slower activity after some minutes or hours, the process is based on the acquisition of images at a time rate that is the same in moments of high and low activity. In this work, we present an alternative approach to track the drying process of protective layers and other painting conservation processes that take a long time to reduce their levels of activity. We illuminate, using three different wavelength lasers, a temporary protector (cyclododecane) and a varnish, and monitor them using a low fps rate during long-term drying. The results are compared to the traditional method. This work also presents a monitoring method that uses portable equipment. The results present the feasibility of using the portable device and show the improved sensitivity of the dynamic laser speckle when sensing the long-term process for drying cyclododecane and varnish in conservation. PMID:29324692

  17. Tracking Land Use/Land Cover Dynamics in Cloud Prone Areas Using Moderate Resolution Satellite Data: A Case Study in Central Africa

    Directory of Open Access Journals (Sweden)

    Bikash Basnet

    2015-05-01

    Full Text Available Tracking land surface dynamics over cloud prone areas with complex mountainous terrain is an important challenge facing the Earth Science community. One such region is the Lake Kivu region in Central Africa. We developed a processing chain to systematically monitor the spatio-temporal land use/land cover dynamics of this region over the years 1988, 2001, and 2011 using Landsat data, complemented by ancillary data. Topographic compensation was performed on Landsat reflectances to avoid the strong illumination angle impacts and image compositing was used to compensate for frequent cloud cover and thus incomplete annual data availability in the archive. A systematic supervised classification was applied to the composite Landsat imagery to obtain land cover thematic maps with overall accuracies of 90% and higher. Subsequent change analysis between these years found extensive conversions of the natural environment as a result of human related activities. The gross forest cover loss for 1988–2001 and 2001–2011 period was 216.4 and 130.5 thousand hectares, respectively, signifying significant deforestation in the period of civil war and a relatively stable and lower deforestation rate later, possibly due to conservation and reforestation efforts in the region. The other dominant land cover changes in the region were aggressive subsistence farming and urban expansion displacing natural vegetation and arable lands. Despite limited data availability, this study fills the gap of much needed detailed and updated land cover change information for this biologically important region of Central Africa. These multi-temporal datasets will be a valuable baseline for land use managers in the region interested in developing ecologically sustainable land management strategies and measuring the impacts of biodiversity conservation efforts.

  18. High-resolution GPS tracking reveals habitat selection and the potential for long-distance seed dispersal by Madagascan flying foxes Pteropus rufus

    Directory of Open Access Journals (Sweden)

    Ryszard Oleksy

    2015-01-01

    Full Text Available Long-distance seed dispersal can be important for the regeneration of forested habitats, especially in regions where deforestation has been severe. Old World fruit bats (Pteropodidae have considerable potential for long-distance seed dispersal. We studied the movement patterns and feeding behaviour of the endemic Madagascan flying fox Pteropus rufus, in Berenty Reserve, southeast Madagascar. Between July and September 2012 (the dry season nine males and six females were tagged with customised GPS loggers which recorded fixes every 2.5 min between 18.00 and 06.00 h. The combined home range of all of the tagged bats during 86 nights exceeded 58,000 ha. Females had larger home ranges and core foraging areas and foraged over longer distances (average 28.1 km; median 26.7 km than males (average 15.4 km; median 9.5 km. Because the study was conducted during the gestation period, the increased energy requirements of females may explain their greater mean foraging area. Compositional analysis revealed that bats show strong preferences for overgrown sisal (Agave sisalana plantations (a mix of shrub, trees and sisal plants and remnant riverside forest patches. Sisal nectar and pollen were abundant food sources during the tracking period and this probably contributed to the selective use of overgrown sisal plantations. The bats also ate large quantities of figs (Ficus grevei during the study, and dispersed seeds of this important pioneer species. The bats flew at an average speed of 9.13 m/s, perhaps to optimise gliding performance. The study confirms that P. rufus has the potential to be a long-distance seed disperser, and is able to fly over a large area, often crossing cleared parts of its habitat. It potentially plays an important role in the regeneration of threatened forest habitats in this biodiversity hotspot.

  19. High-resolution 3D coronary vessel wall imaging with near 100% respiratory efficiency using epicardial fat tracking: reproducibility and comparison with standard methods.

    Science.gov (United States)

    Scott, Andrew D; Keegan, Jennifer; Firmin, David N

    2011-01-01

    To quantitatively assess the performance and reproducibility of 3D spiral coronary artery wall imaging with beat-to-beat respiratory-motion-correction (B2B-RMC) compared to navigator gated 2D spiral and turbo-spin-echo (TSE) acquisitions. High-resolution (0.7 × 0.7 mm) cross-sectional right coronary wall acquisitions were performed in 10 subjects using four techniques (B2B-RMC 3D spiral with alternate (2RR) and single (1RR) R-wave gating, navigator-gated 2D spiral (2RR) and navigator-gated 2D TSE (2RR)) on two occasions. Wall thickness measurements were compared with repeated measures analysis of variance (ANOVA). Reproducibility was assessed with the intraclass correlation coefficient (ICC). In all, 91% (73/80) of acquisitions were successful (failures: four TSE, two 3D spiral (1RR) and one 3D spiral (2RR)). Respiratory efficiency of the B2B-RMC was less variable and substantially higher than for navigator gating (99.6 ± 1.2% vs. 39.0 ± 7.5%, P B2B-RMC permits coronary vessel wall assessment over multiple thin contiguous slices in a clinically feasible duration. Excellent reproducibility of the technique potentially enables studies of disease progression/regression. Copyright © 2010 Wiley-Liss, Inc.

  20. Experimental study on deformation field evolution in rock sample with en echelon faults using digital speckle correlation method

    Science.gov (United States)

    Ma, S.; Ma, J.; Liu, L.; Liu, P.

    2007-12-01

    Digital speckle correlation method (DSCM) is one kind of photomechanical deformation measurement method. DSCM could obtain continuous deformation field contactlessly by just capturing speckle images from specimen surface. Therefore, it is suitable to observe high spatial resolution deformation field in tectonophysical experiment. However, in the general DSCM experiment, the inspected surface of specimen needs to be painted to bear speckle grains in order to obtain the high quality speckle image. This also affects the realization of other measurement techniques. In this study, an improved DSCM system is developed and utilized to measure deformation field of rock specimen without surface painting. The granodiorite with high contrast nature grains is chosen to manufacture the specimen, and a specially designed DSCM algorithm is developed to analyze this kind of nature speckle images. Verification and calibration experiments show that the system could inspect a continuous (about 15Hz) high resolution displacement field (with resolution of 5μm) and strain field (with resolution of 50μɛ), dispensing with any preparation on rock specimen. Therefore, it could be conveniently utilized to study the failure of rock structure. Samples with compressive en echelon faults and extensional en echelon faults are studied on a two-direction servo-control test machine. The failure process of the samples is discussed based on the DSCM results. Experiment results show that: 1) The contours of displacement field could clearly indicate the activities of faults and new cracks. The displacement gradient adjacent to active faults and cracks is much greater than other areas. 2) Before failure of the samples, the mean strain of the jog area is largest for the compressive en echelon fault, while that is smallest for the extensional en echelon fault. This consists with the understanding that the jog area of compressive fault subjects to compression and that of extensional fault subjects to

  1. Track reconstruction at the ILC: the ILD tracking software

    International Nuclear Information System (INIS)

    Gaede, Frank; Aplin, Steven; Rosemann, Christoph; Voutsinas, Georgios; Glattauer, Robin

    2014-01-01

    One of the key requirements for Higgs physics at the International Linear Collider ILC is excellent track reconstruction with very good momentum and impact parameter resolution. ILD is one of the two detector concepts at the ILC. Its central tracking system comprises of an outer Si-tracker, a highly granular TPC, an intermediate silicon tracker and a pixel vertex detector, and it is complemented by silicon tracking disks in the forward direction. Large hit densities from beam induced coherent electron-positron pairs at the ILC pose an additional challenge to the pattern recognition algorithms. We present the recently developed new ILD tracking software, the pattern recognition algorithms that are using clustering techniques, Cellular Automatons and Kalman filter based track extrapolation. The performance of the ILD tracking system is evaluated using a detailed simulation including dead material, gaps and imperfections.

  2. Laser speckle technology in stomatology. diagnostics of stresses and strains of hard biotissues and orthodontic and orthopedic structures

    Science.gov (United States)

    Denisova, Yu. L.; Bazylev, N. B.; Rubnikovich, S. P.; Fomin, N. A.

    2013-07-01

    We have investigated the formation and dynamics of speckle biofi elds formed by hard biotissues of the oral cavity irradiated with low-intensity radiation. We present experimental methods for diagnosing the stressed-strained state of the maxillodental system and orthodontic and orthopedic structures based on speckle technologies and crosscorrelation analysis of speckle biofi elds.

  3. 3D shape measurement using deterministic phase retrieval and a partially developed speckle field

    DEFF Research Database (Denmark)

    Almoro, Percival F.; Waller, Laura; Agour, Mostafa

    2012-01-01

    Fourier domain. The local variations of the recorded speckle patterns and the defocus distance approximate the axial intensity derivative which, in turn, is required to recover the wavefront phase via the transport of intensity equation (TIE). The SLM setup reduces the speckle recording time and the TIE...

  4. Tandem-pulsed acousto-optics: an analytical framework of modulated high-contrast speckle patterns

    NARCIS (Netherlands)

    Resink, Steffen; Steenbergen, Wiendelt

    2015-01-01

    Recently we presented acousto-optic (AO) probing of scattering media using addition or subtraction of speckle patterns due to tandem nanosecond pulses. Here we present a theoretical framework for ideal (polarized, noise-free) speckle patterns with unity contrast that links ultrasound-induced optical

  5. Speckle Interferometry with the McMath-Pierce East Auxiliary Telescope

    Science.gov (United States)

    Harshaw, Richard; Ray, Jimmy; Douglass, David; Prause, Lori; Genet, Russell

    2015-09-01

    Engineering runs and tests on the McMath-Pierce 0.8 meter East Auxiliary telescope successfully configured the telescope for speckle interferometry observations of close visual double stars. This paper reports the procedure and results of the speckle analysis of four double stars.

  6. Electronic speckle pattern interferometry observation of brick–mortar interface behaviour under compression

    NARCIS (Netherlands)

    Vermeltfoort, A.T.; Martens, D.R.W; Zijl, van G.P.A.G.

    2007-01-01

    The brick–mortar interaction is important in the mechanical behaviour of masonry. It affects the load transfer considerably, as shown by detailed deformation measurements taken using electronic speckle pattern interferometry (ESPI), a laser speckle interference technique. A companion paper [Canadian

  7. Shift-Invariant Image Reconstruction of Speckle-Degraded Images Using Bispectrum Estimation

    Science.gov (United States)

    1990-05-01

    process with the requisite negative exponential pelf. I call this model the Negative Exponential Model ( NENI ). The NENI flowchart is seen in Figure 6...Figure ]3d-g. Statistical Histograms and Phase for the RPj NG EXP FDF MULT METHOD FILuteC 14a. Truth Object Speckled Via the NENI HISTOGRAM OF SPECKLE

  8. From synchrotron radiation to lab source: advanced speckle-based X-ray imaging using abrasive paper

    Science.gov (United States)

    Wang, Hongchang; Kashyap, Yogesh; Sawhney, Kawal

    2016-02-01

    X-ray phase and dark-field imaging techniques provide complementary and inaccessible information compared to conventional X-ray absorption or visible light imaging. However, such methods typically require sophisticated experimental apparatus or X-ray beams with specific properties. Recently, an X-ray speckle-based technique has shown great potential for X-ray phase and dark-field imaging using a simple experimental arrangement. However, it still suffers from either poor resolution or the time consuming process of collecting a large number of images. To overcome these limitations, in this report we demonstrate that absorption, dark-field, phase contrast, and two orthogonal differential phase contrast images can simultaneously be generated by scanning a piece of abrasive paper in only one direction. We propose a novel theoretical approach to quantitatively extract the above five images by utilising the remarkable properties of speckles. Importantly, the technique has been extended from a synchrotron light source to utilise a lab-based microfocus X-ray source and flat panel detector. Removing the need to raster the optics in two directions significantly reduces the acquisition time and absorbed dose, which can be of vital importance for many biological samples. This new imaging method could potentially provide a breakthrough for numerous practical imaging applications in biomedical research and materials science.

  9. On the link between the speckle free nature of optoacoustics and visibility of structures in limited-view tomography

    Directory of Open Access Journals (Sweden)

    Xosé Luís Deán-Ben

    2016-12-01

    Full Text Available Similar to pulse-echo ultrasound, optoacoustic imaging encodes the location of optical absorbers by the time-of-flight of ultrasound waves. Yet, signal generation mechanisms are fundamentally different for the two modalities, leading to significant distinction between the optimum image formation strategies. While interference of back-scattered ultrasound waves with random phases causes speckle noise in ultrasound images, speckle formation is hindered by the strong correlation between the optoacoustic responses corresponding to individual sources. However, visibility of structures is severely hampered when attempting to acquire optoacoustic images under limited-view tomographic geometries. In this tutorial article, we systematically describe the basic principles of optoacoustic signal generation and image formation for objects ranging from individual sub-resolution absorbers to a continuous absorption distribution. The results are of relevance for the proper interpretation of optoacoustic images acquired under limited-view scenarios and may also serve as a basis for optimal design of tomographic acquisition geometries and image formation strategies.

  10. Accuracy concerns in digital speckle photography combined with Fresnel digital holographic interferometry

    Science.gov (United States)

    Zhao, Yuchen; Zemmamouche, Redouane; Vandenrijt, Jean-François; Georges, Marc P.

    2018-05-01

    A combination of digital holographic interferometry (DHI) and digital speckle photography (DSP) allows in-plane and out-of-plane displacement measurement between two states of an object. The former can be determined by correlating the two speckle patterns whereas the latter is given by the phase difference obtained from DHI. We show that the amplitude of numerically reconstructed object wavefront obtained from Fresnel in-line digital holography (DH), in combination with phase shifting techniques, can be used as speckle patterns in DSP. The accuracy of in-plane measurement is improved after correcting the phase errors induced by reference wave during reconstruction process. Furthermore, unlike conventional imaging system, Fresnel DH offers the possibility to resize the pixel size of speckle patterns situated on the reconstruction plane under the same optical configuration simply by zero-padding the hologram. The flexibility of speckle size adjustment in Fresnel DH ensures the accuracy of estimation result using DSP.

  11. Development of nuclear track detectors

    International Nuclear Information System (INIS)

    Somogyi, Gyoergy

    1985-01-01

    The birth and development of two decades of a new nuclear detection method is briefly summarized by one of the first inventors. The main steps of the development and broadening application of nuclear solid state track detectors are described underlying the contribution and main results of the research group of ATOMKI, Hungary (i.e. the finding of the proper plastic materials for track detectors, the discovery of correlations between the track diameter and the particle energy, the increasing of energy resolution, explanation of the track developing process, elaboration of new electrochemical track analyzing methods and automatic track analyzers). Recently, this detecting technique has grown to the phase of the industrial mass production and broad application in radiogeochemistry, mining, radioecology, personal monitoring in nuclear power plants, etc. (D.Gy.)

  12. Particle tracking

    International Nuclear Information System (INIS)

    Mais, H.; Ripken, G.; Wrulich, A.; Schmidt, F.

    1986-02-01

    After a brief description of typical applications of particle tracking in storage rings and after a short discussion of some limitations and problems related with tracking we summarize some concepts and methods developed in the qualitative theory of dynamical systems. We show how these concepts can be applied to the proton ring HERA. (orig.)

  13. Timber tracking

    DEFF Research Database (Denmark)

    Düdder, Boris; Ross, Omry

    2017-01-01

    Managing and verifying forest products in a value chain is often reliant on easily manipulated document or digital tracking methods - Chain of Custody Systems. We aim to create a new means of tracking timber by developing a tamper proof digital system based on Blockchain technology. Blockchain...

  14. Rat retinal vasomotion assessed by laser speckle imaging

    DEFF Research Database (Denmark)

    Neganova, Anastasiia Y; Postnov, Dmitry D; Sosnovtseva, Olga

    2017-01-01

    Vasomotion is spontaneous or induced rhythmic changes in vascular tone or vessel diameter that lead to rhythmic changes in flow. While the vascular research community debates the physiological and pathophysiological consequence of vasomotion, there is a great need for experimental techniques...... that can address the role and dynamical properties of vasomotion in vivo. We apply laser speckle imaging to study spontaneous and drug induced vasomotion in retinal network of anesthetized rats. The results reveal a wide variety of dynamical patterns. Wavelet-based analysis shows that (i) spontaneous...

  15. Digital speckle correlation for nondestructive testing of corrosion

    Science.gov (United States)

    Paiva, Raul D., Jr.; Soga, Diogo; Muramatsu, Mikiya; Hogert, Elsa N.; Landau, Monica R.; Ruiz Gale, Maria F.; Gaggioli, Nestor G.

    1999-07-01

    This paper describes the use of optical correlation speckle patterns to detect and analyze the metallic corrosion phenomena, and shows the experimental set-up used. We present some new results in the characterization of the corrosion process using a model based in electroerosion phenomena. We also provide valuable information about surface microrelief changes, which is also useful in numerous engineering applications. The results obtained are good enough for showing that our technique is very useful for giving new possibilities to the analysis of the corrosion and oxidation process, particularly in real time.

  16. Lensless Photoluminescence Hyperspectral Camera Employing Random Speckle Patterns.

    Czech Academy of Sciences Publication Activity Database

    Žídek, Karel; Denk, Ondřej; Hlubuček, Jiří

    2017-01-01

    Roč. 7, č. 1 (2017), č. článku 15309. ISSN 2045-2322 R&D Projects: GA MŠk(CZ) LO1206; GA ČR(CZ) GJ17-26284Y Institutional support: RVO:61389021 Keywords : compressed sensing * photoluminescence imaging * laser speckles * single-pixel camera Subject RIV: BH - Optics, Masers, Lasers OBOR OECD: Optics (including laser optics and quantum optics) Impact factor: 4.259, year: 2016 https://www.nature.com/articles/s41598-017-14443-4

  17. Effect of low-frequency vibrations on speckle interferometry fringes

    International Nuclear Information System (INIS)

    Vikram, C.S.; Pechersky, M.J.

    1998-01-01

    The effects of low-frequency vibrations on speckle correlation fringes have been investigated. The relatively short capture time of the camera in the low-frequency case may yield usable fringe contrast in spite of vibration. It has been shown that the fringes also shift due to the vibration. The study is in agreement with experimental observations of good-contrast correlation fringes even if the object is not on a vibration-isolated table. Some such experimental observations are also presented. copyright 1998 Society of Photo-Optical Instrumentation Engineers

  18. Optoelectronic imaging of speckle using image processing method

    Science.gov (United States)

    Wang, Jinjiang; Wang, Pengfei

    2018-01-01

    A detailed image processing of laser speckle interferometry is proposed as an example for the course of postgraduate student. Several image processing methods were used together for dealing with optoelectronic imaging system, such as the partial differential equations (PDEs) are used to reduce the effect of noise, the thresholding segmentation also based on heat equation with PDEs, the central line is extracted based on image skeleton, and the branch is removed automatically, the phase level is calculated by spline interpolation method, and the fringe phase can be unwrapped. Finally, the imaging processing method was used to automatically measure the bubble in rubber with negative pressure which could be used in the tire detection.

  19. Body size evolution in insular speckled rattlesnakes (Viperidae: Crotalus mitchellii.

    Directory of Open Access Journals (Sweden)

    Jesse M Meik

    2010-03-01

    Full Text Available Speckled rattlesnakes (Crotalus mitchellii inhabit multiple islands off the coast of Baja California, Mexico. Two of the 14 known insular populations have been recognized as subspecies based primarily on body size divergence from putative mainland ancestral populations; however, a survey of body size variation from other islands occupied by these snakes has not been previously reported. We examined body size variation between island and mainland speckled rattlesnakes, and the relationship between body size and various island physical variables among 12 island populations. We also examined relative head size among giant, dwarfed, and mainland speckled rattlesnakes to determine whether allometric differences conformed to predictions of gape size (and indirectly body size evolving in response to shifts in prey size.Insular speckled rattlesnakes show considerable variation in body size when compared to mainland source subspecies. In addition to previously known instances of gigantism on Angel de la Guarda and dwarfism on El Muerto, various degrees of body size decrease have occurred frequently in this taxon, with dwarfed rattlesnakes occurring mostly on small, recently isolated, land-bridge islands. Regression models using the Akaike information criterion (AIC showed that mean SVL of insular populations was most strongly correlated with island area, suggesting the influence of selection for different body size optima for islands of different size. Allometric differences in head size of giant and dwarf rattlesnakes revealed patterns consistent with shifts to larger and smaller prey, respectively.Our data provide the first example of a clear relationship between body size and island area in a squamate reptile species; among vertebrates this pattern has been previously documented in few insular mammals. This finding suggests that selection for body size is influenced by changes in community dynamics that are related to graded differences in area over

  20. SPECKLE INTERFEROMETRY OF SECONDARY COMPONENTS IN NEARBY VISUAL BINARIES

    International Nuclear Information System (INIS)

    Tokovinin, Andrei; Horch, Elliott P.

    2016-01-01

    Statistical characterization of secondary subsystems in binaries helps to distinguish between various scenarios of multiple-star formation. The Differential Speckle Survey Instrument was used at the Gemini-N telescope for several hours in 2015 July to probe the binarity of 25 secondary components in nearby solar-type binaries. Six new subsystems were resolved, with meaningful detection limits for the remaining targets. The large incidence of secondary subsystems agrees with other similar studies. The newly resolved subsystem HIP 115417 Ba,Bb causes deviations in the observed motion of the outer binary from which an astrometric orbit of Ba,Bb with a period of 117 years is deduced.

  1. Making tracks

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1986-10-15

    In many modern tracking chambers, the sense wires, rather than being lined up uniformly, are grouped into clusters to facilitate the pattern recognition process. However, with higher energy machines providing collisions richer in secondary particles, event reconstruction becomes more complicated. A Caltech / Illinois / SLAC / Washington group developed an ingenious track finding and fitting approach for the Mark III detector used at the SPEAR electron-positron ring at SLAC (Stanford). This capitalizes on the detector's triggering, which uses programmable logic circuits operating in parallel, each 'knowing' the cell patterns for all tracks passing through a specific portion of the tracker (drift chamber)

  2. Statistics on gene-based laser speckles with a small number of scatterers: implications for the detection of polymorphism in the Chlamydia trachomatis omp1 gene

    Science.gov (United States)

    Ulyanov, Sergey S.; Ulianova, Onega V.; Zaytsev, Sergey S.; Saltykov, Yury V.; Feodorova, Valentina A.

    2018-04-01

    The transformation mechanism for a nucleotide sequence of the Chlamydia trachomatis gene into a speckle pattern has been considered. The first and second-order statistics of gene-based speckles have been analyzed. It has been demonstrated that gene-based speckles do not obey Gaussian statistics and belong to the class of speckles with a small number of scatterers. It has been shown that gene polymorphism can be easily detected through analysis of the statistical characteristics of gene-based speckles.

  3. Optical characterization of display screens by speckle patterns

    Science.gov (United States)

    Pozo, Antonio M.; Castro, José J.; Rubiño, Manuel

    2013-10-01

    In recent years, flat-panel display (FPD) technology has undergone great development, and now FPDs appear in many devices. A significant element in FPD manufacturing is the display front surface. Manufacturers sell FPDs with different types of front surfaces, which can be matte (also called anti-glare) or glossy screens. Users who prefer glossy screens consider these displays to show more vivid colors compared with matte-screen displays. However, on the glossy screens, external light sources may cause unpleasant reflections that can be reduced by a matte treatment in the front surface. In this work, we present a method to characterize FPD screens using laser-speckle patterns. We characterize three FPDs: a Samsung XL2370 LCD monitor of 23 in. with matte screen, a Toshiba Satellite A100 LCD laptop of 15.4 in. with glossy screen, and a Grammata Papyre 6.1 electronic book reader of 6 in. with ePaper screen (E-ink technology). The results show great differences in speckle-contrast values for the three screens characterized and, therefore, this work shows the feasibility of this method for characterizing and comparing FPDs that have different types of front surfaces.

  4. Accelerated speckle imaging with the ATST visible broadband imager

    Science.gov (United States)

    Wöger, Friedrich; Ferayorni, Andrew

    2012-09-01

    The Advanced Technology Solar Telescope (ATST), a 4 meter class telescope for observations of the solar atmosphere currently in construction phase, will generate data at rates of the order of 10 TB/day with its state of the art instrumentation. The high-priority ATST Visible Broadband Imager (VBI) instrument alone will create two data streams with a bandwidth of 960 MB/s each. Because of the related data handling issues, these data will be post-processed with speckle interferometry algorithms in near-real time at the telescope using the cost-effective Graphics Processing Unit (GPU) technology that is supported by the ATST Data Handling System. In this contribution, we lay out the VBI-specific approach to its image processing pipeline, put this into the context of the underlying ATST Data Handling System infrastructure, and finally describe the details of how the algorithms were redesigned to exploit data parallelism in the speckle image reconstruction algorithms. An algorithm re-design is often required to efficiently speed up an application using GPU technology; we have chosen NVIDIA's CUDA language as basis for our implementation. We present our preliminary results of the algorithm performance using our test facilities, and base a conservative estimate on the requirements of a full system that could achieve near real-time performance at ATST on these results.

  5. Real time speckle monitoring to control retinal photocoagulation

    Science.gov (United States)

    Bliedtner, Katharina; Seifert, Eric; Brinkmann, Ralf

    2017-07-01

    Photocoagulation is a treatment modality for several retinal diseases. Intra- and inter-individual variations of the retinal absorption as well as ocular transmission and light scattering makes it impossible to achieve a uniform effective exposure with one set of laser parameters. To guarantee a uniform damage throughout the therapy a real-time control is highly requested. Here, an approach to realize a real-time optical feedback using dynamic speckle analysis in-vivo is presented. A 532 nm continuous wave Nd:YAG laser is used for coagulation. During coagulation, speckle dynamics are monitored by a coherent object illumination using a 633 nm diode laser and analyzed by a CMOS camera with a frame rate up to 1 kHz. An algorithm is presented that can discriminate between different categories of retinal pigment epithelial damage ex-vivo in enucleated porcine eyes and that seems to be robust to noise in-vivo. Tissue changes in rabbits during retinal coagulation could be observed for different lesion strengths. This algorithm can run on a FPGA and is able to calculate a feedback value which is correlated to the thermal and coagulation induced tissue motion and thus the achieved damage.

  6. Developments In Electronic Speckle Pattern Interferometry For Automotive Vibration Analysis.

    Science.gov (United States)

    Davies, Jeremy C.; Buckberry, Clive H.; Jones, Julian D. C.; Pannell, Chris N.

    1989-01-01

    The incorporation of monomode fibre optics into an argon ion powered Electronic Speckle Pattern Interferometer (ESPI) is reported. The system, consisting of an optics assembly linked to the laser and a CCD camera transceiver, flexibly connected by 40m of monomode fibre optic cable to the optics, has been used to analyse the modal behaviour of structures up to 5m X 3m X 2m in size. Phase modulation of the reference beam in order to operate in a heterodyne mode has been implemented using a piezo-electric crystal operating on the monomode fibre. A new mode of operation - sequential time-average subtraction - and the results of a new processing algorithm are also reported. Their implementation enables speckle free, time-average vibration maps to be generated in real-time on large, unstable structures. Example results for a four cylinder power unit, a vehicle body shell component and an engine oil pan are included. In all cases the analysis was conducted in a general workshop environment without the need for vibration isolation facilities.

  7. Measurement of elasto-plastic deformations by speckle interferometry

    Science.gov (United States)

    Bova, Marco; Bruno, Luigi; Poggialini, Andrea

    2010-09-01

    In the paper the authors present an experimental equipment for elasto-plastic characterization of engineering materials by tensile tests. The stress state is imposed to a dog bone shaped specimen by a testing machine fixed on the optical table and designed for optimizing the performance of a speckle interferometer. All three displacement components are measured by a portable speckle interferometer fed by three laser diodes of 50 mW, by which the deformations of a surface of about 6×8 mm2 can be fully analyzed in details. All the equipment is driven by control electronics designed and realized on purpose, by which it is possible to accurately modify the intensity of the illumination sources, the position of a PZT actuator necessary for applying phase-shifting procedure, and the overall displacement applied to the specimen. The experiments were carried out in National Instrument LabVIEW environment, while the processing of the experimental data in Wolfram Mathematica environment. The paper reports the results of the elasto-plastic characterization of a high strength steel specimen.

  8. Speckle reduction for a laser light sectioning sensor

    Directory of Open Access Journals (Sweden)

    Tutsch Rainer

    2015-01-01

    Full Text Available Automated optical inspection is an important test procedure in electronic circuits assembly. Frequently 3d information is required and laser light sectioning sensors are often applied. However, some effects complicate the reliable automatic detection of the shape of such assemblies and their components. The packages of electronic components often are made of black plastics or ceramics so that the intensity available for the optical detection is quite low, especially in comparison to the surface of the PCBs where the components are mounted on. In addition due to rough surfaces of the components and the coherence length of the laser light speckle structures arise. In the work presented here a piezo actuator is used to oscillate the illuminating laser lines along the direction of the lines. The aim is to reduce the visibility of the speckle structures by averaging while maintaining the geometrical shape of the lines. In addition, image processing methods like segmentation and skeletonization are used to allow the detection of the shape of components and assemblies also if materials with distinct differences in the reflectivity are involved. Investigations include the influence of the parameters amplitude and frequency of the piezo actuator.

  9. The influence of angle of insonation and target depth on speckle-tracking strain

    DEFF Research Database (Denmark)

    Forsha, Daniel; Risum, Niels; Rajagopal, Sudarshan

    2015-01-01

    was to assess the influence of angle and depth on longitudinal peak systolic strain (LPS). METHODS: Thirty-four healthy pediatric subjects (age range, 6-18 years; 47% male) with normal cardiac anatomy and good image quality were prospectively imaged. Angular comparisons of LPS were investigated by examining...

  10. Right atrial and ventricular function evaluated with speckle tracking in patients with acute pulmonary embolism

    DEFF Research Database (Denmark)

    Ramberg, Emilie; Olausson, Maria; Jørgensen, Tem Bendix Salkvist

    2017-01-01

    This pilot study suggests that basal-/mid-segments of RA and RV free wall are more affected in patients with a PE compared with controls. Interestingly, we found no significant difference in myocardial RA and RV damage between patients with a central and a peripheral PE. We advocate that PE no matter central...... of an increased D-dimer in this group. Right ventricular dimensions were more affected among patients with a PE. Compared with controls, segmental RV and RA strain/strain rate in the free wall was significantly reduced in patients with PE (P

  11. Chemotherapy-Induced Cardiotoxicity: Subclinical Cardiac Dysfunction Evidence Using Speckle Tracking Echocardiography

    OpenAIRE

    Monte, Ines; Bottari, Vera Elena; Buccheri, Sergio; Blundo, Anita; Sirugo, Luana; Leggio, Stefano; Licciardi, Salvatore

    2013-01-01

    Objectives: In our study, we aimed to identify early markers of cardiac dysfunction in patients treated with mitoxantrone. We also looked at cardiac functional changes during therapy by analyzing longitudinal deformation and by measuring left ventricular (LV) and left atrial (LA) global strain. Materials and Methods: LA and LV global longitudinal strain were analyzed in 20 patients affected by multiple sclerosis and treated with mitoxantrone. Patients underwent echocardiography before treatme...

  12. Myocardial Deformation Measured by 3-Dimensional Speckle Tracking in Children and Adolescents With Systemic Arterial Hypertension.

    Science.gov (United States)

    Navarini, Susanne; Bellsham-Revell, Hannah; Chubb, Henry; Gu, Haotian; Sinha, Manish D; Simpson, John M

    2017-12-01

    Systemic arterial hypertension predisposes children to cardiovascular risk in childhood and adult life. Despite extensive study of left ventricular (LV) hypertrophy, detailed 3-dimensional strain analysis of cardiac function in hypertensive children has not been reported. The aim of this study was to evaluate LV mechanics (strain, twist, and torsion) in young patients with hypertension compared with a healthy control group and assess factors associated with functional measurements. Sixty-three patients (26 hypertension and 37 normotensive) were enrolled (mean age, 14.3 and 11.4 years; 54% men and 41% men, respectively). All children underwent clinical evaluation and echocardiographic examination, including 3-dimensional strain. There was no difference in LV volumes and ejection fraction between the groups. Myocardial deformation was significantly reduced in those with hypertension compared with controls. For hypertensive and normotensive groups, respectively, global longitudinal strain was -15.1±2.3 versus -18.5±1.9 ( P hypertensive and normotensive children, but children with hypertension had significantly lower strain indices. Whether reduced strain might predict future cardiovascular risk merits further longitudinal study. © 2017 American Heart Association, Inc.

  13. Predicting Paroxysmal Atrial Fibrillation in Cerebrovascular Ischemia Using Tissue Doppler Imaging and Speckle Tracking Echocardiography

    DEFF Research Database (Denmark)

    Olsen, Flemming Javier; Jørgensen, Peter Godsk; Møgelvang, Rasmus

    2016-01-01

    BACKGROUND: Often the underlying cause of cerebral ischemia (CI) cannot be found during a routine diagnostic investigation, but paroxysmal atrial fibrillation (PAF) could be the culprit. AIM: The objective of the study is to investigate whether advanced echocardiography improves the diagnostic ap...

  14. Signal-to-noise based local decorrelation compensation for speckle interferometry applications

    International Nuclear Information System (INIS)

    Molimard, Jerome; Cordero, Raul; Vautrin, Alain

    2008-01-01

    Speckle-based interferometric techniques allow assessing the whole-field deformation induced on a specimen due to the application of load. These high sensitivity optical techniques yield fringe images generated by subtracting speckle patterns captured while the specimen undergoes deformation. The quality of the fringes, and in turn the accuracy of the deformation measurements, strongly depends on the speckle correlation. Specimen rigid body motion leads to speckle decorrelation that, in general, cannot be effectively counteracted by applying a global translation to the involved speckle patterns. In this paper, we propose a recorrelation procedure based on the application of locally evaluated translations. The proposed procedure implies dividing the field into several regions, applying a local translation, and calculating, in every region, the signal-to-noise ratio (SNR). Since the latter is a correlation indicator (the noise increases with the decorrelation) we argue that the proper translation is that which maximizes the locally evaluated SNR. The search of the proper local translations is, of course, an interactive process that can be facilitated by using a SNR optimization algorithm. The performance of the proposed recorrelation procedure was tested on two examples. First, the SNR optimization algorithm was applied to fringe images obtained by subtracting simulated speckle patterns. Next, it was applied to fringe images obtained by using a shearography optical setup from a specimen subjected to mechanical deformation. Our results show that the proposed SNR optimization method can significantly improve the reliability of measurements performed by using speckle-based techniques

  15. Compensation for the signal processing characteristics of ultrasound B-mode scanners in adaptive speckle reduction.

    Science.gov (United States)

    Crawford, D C; Bell, D S; Bamber, J C

    1993-01-01

    A systematic method to compensate for nonlinear amplification of individual ultrasound B-scanners has been investigated in order to optimise performance of an adaptive speckle reduction (ASR) filter for a wide range of clinical ultrasonic imaging equipment. Three potential methods have been investigated: (1) a method involving an appropriate selection of the speckle recognition feature was successful when the scanner signal processing executes simple logarithmic compressions; (2) an inverse transform (decompression) of the B-mode image was effective in correcting for the measured characteristics of image data compression when the algorithm was implemented in full floating point arithmetic; (3) characterising the behaviour of the statistical speckle recognition feature under conditions of speckle noise was found to be the method of choice for implementation of the adaptive speckle reduction algorithm in limited precision integer arithmetic. In this example, the statistical features of variance and mean were investigated. The third method may be implemented on commercially available fast image processing hardware and is also better suited for transfer into dedicated hardware to facilitate real-time adaptive speckle reduction. A systematic method is described for obtaining ASR calibration data from B-mode images of a speckle producing phantom.

  16. Why tracks

    International Nuclear Information System (INIS)

    Burchart, J.; Kral, J.

    1979-01-01

    A comparison is made of two methods of determining the age of rocks, ie., the krypton-argon method and the fission tracks method. The former method is more accurate but is dependent on the temperature and on the grain size of the investigated rocks (apatites, biotites, muscovites). As for the method of fission tracks, the determination is not dependent on grain size. This method allows dating and the determination of uranium concentration and distribution in rocks. (H.S.)

  17. Application of electronic speckle-pattern interferometry to measure in-plane thermal displacement in flip-chip packages

    International Nuclear Information System (INIS)

    Lee, Baik-Woo; Jang, Woosoon; Kim, Dong-Won; Jeong, Jeung-hyun; Nah, Jae-Woong; Paik, Kyung-Wook; Kwon, Dongil

    2004-01-01

    Electronic speckle-pattern interferometry (ESPI) was applied for noncontact, real-time evaluation of thermal deformation in a flip-chip package. The spatial resolution of ESPI was increased to submicron scale by magnifying the areas studied in order to measure the deformation of such small-scale components as the solder in the flip-chip package. Thermal deformation in the horizontal and vertical directions around the solder joints was measured as two-dimensional mappings during heating from 25 to 125 deg. C. ESPI was successful in obtaining information on the complicated deformation field around the solder joints. Furthermore, the shear strain could also be calculated using the measured thermal deformation around each solder joint. The applicability of ESPI to flip-chip packages was verified by comparing the ESPI results with those of finite-element analysis (FEA)

  18. Synchronized renal blood flow dynamics mapped with wavelet analysis of laser speckle flowmetry data

    DEFF Research Database (Denmark)

    Brazhe, Alexey R; Marsh, Donald J; von Holstein-Rathlou, Niels-Henrik

    2014-01-01

    of rat kidneys. The regulatory mechanism in the renal microcirculation generates oscillations in arterial blood flow at several characteristic frequencies. Our approach to laser speckle image processing allows detection of frequency and phase entrainments, visualization of their patterns, and estimation......Full-field laser speckle microscopy provides real-time imaging of superficial blood flow rate. Here we apply continuous wavelet transform to time series of speckle-estimated blood flow from each pixel of the images to map synchronous patterns in instantaneous frequency and phase on the surface...... of the extent of synchronization in renal cortex dynamics....

  19. Investigation of Portevin-Le Chatelier band with temporal phase analysis of speckle interferometry

    Science.gov (United States)

    Jiang, Zhenyu; Zhang, Qingchuan; Wu, Xiaoping

    2003-04-01

    A new method combining temporal phase analysis with dynamic digital speckle pattern interferometry is proposed to study Portevin-Le Chatelier effect quantitatively. The principle bases on that the phase difference of interference speckle patterns is a time-dependent function related to the object deformation. The interference speckle patterns of specimen are recorded with high sampling rate while PLC effect occurs, and the 2D displacement map of PLC band and its width are obtained by analyzing the displacement of specimen with proposed method.

  20. Detection of radiation deformation in crystalline polymers using the speckle photography technique

    International Nuclear Information System (INIS)

    El-Ghandoor, H.; Hashem, A.A.; Sharaf, F.

    1995-01-01

    In order to measure the resulting deformation due to gamma irradiation of polymers, a new optical technique, namely speckle-photography, was established and used. Thin films of tetrafluoroethene, with constant thickness were irradiated by different doses of gamma rays and the diffraction patterns of a laser beam passing through these films were recorded using the speckle photography technique. This technique has been applied to detect the radiation deformation in (Teflon) TFE, which is a crystalline polymer. A diffraction pattern due to the TFE thin layer is obtained and superimposed on the interference pattern displaying the speckle pattern pairs recorded on the same emulsion. (author)

  1. Overcoming turbulence-induced space-variant blur by using phase-diverse speckle.

    Science.gov (United States)

    Thelen, Brian J; Paxman, Richard G; Carrara, David A; Seldin, John H

    2009-01-01

    Space-variant blur occurs when imaging through volume turbulence over sufficiently large fields of view. Space-variant effects are particularly severe in horizontal-path imaging, slant-path (air-to-ground or ground-to-air) geometries, and ground-based imaging of low-elevation satellites or astronomical objects. In these geometries, the isoplanatic angle can be comparable to or even smaller than the diffraction-limited resolution angle. We report on a postdetection correction method that seeks to correct for the effects of space-variant aberrations, with the goal of reconstructing near-diffraction-limited imagery. Our approach has been to generalize the method of phase-diverse speckle (PDS) by using a physically motivated distributed-phase-screen model. Simulation results are presented that demonstrate the reconstruction of near-diffraction-limited imagery under both matched and mismatched model assumptions. In addition, we present evidence that PDS could be used as a beaconless wavefront sensor in a multiconjugate adaptive optics system when imaging extended scenes.

  2. Comparison of cerebral microcirculation of alloxan diabetes and healthy mice using laser speckle contrast imaging

    Science.gov (United States)

    Timoshina, Polina A.; Shi, Rui; Zhang, Yang; Zhu, Dan; Semyachkina-Glushkovskaya, Oxana V.; Tuchin, Valery V.; Luo, Qingming

    2015-03-01

    The study of blood microcirculation is one of the most important problems of the medicine. This paper presents results of experimental study of cerebral blood flow microcirculation in mice with alloxan-induced diabetes using Temporal Laser Speckle Imaging (TLSI). Additionally, a direct effect of glucose water solution (concentration 20% and 45%) on blood flow microcirculation was studied. In the research, 20 white laboratory mice weighing 20-30 g were used. The TLSI method allows one to investigate time dependent scattering from the objects with complex dynamics, since it possesses greater temporal resolution. Results show that in brain of animal diabetic group diameter of sagittal vein is increased and the speed of blood flow reduced relative to the control group. Topical application of 20%- or 45%-glucose solutions also causes increase of diameter of blood vessels and slows down blood circulation. The results obtained show that diabetes development causes changes in the cerebral microcirculatory system and TLSI techniques can be effectively used to quantify these alterations.

  3. Fabrication of Random Microwell Arrays as Pseudo-Thermal Speckle Light Source

    Directory of Open Access Journals (Sweden)

    Axiu Cao

    2018-05-01

    Full Text Available Quantum correlated imaging using the intensity fluctuations of thermal light possesses advantages of high resolution and strong anti-interference ability. The common method to produce pseudo-thermal light source is using a rotary ground glass and transmission of laser beam. In the present work, we propose a method for the fabrication of microwell arrays with randomly varied diameters, which could be used as a new structural element for pseudo-thermal speckle light source. If these are etched with random sizes then they may also have random and complex varying curvatures (diffusion limited etching leading to random destructive interference of the coherent beam which could be a good thing. The microwell arrays, with diameters randomly varying from 5 μm to 40 μm, height varying from 200 nm to 20 μm, were fabricated by photolithography combined with acid etching. The experimental conditions are simple and can be scaled up to for large structures. The produced microwell arrays can transform the laser beam to a pseudo-thermal light source with a certain divergent angle by rational designing of mask and adjustable process parameters.

  4. A dynamic monitoring approach for the surface morphology evolution measurement of plasma facing components by means of speckle interferometry

    Science.gov (United States)

    Wang, Hongbei; Cui, Xiaoqian; Feng, Chunlei; Li, Yuanbo; Zhao, Mengge; Luo, Guangnan; Ding, Hongbin

    2017-11-01

    Plasma Facing Components (PFCs) in a magnetically confined fusion plasma device will be exposed to high heat load and particle fluxes, and it would cause PFCs' surface morphology to change due to material erosion and redeposition from plasma wall interactions. The state of PFCs' surface condition will seriously affect the performance of long-pulse or steady state plasma discharge in a tokamak; it will even constitute an enormous threat to the operation and the safety of fusion plasma devices. The PFCs' surface morphology evolution measurement could provide important information about PFCs' real-time status or damage situation and it would help to a better understanding of the plasma wall interaction process and mechanism. Meanwhile through monitoring the distribution of dust deposition in a tokamak and providing an upper limit on the amount of loose dust, the PFCs' surface morphology measurement could indirectly contribute to keep fusion operational limits and fusion device safety. Aiming at in situ dynamic monitoring PFCs' surface morphology evolution, a laboratory experimental platform DUT-SIEP (Dalian University of Technology-speckle interferometry experimental platform) based on the speckle interferometry technique has been constructed at Dalian University of Technology (DUT) in China. With directional specific designing and focusing on the real detection condition of EAST (Experimental Advanced Superconducting Tokamak), the DUT-SIEP could realize a variable measurement range, widely increased from 0.1 μm to 300 μm, with high spatial resolution (<1 mm) and ultra-high time resolution (<2 s for EAST measuring conditions). Three main components of the DUT-SIEP are all integrated and synchronized by a time schedule control and data acquisition terminal and coupled with a three-dimensional phase unwrapping algorithm, the surface morphology information of target samples can be obtained and reconstructed in real-time. A local surface morphology of the real divertor

  5. The DOe Silicon Track Trigger

    International Nuclear Information System (INIS)

    Steinbrueck, Georg

    2003-01-01

    We describe a trigger preprocessor to be used by the DOe experiment for selecting events with tracks from the decay of long-lived particles. This Level 2 impact parameter trigger utilizes information from the Silicon Microstrip Tracker to reconstruct tracks with improved spatial and momentum resolutions compared to those obtained by the Level 1 tracking trigger. It is constructed of VME boards with much of the logic existing in programmable processors. A common motherboard provides the I/O infrastructure and three different daughter boards perform the tasks of identifying the roads from the tracking trigger data, finding the clusters in the roads in the silicon detector, and fitting tracks to the clusters. This approach provides flexibility for the design, testing and maintenance phases of the project. The track parameters are provided to the trigger framework in 25 μs. The effective impact parameter resolution for high-momentum tracks is 35 μm, dominated by the size of the Tevatron beam

  6. Tracking and vertex finding with drift chambers and neural networks

    International Nuclear Information System (INIS)

    Lindsey, C.

    1991-09-01

    Finding tracks, track vertices and event vertices with neural networks from drift chamber signals is discussed. Simulated feed-forward neural networks have been trained with back-propagation to give track parameters using Monte Carlo simulated tracks in one case and actual experimental data in another. Effects on network performance of limited weight resolution, noise and drift chamber resolution are given. Possible implementations in hardware are discussed. 7 refs., 10 figs

  7. Simulations of multi-contrast x-ray imaging using near-field speckles

    Energy Technology Data Exchange (ETDEWEB)

    Zdora, Marie-Christine [Lehrstuhl für Biomedizinische Physik, Physik-Department & Institut für Medizintechnik, Technische Universität München, 85748 Garching (Germany); Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, United Kingdom and Department of Physics & Astronomy, University College London, London, WC1E 6BT (United Kingdom); Thibault, Pierre [Department of Physics & Astronomy, University College London, London, WC1E 6BT (United Kingdom); Herzen, Julia; Pfeiffer, Franz [Lehrstuhl für Biomedizinische Physik, Physik-Department & Institut für Medizintechnik, Technische Universität München, 85748 Garching (Germany); Zanette, Irene [Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE (United Kingdom); Lehrstuhl für Biomedizinische Physik, Physik-Department & Institut für Medizintechnik, Technische Universität München, 85748 Garching (Germany)

    2016-01-28

    X-ray dark-field and phase-contrast imaging using near-field speckles is a novel technique that overcomes limitations inherent in conventional absorption x-ray imaging, i.e. poor contrast for features with similar density. Speckle-based imaging yields a wealth of information with a simple setup tolerant to polychromatic and divergent beams, and simple data acquisition and analysis procedures. Here, we present a simulation software used to model the image formation with the speckle-based technique, and we compare simulated results on a phantom sample with experimental synchrotron data. Thorough simulation of a speckle-based imaging experiment will help for better understanding and optimising the technique itself.

  8. Software phantom with realistic speckle modeling for validation of image analysis methods in echocardiography

    Science.gov (United States)

    Law, Yuen C.; Tenbrinck, Daniel; Jiang, Xiaoyi; Kuhlen, Torsten

    2014-03-01

    Computer-assisted processing and interpretation of medical ultrasound images is one of the most challenging tasks within image analysis. Physical phenomena in ultrasonographic images, e.g., the characteristic speckle noise and shadowing effects, make the majority of standard methods from image analysis non optimal. Furthermore, validation of adapted computer vision methods proves to be difficult due to missing ground truth information. There is no widely accepted software phantom in the community and existing software phantoms are not exible enough to support the use of specific speckle models for different tissue types, e.g., muscle and fat tissue. In this work we propose an anatomical software phantom with a realistic speckle pattern simulation to _ll this gap and provide a exible tool for validation purposes in medical ultrasound image analysis. We discuss the generation of speckle patterns and perform statistical analysis of the simulated textures to obtain quantitative measures of the realism and accuracy regarding the resulting textures.

  9. Speckle evolution with multiple steps of least-squares phase removal

    CSIR Research Space (South Africa)

    Chen, M

    2011-08-01

    Full Text Available vortex density and scintillation index. Statistical results show that almost all the optical vortices can be removed from a speckle field, which finally decays into a quasiplane wave after such an iterative process....

  10. M2 FILTER FOR SPECKLE NOISE SUPPRESSION IN BREAST ULTRASOUND IMAGES

    Directory of Open Access Journals (Sweden)

    E.S. Samundeeswari

    2016-11-01

    Full Text Available Breast cancer, commonly found in women is a serious life threatening disease due to its invasive nature. Ultrasound (US imaging method plays an effective role in screening early detection and diagnosis of Breast cancer. Speckle noise generally affects medical ultrasound images and also causes a number of difficulties in identifying the Region of Interest. Suppressing speckle noise is a challenging task as it destroys fine edge details. No specific filter is designed yet to get a noise free BUS image that is contaminated by speckle noise. In this paper M2 filter, a novel hybrid of linear and nonlinear filter is proposed and compared to other spatial filters with 3×3 kernel size. The performance of the proposed M2 filter is measured by statistical quantity parameters like MSE, PSNR and SSI. The experimental analysis clearly shows that the proposed M2 filter outperforms better than other spatial filters by 2% high PSNR values with regards to speckle suppression.

  11. Evolution of the optical vortex density in phase corrected speckle fields

    CSIR Research Space (South Africa)

    Roux, FS

    2010-09-01

    Full Text Available In an attempt to understand the process whereby the phase modulation due to atmospheric turbulance causes phase singularities (also called optical vortices), the authors investigated the effect of phase perturbations in speckle beams. They perturb...

  12. SPECKLE OBSERVATIONS OF BINARY STARS WITH THE WIYN TELESCOPE. VII. MEASURES DURING 2008-2009

    International Nuclear Information System (INIS)

    Horch, Elliott P.; Bahi, Lizzie Anne P.; Gaulin, Joseph R.; Howell, Steve B.; Sherry, William H.; Baena Gallé, Roberto; Van Altena, William F.

    2012-01-01

    Five hundred thirty-one speckle measures of binary stars are reported. These data were taken mainly during the period 2008 June through 2009 October at the WIYN 3.5 m Telescope at Kitt Peak and represent the last data set of single-filter speckle observations taken in the WIYN speckle program prior to the use of the current two-channel speckle camera. The astrometric and photometric precision of these observations is consistent with previous papers in this series: we obtain a typical linear measurement uncertainty of approximately 2.5 mas, and the magnitude differences reported have typical uncertainties in the range of 0.1-0.14 mag. In combination with measures already in the literature, the data presented here permit the revision of the orbit of A 1634AB (= HIP 76041) and the first determination of visual orbital elements for HDS 1895 (= HIP 65982).

  13. Fabrication of nanoscale speckle using broad ion beam milling on polymers for deformation analysis

    Directory of Open Access Journals (Sweden)

    Qinghua Wang

    2016-07-01

    Full Text Available We first report a fabrication technique of nanoscale speckle patterns on polymers using broad ion beam milling. The proposed technique is simple and low-cost to produce speckles ranging from dozens of nanometers to less than three micrometers in a large area of several millimeters. Random patterns were successfully produced with an argon (Ar ion beam on the surfaces of four kinds of polymers: the epoxy matrix of carbon fiber reinforced plastic, polyester, polyvinyl formal-acetal, and polyimide. The speckle morphologies slightly vary with different polymers. The fabricated speckle patterns have good time stability and are promising to be used to measure the nanoscale deformations of polymers using the digital image correlation method.

  14. Nephron blood flow dynamics measured by laser speckle contrast imaging

    DEFF Research Database (Denmark)

    von Holstein-Rathlou, Niels-Henrik; Sosnovtseva, Olga V; Pavlov, Alexey N

    2011-01-01

    Tubuloglomerular feedback (TGF) has an important role in autoregulation of renal blood flow and glomerular filtration rate (GFR). Because of the characteristics of signal transmission in the feedback loop, the TGF undergoes self-sustained oscillations in single-nephron blood flow, GFR, and tubular...... simultaneously. The interacting nephron fields are likely to be more extensive. We have turned to laser speckle contrast imaging to measure the blood flow dynamics of 50-100 nephrons simultaneously on the renal surface of anesthetized rats. We report the application of this method and describe analytic...... pressure and flow. Nephrons interact by exchanging electrical signals conducted electrotonically through cells of the vascular wall, leading to synchronization of the TGF-mediated oscillations. Experimental studies of these interactions have been limited to observations on two or at most three nephrons...

  15. Angular diameters of Magellanic Cloud plantary nebulae. I. Speckle interferometry

    International Nuclear Information System (INIS)

    Wood, P.R.; Bessell, M.S.; Dopita, M.A.

    1986-01-01

    Speckle interferometric angular diameters of Magellanic Cloud planetary nebulae are presented. The mass of ionized gas in each nebula has been derived from the angular diameter and published H-beta line fluxes; the derives masses range from less than 0.006 to more than 0.19 solar mass. The planetary nebulae observed were the brightest in the Magellanic Clouds; consequently, they are all relatively small, young, bright, and dense. They are almost certainly only partially ionized, so that the masses derived for the ionized parts of the nebula are lower limits to the total nebula mass. The properties of the Magellanic Cloud nebulae are compared with those of planetary nebulae at the galactic center. 27 references

  16. Speckle Noise Reduction via Nonconvex High Total Variation Approach

    Directory of Open Access Journals (Sweden)

    Yulian Wu

    2015-01-01

    Full Text Available We address the problem of speckle noise removal. The classical total variation is extensively used in this field to solve such problem, but this method suffers from the staircase-like artifacts and the loss of image details. In order to resolve these problems, a nonconvex total generalized variation (TGV regularization is used to preserve both edges and details of the images. The TGV regularization which is able to remove the staircase effect has strong theoretical guarantee by means of its high order smooth feature. Our method combines the merits of both the TGV method and the nonconvex variational method and avoids their main drawbacks. Furthermore, we develop an efficient algorithm for solving the nonconvex TGV-based optimization problem. We experimentally demonstrate the excellent performance of the technique, both visually and quantitatively.

  17. Speckle interferometry application for erosion measurements in fusion devices

    Energy Technology Data Exchange (ETDEWEB)

    Gauthier, E.; Roupillard, R. [Association Euratom-CEA Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee

    2003-07-01

    In order to measure erosion/redeposition in fusion devices, a new diagnostic based on speckle interferometry is investigated. First experiments performed on carbon fibre composite (CFC) materials have shown that this technique is able to measure a modification of the surface in the range of 1 {mu}m. Further experiments have been performed on different materials using a second wavelength in order to carry out 3-dimensional measurements of the surface and to increase the dynamic range of the depth measurement. A diagnostic, based on two-wavelength TV-holography to measure in situ erosion/redeposition during long duration discharges on the CIEL limiter in Tore Supra, is under development at CEA Cadarache. (authors)

  18. Damage monitoring in historical murals by speckle interferometry

    Science.gov (United States)

    Hinsch, Klaus D.; Gulker, Gerd; Joost, Holger

    2003-11-01

    In the conservation of historical murals it is important to identify loose plaster sections that threaten to fall off. Electronic speckle interferometry in combination with acoustic excitation of the object has been employed to monitor loose areas. To avoid disadvantages of high sound irradiation of the complete building a novel directional audio-sound source based on nonlinear mixing of ultrasound has been introduced. The optical system was revised for optimum performance in the new environment. Emphasis is placed on noise suppression to increase sensitivity. Furthermore, amplitude and phase data of object response over the frequency-range inspected are employed to gain additional information on the state of the plaster or paint. Laboratory studies on sample specimen supplement field campaigns at historical sites.

  19. Dynamic-speckle profilometer for online measurements of coating thickness

    Energy Technology Data Exchange (ETDEWEB)

    Kamshilin, A A [Laboratory of Optical Sensor Technology, Department of Physics, University of Kuopio, PO Box 1627, FIN-70211 Kuopio (Finland); Semenov, D V [Laboratory of Optical Sensor Technology, Department of Physics, University of Kuopio, PO Box 1627, FIN-70211 Kuopio (Finland); Nippolainen, E [Laboratory of Optical Sensor Technology, Department of Physics, University of Kuopio, PO Box 1627, FIN-70211 Kuopio (Finland); Miridonov, S [Optics Department, CICESE, Carr. Tijuana-Ensenada km 107, C.P. 22860, A.P. 360, Ensenada, B.C. (Mexico)

    2007-10-15

    Online control of thickness of as-deposited coatings is of great importance because it directly affects the quality of protective coatings. We present a novel approach that enables online, real-time and non-contact measurements thickness of thermally sprayed coatings. The proposed technique uses dynamic speckles generated by rapidly deflecting laser beam. Within 10 ms the system can scan 500 times a small area of the deposited layer thus resulting in measurement accuracy of 5 microns irrespectively of the layer roughness. In comparison with traditional optical triangulation technique of distance measurements, our system has following advantages: (i) much simpler optical scheme that includes conventional photodiode to measure the scattered light, (ii) much simpler electronics for real-time data processing, (iii) much higher speed of measurements.

  20. Dynamic-speckle profilometer for online measurements of coating thickness

    International Nuclear Information System (INIS)

    Kamshilin, A A; Semenov, D V; Nippolainen, E; Miridonov, S

    2007-01-01

    Online control of thickness of as-deposited coatings is of great importance because it directly affects the quality of protective coatings. We present a novel approach that enables online, real-time and non-contact measurements thickness of thermally sprayed coatings. The proposed technique uses dynamic speckles generated by rapidly deflecting laser beam. Within 10 ms the system can scan 500 times a small area of the deposited layer thus resulting in measurement accuracy of 5 microns irrespectively of the layer roughness. In comparison with traditional optical triangulation technique of distance measurements, our system has following advantages: (i) much simpler optical scheme that includes conventional photodiode to measure the scattered light, (ii) much simpler electronics for real-time data processing, (iii) much higher speed of measurements

  1. Complex-Valued ABCD Matrices and Speckle Metrology

    DEFF Research Database (Denmark)

    Hanson, Steen Grüner; Jakobsen, Michael Linde; Yura, Harold T.

    2016-01-01

    coherent light sources, optical elements of finite size, and distributed random inhomogeneity along the optical path. In many cases (e.g., laser beam propagation and Gaussian optics) we have been able to derive simple analytical expressions for the optical field quantities at an observation plane. A series......We demonstrate that within the paraxial ray approximation the propagation of light through a complex optical system can be formulated in terms of a Huygens principle expressed with the complete system’s ABCD-matrix elements. As such, propagation through an optical system reduces...... of laser-based optical measurement systems have been analyzed and analytical expressions for their main parameters have been given. Specifically, scattering from rough surfaces not giving rise to a fully developed speckle field, various anemometers and systems for measuring rotational velocity have been...

  2. Laser speckle contrast imaging using light field microscope approach

    Science.gov (United States)

    Ma, Xiaohui; Wang, Anting; Ma, Fenghua; Wang, Zi; Ming, Hai

    2018-01-01

    In this paper, a laser speckle contrast imaging (LSCI) system using light field (LF) microscope approach is proposed. As far as we known, it is first time to combine LSCI with LF. To verify this idea, a prototype consists of a modified LF microscope imaging system and an experimental device was built. A commercially used Lytro camera was modified for microscope imaging. Hollow glass tubes with different depth fixed in glass dish were used to simulate the vessels in brain and test the performance of the system. Compared with conventional LSCI, three new functions can be realized by using our system, which include refocusing, extending the depth of field (DOF) and gathering 3D information. Experiments show that the principle is feasible and the proposed system works well.

  3. Thermal strain measurements in graphite using electronic speckle pattern interferometry

    International Nuclear Information System (INIS)

    Tamulevicius, S.; Augulis, L.; Augulis, R.; Zabarskas, V.; Levinskas, R.; Poskas, P.

    2001-01-01

    Two 1500 MW(e) RBMK Units are operated at Ignalina NPP in Lithuania. Due to recent decision of the Parliament on the earlier closure of Unit 1, preparatory work for decommissioning have been initiated. Preferred decommissioning strategy is based on delayed dismantling after rather long safe enclosure period. Since graphite is one of the basic and probably the most voluminous components of the reactor internals, a sufficient information on status and behaviour of graphite moderator and reflector during long time safe enclosure period is of special significance. In this context, thermal strain in graphite is one of the parameters requiring particular interest. Electronic speckle pattern interferometry has been proposed and successfully tested to control this parameter using the real samples of graphite from Ignalina NPP Units. (author)

  4. Analysis of eroded bovine teeth through laser speckle imaging

    Science.gov (United States)

    Koshoji, Nelson H.; Bussadori, Sandra K.; Bortoletto, Carolina C.; Oliveira, Marcelo T.; Prates, Renato A.; Deana, Alessandro M.

    2015-02-01

    Dental erosion is a non-carious lesion that causes progressive tooth wear of structure through chemical processes that do not involve bacterial action. Its origin is related to eating habits or systemic diseases involving tooth contact with substances that pose a very low pH. This work demonstrates a new methodology to quantify the erosion by coherent light scattering of tooth surface. This technique shows a correlation between acid etch duration and laser speckle contrast map (LASCA). The experimental groups presented a relative contrast between eroded and sound tissue of 17.8(45)%, 23.4 (68)% 39.2 (40)% and 44.3 (30)%, for 10 min, 20 min, 30 min and 40 min of acid etching, respectively.

  5. Early diagnosis of teeth erosion using polarized laser speckle imaging

    Science.gov (United States)

    Nader, Christelle Abou; Pellen, Fabrice; Loutfi, Hadi; Mansour, Rassoul; Jeune, Bernard Le; Brun, Guy Le; Abboud, Marie

    2016-07-01

    Dental erosion starts with a chemical attack on dental tissue causing tooth demineralization, altering the tooth structure and making it more sensitive to mechanical erosion. Medical diagnosis of dental erosion is commonly achieved through a visual inspection by the dentist during dental checkups and is therefore highly dependent on the operator's experience. The detection of this disease at preliminary stages is important since, once the damage is done, cares become more complicated. We investigate the difference in light-scattering properties between healthy and eroded teeth. A change in light-scattering properties is observed and a transition from volume to surface backscattering is detected by means of polarized laser speckle imaging as teeth undergo acid etching, suggesting an increase in enamel surface roughness.

  6. Holographic interferometry and laser speckle photography as aids to assessment of pressurized components

    International Nuclear Information System (INIS)

    Martin, D.J.V.

    1975-01-01

    This paper gives details of the defect detection holographic technique and describes laser speckle photography to evaluate in phase movement and strain in pressurized components. The new fibre optic technique and system appraisal is included. The holographic tests show that it is possible to detect on the outside of tubes defects in the bore approximately 10% of thickness deep. Speckle photography gives object lateral movement, direction and strain. (Auth.)

  7. Single-shot speckle reduction in numerical reconstruction of digitally recorded holograms.

    Science.gov (United States)

    Hincapie, Diego; Herrera-Ramírez, Jorge; Garcia-Sucerquia, Jorge

    2015-04-15

    A single-shot method to reduce the speckle noise in the numerical reconstructions of electronically recorded holograms is presented. A recorded hologram with the dimensions N×M is split into S=T×T sub-holograms. The uncorrelated superposition of the individually reconstructed sub-holograms leads to an image with the speckle noise reduced proportionally to the 1/S law. The experimental results are presented to support the proposed methodology.

  8. Modeling laser speckle imaging of perfusion in the skin (Conference Presentation)

    Science.gov (United States)

    Regan, Caitlin; Hayakawa, Carole K.; Choi, Bernard

    2016-02-01

    Laser speckle imaging (LSI) enables visualization of relative blood flow and perfusion in the skin. It is frequently applied to monitor treatment of vascular malformations such as port wine stain birthmarks, and measure changes in perfusion due to peripheral vascular disease. We developed a computational Monte Carlo simulation of laser speckle contrast imaging to quantify how tissue optical properties, blood vessel depths and speeds, and tissue perfusion affect speckle contrast values originating from coherent excitation. The simulated tissue geometry consisted of multiple layers to simulate the skin, or incorporated an inclusion such as a vessel or tumor at different depths. Our simulation used a 30x30mm uniform flat light source to optically excite the region of interest in our sample to better mimic wide-field imaging. We used our model to simulate how dynamically scattered photons from a buried blood vessel affect speckle contrast at different lateral distances (0-1mm) away from the vessel, and how these speckle contrast changes vary with depth (0-1mm) and flow speed (0-10mm/s). We applied the model to simulate perfusion in the skin, and observed how different optical properties, such as epidermal melanin concentration (1%-50%) affected speckle contrast. We simulated perfusion during a systolic forearm occlusion and found that contrast decreased by 35% (exposure time = 10ms). Monte Carlo simulations of laser speckle contrast give us a tool to quantify what regions of the skin are probed with laser speckle imaging, and measure how the tissue optical properties and blood flow affect the resulting images.

  9. Developing and setting up optical methods to study the speckle patterns created by optical beam smoothing

    International Nuclear Information System (INIS)

    Surville, J.

    2005-12-01

    We have developed three main optical methods to study the speckles generated by a smoothed laser source. The first method addresses the measurement of the temporal and spatial correlation functions of the source, with a modified Michelson interferometer. The second one is a pump-probe technique created to shoot a picture of a speckle pattern generated at a set time. And the third one is an evolution of the second method dedicated to time-frequency coding, thanks to a frequency chirped probe pulse. Thus, the speckles can be followed in time and their motion can be described. According to these three methods, the average size and duration of the speckles can be measured. It is also possible to measure the size and the duration of each of them and mostly their velocity in a given direction. All the results obtained have been confronted to the different existing theories. We show that the statistical distributions of the measured speckles'size and speckles'intensity agree satisfactorily with theoretical values

  10. Online Tracking

    Science.gov (United States)

    ... can disable blocking on those sites. Tagged with: computer security , cookies , Do Not Track , personal information , privacy June ... email Looking for business guidance on privacy and ... The Federal Trade Commission (FTC) is the nation’s consumer protection agency. The FTC works to prevent fraudulent, deceptive ...

  11. Investigations of High Resolution Imaging through the Earth’s Atmosphere Using Speckle Interferometry.

    Science.gov (United States)

    1987-03-15

    Jeffreys, W. H. 1980. A.J., 85 177 - 1982, Asir. Ap., 115. 253. . 1981AJ..86 149 Bonneau. D..and Lebeyne. A . 1973.4 p. J. (Letters. 181. LI. Karovska . M...supergiant and the nearby companion recently proposed by Karovska et al. (1986). 4 65 ’ A ,-"’ A V.. -Y U . ....WW WVWV 2 Imaging Technique The WSA...91-96. 9 Nisenson,P., R.V. Stachnik, M. Karovska , and R. Noyes (1985). A new optical source associated with T Tauri. Astrophs. J. 297, L17-L20

  12. Improving high resolution retinal image quality using speckle illumination HiLo imaging.

    Science.gov (United States)

    Zhou, Xiaolin; Bedggood, Phillip; Metha, Andrew

    2014-08-01

    Retinal image quality from flood illumination adaptive optics (AO) ophthalmoscopes is adversely affected by out-of-focus light scatter due to the lack of confocality. This effect is more pronounced in small eyes, such as that of rodents, because the requisite high optical power confers a large dioptric thickness to the retina. A recently-developed structured illumination microscopy (SIM) technique called HiLo imaging has been shown to reduce the effect of out-of-focus light scatter in flood illumination microscopes and produce pseudo-confocal images with significantly improved image quality. In this work, we adopted the HiLo technique to a flood AO ophthalmoscope and performed AO imaging in both (physical) model and live rat eyes. The improvement in image quality from HiLo imaging is shown both qualitatively and quantitatively by using spatial spectral analysis.

  13. Deformable Models for Eye Tracking

    DEFF Research Database (Denmark)

    Vester-Christensen, Martin; Leimberg, Denis; Ersbøll, Bjarne Kjær

    2005-01-01

    A deformable template method for eye tracking on full face images is presented. The strengths of the method are that it is fast and retains accuracy independently of the resolution. We compare the me\\$\\backslash\\$-thod with a state of the art active contour approach, showing that the heuristic...

  14. Integrating single-point vibrometer and full-field electronic speckle pattern interferometer to evaluate a micro-speaker

    Science.gov (United States)

    Chang, Wen-Chi; Chen, Yu-Chi; Chien, Chih-Jen; Wang, An-Bang; Lee, Chih-Kung

    2011-04-01

    A testing system contains an advanced vibrometer/interferometer device (AVID) and a high-speed electronic speckle pattern interferometer (ESPI) was developed. AVID is a laser Doppler vibrometer that can be used to detect single-point linear and angular velocity with DC to 20 MHz bandwidth and with nanometer resolution. In swept frequency mode, frequency response from mHz to MHz of the structure of interest can be measured. The ESPI experimental setup can be used to measure full-field out-of-plane displacement. A 5-1 phase shifting method and a correlation algorithm were used to analyze the phase difference between the reference signal and the speckle signal scattered from the sample surface. In order to show the efficiency and effectiveness of AVID and ESPI, we designed a micro-speaker composed of a plate with fixed boundaries and two piezo-actuators attached to the sides of the plate. The AVID was used to measure the vibration of one of the piezo-actuators and the ESPI was adopted to measure the two-dimensional out-of-plane displacement of the plate. A microphone was used to measure the acoustic response created by the micro-speaker. Driving signal includes random signal, sinusoidal signal, amplitude modulated high-frequency carrier signal, etc. Angular response induced by amplitude modulated high-frequency carrier signal was found to be significantly narrower than the frequency responses created by other types of driving signals. The validity of our newly developed NDE system are detailed by comparing the relationship between the vibration signal of the micro-speaker and the acoustic field generated.

  15. Particle tracking at the SSC

    International Nuclear Information System (INIS)

    Freeman, J.E.; Williams, H.H.

    1984-01-01

    The intent of this study was to get some idea of how difficult tracking will be at √s = 40 TeV for events involving momentum transfers in the vicinity of several hundred GeV. While some studies have been done to determine the minimum separation between two random tracks as a function of radius, the authors know of no previous study in this energy range which has considered the ''observability'' of a track along its entire path length, including the effects of magnetic field and finite double track resolution. They have not considered the effects of pileup due to multiple events, concentrating instead of the inherent difficulties of single high p/sub T/ events

  16. Holographic interferometry and laser speckle photography as aids to assessment of pressurised components

    International Nuclear Information System (INIS)

    Martin, D.J.V.

    1975-01-01

    This summary gives defect detection holographic technique and describes laser speckle photography to evaluate in-plane movement and strain in pressurized components and conclusions. In holography no lens is used, coherent light is reflected from all points of an object to all parts of a photosensitive surface, such as a photographic plate, simultaneously light of the same wave length and coherence is made to illuminate at a different angle the same plate. These two beams, the object and the reference, cause primary fringes. The developed plate when illuminated with the reference reconstructs the original object in three dimensions. If a double exposure is made on the same plate and if parts of the object have moved between exposure the reconstructed object will be lined with secondary fringes, each fringe representing displacement down the line of sight of one wavelength of the light used. Speckle photography is the same as conventional photography excepting, that instead of using daylight or a flash lamp a coherent light beam is used. Minute points on the object illuminated by divergent laser beam act as point sources of light giving the surface a speckled appearance. In speckle photography a camera records on the plate the object and speckles. A double exposure taken on the same plate when the object has moved between exposures will, after development, when illuminated with the laser beam from Youngs fringes. Speckles and fringes are related to points on the object therefore it is possible to obtain movement and strain. The holographic tests show that it is possible to detect on the outside of tube defects in the bore approximately 10% of thickness deep. Speckle photography gives object lateral movement, direction and strain

  17. CDKL5 influences RNA splicing activity by its association to the nuclear speckle molecular machinery.

    Science.gov (United States)

    Ricciardi, Sara; Kilstrup-Nielsen, Charlotte; Bienvenu, Thierry; Jacquette, Aurélia; Landsberger, Nicoletta; Broccoli, Vania

    2009-12-01

    Mutations in the human X-linked cyclin-dependent kinase-like 5 (CDKL5) gene have been shown to cause severe neurodevelopmental disorders including infantile spasms, encephalopathy, West-syndrome and an early-onset variant of Rett syndrome. CDKL5 is a serine/threonine kinase whose involvement in Rett syndrome can be inferred by its ability to directly bind and mediate phosphorylation of MeCP2. However, it remains to be elucidated how CDKL5 exerts its function. Here, we report that CDKL5 localizes to specific nuclear foci referred to as nuclear speckles in both cell lines and tissues. These sub-nuclear structures are traditionally considered as storage/modification sites of pre-mRNA splicing factors. Interestingly, we provide evidence that CDKL5 regulates the dynamic behaviour of nuclear speckles. Indeed, CDKL5 overexpression leads to nuclear speckle disassembly, and this event is strictly dependent on its kinase activity. Conversely, its down-regulation affects nuclear speckle morphology leading to abnormally large and uneven speckles. Similar results were obtained for primary adult fibroblasts isolated from CDKL5-mutated patients. Altogether, these findings indicate that CDKL5 controls nuclear speckle morphology probably by regulating the phosphorylation state of splicing regulatory proteins. Nuclear speckles are dynamic sites that can continuously supply splicing factors to active transcription sites, where splicing occurs. Notably, we proved that CDKL5 influences alternative splicing, at least as proved in heterologous minigene assays. In conclusion, we provide evidence that CDKL5 is involved indirectly in pre-mRNA processing, by controlling splicing factor dynamics. These findings identify a biological process whose disregulation might affect neuronal maturation and activity in CDKL5-related disorders.

  18. Multi-wavelength speckle reduction for laser pico-projectors using diffractive optics

    Science.gov (United States)

    Thomas, Weston H.

    Personal electronic devices, such as cell phones and tablets, continue to decrease in size while the number of features and add-ons keep increasing. One particular feature of great interest is an integrated projector system. Laser pico-projectors have been considered, but the technology has not been developed enough to warrant integration. With new advancements in diode technology and MEMS devices, laser-based projection is currently being advanced for pico-projectors. A primary problem encountered when using a pico-projector is coherent interference known as speckle. Laser speckle can lead to eye irritation and headaches after prolonged viewing. Diffractive optical elements known as diffusers have been examined as a means to lower speckle contrast. Diffusers are often rotated to achieve temporal averaging of the spatial phase pattern provided by diffuser surface. While diffusers are unable to completely eliminate speckle, they can be utilized to decrease the resultant contrast to provide a more visually acceptable image. This dissertation measures the reduction in speckle contrast achievable through the use of diffractive diffusers. A theoretical Fourier optics model is used to provide the diffuser's stationary and in-motion performance in terms of the resultant contrast level. Contrast measurements of two diffractive diffusers are calculated theoretically and compared with experimental results. In addition, a novel binary diffuser design based on Hadamard matrices will be presented. Using two static in-line Hadamard diffusers eliminates the need for rotation or vibration of the diffuser for temporal averaging. Two Hadamard diffusers were fabricated and contrast values were subsequently measured, showing good agreement with theory and simulated values. Monochromatic speckle contrast values of 0.40 were achieved using the Hadamard diffusers. Finally, color laser projection devices require the use of red, green, and blue laser sources; therefore, using a

  19. Application of laser speckle displacement analysis to clinical dentistry

    Science.gov (United States)

    Cumberpatch, G. K. D.; Hood, J. A. A.

    1997-03-01

    Success of dental restorations is dependent on the integrity of the tooth/restoration interface. Distortion of teeth due to operative procedures has previously been measured using LVDT's and strain-gauges and has provided useful but limited information. This paper reports on the verification of a system for laser speckle photography and its use to quantitative distortions in teeth from matrix band application and the use of bonded composite resin restorations. Tightening of matrix bands around teeth results in an inward deformation of the cusps, increasing incrementally as the band is tightened. Deflections of 50 micrometer/cusp were recorded. A delayed recovery was noted consistent with the viscoelastic behavior of dentine. For bonded restorations recovery will place the adhesion interface in a state of tension when the band is released and may cause premature failure. Premolar teeth restored with bonded resin restorations exhibited inward displacement of cusps of 12 - 15 micrometer. Deformation was not within the buccal-lingual axis as suggested by prior studies. Molar teeth bonded with composite resin restoration exhibit complex and variable cusp displacement in both magnitude (0 - 30 micrometer) and direction. Complete and partial debonding could be detected. Interproximal cusp bending could be quantitated and lifting of the restoration from the cavity floor was detectable. Deformations evidenced indicate the tooth/restoration interface is in a stressed state and this may subsequently lead to failure. The technique has the potential to aid in development of restoration techniques that minimize residual stress.

  20. Alanine repeats influence protein localization in splicing speckles and paraspeckles.

    Science.gov (United States)

    Chang, Shuo-Hsiu; Chang, Wei-Lun; Lu, Chia-Chen; Tarn, Woan-Yuh

    2014-12-16

    Mammalian splicing regulatory protein RNA-binding motif protein 4 (RBM4) has an alanine repeat-containing C-terminal domain (CAD) that confers both nuclear- and splicing speckle-targeting activities. Alanine-repeat expansion has pathological potential. Here we show that the alanine-repeat tracts influence the subnuclear targeting properties of the RBM4 CAD in cultured human cells. Notably, truncation of the alanine tracts redistributed a portion of RBM4 to paraspeckles. The alanine-deficient CAD was sufficient for paraspeckle targeting. On the other hand, alanine-repeat expansion reduced the mobility of RBM4 and impaired its splicing activity. We further took advantage of the putative coactivator activator (CoAA)-RBM4 conjoined splicing factor, CoAZ, to investigate the function of the CAD in subnuclear targeting. Transiently expressed CoAZ formed discrete nuclear foci that emerged and subsequently separated-fully or partially-from paraspeckles. Alanine-repeat expansion appeared to prevent CoAZ separation from paraspeckles, resulting in their complete colocalization. CoAZ foci were dynamic but, unlike paraspeckles, were resistant to RNase treatment. Our results indicate that the alanine-rich CAD, in conjunction with its conjoined RNA-binding domain(s), differentially influences the subnuclear localization and biogenesis of RBM4 and CoAZ. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

  1. A PHOTOMETRIC ANALYSIS OF SEVENTEEN BINARY STARS USING SPECKLE IMAGING

    International Nuclear Information System (INIS)

    Davidson, James W.; Baptista, Brian J.; Horch, Elliott P.; Franz, Otto; Van Altena, William F.

    2009-01-01

    Magnitude differences obtained from speckle imaging are used in combination with other data in the literature to place the components of binary star systems on the H-R diagram. Isochrones are compared with the positions obtained, and a best-fit isochrone is determined for each system, yielding both masses of the components as well as an age range consistent with the system parameters. Seventeen systems are studied, 12 of which were observed with the 0.6 m Lowell-Tololo Telescope at Cerro Tololo Inter-American Observatory and six of which were observed with the WIYN 3.5 m Telescope (The WIYN Observatory is a joint facility of the University of Wisconsin-Madison, Indiana University, Yale University, and the National Optical Astronomy Observatories) at Kitt Peak. One system was observed from both sites. In comparing photometric masses to mass information from orbit determinations, we find that the photometric masses agree very well with the dynamical masses, and are generally more precise. For three systems, no dynamical masses exist at present, and therefore the photometrically determined values are the first mass estimates derived for these components.

  2. Optimized digital speckle patterns for digital image correlation by consideration of both accuracy and efficiency.

    Science.gov (United States)

    Chen, Zhenning; Shao, Xinxing; Xu, Xiangyang; He, Xiaoyuan

    2018-02-01

    The technique of digital image correlation (DIC), which has been widely used for noncontact deformation measurements in both the scientific and engineering fields, is greatly affected by the quality of speckle patterns in terms of its performance. This study was concerned with the optimization of the digital speckle pattern (DSP) for DIC in consideration of both the accuracy and efficiency. The root-mean-square error of the inverse compositional Gauss-Newton algorithm and the average number of iterations were used as quality metrics. Moreover, the influence of subset sizes and the noise level of images, which are the basic parameters in the quality assessment formulations, were also considered. The simulated binary speckle patterns were first compared with the Gaussian speckle patterns and captured DSPs. Both the single-radius and multi-radius DSPs were optimized. Experimental tests and analyses were conducted to obtain the optimized and recommended DSP. The vector diagram of the optimized speckle pattern was also uploaded as reference.

  3. ARTIFICIAL INCOHERENT SPECKLES ENABLE PRECISION ASTROMETRY AND PHOTOMETRY IN HIGH-CONTRAST IMAGING

    Energy Technology Data Exchange (ETDEWEB)

    Jovanovic, N.; Guyon, O.; Pathak, P.; Kudo, T. [National Astronomical Observatory of Japan, Subaru Telescope, 650 North A’Ohoku Place, Hilo, HI, 96720 (United States); Martinache, F. [Observatoire de la Cote d’Azur, Boulevard de l’Observatoire, F-06304 Nice (France); Hagelberg, J., E-mail: jovanovic.nem@gmail.com [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)

    2015-11-10

    State-of-the-art coronagraphs employed on extreme adaptive optics enabled instruments are constantly improving the contrast detection limit for companions at ever-closer separations from the host star. In order to constrain their properties and, ultimately, compositions, it is important to precisely determine orbital parameters and contrasts with respect to the stars they orbit. This can be difficult in the post-coronagraphic image plane, as by definition the central star has been occulted by the coronagraph. We demonstrate the flexibility of utilizing the deformable mirror in the adaptive optics system of the Subaru Coronagraphic Extreme Adaptive Optics system to generate a field of speckles for the purposes of calibration. Speckles can be placed up to 22.5 λ/D from the star, with any position angle, brightness, and abundance required. Most importantly, we show that a fast modulation of the added speckle phase, between 0 and π, during a long science integration renders these speckles effectively incoherent with the underlying halo. We quantitatively show for the first time that this incoherence, in turn, increases the robustness and stability of the adaptive speckles, which will improve the precision of astrometric and photometric calibration procedures. This technique will be valuable for high-contrast imaging observations with imagers and integral field spectrographs alike.

  4. Sound recovery via intensity variations of speckle pattern pixels selected with variance-based method

    Science.gov (United States)

    Zhu, Ge; Yao, Xu-Ri; Qiu, Peng; Mahmood, Waqas; Yu, Wen-Kai; Sun, Zhi-Bin; Zhai, Guang-Jie; Zhao, Qing

    2018-02-01

    In general, the sound waves can cause the vibration of the objects that are encountered in the traveling path. If we make a laser beam illuminate the rough surface of an object, it will be scattered into a speckle pattern that vibrates with these sound waves. Here, an efficient variance-based method is proposed to recover the sound information from speckle patterns captured by a high-speed camera. This method allows us to select the proper pixels that have large variances of the gray-value variations over time, from a small region of the speckle patterns. The gray-value variations of these pixels are summed together according to a simple model to recover the sound with a high signal-to-noise ratio. Meanwhile, our method will significantly simplify the computation compared with the traditional digital-image-correlation technique. The effectiveness of the proposed method has been verified by applying a variety of objects. The experimental results illustrate that the proposed method is robust to the quality of the speckle patterns and costs more than one-order less time to perform the same number of the speckle patterns. In our experiment, a sound signal of time duration 1.876 s is recovered from various objects with time consumption of 5.38 s only.

  5. Vegetation Detection in Stress of Moisture Shortage Based on Laser Speckle Recognition

    Science.gov (United States)

    Ishizawa, Hiroaki; Matsuo, Tsukasa; Miki, Takashi

    This paper describes a new measuring method of plant vigor by using Laser speckle pattern. Furthermore, this proposes a practical application of this presented measurement system. The measuring instrument is consisted by a He-Ne Laser as the light source, and a set of optics, such as reflectors, a beam expander. The speckle pattern could be measured by a CCD camera through lenses. A Pothos (Epiremnum aureum) and Japanese morning glory (Ipomoea nil) were used as the sample plant. Their intact leaves were measured the speckle pattern images. Visible but small vigor veins could be clearly observed in the images obtained by the speckle patterns. On the other hand, withered ones have shown different images. The relationship has been obtained between the feature of the images and the chlorophyll degradation. It would be expected that the symptom of plant against some stress could be detected by measuring the Laser speckle pattern. It could be used as the sensor of the field server system at every field monitoring site.

  6. Recruitment of phosphorylated small heat shock protein Hsp27 to nuclear speckles without stress

    International Nuclear Information System (INIS)

    Bryantsev, A.L.; Chechenova, M.B.; Shelden, E.A.

    2007-01-01

    During stress, the mammalian small heat shock protein Hsp27 enters cell nuclei. The present study examines the requirements for entry of Hsp27 into nuclei of normal rat kidney (NRK) renal epithelial cells, and for its interactions with specific nuclear structures. We find that phosphorylation of Hsp27 is necessary for the efficient entry into nuclei during heat shock but not sufficient for efficient nuclear entry under control conditions. We further report that Hsp27 is recruited to an RNAse sensitive fraction of SC35 positive nuclear speckles, but not other intranuclear structures, in response to heat shock. Intriguingly, Hsp27 phosphorylation, in the absence of stress, is sufficient for recruitment to speckles found in post-anaphase stage mitotic cells. Additionally, pseudophosphorylated Hsp27 fused to a nuclear localization peptide (NLS) is recruited to nuclear speckles in unstressed interphase cells, but wildtype and nonphosphorylatable Hsp27 NLS fusion proteins are not. The expression of NLS-Hsp27 mutants does not enhance colony forming abilities of cells subjected to severe heat shock, but does regulate nuclear speckle morphology. These data demonstrate that phosphorylation, but not stress, mediates Hsp27 recruitment to an RNAse soluble fraction of nuclear speckles and support a site-specific role for Hsp27 within the nucleus

  7. Enhanced diagnostic of skin conditions by polarized laser speckles: phantom studies and computer modeling

    Science.gov (United States)

    Tchvialeva, Lioudmila; Lee, Tim K.; Markhvida, Igor; Zeng, Haishan; Doronin, Alexander; Meglinski, Igor

    2014-03-01

    The incidence of the skin melanoma, the most commonly fatal form of skin cancer, is increasing faster than any other potentially preventable cancer. Clinical practice is currently hampered by the lack of the ability to rapidly screen the functional and morphological properties of tissues. In our previous study we show that the quantification of scattered laser light polarization provides a useful metrics for diagnostics of the malignant melanoma. In this study we exploit whether the image speckle could improve skin cancer diagnostic in comparison with the previously used free-space speckle. The study includes skin phantom measurements and computer modeling. To characterize the depolarization of light we measure the spatial distribution of speckle patterns and analyse their depolarization ratio taken into account radial symmetry. We examine the dependences of depolarization ratio vs. roughness for phantoms which optical properties are of the order of skin lesions. We demonstrate that the variation in bulk optical properties initiates the assessable changes in the depolarization ratio. We show that image speckle differentiates phantoms significantly better than free-space speckle. The results of experimental measurements are compared with the results of Monte Carlo simulation.

  8. Intrinsic speckle noise in in-line particle holography due to polydisperse and continuous particle sizes

    Science.gov (United States)

    Edwards, Philip J.; Hobson, Peter R.; Rodgers, G. J.

    2000-08-01

    In-line particle holography is subject to image deterioration due to intrinsic speckle noise. The resulting reduction in the signal to noise ratio (SNR) of the replayed image can become critical for applications such as holographic particle velocimetry (HPV) and 3D visualisation of marine plankton. Work has been done to extend the mono-disperse model relevant to HPV to include poly-disperse particle fields appropriate for the visualisation of marine plankton. Continuous and discrete particle fields are both considered. It is found that random walk statistics still apply for the poly-disperse case. The speckle field is simply the summation of the individual speckle patters due to each scatter size. Therefor the characteristic speckle parameter (which encompasses particle diameter, concentration and sample depth) is alos just the summation of the individual speckle parameters. This reduces the SNR calculation to the same form as for the mono-disperse case. For the continuous situation three distributions, power, exponential and Gaussian are discussed with the resulting SNR calcuated. The work presented here was performed as part of the Holomar project to produce a working underwater holographic camera for recording plankton.

  9. Laser speckle: theory and applications. January 1970-May 1988 (Citations from the Engineering Index data base). Report for January 1970-May 1988

    International Nuclear Information System (INIS)

    1988-05-01

    This bibliography contains citations concerning applications and theoretical considerations pertaining to laser speckle interferometry. Topics include experimental and theoretical investigations, applications in stress and vibrational analysis, velocity and displacement measurement, and surface analysis. Speckle noise-reduction techniques and speckle photography are also treated. (This updated bibliography contains 247 citations, 22 of which are new entries to the previous edition.)

  10. Intraoperative laser speckle contrast imaging for monitoring cerebral blood flow: results from a 10-patient pilot study

    Science.gov (United States)

    Richards, Lisa M.; Weber, Erica L.; Parthasarathy, Ashwin B.; Kappeler, Kaelyn L.; Fox, Douglas J.; Dunn, Andrew K.

    2012-02-01

    Monitoring cerebral blood flow (CBF) during neurosurgery can provide important physiological information for a variety of surgical procedures. Although multiple intraoperative vascular monitoring technologies are currently available, a quantitative method that allows for continuous monitoring is still needed. Laser speckle contrast imaging (LSCI) is an optical imaging method with high spatial and temporal resolution that has been widely used to image CBF in animal models in vivo. In this pilot clinical study, we adapted a Zeiss OPMI Pentero neurosurgical microscope to obtain LSCI images by attaching a camera and a laser diode. This LSCI adapted instrument has been used to acquire full field flow images from 10 patients during tumor resection procedures. The patient's ECG was recorded during acquisition and image registration was performed in post-processing to account for pulsatile motion artifacts. Digital photographs confirmed alignment of vasculature and flow images in four cases, and a relative change in blood flow was observed in two patients after bipolar cautery. The LSCI adapted instrument has the capability to produce real-time, full field CBF image maps with excellent spatial resolution and minimal intervention to the surgical procedure. Results from this study demonstrate the feasibility of using LSCI to monitor blood flow during neurosurgery.

  11. Latent tracks in polymeric etched track detectors

    International Nuclear Information System (INIS)

    Yamauchi, Tomoya

    2013-01-01

    Track registration properties in polymeric track detectors, including Poly(allyl diglycol carbonate), Bispenol A polycarbonate, Poly(ethylen terephtarate), and Polyimide, have been investigated by means of Fourie transform Infararede FT-IR spectrometry. Chemical criterion on the track formation threshold has been proposes, in stead of the conventional physical track registration models. (author)

  12. Tracking telecommuting

    Energy Technology Data Exchange (ETDEWEB)

    Stastny, P.

    2007-03-15

    Many employees are now choosing to work from home using laptops and telephones. Employers in the oil and gas industry are now reaping a number of benefits from their telecommuting employees, including increased productivity; higher levels of employee satisfaction, and less absenteeism. Providing a telecommunication option can prove to be advantageous for employers wishing to hire or retain employees. Telecommuting may also help to reduce greenhouse gas (GHG) emissions. This article provided details of Teletrips Inc., a company that aids in the production of corporate social responsibility reports. Teletrips provides reports that document employee savings in time, vehicle depreciation maintenance, and gasoline costs. Teletrips currently tracks 12 companies in Calgary, and plans to grow through the development of key technology partnerships. The company is also working with the federal government to provide their clients with emission trading credits, and has forged a memorandum of understanding with the British Columbia government for tracking emissions. Calgary now openly supports telecommuting and is encouraging businesses in the city to adopt telecommuting on a larger scale. It was concluded that the expanding needs for road infrastructure and the energy used by cars to move workers in and out of the city are a massive burden to the city's tax base. 1 fig.

  13. INNER TRACKING

    CERN Document Server

    P. Sharp

    The CMS Inner Tracking Detector continues to make good progress. The Objective for 2006 was to complete all of the CMS Tracker sub-detectors and to start the integration of the sub-detectors into the Tracker Support Tube (TST). The Objective for 2007 is to deliver to CMS a completed, installed, commissioned and calibrated Tracking System (Silicon Strip and Pixels) aligned to < 100µ in April 2008 ready for the first physics collisions at LHC. In November 2006 all of the sub-detectors had been delivered to the Tracker Integration facility (TIF) at CERN and the tests and QA procedures to be carried out on each sub-detector before integration had been established. In December 2006, TIB/TID+ was integrated into TOB+, TIB/TID- was being prepared for integration, and TEC+ was undergoing tests at the final tracker operating temperature (-100 C) in the Lyon cold room. In February 2007, TIB/TID- has been integrated into TOB-, and the installation of the pixel support tube and the services for TI...

  14. An optical sensor for local strain measuring of an object by means of a speckle correlation method

    Czech Academy of Sciences Publication Activity Database

    Horváth, P.; Šmíd, Petr; Hrabovský, M.; Hamarová, Ivana

    2012-01-01

    Roč. 106, s3 (2012), s. 425-427 ISSN 0009-2770 R&D Projects: GA AV ČR KAN301370701 Institutional research plan: CEZ:AV0Z10100521 Keywords : non-contact measurement * strain * speckle * speckle correlation Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.453, year: 2012

  15. Selectivity and balance of spatial filtering velocimetry of objective speckles for measuring out-of-plane motion

    DEFF Research Database (Denmark)

    Jakobsen, Michael Linde; Yura, Hal T.; Hanson, Steen Grüner

    2015-01-01

    We probe the dynamics of objective laser speckles as the axial distance between the object and the observation plane changes. With the purpose of measuring out-of-plane motion in real time, we apply optical spatial filtering velocimetry to the speckle dynamics. To achieve this, a rotationally sym...

  16. Automatic measurement for solid state track detectors

    International Nuclear Information System (INIS)

    Ogura, Koichi

    1982-01-01

    Since in solid state track detectors, their tracks are measured with a microscope, observers are forced to do hard works that consume time and labour. This causes to obtain poor statistic accuracy or to produce personal error. Therefore, many researches have been done to aim at simplifying and automating track measurement. There are two categories in automating the measurement: simple counting of the number of tracks and the requirements to know geometrical elements such as the size of tracks or their coordinates as well as the number of tracks. The former is called automatic counting and the latter automatic analysis. The method to generally evaluate the number of tracks in automatic counting is the estimation of the total number of tracks in the total detector area or in a field of view of a microscope. It is suitable for counting when the track density is higher. The method to count tracks one by one includes the spark counting and the scanning microdensitometer. Automatic analysis includes video image analysis in which the high quality images obtained with a high resolution video camera are processed with a micro-computer, and the tracks are automatically recognized and measured by feature extraction. This method is described in detail. In many kinds of automatic measurements reported so far, frequently used ones are ''spark counting'' and ''video image analysis''. (Wakatsuki, Y.)

  17. Phase conjugation of speckle-inhomogeneous radiation in a holographic Nd:YAG laser with a short thermal hologram

    International Nuclear Information System (INIS)

    Yarovoi, V V; Kirsanov, A V

    2002-01-01

    A model of the so-called short hologram, which does not exhibit in-depth diffraction deformation of the fine speckle pattern of the recording fields, is studied. The investigation is performed by the example of a thermal hologram recorded by two speckle waves, which is the output mirror of a ring laser produced as a result of this recording. It is shown that the ability of this short hologram to select a wave conjugated to a speckle signal in the mode of the holographic laser depends both on the degree of mutual mixing of the speckles of recording beams in the hologram volume and on the effects of its saturation by the beams. The maximum accuracy of phase conjugation of speckle radiation in the holographic Nd:YAG laser achieved upon the best selection of the conjugate wave by the short thermal hologram was 93%. (nonlinear optical phenomena)

  18. Three-dimensional displacement measurement by fringe projection and speckle photography

    International Nuclear Information System (INIS)

    Barrientos, B.; Garcia-Marquez, J.; Cerca, M.; Hernandez-Bernal, C.

    2008-01-01

    3D displacement fields are measured by the combination of two optical methods, fringe projection and speckle photography. The use of only one camera recording the necessary information implies that no calibration procedures are necessary as is the case in techniques based on stereoscopy. The out-of-plane displacement is measured by fringe projection whereas speckle photography yields the 2-D in-plane component. To show the feasibility of the technique, we analyze a detailed morphological spatio-temporal evolution of a model of the Earth's crust while subjected to compression forces. The results show that the combination of fringe projection and speckle photography is well suited for this type of studies

  19. Quantitative X-ray dark-field and phase tomography using single directional speckle scanning technique

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hongchang, E-mail: hongchang.wang@diamond.ac.uk; Kashyap, Yogesh; Sawhney, Kawal [Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE (United Kingdom)

    2016-03-21

    X-ray dark-field contrast tomography can provide important supplementary information inside a sample to the conventional absorption tomography. Recently, the X-ray speckle based technique has been proposed to provide qualitative two-dimensional dark-field imaging with a simple experimental arrangement. In this letter, we deduce a relationship between the second moment of scattering angle distribution and cross-correlation degradation of speckle and establish a quantitative basis of X-ray dark-field tomography using single directional speckle scanning technique. In addition, the phase contrast images can be simultaneously retrieved permitting tomographic reconstruction, which yields enhanced contrast in weakly absorbing materials. Such complementary tomography technique can allow systematic investigation of complex samples containing both soft and hard materials.

  20. Demonstration of a Speckle Based Sensing with Pulse-Doppler Radar for Vibration Detection.

    Science.gov (United States)

    Ozana, Nisan; Bauer, Reuven; Ashkenazy, Koby; Sasson, Nissim; Schwarz, Ariel; Shemer, Amir; Zalevsky, Zeev

    2018-05-03

    In previous works, an optical technique for extraction and separation of remote static vibrations has been demonstrated. In this paper, we will describe an approach in which RF speckle movement is used to extract remote vibrations of a static target. The use of conventional radar Doppler methods is not suitable for detecting vibrations of static targets. In addition, the speckle method has an important advantage, in that it is able to detect vibrations at far greater distances than what is normally detected in classical optical methods. The experiment described in this paper was done using a motorized vehicle, which engine was turned on and off. The results showed that the system was able to distinguish between the different engine states, and in addition, was able to determine the vibration frequency of the engine. The first step towards real time detection of human vital signs using RF speckle patterns is presented.

  1. Demonstration of a Speckle Based Sensing with Pulse-Doppler Radar for Vibration Detection

    Directory of Open Access Journals (Sweden)

    Nisan Ozana

    2018-05-01

    Full Text Available In previous works, an optical technique for extraction and separation of remote static vibrations has been demonstrated. In this paper, we will describe an approach in which RF speckle movement is used to extract remote vibrations of a static target. The use of conventional radar Doppler methods is not suitable for detecting vibrations of static targets. In addition, the speckle method has an important advantage, in that it is able to detect vibrations at far greater distances than what is normally detected in classical optical methods. The experiment described in this paper was done using a motorized vehicle, which engine was turned on and off. The results showed that the system was able to distinguish between the different engine states, and in addition, was able to determine the vibration frequency of the engine. The first step towards real time detection of human vital signs using RF speckle patterns is presented.

  2. Complementary Speckle Patterns: Deterministic Interchange of Intrinsic Vortices and Maxima through Scattering Media.

    Science.gov (United States)

    Gateau, Jérôme; Rigneault, Hervé; Guillon, Marc

    2017-01-27

    Intensity maxima and zeros of speckle patterns obtained behind a diffuser are experimentally interchanged by applying a spiral phase delay of charge ±1 to the impinging coherent beam. This transform arises from the expectation that tightly focused beams, which have a planar wave front around the focus, are so changed into vortex beams and vice versa. The statistics of extrema locations and the intensity distribution of the so-generated "complementary" patterns are characterized by numerical simulations. It is demonstrated experimentally that the incoherent superposition of the three "complementary speckle patterns" yield a synthetic speckle grain size enlarged by a factor of sqrt[3]. A cyclic permutation of optical vortices and intensity maxima is unexpectedly observed and discussed.

  3. Speckle suppression via sparse representation for wide-field imaging through turbid media.

    Science.gov (United States)

    Jang, Hwanchol; Yoon, Changhyeong; Chung, Euiheon; Choi, Wonshik; Lee, Heung-No

    2014-06-30

    Speckle suppression is one of the most important tasks in the image transmission through turbid media. Insufficient speckle suppression requires an additional procedure such as temporal ensemble averaging over multiple exposures. In this paper, we consider the image recovery process based on the so-called transmission matrix (TM) of turbid media for the image transmission through the media. We show that the speckle left unremoved in the TM-based image recovery can be suppressed effectively via sparse representation (SR). SR is a relatively new signal reconstruction framework which works well even for ill-conditioned problems. This is the first study to show the benefit of using the SR as compared to the phase conjugation (PC) a de facto standard method to date for TM-based imaging through turbid media including a live cell through tissue slice.

  4. Noise reduction in digital speckle pattern interferometry using bidimensional empirical mode decomposition

    International Nuclear Information System (INIS)

    Bernini, Maria Belen; Federico, Alejandro; Kaufmann, Guillermo H.

    2008-01-01

    We propose a bidimensional empirical mode decomposition (BEMD) method to reduce speckle noise in digital speckle pattern interferometry (DSPI) fringes. The BEMD method is based on a sifting process that decomposes the DSPI fringes in a finite set of subimages represented by high and low frequency oscillations, which are named modes. The sifting process assigns the high frequency information to the first modes, so that it is possible to discriminate speckle noise from fringe information, which is contained in the remaining modes. The proposed method is a fully data-driven technique, therefore neither fixed basis functions nor operator intervention are required. The performance of the BEMD method to denoise DSPI fringes is analyzed using computer-simulated data, and the results are also compared with those obtained by means of a previously developed one-dimensional empirical mode decomposition approach. An application of the proposed BEMD method to denoise experimental fringes is also presented

  5. Speckle and fringe dynamics in imagingspeckle-pattern interferometry for spatial-filtering velocimetry

    DEFF Research Database (Denmark)

    Jakobsen, Michael Linde; Iversen, Theis F. Q.; Yura, Harold T.

    2011-01-01

    This paper analyzes the dynamics of laser speckles and fringes, formed in an imaging-speckle-pattern interferometer with the purpose of sensing linear three-dimensional motion and out-of-plane components of rotation in real time, using optical spatial-filtering-velocimetry techniques. The ensemble......-average definition of the cross-correlation function is applied to the intensity distributions, obtained in the observation plane at two positions of the object. The theoretical analysis provides a description for the dynamics of both the speckles and the fringes. The analysis reveals that both the magnitude...... and direction of all three linear displacement components of the object movement can be determined. Simultaneously, out-ofplane rotation of the object including the corresponding directions can be determined from the spatial gradient of the in-plane fringe motion throughout the observation plane. The theory...

  6. Accelerated numerical processing of electronically recorded holograms with reduced speckle noise.

    Science.gov (United States)

    Trujillo, Carlos; Garcia-Sucerquia, Jorge

    2013-09-01

    The numerical reconstruction of digitally recorded holograms suffers from speckle noise. An accelerated method that uses general-purpose computing in graphics processing units to reduce that noise is shown. The proposed methodology utilizes parallelized algorithms to record, reconstruct, and superimpose multiple uncorrelated holograms of a static scene. For the best tradeoff between reduction of the speckle noise and processing time, the method records, reconstructs, and superimposes six holograms of 1024 × 1024 pixels in 68 ms; for this case, the methodology reduces the speckle noise by 58% compared with that exhibited by a single hologram. The fully parallelized method running on a commodity graphics processing unit is one order of magnitude faster than the same technique implemented on a regular CPU using its multithreading capabilities. Experimental results are shown to validate the proposal.

  7. Color quality improvement of reconstructed images in color digital holography using speckle method and spectral estimation

    Science.gov (United States)

    Funamizu, Hideki; Onodera, Yusei; Aizu, Yoshihisa

    2018-05-01

    In this study, we report color quality improvement of reconstructed images in color digital holography using the speckle method and the spectral estimation. In this technique, an object is illuminated by a speckle field and then an object wave is produced, while a plane wave is used as a reference wave. For three wavelengths, the interference patterns of two coherent waves are recorded as digital holograms on an image sensor. Speckle fields are changed by moving a ground glass plate in an in-plane direction, and a number of holograms are acquired to average the reconstructed images. After the averaging process of images reconstructed from multiple holograms, we use the Wiener estimation method for obtaining spectral transmittance curves in reconstructed images. The color reproducibility in this method is demonstrated and evaluated using a Macbeth color chart film and staining cells of onion.

  8. X-ray speckle contrast variation at a sample-specific absorption edges

    International Nuclear Information System (INIS)

    Retsch, C. C.; Wang, Y.; Frigo, S. P.; Stephenson, G. B.; McNulty, I.

    2000-01-01

    The authors measured static x-ray speckle contrast variation with the incident photon energy across sample-specific absorption edges. They propose that the variation depends strongly on the spectral response function of the monochromator. Speckle techniques have been introduced to the x-ray regime during recent years. Most of these experiments, however, were done at photon energies above 5 keV. They are working on this technique in the 1 to 4 keV range, an energy range that includes many important x-ray absorption edges, e.g., in Al, Si, P, S, the rare-earths, and others. To their knowledge, the effect of absorption edges on speckle contrast has not yet been studied. In this paper, they present their initial measurements and understanding of the observed phenomena

  9. A New Approach for Speckle Reduction in Holographic 3D printer

    International Nuclear Information System (INIS)

    Utsugi, Takeru; Yamaguchi, Masahiro

    2013-01-01

    A Holographic 3D printer produces a high quality 3D image reproduced by a full-color, full-parallax holographic stereogram with high-density light-ray recording. But speckle-pattern noise localized behind the reconstructed image is causing a loss of the display quality. This noise is originated from the speckle generated by a diffuser for equalizing the intensity distribution of the object light on the recording medium. We analyze some conventional ways for speckle reduction using a band-limited diffuser, and it is found that these ways cannot reduce the noise sufficiently. Then we propose two methods, one introduces a moving diffuser and the other introduces multiple exposures and a digital diffuser called as 4L-PRPS.

  10. Coherence and Polarization of Polarization Speckle Generated by Depolarizers and Their Changes through Complex ABCD Matrix

    DEFF Research Database (Denmark)

    Ma, Ning; Hanson, Steen Grüner; Lee, Tim K.

    2015-01-01

    Recent research work on speckle patterns indicates a variation of the polarization state during propagation and its nonuniformly spatial distribution. The preliminary step for the investigation of this polarization speckle is the generation of the corresponding field. In this paper, a kind...... of special depolarizer: the random roughness birefringent screen (RRBS) is introduced to meet this requirement. The statistical properties of the field generated by the depolarizer is investigated and illustrated in terms of the 2x2 beam coherence and polarization matrix (BCPM) with the corresponding degree...... of coherence (DoC). and degree of polarization (DoP) P. The changes of the coherence and polarization when the speckle field propagates through any optical system are analysed within the framework of the complex ABCD-matrix theory....

  11. Monitoring of bread cooling by statistical analysis of laser speckle patterns

    Science.gov (United States)

    Lyubenova, Tanya; Stoykova, Elena; Nacheva, Elena; Ivanov, Branimir; Panchev, Ivan; Sainov, Ventseslav

    2013-03-01

    The phenomenon of laser speckle can be used for detection and visualization of physical or biological activity in various objects (e.g. fruits, seeds, coatings) through statistical description of speckle dynamics. The paper presents the results of non-destructive monitoring of bread cooling by co-occurrence matrix and temporal structure function analysis of speckle patterns which have been recorded continuously within a few days. In total, 72960 and 39680 images were recorded and processed for two similar bread samples respectively. The experiments proved the expected steep decrease of activity related to the processes in the bread samples during the first several hours and revealed its oscillating character within the next few days. Characterization of activity over the bread sample surface was also obtained.

  12. Analysis of strain in reinforced concrete components by laser speckle photography

    International Nuclear Information System (INIS)

    Gross, K.P.

    1982-01-01

    Laser speckle photography is an optical process for non-contact measurement of strain in a plane at right angles to the axis of the optical system. The material composition and relief of the surface of a test sample have a great effect on the applicability of the process. Bodies with too smooth or too rough surfaces, and bodies of a transparent structure (salt bearing rocks) cannot be examined by speckle photography without previous surface treatment. The principle of the process and its application to the examination of reinforced concrete components is described. The capability of speckle photography, the accuracy of measurement which can be achieved and possible sources of error are discussed. (orig./RW) [de

  13. Theoretical investigations on dual-beam illumination electronic speckle pattern interferometry

    International Nuclear Information System (INIS)

    Goudemand, Nicolas

    2006-01-01

    Contrary to what is found in most of the existing scientific literature,where a specific frame is developed, the theory of speckle interferometry is (conveniently) presented here as a particular case of the more general theory of holographic interferometry. In addition to the intellectual benefit of dealing with a single unified theory, this brings about many advantages when it comes to discuss fundamental topics such as the three-dimensional evolution of the complex amplitude of the diffuse optical wave fronts, the degree of approximation of the leading formulas, the loss of fringe contrast,the decorrelation effects, the real influence of the terms generally neglected in out-of-focus regions. In the same way, the statistical properties of the speckle fields, usually treated as a separate subject matter, are also integrated in the theory, thus providing a comprehensive knowledge of the qualitative features of speckle interferometry methods, otherwise difficult to understand

  14. Theoretical investigations on dual-beam illumination electronic speckle pattern interferometry

    Science.gov (United States)

    Goudemand, Nicolas

    2006-07-01

    Contrary to what is found in most of the existing scientific literature, where a specific frame is developed, the theory of speckle interferometry is (conveniently) presented here as a particular case of the more general theory of holographic interferometry. In addition to the intellectual benefit of dealing with a single unified theory, this brings about many advantages when it comes to discuss fundamental topics such as the three-dimensional evolution of the complex amplitude of the diffuse optical wavefronts, the degree of approximation of the leading formulas, the loss of fringe contrast, the decorrelation effects, the real influence of the terms generally neglected in out-of-focus regions. In the same way, the statistical properties of the speckle fields, usually treated as a separate subject matter, are also integrated in the theory, thus providing a comprehensive knowledge of the qualitative features of speckle interferometry methods, otherwise difficult to understand.

  15. Digital Image Speckle Correlation for the Quantification of the Cosmetic Treatment with Botulinum Toxin Type A (BTX-A)

    Science.gov (United States)

    Bhatnagar, Divya; Conkling, Nicole; Rafailovich, Miriam; Dagum, Alexander

    2012-02-01

    The skin on the face is directly attached to the underlying muscles. Here, we successfully introduce a non-invasive, non-contact technique, Digital Image Speckle Correlation (DISC), to measure the precise magnitude and duration of facial muscle paralysis inflicted by BTX-A. Subjective evaluation by clinicians and patients fail to objectively quantify the direct effect and duration of BTX-A on the facial musculature. By using DISC, we can (a) Directly measure deformation field of the facial skin and determine the locus of facial muscular tension(b)Quantify and monitor muscular paralysis and subsequent re-innervation following injection; (c) Continuously correlate the appearance of wrinkles and muscular tension. Two sequential photographs of slight facial motion (frowning, raising eyebrows) are taken. DISC processes the images to produce a vector map of muscular displacement from which spatially resolved information is obtained regarding facial tension. DISC can track the ability of different muscle groups to contract and can be used to predict the site of injection, quantify muscle paralysis and the rate of recovery following BOTOX injection.

  16. Tracking Porters

    DEFF Research Database (Denmark)

    Bruun, Maja Hojer; Krause-Jensen, Jakob; Saltofte, Margit

    2015-01-01

    . In this chapter, we argue that although anthropology has its specific methodology – including a myriad of ethnographic data-gathering tools, techniques, analytical approaches and theories – it must first and foremost be understood as a craft. Anthropology as craft requires a specific ‘anthropological sensibility......’ that differs from the standardized procedures of normal science. To establish our points we use an example of problem-based project work conducted by a group of Techno-Anthropology students at Aalborg University, we focus on key aspects of this craft and how the students began to learn it: For two weeks...... the students followed the work of a group of porters. Drawing on anthropological concepts and research strategies the students gained crucial insights about the potential effects of using tracking technologies in the hospital....

  17. Fibre tracking

    International Nuclear Information System (INIS)

    Gaillard, J.M.

    1994-03-01

    A large-size scintillating plastic fibre tracking detector was built as part of the upgrade of the UA2 central detector at the SPS proton-antiproton collider. The cylindrical fibre detector of average radius of 40 cm consisted of 60000 plastic fibres with an active length of 2.1 m. One of the main motivations was to improve the electron identification. The fibre ends were bunched to be coupled to read-out systems of image intensifier plus CCD, 32 in total. The quality and the reliability of the UA2 fibre detector performance exceeded expectations throughout its years of operation. A few examples of the use of image intensifiers and of scintillating fibres in biological instrumentation are described. (R.P.) 11 refs., 15 figs., 2 tabs

  18. Comparison of phase unwrapping algorithms for topography reconstruction based on digital speckle pattern interferometry

    Science.gov (United States)

    Li, Yuanbo; Cui, Xiaoqian; Wang, Hongbei; Zhao, Mengge; Ding, Hongbin

    2017-10-01

    Digital speckle pattern interferometry (DSPI) can diagnose the topography evolution in real-time, continuous and non-destructive, and has been considered as a most promising technique for Plasma-Facing Components (PFCs) topography diagnostic under the complicated environment of tokamak. It is important for the study of digital speckle pattern interferometry to enhance speckle patterns and obtain the real topography of the ablated crater. In this paper, two kinds of numerical model based on flood-fill algorithm has been developed to obtain the real profile by unwrapping from the wrapped phase in speckle interference pattern, which can be calculated through four intensity images by means of 4-step phase-shifting technique. During the process of phase unwrapping by means of flood-fill algorithm, since the existence of noise pollution, and other inevitable factors will lead to poor quality of the reconstruction results, this will have an impact on the authenticity of the restored topography. The calculation of the quality parameters was introduced to obtain the quality-map from the wrapped phase map, this work presents two different methods to calculate the quality parameters. Then quality parameters are used to guide the path of flood-fill algorithm, and the pixels with good quality parameters are given priority calculation, so that the quality of speckle interference pattern reconstruction results are improved. According to the comparison between the flood-fill algorithm which is suitable for speckle pattern interferometry and the quality-guided flood-fill algorithm (with two different calculation approaches), the errors which caused by noise pollution and the discontinuous of the strips were successfully reduced.

  19. Speckle metrology in the nanoworld, as it is perceived today, and how it may affect industry

    Science.gov (United States)

    Pryputniewicz, Ryszard J.

    2010-09-01

    accelerometers, require the use of computational modeling and simulation coupled/combined with physical measurements. This author believes that successful combination of computer aided design (CAD) and multiphysics as well as multiscale simulation tools with the state-of-the-art (SOTA) measurement methodology will contribute to reduction of high prototyping costs, long product development cycles, and time-tomarket pressures while developing new sensors with nanoscale characteristics for various applications we use now and those that we will need in the future. In our approach we combine/hybridize a unique, fully integrated, software environment for multiscale, multiphysics, high fidelity analysis of the contemporary sensors with the SOTA optoelectronic laser interferometric microscope (OELIM) methodology, which is based on recent developments in speckle. The speckle-based OELIM methodology allows remote, noninvasive, full-field-of-view (FFV) measurements of deformations with high spatial resolution, nanometer accuracy, and in near real-time. In this paper, both, the software environment and the OELIM methodology are described and their applications are illustrated with representative examples demonstrating viability of the completely autonomous computer-based procedures for the development of contemporary sensors with nanocharacteristics suitable for the advancement of new evolving technologies that will shape our future. This process is demonstrated using devices of contemporary interest. The preliminary examples demonstrate capability of our approach to quantitatively determine effects of static and dynamic loads on the performance of sensors. In addition, potential economic rewards of the technology, projected into near future, will also be discussed.

  20. Track reconstruction in CMS high luminosity environment

    CERN Document Server

    AUTHOR|(CDS)2067159

    2016-01-01

    The CMS tracker is the largest silicon detector ever built, covering 200 square meters and providing an average of 14 high-precision measurements per track. Tracking is essential for the reconstruction of objects like jets, muons, electrons and tau leptons starting from the raw data from the silicon pixel and strip detectors. Track reconstruction is widely used also at trigger level as it improves objects tagging and resolution.The CMS tracking code is organized in several levels, known as iterative steps, each optimized to reconstruct a class of particle trajectories, as the ones of particles originating from the primary vertex or displaced tracks from particles resulting from secondary vertices. Each iterative step consists of seeding, pattern recognition and fitting by a kalman filter, and a final filtering and cleaning. Each subsequent step works on hits not yet associated to a reconstructed particle trajectory.The CMS tracking code is continuously evolving to make the reconstruction computing load compat...