Relevant bibliographies by topics / Multi Exposure Speckle Imaging

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  1. Journal articles
  2. Dissertations / Theses
  3. Book chapters
  4. Conference papers

Academic literature on the topic 'Multi Exposure Speckle Imaging'

Author: Grafiati
Published: 4 June 2021
Last updated: 2 February 2022

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Journal articles on the topic "Multi Exposure Speckle Imaging"

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Parthasarathy, Ashwin B., W. J. Tom, Ashwini Gopal, Xiaojing Zhang, and Andrew K. Dunn. "Robust flow measurement with multi-exposure speckle imaging." Optics Express 16, no. 3 (2008): 1975. http://dx.doi.org/10.1364/oe.16.001975.

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Kazmi, Syed Mohammad Shams, Ashwin B. Parthasarthy, Nelly E. Song, Theresa A. Jones, and Andrew K. Dunn. "Chronic Imaging of Cortical Blood Flow using Multi-Exposure Speckle Imaging." Journal of Cerebral Blood Flow & Metabolism 33, no. 6 (April 10, 2013): 798–808. http://dx.doi.org/10.1038/jcbfm.2013.57.

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Chronic imaging of cerebral blood flow (CBF) is an important tool for investigating vascular remodeling after injury such as stroke. Although techniques such as Laser Speckle Contrast Imaging (LSCI) have emerged as valuable tools for imaging CBF in acute experiments, their utility for chronic measurements or cross-animal comparisons has been limited. Recently, an extension to LSCI called Multi-Exposure Speckle Imaging (MESI) was introduced that increases the quantitative accuracy of CBF images. In this paper, we show that estimates of chronic blood flow are better with MESI than with traditional LSCI. We evaluate the accuracy of the MESI flow estimates using red blood cell (RBC) photographic tracking as an absolute flow calibration in mice over several days. The flow measures computed using the MESI and LSCI techniques were found to be on average 10% and 24% deviant ( n = 9 mice), respectively, compared with RBC velocity changes. We also map CBF dynamics after photo-thrombosis of selected cortical microvasculature. Correlations of flow dynamics with RBC tracking were closer with MESI ( r = 0.88) than with LSCI ( r = 0.65) up to 2 weeks from baseline. With the increased quantitative accuracy, MESI can provide a platform for studying the efficacy of stroke therapies aimed at flow restoration.
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Richards, Lisa M., SM Shams Kazmi, Katherine E. Olin, James S. Waldron, Douglas J. Fox, and Andrew K. Dunn. "Intraoperative multi-exposure speckle imaging of cerebral blood flow." Journal of Cerebral Blood Flow & Metabolism 37, no. 9 (January 23, 2017): 3097–109. http://dx.doi.org/10.1177/0271678x16686987.

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Multiple studies have demonstrated that laser speckle contrast imaging (LSCI) has high potential to be a valuable cerebral blood flow monitoring technique during neurosurgery. However, the quantitative accuracy and sensitivity of LSCI is limited, and highly dependent on the exposure time. An extension to LSCI called multi-exposure speckle imaging (MESI) overcomes these limitations, and was evaluated intraoperatively in patients undergoing brain tumor resection. This clinical study ( n = 8) recorded multiple exposure times from the same cortical tissue area spanning 0.5–20 ms, and evaluated images individually as single-exposure LSCI and jointly using the MESI model. This study demonstrated that the MESI estimates provided the broadest flow sensitivity for sampling the flow magnitude in the human brain, closely followed by the shorter exposure times. Conservation of flow analysis on vascular bifurcations was used to validate physiological accuracy, with highly conserved flow estimates (<10%) from both MESI and 1 ms LSCI ( n = 14 branches). The MESI model had high goodness-of-fit with proper image calibration and acquisition, and was used to monitor blood flow changes after tissue cautery. Results from this study demonstrate that intraoperative MESI can be performed with high quantitative accuracy and sensitivity for cerebral blood flow monitoring.
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Wu, Qiong, Jialin Liu, Baoteng Xu, Wei Zhou, Chi Wang, Xibin Yang, and Daxi Xiong. "Laparoscopic multi-exposure speckle imaging for quantitative flow measurement." AIP Advances 11, no. 1 (January 1, 2021): 015031. http://dx.doi.org/10.1063/5.0033464.

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Shams Kazmi, S. M., Rebecca K. Wu, and Andrew K. Dunn. "Evaluating multi-exposure speckle imaging estimates of absolute autocorrelation times." Optics Letters 40, no. 15 (July 30, 2015): 3643. http://dx.doi.org/10.1364/ol.40.003643.

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Kazmi, S. M. Shams, Satyajit Balial, and Andrew K. Dunn. "Optimization of camera exposure durations for multi-exposure speckle imaging of the microcirculation." Biomedical Optics Express 5, no. 7 (June 10, 2014): 2157. http://dx.doi.org/10.1364/boe.5.002157.

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Parthasarathy, Ashwin B., S. M. Shams Kazmi, and Andrew K. Dunn. "Quantitative imaging of ischemic stroke through thinned skull in mice with Multi Exposure Speckle Imaging." Biomedical Optics Express 1, no. 1 (July 16, 2010): 246. http://dx.doi.org/10.1364/boe.1.000246.

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Sivakumar, Panneer Selvam, Keiichiro Kagawa, Christian Crouzet, Bernard Choi, Keita Yasutomi, and Shoji Kawahito. "Multi-exposure laser speckle contrast imaging using a video-rate multi-tap charge modulation image sensor." Optics Express 27, no. 18 (August 30, 2019): 26175. http://dx.doi.org/10.1364/oe.27.026175.

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Dragojević, Tanja, Danilo Bronzi, Hari M. Varma, Claudia P. Valdes, Clara Castellvi, Federica Villa, Alberto Tosi, Carles Justicia, Franco Zappa, and Turgut Durduran. "High-speed multi-exposure laser speckle contrast imaging with a single-photon counting camera." Biomedical Optics Express 6, no. 8 (July 14, 2015): 2865. http://dx.doi.org/10.1364/boe.6.002865.

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Rice, Tyler B., Elliott Kwan, Carole K. Hayakawa, Anthony J. Durkin, Bernard Choi, and Bruce J. Tromberg. "Quantitative, depth-resolved determination of particle motion using multi-exposure, spatial frequency domain laser speckle imaging." Biomedical Optics Express 4, no. 12 (November 19, 2013): 2880. http://dx.doi.org/10.1364/boe.4.002880.

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Dissertations / Theses on the topic "Multi Exposure Speckle Imaging"

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Soleimanzad, Haleh. "Development and application of quantitative imaging to study cerebral blood flow in a mouse model of obesity." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS604.

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Selon l’organisation mondiale de la santé, dans les pays en développement, la proportion de personnes obèses a presque triplé depuis 1980 et presque doublé dans les pays à revenu élevé. Parmi ces statistiques, en France, 16,8% des hommes et 17,4% des femmes sont obèses. Les taux mondiaux d'obésité devraient monter au cours de la prochaine décennie pour atteindre un cinquième des adultes en 2025. L'obésité est due à de multiples facteurs, dont la consommation excessive d’aliments riches en gras et en sucres, ainsi que des facteurs génétiques, psychosociaux et environnementaux. L'incidence de maladies telles que le cancer, le diabète et les maladies cardiovasculaires est supérieure chez les personnes obèses. L’obésité a également un impact néfaste sur le fonctionnement du cerveau, ce qui entraîne davantage d’accidents vasculaires cérébraux et des maladies neurodégénératives chez les personnes obèses. Une activité cérébrale normale impose des besoins énergétiques dynamiques qui sont satisfaits par le flux sanguin cérébral (Cerebral Blood Flow, CBF). La perfusion adéquate des tissus cérébraux au bon moment et au bon endroit parmi les quelques 160 milliards de cellules qui composent le cerveau adulte humain est vital. Malgré des données obtenues sur des tranches de cerveau concernant les problèmes de barrière hémato-encéphalique chez les personnes obèses, le devenir du CBF au cours de l'obésité n'a pas encore été étudié. Une des raisons à cela est la difficulté à enregistrer le CBF in vivo et de le suivre dans le temps, pendant une activation cérébrale et sur une large échelle avec une résolution spatio-temporelle appropriée. Afin d'évaluer l'influence de l'obésité sur le CBF, au repos et pendant la stimulation sensorielle, nous avons développé une technique optique appelée l'imagerie de contraste laser par exposition multiple (MESI). La technique repose sur le calcul du contraste de speckle, qui est lié à la vitesse des diffuseurs (globules rouges). Il permet une imagerie superficielle à large champ des variations relatives de flux sanguin dans le cortex de la souris. Nous avons caractérisé les performances du système en utilisant des fantômes microfluidiques. L’acquisition du contraste pour différentes durées d’exposition permet de discriminer les diffuseurs statiques et dynamiques (en mouvement) et donc d’obtenir une image quantitative des variations du CBF. Nous avons étudié l'activation cérébrale en utilisant la stimulation olfactive par des flux d'odeurs contrôlés présentés à la souris anesthésiée. Le bulbe olfactif est une structure sensorielle essentielle des mammifères pour le codage des odeurs et il est bien adapté à l'imagerie optique car l’activité neuronale et vasculaire est détectée dans les régions superficielles de cette structure. Nous avons observé une diminution significative du CBF évoqué par stimulation odorante chez les souris obèses (sous régime hyperlipidique) par rapport aux souris témoins (sous régime standard). Chez les souris contrôles, les variations de CBF sont élevées dans les vaisseaux sanguins de grand diamètre et diminuent dans les vaisseaux sanguins de petit calibre. Cette variation dépendant du diamètre est perdue chez les souris obèses qui présentent même un CBF significativement réduit au repos, au cours d'une activité vasculaire spontanée. De plus, afin de mieux comprendre la morphologie du système vasculaire, nous avons commencé l’étude par iDISCO de la densité et la distribution des vaisseaux dans l’ensemble du cerveau in vitro chez des souris obèses comparées aux contrôles. En conclusion, les résultats obtenus sur le CBF chez les souris obèses par la mise au point d’une technique d’imagerie optique à large champ MESI, indiquent que l'obésité impacte le fonctionnement vasculaire en dérégulant le débit sanguin cérébral
Obesity is a global health threat. Since 1980 the proportion of obese or overweight individuals tripled in developing countries and doubled in high-income countries. In France 16.8% of men and 17.4% of women are obese. In the actual tendency persists, one-fifth of adults worldwide will be obese by 2025. Obesity is characterized by exaggerated weight gain and accumulation of fat tissue and is due to multiple factors including excessive consumption of high fat-sweet food and genetic, psychosocial and environmental factors. It is linked to an increase in the incidence of diseases such as cancer, diabetes and cardiovascular disease. Obesity has also a detrimental impact on brain function leading to higher rate of stroke and neurodegenerative diseases. Normal brain activity imposes dynamic energy requirements. Energy needs are fulfilled by Cerebral Blood Flow (CBF) to perfuse the brain tissue at the right time and the right place among the hundred of billons of cells that compose the human adult brain. Although dysfunction of the blood brain barrier was observed in brain slices, the fate of CBF during obesity in vivo is unknown. One reason for this is the difficulty to record CBF over time in vivo and to follow the time course of activation of large populations of cells with an appropriate spatiotemporal resolution. In order to evaluate the influence of obesity on CBF, at rest and during sensory stimulation, we have developed an optical technique termed multi-exposure speckle contrast imaging (MESI). In the last years, MESI has been validated for imaging relative changes in CBF at the surface of the rodent brain in vivo, the standard mammalian model for brain studies. The technique relies on the calculation of the spatial speckle contrast, which is related to the velocity of scatterers (red blood cells), and allows wide-field imaging of CBF at the mesoscopic level. We have characterized the performances of the system using microfluidic phantoms. We further demonstrated the ability of our MESI system to discriminate the moving and static diffusers contribution and therefore to provide accurate estimate of CBF changes in vivo. The olfactory bulb is a major hub for the processing of olfactory information in the brain of all mammals. It is well suited for optical imaging of brain activation since neuronal and vascular activities are detected very superficial at the surface of this structure. Using MESI, we have studied brain activation in control and obese mice. We have performed olfactory activation by delivering controlled odorants fluxes to anesthetized mice. We observed a significant decrease in odor-evoked CBF with a loss of diameter-dependent regulation of CBF in obese mice (high fat diet) compared to control lean mice (standard diet). We showed that CBF regulation was lost in obese mice even at rest without any stimulation. Furthermore, to gain insights into the morphology of the vascular network, we started the study of the vessels density and distribution in the entire brain using an in vitro iDISCO approach in obese mice compared to control mice. Overall, these findings indicate that obesity can adversely affect CBF at rest and in response to neuronal activation in vivo
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Maimaiti, Abdula. "Multi Exposure Droplet Imaging System – MEDIS." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-52745.

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A new fast flash photography fast imaging system is devised to develop for studying the evolution of micron sized droplets travelling from the ink jet nozzle to substrate at 5 - 20 m/s. using flash illumination of 10 short pulses from different angles consecutively, sharp images of evolving droplets are expected to be captured. The electrical and optical characterization of the laser driver and photodetector is presented along with corresponding measurements. Detailed schematics of the whole optical system design are presented.
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Jahůdková, Michaela. "Optické metody pro měření průtoku založené na kontrastu speklí." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-316827.

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This thesis deals with introduction to optical method called laser speckle contrast imaging (LSCI). The thesis contains a description of the basic theory that is related to the method, the LSCI own principle, the characteristics of this technique, its applications and also a description of various variants of LSCI. The second part of the thesis deals with the modification of acquisition software to be suitable for measurement of multi-exposure LSCI (MESI), verification of this method by experiment and conclusions of evaluated of data.
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Wieland, Marc [Verfasser], Stefano [Akademischer Betreuer] Parolai, Yuri [Akademischer Betreuer] Petryna, Stavros [Akademischer Betreuer] Savidis, and Hannes [Akademischer Betreuer] Taubenböck. "Exposure estimation for rapid seismic vulnerability assessment : an integrated approach based on multi-source imaging / Marc Wieland. Gutachter: Yuri Petryna ; Stavros Savidis ; Stefano Parolai ; Hannes Taubenböck. Betreuer: Stefano Parolai." Berlin : Technische Universität Berlin, 2013. http://d-nb.info/1065665253/34.

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Gil, Rodríguez Raquel. "Digital camera colour processing pipeline for high dynamic range imaging and colour stabilisation for cinema." Doctoral thesis, Universitat Pompeu Fabra, 2018. http://hdl.handle.net/10803/664378.

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In this thesis we focus on two different image processing challenges: high dynamic range (HDR) image/video generation, and colour matching. In both cases, we redefine these tasks by taking into account the prior knowledge from the different processes the camera performs when capturing the image. High dynamic range techniques have recently become very popular, thanks to the emergence of HDR recording and displaying technology. We propose two different approaches for HDR creation, one for still images, and one for video creation. In case of still images, most of previous methods follow a multiple exposure combination approach. These methods share a set of building assump-tions: i) the full dynamic range of the scene can be recovered, ii) colour channels are independent, and iii) the camera response function remains constant while varying the exposure time. First, we highlight how these assumptions do not apply in general for digital cameras, and then, we propose a method to im-prove multiple exposure combination. Our results outperform state-of-the-art multiple exposure techniques.In case of HDR video, we present a simple and affordable method to gen-erate high quality video from an HDR scene. Our input is an interlaced video alternating row pairs with different ISO values, as some DSLR camera models can provide. The proposed algorithm involves two main steps: i) the compu-tation of two single-ISO full-frame images (one for each ISO value) using an inpainting-based deinterlacing method, and ii) the linear combination of the full-frame ISO’s into a single HDR frame. Finally, the results are tone-mapped into an LDR frame ready for display. Results are free of ghosting artefacts and present little noise.Colour matching approaches attempt to transfer the colours of a reference image, to another source image. In this context, we focus on colour matching two images taken from the same scene. First, we propose a method that mod-ifies logarithmic encoded images, used in cinema for HDR content, in order to behave as gamma encoded images, used in most digital cameras. Then, we ex-tend a previous approach defined just for gamma encoded images. We redefine the transformation between the two images, by considering a projective trans-form, and we estimate the method parameters in a single optimisation step. The method outperforms the state-of-the-art methods and can handle real-life examples.
En aquesta tesi ens centrem en dos problemes de processament d’imatges diferents: generació d’imatge/vídeo d’alt rang dinàmic (HDR) i coloració. En tots dos casos, redefinim aquestes tasques tenint en compte el coneixement previ dels diferents processos que realitza la càmera en capturar la imatge. Actualment, les tèniques d’alt rang dinàmic s’han tornat molt populars, gràcies a l’aparició de la tecnologia per capturar i visualitzar HDR. Proposem dos enfocaments diferents per a la creació d’HDR, un per a imatges i un altre per a la creació de video. En el cas d’imatges, la majoria de mètodes combinen múltiples exposicions. Aquests mètodes comparteixen un conjunt d’hipòtesis: i) la recuperació del rang dinàmic complet de l’escena, ii) els canals de color són independents, i iii) la funció de resposta de la càmera es manté constant mentre es varia el temps d’exposició. En primer lloc, destaquem com aquestes suposicions no s’apliquen, en general, a les càmeres digitals, i després proposem un mètode per millorar aquesta tècnica. Els nostres resultats superen l’estat de l’art. En el cas de vídeo HDR, presentem un mètode senzill i assequible per generar vídeos d’alta qualitat d’una escena HDR. El nostre input és un vídeo entrellaçat alternant parells de fileres amb diferents valors d’ISO, com alguns models de càmeres DSLR poden proporcionar. L’algorisme inclou dos passos principals: i) el càlcul de dues imatges full-frame ISO (una per a cada valor d’ISO) utilizant un mètode de desentrella¸cat basat en inpainting, ii) la combinació lineal dels ISOs full-frame en un HDR únic. Finalment, els resultats es mapegen tonalment per obtenir un LDR per mostrar per pantalla. Els resultats no tenen artefactes de ghosting i presenten poc soroll. Els mètodes d’igualació de colors intenten transferir els colors d’una imatge de referència, a una altra imatge d’origen. En aquest context, ens centrem en el cas de dues imatges capturades a la mateixa escena. En primer lloc, proposem un mètode que modifica imatges codificades logarítmicament, utilitzades en el cinema per a continguts HDR, per tal de comportar-se com imatges gamma codificades, que s’utilitzen en la majoria de les càmeres digitals. A continuació, extenem un mètode definit prèviament només per imatges gamma codificades, redefinint la transformació entre les dues imatges, considerant una transformació projectiva i estimant els paràmetres del mètode en un únic pas d’optimització. El mètode supera l’estat de l’art i pot tractar exemples de la vida real.
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Parthasarathy, Ashwin Bharadwaj. "Quantitative cerebral blood flow measurement with Multi Exposure Speckle Imaging." Thesis, 2010. http://hdl.handle.net/2152/ETD-UT-2010-05-996.

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Cerebral blood flow (CBF) measures are central to the investigation of ischemic strokes, spreading depressions, functional and neuronal activation. Laser Speckle Contrast Imaging (LSCI) is an optical imaging technique that has been used to obtain CBF measures in vivo at high spatial and temporal resolutions, by quantifying the localized spatial blurring of backscattered coherent light induced by blood flow. Despite being widely used for biomedical applications, LSCI's critical limitations such as its tendency to underestimate large flow changes and its inability to accurately estimate CBF through a thinned skull have not been overcome. This dissertation presents a new Multi Exposure Speckle Imaging (MESI) technique that combines a new instrument and mathematical model to overcome these limitations. Additionally, in a pilot clinical study, an adapted neurosurgical microscope was used to obtain intra-operative LSCI images of CBF in humans. The MESI instrument accurately estimates experimental constants by imaging backscattered speckles over a wide range of the camera's exposure durations. The MESI mathematical model helps account for light that has scattered from both static and moving particles. In controlled flow experiments using tissue simulating phantoms, the MESI technique was found to estimate large changes in flow accurately and the estimates of flow changes were found to be unaffected by the presence of static particles in these phantoms. In an in vivo experiment in which the middle cerebral artery in mice was occluded to induce ~100% reduction in CBF, not only was the reduction in CBF accurately estimated by the MESI technique but these estimates of CBF changes were found to be unaffected by the presence of a thinned skull. The validity of statistical models used to derive the MESI mathematical model was confirmed using in vivo dynamic light scattering (DLS) measurements of CBF in mice. The MESI technique's potential to estimate absolute values of CBF in vivo was demonstrated by comparing CBF estimates obtained using the MESI technique to DLS measurements. The MESI technique's ability to measure CBF changes quantitatively through a thinned skull makes it particularly useful in chronic and long term studies leading to the development of better, more accurate stroke models.
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Schrandt, Christian John. "Chronic monitoring of cortical hemodynamics after ischemic stroke using funcional optical imaging techniques." Thesis, 2015. http://hdl.handle.net/2152/30334.

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The roles of the vascular architecture and blood flow in response to neurovascular diseases are important in predicting physiological outcomes. Observing these parameters chronically with optical imaging techniques provides insight into the neurovascular recovery process. We develop and deploy optical imaging systems for monitoring the progression of vascular structure, perfusion, and functional blood response after ischemic stroke in a chronic rodent model to observe vascular dynamics of the cortex under normal and diseased pathologies. Specifically, we monitor the progression of the vascular structure and cerebral blood flow (CBF) over a chronic period in the rodent cortex after photo-thrombotic occlusion. Multi-Exposure Speckle Imaging (MESI) provides surface measurements of microvascular flow dynamics while Two-Photon Fluorescence Microscopy offers direct visualization of the microvascular structure. We observe the occurrence of vascular reorientation in the sub-surface microvascular structure over a 35 day post-occlusion period. We also correlate MESI flow estimates in the parenchyma with sub-surface microvascular volume fractions from two-photon microscopy to assess how vascular density influences the surface-integrated MESI measurements. Next, we develop and validate a MESI technique for measuring absolute changes of the functional blood flow response to forepaw stimulation in rodents, termed FA MESI. The optimal camera exposures for capturing the CBF response to forepaw stimulation are extracted from a training set of animal data and the feasibility of the technique is demonstrated in a testing animal set by comparing functional response results between new and existing techniques. We then deploy this system in a chronic study monitoring the progression of hemodynamic parameters after ischemic stroke within the functionally responding area of the cortex. The progression of the regional CBF perfusion and absolute changes in the magnitude of the functional blood flow response are monitored chronically after photo-thrombotic occlusion. We compare the differences between absolute and relative measurements of the functional blood flow responses, and validate FA MESI by comparing baseline measurements to 15-exposure MESI over the sampled flow distributions. We demonstrate the differences measured between the functional outcomes and the regional CBF perfusion over a three week post-occlusion time period.
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Sheu, ChengTing, and 許承庭. "A Gradient Deghosting Method for Multi-exposure High Dynamic Range Imaging." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/05893677426384845845.

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碩士
輔仁大學
電機工程學系碩士班
105
Multi-exposure fusion is a classical and important approach for high-dynamic range imaging. However, ghost artifacts are easily induced when we fuse mul-ti-exposure images in the dynamic scene with moving objects. A deghost method for multi-exposure fusion is proposed in this paper by using both pixel intensity and gra-dient information to identify the moving objects in the multiple images. We develop a new consistency assessment method that adopts more than one channel information to comparatively eliminate the ghost effect. In addition to dynamic scene, night scene is a more challenging situation that has not only moving objects but also the noise caused by high ISO. We propose a denoise scene applied after the fusion of multiple images. The denoise scheme extends a well-known method called block-matching 3D filtering from only gray channel to all the three color channels. Our experiments are conducted on both daytime and nighttime situations. Compared with several existing deghosting methods, our method obtains better high-dynamic range images with good details, less noise and less ghost artifact.
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Ponticorvo, Adrien. "Novel optical techniques for imaging oxygen and other hemodynamic parameters during physiological events." Thesis, 2010. http://hdl.handle.net/2152/ETD-UT-2010-12-2044.

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This dissertation presents the development and use of a novel optical imaging system capable of monitoring changes in blood flow, oxygenated hemoglobin, deoxygenated hemoglobin, and absolute pO₂ in the brain. There are several imaging modalities capable of monitoring these parameters separately. Laser speckle contrast imaging (LSCI) and multi-spectral reflectance imaging (MSRI) have been used to monitor relative blood flow and hemoglobin changes respectively. Phosphorescence quenching, while not typically used for imaging, is capable of noninvasive measurements of pO₂. Combining these three techniques has led to the development of an imaging system that could ultimately lead to a better understanding of brain physiology. By combining techniques such as LSCI and MSRI, it becomes possible to estimate the cerebral metabolic rate of oxygen (CMRO₂), an important indicator of neuronal function. It is equally important to understand absolute pO₂ levels so that oxygen metabolism can be examined in context. Integrating phosphorescence quenching and a spatial light modulator into the imaging system allowed absolute pO₂ to be simultaneously measured in distinct regions. This new combined system was used to investigate pathophysiological conditions such as cortical spreading depression (CSD) and ischemia. The observed hemodynamic changes associated with these events were largely dictated by baseline oxygen levels and varied significantly in different regions. This finding highlighted the importance of having a system capable of monitoring hemodynamic changes and absolute pO₂ simultaneously while maintaining enough spatial resolution to distinguish the changes in different regions. It was found that animals with low baseline pO₂ were unable to deliver enough oxygen to the brain during events like CSD because of the high metabolic demand. In order for this technique to become more prevalent among researchers, it is essential to make it cost effective and simple to use. This was accomplished by replacing the expensive excitation sources with cheaper light emitting diodes (LEDs) and redesigning the software interface so that it was easier to control the entire device. The final system shows the potential to become a key tool for researchers studying the role of absolute pO₂ and other hemodynamic parameters during pathophysiological conditions such as CSD and ischemia.
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Book chapters on the topic "Multi Exposure Speckle Imaging"

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Reinheimer, T., K. H. Hofmann, and G. Weigelt. "Optical Interferometry in the Multi-Speckle Mode." In Very High Angular Resolution Imaging, 373–75. Dordrecht: Springer Netherlands, 1994. http://dx.doi.org/10.1007/978-94-011-0880-5_71.

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Suda, Takeru, Masayuki Tanaka, Yusuke Monno, and Masatoshi Okutomi. "Deep Snapshot HDR Imaging Using Multi-exposure Color Filter Array." In Computer Vision – ACCV 2020, 353–70. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-69532-3_22.

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Reinheimer, Th, K. H. Hofmann, M. Schöller, and G. Weigelt. "Multi-Speckle Interferometric Imaging with the VLTI and the LBT at Optical Wavelengths." In Science with the VLT Interferometer, 387–88. Berlin, Heidelberg: Springer Berlin Heidelberg, 1997. http://dx.doi.org/10.1007/978-3-540-69398-7_59.

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Compas, Colin B., Ben A. Lin, Smita Sampath, Congxian Jia, Qifeng Wei, Albert J. Sinusas, and James S. Duncan. "Multi-frame Radial Basis Functions to Combine Shape and Speckle Tracking for Cardiac Deformation Analysis in Echocardiography." In Functional Imaging and Modeling of the Heart, 113–20. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-21028-0_14.

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Reinheimer, Th, and G. Weigelt. "Infrared Interferometric Imaging with the VLTI in the Multi-Speckle Mode with a Combination of the 8 m UTs and the 2 m ATs." In Science with the VLT Interferometer, 389–90. Berlin, Heidelberg: Springer Berlin Heidelberg, 1997. http://dx.doi.org/10.1007/978-3-540-69398-7_60.

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Amitab, Khwairakpam, Debdatta Kandar, and Arnab K. Maji. "Speckle Noise Filtering Using Back-Propagation Multi-Layer Perceptron Network in Synthetic Aperture Radar Image." In Research Advances in the Integration of Big Data and Smart Computing, 280–301. IGI Global, 2016. http://dx.doi.org/10.4018/978-1-4666-8737-0.ch016.

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Synthetic Aperture Radar (SAR) are imaging Radar, it uses electromagnetic radiation to illuminate the scanned surface and produce high resolution images in all-weather condition, day and night. Interference of signals causes noise and degrades the quality of the image, it causes serious difficulty in analyzing the images. Speckle is multiplicative noise that inherently exist in SAR images. Artificial Neural Network (ANN) have the capability of learning and is gaining popularity in SAR image processing. Multi-Layer Perceptron (MLP) is a feed forward artificial neural network model that consists of an input layer, several hidden layers, and an output layer. We have simulated MLP with two hidden layer in Matlab. Speckle noises were added to the target SAR image and applied MLP for speckle noise reduction. It is found that speckle noise in SAR images can be reduced by using MLP. We have considered Log-sigmoid, Tan-Sigmoid and Linear Transfer Function for the hidden layers. The MLP network are trained using Gradient descent with momentum back propagation, Resilient back propagation and Levenberg-Marquardt back propagation and comparatively evaluated the performance.
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Amitab, Khwairakpam, Debdatta Kandar, and Arnab K. Maji. "Speckle Noise Filtering Using Back-Propagation Multi-Layer Perceptron Network in Synthetic Aperture Radar Image." In Deep Learning and Neural Networks, 489–510. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-7998-0414-7.ch028.

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Synthetic Aperture Radar (SAR) are imaging Radar, it uses electromagnetic radiation to illuminate the scanned surface and produce high resolution images in all-weather condition, day and night. Interference of signals causes noise and degrades the quality of the image, it causes serious difficulty in analyzing the images. Speckle is multiplicative noise that inherently exist in SAR images. Artificial Neural Network (ANN) have the capability of learning and is gaining popularity in SAR image processing. Multi-Layer Perceptron (MLP) is a feed forward artificial neural network model that consists of an input layer, several hidden layers, and an output layer. We have simulated MLP with two hidden layer in Matlab. Speckle noises were added to the target SAR image and applied MLP for speckle noise reduction. It is found that speckle noise in SAR images can be reduced by using MLP. We have considered Log-sigmoid, Tan-Sigmoid and Linear Transfer Function for the hidden layers. The MLP network are trained using Gradient descent with momentum back propagation, Resilient back propagation and Levenberg-Marquardt back propagation and comparatively evaluated the performance.
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Tiwari, Shailendra, and Rajeev Srivastava. "Research and Developments in Medical Image Reconstruction Methods and Its Applications." In Medical Imaging, 491–535. IGI Global, 2017. http://dx.doi.org/10.4018/978-1-5225-0571-6.ch019.

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Image reconstruction from projection is the field that lays the foundation for Medical Imaging or Medical Image Processing. The rapid and proceeding progress in medical image reconstruction, and the related developments in analysis methods and computer-aided diagnosis, has promoted medical imaging into one of the most important sub-fields in scientific imaging. Computer technology has enabled tomographic and three-dimensional reconstruction of images, illustrating both anatomical features and physiological functioning, free from overlying structures. In this chapter, the authors share their opinions on the research and development in the field of Medical Image Reconstruction Techniques, Computed Tomography (CT), challenges and the impact of future technology developments in CT, Computed Tomography Metrology in industrial research & development, technology, and clinical performance of different CT-scanner generations used for cardiac imaging, such as Electron Beam CT (EBCT), single-slice CT, and Multi-Detector row CT (MDCT) with 4, 16, and 64 simultaneously acquired slices. The authors identify the limitations of current CT-scanners, indicate potential of improvement and discuss alternative system concepts such as CT with area detectors and Dual Source CT (DSCT), recent technology with a focus on generation and detection of X-rays, as well as image reconstruction are discussed. Furthermore, the chapter includes aspects of applications, dose exposure in computed tomography, and a brief overview on special CT developments. Since this chapter gives a review of the major accomplishments and future directions in this field, with emphasis on developments over the past 50 years, the interested reader is referred to recent literature on computed tomography including a detailed discussion of CT technology in the references section.
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Ntoskas, Theodoros. "Cardio-Oncology: The Role of Echocardiography in Cancer Patients." In Advanced Concepts in Endocarditis - 2021. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.93085.

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Cardio-oncology is a rapidly emerging medical field that focusses on the improvement of the quality of life of cancer patients by preventing and treating the adverse cardiovascular complications of cancer therapy. Early recognition of cancer therapy-related cardiac dysfunction (CTRCD) provides an opportunity to mitigate cardiac injury and risk of developing late cardiac events. Cardiac imaging, and in particular, transthoracic echocardiography, plays an essential role in the baseline assessment, the detection and the surveillance of CRTCD in patients during and after the cancer therapy. Although the frequency of screening for the cardiotoxicity in patients undergoing active treatments and cancer survivors remains a topic of debate and ongoing research, echocardiography continues to be the leader for continuous monitoring by imaging due to the wide availability, lack of exposure to radiation, ability to recognise the effects on cardiac function and assess haemodynamics and other cardiac structures. The cardiac imaging applied to cardio-oncology includes standard and advanced (speckle tracking and three-dimensional (3D)) echocardiography.
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Etkind, Masha, Ron S. Kenett, and Uri Shafrir. "Learning in the Digital Age with Meaning Equivalence Reusable Learning Objects (MERLO)." In Handbook of Research on Applied Learning Theory and Design in Modern Education, 310–33. IGI Global, 2016. http://dx.doi.org/10.4018/978-1-4666-9634-1.ch015.

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In this chapter we describe a novel pedagogy for conceptual thinking and peer cooperation with Meaning Equivalence Reusable Learning Objects (MERLO) that enhances higher-order thinking; deepen comprehension of conceptual content; and improves learning outcomes. The evolution of this instructional methodology follows insights from four recent developments: analysis of patterns of content and structure of labeled patterns in human experience, that led to the emergence of concept science; development of digital cyber-infrastructure of networked information; research in neuroscience and brain imaging, showing that exposure of learners to multi-semiotic inductive problems enhance cognitive control of inter-hemispheric attentional processing in the lateral brain, and increase higher-order thinking; research in evolutionary dynamics on peer cooperation and indirect reciprocity, that document the motivational effect of knowledge of being observed, a psychological imperative that motivate individuals to cooperate and to contribute to the common good.
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Conference papers on the topic "Multi Exposure Speckle Imaging"

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Soleimanzad, Haleh, Hirac Gurden, and Frédéric Pain. "Development of a multi-exposure speckle imaging for mice brain imaging." In SPIE BiOS, edited by Qingming Luo and Jun Ding. SPIE, 2017. http://dx.doi.org/10.1117/12.2255816.

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Dunn, Andrew K., and Ashwin B. Parthasarathy. "Quantitative blood flow measurements with Multi-Exposure Speckle contrast imaging." In 2008 Conference on Lasers and Electro-Optics (CLEO). IEEE, 2008. http://dx.doi.org/10.1109/cleo.2008.4551408.

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Hirst, Evan, Mike Andrews, and Oliver Thompson. "Multi-exposure laser speckle perfusion imaging for retinal blood flow." In SPIE BiOS, edited by Valery V. Tuchin, Donald D. Duncan, Kirill V. Larin, Martin J. Leahy, and Ruikang K. Wang. SPIE, 2012. http://dx.doi.org/10.1117/12.907619.

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Thompson, Oliver, Jimmy Bakker, Carla Kloeze, Erwin Hondebrink, and Wiendelt Steenbergen. "Experimental comparison of perfusion imaging systems using multi-exposure laser speckle, single-exposure laser speckle, and full-field laser Doppler." In SPIE BiOS, edited by Valery V. Tuchin, Donald D. Duncan, Kirill V. Larin, Martin J. Leahy, and Ruikang K. Wang. SPIE, 2012. http://dx.doi.org/10.1117/12.907618.

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Hultman, Martin, Ingemar Fredriksson, Marcus Larsson, and Tomas Strömberg. "Evaluation of a high framerate multi-exposure laser speckle contrast imaging setup." In High-Speed Biomedical Imaging and Spectroscopy III: Toward Big Data Instrumentation and Management, edited by Keisuke Goda and Kevin K. Tsia. SPIE, 2018. http://dx.doi.org/10.1117/12.2286248.

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Song, Lipei, and Daniel S. Elson. "Multi-exposure speckle imaging using phantoms for blood flow and tissue perfusion." In The Pacific Rim Conference on Lasers and Electro-Optics (CLEO/PACIFIC RIM). IEEE, 2009. http://dx.doi.org/10.1109/cleopr.2009.5292645.

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Parthasarathy, Ashwin B., Adrien Ponticorvo, S. M. Shams Kazmi, and Andrew K. Dunn. "Quantitative Cerebral Blood Flow Measurement Through Thinned Skull with Multi Exposure Speckle Imaging." In Frontiers in Optics. Washington, D.C.: OSA, 2009. http://dx.doi.org/10.1364/fio.2009.fme2.

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Dragojević, Tanja, Danilo Bronzi, Hari M. Varma, Claudia P. Valdes, Clara Castellvi, Federica Villa, Alberto Tosi, Carles Justicia, Franco Zappa, and Turgut Durduran. "A new method utilizing novel single-photon avalanche diode arrays for multi-exposure laser speckle flowmetry." In Cancer Imaging and Therapy. Washington, D.C.: OSA, 2016. http://dx.doi.org/10.1364/cancer.2016.jw3a.13.

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Richards, Lisa M., S. M. S. Kazmi, Katherine E. Olin, James S. Waldron, Douglas J. Fox, and Andrew K. Dunn. "Multi-exposure speckle imaging of cerebral blood flow: a pilot clinical study (Conference Presentation)." In Dynamics and Fluctuations in Biomedical Photonics XIV, edited by Valery V. Tuchin, Kirill V. Larin, Martin J. Leahy, and Ruikang K. Wang. SPIE, 2017. http://dx.doi.org/10.1117/12.2251020.

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Parthasarathy, Ashwin B., S. M. Shams Kazmi, Anthony Salvaggio, and Andrew K. Dunn. "Quantitative cerebral blood flow measurement of ischemic stroke in mice with Multi Exposure Speckle Imaging." In Biomedical Optics. Washington, D.C.: OSA, 2010. http://dx.doi.org/10.1364/biomed.2010.bwa5.

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You might also be interested in the extended bibliographies on the topic 'Multi Exposure Speckle Imaging' for particular source types:
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