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Depth resolution in multifocus laser speckle contrast imaging
Optics Letters, 2021Laser speckle contrast imaging (LSCI) can be used to evaluate blood flow based on spatial or temporal speckle statistics, but its accuracy is undermined by out-of-focus image blur. In this Letter, we show how the fraction of dynamic versus static light scattering is dependent on focus, and describe a deconvolution strategy to correct for out-of-focus ...
Shuqi Zheng +4 more
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61.3: Simulation and Measurement of Laser Speckle and Speckle Contrast
SID Symposium Digest of Technical Papers, 2012Abstract The simulation and experimental results of laser speckle and speckle contrast are presented. The correct speckle contrast was obtained when the ratio of the speckle size to the CCD pixel size is larger than 3.5, and the ratio of the maximum speckle intensity to the CCD saturation is in 0.3∼1.0.
Wei‐Feng Hsu +2 more
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Detrimental effects of speckle-pixel size matching in laser speckle contrast imaging
Optics Letters, 2008Through a series of simulations and experiments, we demonstrate that the frequently cited criterion of matching speckle size to detector element (pixel) size in laser speckle contrast imaging (LSCI) has the detrimental effect of reducing the contrast and thereby decreasing the variation in the laser speckle contrast image.
Sean J, Kirkpatrick +2 more
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Geometry influence on polychromatic speckle contrast
SPIE Proceedings, 2006Speckle contrast is widely used in various applications. In this work we develop a simple model to examine the influence of optical geometry on contrast reduction for polychromatic speckle the Fresnel diffraction zone. The model is based on the known fact that the sum of N independent speckle patterns decreases the contrast of the resultant pattern ...
Lioudmila Tchvialeva +5 more
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Contrast of Photographically Recorded Speckle Patterns
Optica Acta: International Journal of Optics, 1976The probability density function of the irradiance distribution of the incoherent superposition of uncorrelated speckle patterns is calculated. Using this probability density function the contrast of a photographic recording of the irradiance distribution is determined, taking the non-linearity of the film characteristic into account.
B. Eliasson, R. Dändliker
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Surgical Innovation, 2019
Background. The main limitation of perfusion assessment with indocyanine green fluorescence angiography during colorectal surgery is that the surgeon assesses the quality of perfusion subjectively.
Shigehiro Kojima +5 more
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Background. The main limitation of perfusion assessment with indocyanine green fluorescence angiography during colorectal surgery is that the surgeon assesses the quality of perfusion subjectively.
Shigehiro Kojima +5 more
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Small-N Speckle: Phase-Contrast Approach
SPIE Proceedings, 1985The theory of image plane speckle is very well confirmed by experimental data, except the case in which a considerably small-N speckle ...
M. Kowalczyk, P. Zalicki
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Calibration in laser speckle contrast imaging
Biomedical Optics, 2006We provided a novel calibration procedure in laser speckle contrast imaging that can efficiently compensate systematic errors in speckle contrast caused by speckle/pixel size mismatch and static scatters in the tissue.
Shuai Yuan +2 more
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Journal of Biophotonics, 2019
Moderate heating of collagenous tissues such as cartilage and cornea by infrared laser irradiation can produce biologically nondestructive structural rearrangements and relaxation of internal stresses resulting in the tissue reshaping.
O. Baum +8 more
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Moderate heating of collagenous tissues such as cartilage and cornea by infrared laser irradiation can produce biologically nondestructive structural rearrangements and relaxation of internal stresses resulting in the tissue reshaping.
O. Baum +8 more
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Perceptual assessment of laser‐speckle contrast
Journal of the Society for Information Display, 2012Abstract— A procedure is described for perceptually assessing the effects of laser speckle on target discrimination in the context of developing a laser‐display measurement standard. The perceptual approach avoids the difficulties inherent in assessing speckle contrast photometrically.
George A. Geri, Logan A. Williams
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