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TitleLaser speckle contrast imaging: Theoretical and practical limitations
Publication TypeJournal Article
Year of Publication2013
AuthorsBriers, D., Duncan D.D., Hirst E., Kirkpatrick S.J., Larsson M., Steenbergen W., Stromberg T., and Thompson O.B.
JournalJournal of Biomedical Optics
Date Published2013
ISSN10833668 (ISSN)
Keywordsalgorithm, Algorithms, Blood flow, blood flow velocity, Contrast Media, contrast medium, Doppler effect, Doppler flowmetry, erythrocyte, Erythrocytes, Hemodynamics, human, Humans, laser, Laser doppler, Laser speckle, Lasers, Medical imaging, methodology, Microcirculation, Optics, Optics and Photonics, pathology, Perfusion, physiology, procedures, Regional Blood Flow, retina blood vessel, Retinal vessels, review, Speckle, Time-varying speckle, Ultrasonography, Doppler
AbstractWhen laser light illuminates a diffuse object, it produces a random interference effect known as a speckle pattern. If there is movement in the object, the speckles fluctuate in intensity. These fluctuations can provide information about the movement. A simple way of accessing this information is to image the speckle pattern with an exposure time longer than the shortest speckle fluctuation time scale-the fluctuations cause a blurring of the speckle, leading to a reduction in the local speckle contrast. Thus, velocity distributions are coded as speckle contrast variations. The same information can be obtained by using the Doppler effect, but producing a two-dimensional Doppler map requires either scanning of the laser beam or imaging with a high-speed camera: laser speckle contrast imaging (LSCI) avoids the need to scan and can be performed with a normal CCD-or CMOS-camera. LSCI is used primarily to map flow systems, especially blood flow. The development of LSCI is reviewed and its limitations and problems are investigated. © The Authors.

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