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This article is cited in 5 scientific papers (total in 5 papers)
Saratov Fall Meeting 19: 7th International Symposium ''Optics and Biophotonics'', 23d International School for Junior Scientists and Students on Optics, Laser Physics & Biophotonics and 4th School on Advanced Fluorescence Imaging Methods
Biophotonics
Blood flow visualization by means of laser speckle-contrast measurements under the conditions of nonergodicity
A. Yu. Sdobnova, V. V. Kalchenkob, A. V. Bykova, A. P. Popova, G. Molodijb, I. V. Meglinskiacdef a Optoelectronics and Measurements Techniques Laboratory, University of Oulu, Finland
b Department of Veterinary Resources, Weizmann Institute of Science, Rehovot, Israel
c Interdisciplinary Laboratory for Biophotonics, National Research Tomsk State University, Tomsk, Russia
d Institute of Engineering Physics for Biomedicine, National Research Nuclear University (MEPhI), Moscow, Russia
e Aston Institute of Materials Research, School of Engineering and Applied Science, Aston University, Birmingham, UK
f School of Life and Health Sciences, Aston University, UK
Abstract:
The influence of stationary structural inclusions in inhomogeneous strongly scattering media such as biotissues on the results of speckle-contrast measurements using temporal and spatial methods of image processing by means of laser speckle-contrast imaging is investigated. The limits of applicability of the method of laser speckle-contrast imaging are established in detail for the case in which ergodicity conditions are not fulfilled. Based on model experiments, it is demonstrated that an increase in the number of stationary scatterers relative to that of the dynamic ones in the sampling volume introduces substantial error into the results of spatial and temporal processing of speckle images for given exposure time of the detector. At the same time, analysis of spatial and temporal speckle contrasts, the values of the coefficient of speckle dynamics, along with the results of Monte-Carlo simulation of the sampling volume, revealed that the presence of a relatively thin, up to 30% of entire volume, static layer does not introduce considerable changes into the results of measurements by the method of laser speckle-contrast imaging. The exposure time of the camera, along with the number of frames used for image processing, can be varied and chosen individually for each experiment. The developed algorithms of spatial and temporal processing of images obtained by the method of laser speckle-contrast imaging were tested in the experiments on transcranial visualization of the cerebral blood flow of a mouse.
Keywords:
scattering, laser radiation, laser speckle-contrast imaging, ergodicity, noninvasive imaging, blood flow, brain.
Received: 10.12.2019 Revised: 03.02.2020 Accepted: 28.02.2020
Citation:
A. Yu. Sdobnov, V. V. Kalchenko, A. V. Bykov, A. P. Popov, G. Molodij, I. V. Meglinski, “Blood flow visualization by means of laser speckle-contrast measurements under the conditions of nonergodicity”, Optics and Spectroscopy, 128:6 (2020), 773–782; Optics and Spectroscopy, 128:6 (2020), 778–786
Linking options:
https://www.mathnet.ru/eng/os399 https://www.mathnet.ru/eng/os/v128/i6/p773
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