Evaluation of flow volume in a capillary using dynamic laser speckles based on the photon correlation

Aizu, Yoshihisa; Asakura, Toshimitsu; Ogino, K.; Sugita, Toshiaki

doi:10.1016/0030-4018(90)90495-f

Cited by 21 publications

(7 citation statements)

References 5 publications

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“…The mean frequency was also used in later work on blood flow in the retina and choroid of rabbits. The Sapporo group has also used photon correlation techniques to measure blood flow, for example in the ocular fundus of human subjects and at selected points on the retina (Aizu et al 1989(Aizu et al , 1990a(Aizu et al , 1990b(Aizu et al , 1992. All this work, including its relationship to other work, has been reviewed by Aizu and Asakura (1991).…”

Section: Time-varying Specklementioning

confidence: 99%

Laser Doppler, speckle and related techniques for blood perfusion mapping and imaging

Briers¹

2001

Physiol. Meas.

626

489

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Laser Doppler velocimetry uses the frequency shift produced by the Doppler effect to measure velocity. It can be used to monitor blood flow or other tissue movement in the body. Laser speckle is a random interference effect that gives a grainy appearance to objects illuminated by laser light. If the object consists of individual moving scatterers (such as blood cells), the speckle pattern fluctuates. These fluctuations provide information about the velocity distribution of the scatterers. It can be shown that the speckle and Doppler approaches are different ways of looking at the same phenomenon. Both these techniques measure at a single point. If a map of the velocity distribution is required, some form of scanning must be introduced. This has been done for both time-varying speckle and laser Doppler. However, with the speckle technique it is also possible to devise a full-field technique that gives an instantaneous map of velocities in real time. This review article presents the theory and practice of these techniques using a tutorial approach and compares the relative merits of the scanning and full-field approaches to velocity map imaging. The article concludes with a review of reported applications of these techniques to blood perfusion mapping and imaging.

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Section: Time-varying Specklementioning

confidence: 99%

Laser Doppler, speckle and related techniques for blood perfusion mapping and imaging

Briers¹

2001

Physiol. Meas.

626

489

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show abstract

“…This can lead to multiple scattering, which can cause a problem with the metrological use of speckle fluctuations. Previous studies 31,40 show that the reciprocal of a correlation time increases with an increasing vessel diameter or an increasing background reflectance. In those measurements, such increases of the diameter and reflectance probably enhance the order of multiple scattering in two ways: one is within the vessel and another is by backscattering from the background.…”

Section: Multiple Scattering Effectsmentioning

confidence: 92%

Coherent Optical Techniques for Diagnostics of Retinal Blood Flow

Aizu

Asakura

1999

J. Biomed. Opt.

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Up to now, a variety of coherent optical techniques have been proposed and extensively studied for diagnostics of the retinal blood flow. These techniques are mainly based on dynamic laser light-scattering phenomena such as the laser Doppler effect and the laser speckle fluctuation. This paper reviews, first, spectral reflectance properties of the ocular fundus tissue layers and, then, principles of the techniques with the comparison of the Doppler and the speckle methods. Some physical phenomena are also discussed in the origin of the techniques such as heterodyne and homodyne beatings, and time-varying speckles. Developing processes of each technique are briefly outlined. Peculiarities of blood flow measurements at the retina are finally examined from the methodological point of view. © 1999 Society of Photo-Optical Instrumentation Engineers.

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“…The frequency position of Doppler peak is defined not only by the angle of observation and velocity of scattering microflow, but also by the number of scatterers as well. Statistical properties of the non-Gaussian speckles with a small number of scatterers, in general, with the applications to high-resolution microflow measurements, also have been analyzed in several papers (13)(14)(15)(16)(17)(18). Characteristics of speckled speckles (19), which are obtained at the diffraction of focused coherent beams, have been considered in the paper (20).…”

Section: Introductionmentioning

confidence: 99%

Amplification of speckle-microscope signal by using gold nanoparticle stable of contents

Ulianova¹,

Filonova²,

Ulyanov³

et al. 2020

Front Biosci

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Evaluation of flow volume in a capillary using dynamic laser speckles based on the photon correlation

Cited by 21 publications

References 5 publications

Laser Doppler, speckle and related techniques for blood perfusion mapping and imaging

Laser Doppler, speckle and related techniques for blood perfusion mapping and imaging

Coherent Optical Techniques for Diagnostics of Retinal Blood Flow

Amplification of speckle-microscope signal by using gold nanoparticle stable of contents

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