Evaluation of retinal blood flow using laser speckle phenomena

Aizu, Yoshihisa; Ogino, K.; Koyama, Tanetoshi; Takai, Nobuharù; Asakura, Toshimitsu

doi:10.2530/jslsm1980.8.3_89

Cited by 7 publications

(8 citation statements)

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“…They used band-pass filters to facilitate the calculation of this ratio and applied the technique to measure blood flow in the skin, for example at the palm, cheek, chest and leg. Later work showed that this approach was not always applicable, and the mean frequency of the oscillations was used as the velocity indicator instead (Aizu et al 1987). The mean frequency was also used in later work on blood flow in the retina and choroid of rabbits.…”

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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“…This approach was, then, modified and applied to an evaluation of blood flows at the ocular fundus of an albino rabbit 60 and human subjects. 61,62 Figure 5 shows the basic optical system of this type of the biospeckle flowmeter. The laser light illuminates a certain retinal area with an extended spot having a diameter of 1-3 mm, and is scattered by moving RBCs in blood vessels and capillaries and by ocular fundus tissues.…”

Section: Blood Flow Parameter In a Small Areamentioning

confidence: 99%

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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“…Dunn et al 6 also studied cerebral blood-flow imaging using speckles. After that, various studies on speckle blood-flow imaging have been reported including blood flow in skin tissue and retina by Fujii et al [7][8][9][10][11] , Fercher et al 12 , Briers et al 13 , and Aizu et al [14][15][16][17][18] . Other studies have been also presented on performance improvement and animal experiments [19][20][21][22][23] .…”

Section: Introductionmentioning

confidence: 99%

Simultaneous imaging of blood flow and hemoglobin concentration change in skin tissue using NIR speckle patterns

et al. 2009

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Evaluation of retinal blood flow using laser speckle phenomena

Abstract: A new method has been developed to evaluate the retinal blood flow using laser speckle phenomena.

Cited by 7 publications

References 0 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

Simultaneous imaging of blood flow and hemoglobin concentration change in skin tissue using NIR speckle patterns

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