High-resolution speckle-microscopy: study of the spatial structure of a bioflow.

Perspectives of velocity measurements of a random bioflow and its spatial structure by speckle-methods are studied in this paper. The mechanism of output signal formation and the optical scheme of the speckle-microscope are described. Amplitude, phase and frequency characteristics of this measuring system are investigated. The main types of signal distortions in the speckle-microscope are considered. Results of the analysis of output characteristics are applied to measurements of the spatial distribution of the refractive index of a blood flow in a small single microvessel. It is shown that the minimal size of flow inhomogeneities (with fluctuations in the optical path of the investigated object, less than 0.01 lambda) that can be resolved by the speckle-microscope is about a quarter of the waist beam diameter.

[1]  Y. Aizu,et al.  Bio-Speckle Phenomena for Blood Flow Measurements: Speckle Fluctuations and Doppler Effects , 2000 .

[2]  Y. Aizu,et al.  Evaluation of blood flow at ocular fundus by using laser speckle. , 1992, Applied optics.

[3]  Experimental study of intensity probability density function in the speckle pattern formed by a small number of scatterers , 1993 .

[4]  B. Petrig,et al.  Choroidal blood flow by laser Doppler flowmetry , 1995 .

[5]  C. Riva,et al.  Laser Doppler measurements of blood flow in capillary tubes and retinal arteries. , 1972, Investigative ophthalmology.

[6]  A. P. Shepherd,et al.  Laser-Doppler Blood Flowmetry , 2010, Developments in Cardiovascular Medicine.

[7]  H. M. Escamilla,et al.  Speckle Contrast in the Diffraction Field of a Weak Random-phase Screen When the Illuminated Region Contains a Few Correlation Areas , 1983 .

[8]  Tomoaki Eiju,et al.  Microscopic laser Doppler velocimeter for blood velocity measurement , 1993 .

[9]  Toshimitsu Asakura,et al.  NONINVASIVE EVALUATION OF THE RETINAL BLOOD CIRCULATION USING LASER SPECKLE PHENOMENA , 1990 .

[10]  H. Mishina,et al.  A laser Doppler microscope , 1974 .

[11]  T. Asakura,et al.  Measurements of flow velocity in a microscopic region using dynamic laser speckles based on the photon correlation , 1989 .

[12]  Toshimitsu Asakura,et al.  Bio-speckle phenomena and their application to the evaluation of blood flow , 1991 .

[13]  P. Chandley,et al.  Speckle from a rough surface when the illuminated region contains few correlation areas: The effect of changing the surface height variance , 1979 .

[14]  Y. Aizu,et al.  Coherent optical techniques for diagnostics of retinal blood flow. , 1999, Journal of biomedical optics.

[15]  Valery V. Tuchin,et al.  Fundamentals and applications of dynamic speckles induced by focused laser beam scattering , 1994 .

[16]  M. H. Koelink,et al.  Laser Doppler blood flowmetry using two wavelengths: Monte Carlo simulations and measurements. , 1994, Applied optics.

[17]  A. P. Shepherd.  History of Laser-Doppler Blood Flowmetry , 1990 .

[18]  S. Ulyanov.  Speckled speckle statistics with a small number of scatterers: implication for blood flow measurement. , 1998, Journal of biomedical optics.

[19]  Sergey S. Ulyanov,et al.  Dynamic speckles formed by focused coherent field scattering from rough surfaces with non-Gaussian statistics , 1995, Optics & Photonics.

[20]  Toshimitsu Asakura,et al.  Evaluation of flow volume in a capillary using dynamic laser speckles based on the photon correlation , 1990 .

[21]  J D Briers,et al.  Laser speckle contrast analysis (LASCA): a nonscanning, full-field technique for monitoring capillary blood flow. , 1996, Journal of biomedical optics.

[22]  Sergey S. Ulyanov.  New type of manifestation of the Doppler effect: an application to blood and lymph flow measurements , 1995 .

[23]  J. David Briers,et al.  Laser Doppler and time-varying speckle: a reconciliation , 1996 .

[24]  Charles E. Riva,et al.  Fundus camera based retinal LDV. , 1981, Applied optics.

[25]  D. Fried,et al.  Laser eye safety: the implications of ordinary speckle statistics and of speckled-speckle statistics. , 1981, Journal of the Optical Society of America.

[26]  Valery V. Tuchin,et al.  In-vivo laser measurements of blood and lymph flow with a small number of scatterers , 1996, Other Conferences.

[27]  J. Lacuara,et al.  Comparison of the Effects of He:Neon and Nd:YAG Laser Radiation on Mitotic Activity of Meristematic Cells of Allium cepa L. Bulbs , 1990 .

[28]  J. Goodman.  Introduction to Fourier optics , 1969 .

[29]  A Yoshida,et al.  Laser based instruments for ocular blood flow assessment. , 1998, Journal of biomedical optics.

[30]  Y Aizu,et al.  Compensation of eye movements in retinal speckle flowmetry using flexible correlation analysis based on the specific variance. , 1998, Journal of biomedical optics.

[31]  E. Jakeman.  Speckle Statistics With A Small Number Of Scatterers , 1984 .

[32]  Dynamics of statistically inhomogeneous speckles: a new type of manifestation of the Doppler effect. , 1995, Optics letters.