N. D. Abramovich, V. V. Barun, S. K. Dick, and A. S. Terekh, Belarus State University of Informatics and Radioelectronics,Brovka Str. 6, Minsk 220013, Belarus
The speckle structure of scattered light is known to be currently used for solving a number of inverse problems of biomedical optics. The examples are the diagnostics of various structural and biophysical parameters of tissues and, in particular, of blood flow velocity, the monitoring of therapy efficiency, including low-level light and photodynamic therapies, and the control of mechanical properties of tissues. This paper analytically simulates speckle patterns observed in tissue-reflected light. Multiple scattering and layered structure of the medium are accounted for. The investigations use the combination of the known engineering methods of light scattering optics, namely, the analytical approaches to solve the radiation transfer equation, the relation between the radiative transfer and coherence theories, and the methods of describing image transfer through a scattering medium. The main simulated parameters are the limiting contrast of the speckle pattern and the speckle sizes. The limiting contrast is meant the maximal contrast value observed for stationary scatterers. This quantity is useful for practical evaluations of what one can expect from a specific experimental setup for a particular tissue in the “best” case, whereas in practice the contrast will be poorer owing to the movement of scatterers. The examples of the above two parameters are given for various structural and biophysical characteristics of skin tissue, illumination wavelengths, and pixel sizes of an imaging device.
Mr. Vladimir Barun
Institute of Physics, Researcher
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