Authors:
Denis Lapitan
1
;
Dmitry Rogatkin
1
;
Saydulla Persheyev
2
and
Andrey Rogatkin
3
Affiliations:
1
Moscow Regional Research and Clinical Institute "MONIKI" named after M.F.Vladimirsky, Russian Federation
;
2
School of Physics and Astronomy, St Andrews University, United Kingdom
;
3
LLC "Research & Development Center EOS-Medica", Russian Federation
Keyword(s):
Doppler Effect, Laser, Flowmetry, Noninvasive, Blood Flow, Tissue, Model, Spectrum, Intensity, Frequency.
Abstract:
Laser Doppler flowmetry (LDF) for measurements of tissue blood flow is well-known today. The basic theory of forming the registered optical signal in LDF is the model developed by R.Bonner and R. Nossal. However, claiming to be a detailed and comprehensive analysis of the interaction of light with tissues, it does not describe many phenomena. Multiple simplifications and assumptions in the model diminish the efforts on the analysis of peculiarities of light scattering inside the tissue, resulting in a very approximate output. In this our study, a qualitatively similar result was obtained with the use of more simple and general approach. It was shown, that the power spectra of analyzed signals in the form of the exponential decay, similar to a fractal noise (1/f noise), is a consequence mainly of the Maxwell’s distribution of moving particles’ velocities. Moreover, in contrast to the classic model, our model shows that the first moment of the frequency is linearly proportional not onl
y to the velocity of red blood cells, but also is inversely proportional to the wavelength of illuminating radiation, that is more physically grounded.
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