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Journal of Biomedical Optics • Open Access

On the equivalence and differences between laser Doppler flowmetry and laser speckle contrast analysis
Author(s): Ingemar Fredriksson; Marcus Larsson

Paper Abstract

Laser Doppler flowmetry (LDF) and laser speckle contrast analysis (LASCA) both utilize the spatiotemporal properties of laser speckle patterns to assess microcirculatory blood flow in tissue. Although the techniques analyze the speckle pattern differently, there is a close relationship between them. We present a theoretical overview describing how the LDF power spectrum and the LASCA contrast can be calculated from each other, and how both these can be calculated from an optical Doppler spectrum containing various degrees of Doppler shifted light. The theoretical relationships are further demonstrated using time-resolved speckle simulations. A wide range of Monte Carlo simulated tissue models is then used to show how perfusion estimates for LDF and LASCA are affected by changes in blood concentration and speed distribution, as well as by geometrical and optical properties. We conclude that perfusion estimates from conventional single exposure time LASCA are in general more sensitive to changes in optical and geometrical properties and are less accurate in the prediction of real perfusion changes, especially speed changes. Since there is a theoretical one-to-one relationship between Doppler power spectrum and contrast, one can conclude that those drawbacks with the LASCA technique can be overcome using a multiple exposure time setup.

Paper Details

Date Published: 23 December 2016
PDF: 11 pages
J. Biomed. Opt. 21(12) 126018 doi: 10.1117/1.JBO.21.12.126018
Published in: Journal of Biomedical Optics Volume 21, Issue 12
Show Author Affiliations
Ingemar Fredriksson, Linköping Univ. (Sweden)
Perimed AB (Sweden)
Marcus Larsson, Linköping Univ. (Sweden)

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