Model-based quantitative laser Doppler flowmetry in skin
2010 (English)In: Journal of Biomedical Optics, ISSN 1083-3668, Vol. 15, no 5Article in journal (Refereed) Published
Laser Doppler Flowmetry (LDF) can be used for assessing the microcirculatory perfusion. However, conventional LDF (cLDF) gives only a relative perfusion estimate in an unknown measurement volume. To overcome these limitations a model-based analysis method for quantitative LDF (qLDF) is proposed. The method uses an inverse Monte Carlo technique with an adaptive three layer skin model. By analyzing the optimal model where measured and simulated LDF spectra using two different source-detector separations match, the absolute microcirculatory perfusion for a specified velocity region in a predefined volume is determined. The robustness of the qLDF method and how much it is affected by physiologically relevant variations in optical properties were evaluated using additional Monte Carlo simulations. When comparing qLDF to cLDF, a much smaller deviation from the true perfusion was attained. For physiologically relevant variations in the optical properties of static tissue and blood absorption, qLDF displayed errors <12%. Variations in the scattering properties of blood displayed larger errors (<58%). Evaluations on inhomogeneous models containing small blood vessels, hair and sweat glands displayed errors <5%. For extremely inhomogeneous models containing larger blood vessels, the error increased substantially, but this was detected by analyzing the qLDF model residual. The qLDF algorithm was applied to an in vivo local heat provocation. The perfusion increase was higher with qLDF than cLDF, due to non-linear effects in the latter. The qLDF showed that the perfusion increase was due to an increased amount of blood cells with a velocity > 1 mm/s.
Place, publisher, year, edition, pages
Society of Photo-optical Instrumentation Engineers , 2010. Vol. 15, no 5
laser Doppler flowmetry, microcirculation, tissue modeling, inverse Monte Carlo, quantitative measures, flow speed differentiation
Medical Laboratory and Measurements Technologies
IdentifiersURN: urn:nbn:se:liu:diva-20445DOI: 10.1117/1.3484746ISI: 000284837400046OAI: oai:DiVA.org:liu-20445DiVA: diva2:234423