@inproceedings{a619374eb03144dd9724ac02128b7cc7,
title = "Modified beer-lambert law for blood flow",
abstract = "The modified Beer-Lambert law is among the most widely used approaches for analysis of near-infrared spectroscopy (NIRS) reflectance signals for measurements of tissue blood volume and oxygenation. Briefly, the modified Beer-Lambert paradigm is a scheme to derive changes in tissue optical properties based on continuous-wave (CW) diffuse optical intensity measurements. In its simplest form, the scheme relates differential changes in light transmission (in any geometry) to differential changes in tissue absorption. Here we extend this paradigm to the measurement of tissue blood flow by diffuse correlation spectroscopy (DCS). In the new approach, differential changes of the intensity temporal auto-correlation function at a single delay-time are related to differential changes in blood flow. The key theoretical results for measurement of blood flow changes in any tissue geometry are derived, and we demonstrate the new method to monitor cerebral blood flow in a pig under conditions wherein the semi-infinite geometry approximation is fairly good. Specifically, the drug dinitrophenol was injected in the pig to induce a gradual 200% increase in cerebral blood flow, as measured with MRI velocity flow mapping and by DCS. The modified Beer-Lambert law for flow accurately recovered these flow changes using only a single delay-time in the intensity auto-correlation function curve. The scheme offers increased DCS measurement speed of blood flow. Further, the same techniques using the modified Beer-Lambert law to filter out superficial tissue effects in NIRS measurements of deep tissues can be applied to the DCS modified Beer-Lambert law for blood flow monitoring of deep tissues.",
keywords = "Optical blood flow monitoring, Spectroscopy, speckle",
author = "Baker, {Wesley B.} and Parthasarathy, {Ashwin B.} and Busch, {David R.} and Mesquita, {Rickson C.} and Greenberg, {Joel H.} and Yodh, {A. G.}",
note = "Publisher Copyright: {\textcopyright} 2015 SPIE.; Optical Tomography and Spectroscopy of Tissue XI ; Conference date: 09-02-2015 Through 11-02-2015",
year = "2015",
doi = "10.1117/12.2080185",
language = "English (US)",
series = "Progress in Biomedical Optics and Imaging - Proceedings of SPIE",
publisher = "SPIE",
editor = "Alfano, {Robert R.} and Sevick-Muraca, {Eva M.} and Tromberg, {Bruce J.} and Yodh, {Arjun G.}",
booktitle = "Optical Tomography and Spectroscopy of Tissue XI",
}