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A method for monitoring of oxygen saturation changes in brain tissue using diffuse reflectance spectroscopy
Author(s) -
Rejmstad Peter,
Johansson Johannes D.,
HajHosseini Neda,
Wårdell Karin
Publication year - 2017
Publication title -
journal of biophotonics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.877
H-Index - 66
eISSN - 1864-0648
pISSN - 1864-063X
DOI - 10.1002/jbio.201500334
Subject(s) - diffuse reflectance infrared fourier transform , reflectivity , diffuse reflection , brain tissue , spectroscopy , saturation (graph theory) , materials science , oxygen saturation , oxygen , analytical chemistry (journal) , nuclear magnetic resonance , optics , biomedical engineering , chemistry , medicine , physics , mathematics , environmental chemistry , biochemistry , organic chemistry , photocatalysis , combinatorics , catalysis , quantum mechanics
Continuous measurement of local brain oxygen saturation (SO 2 ) can be used to monitor the status of brain trauma patients in the neurocritical care unit. Currently, micro‐oxygen‐electrodes are considered as the “gold standard” in measuring cerebral oxygen pressure (pO 2 ), which is closely related to SO 2 through the oxygen dissociation curve (ODC) of hemoglobin, but with the drawback of slow in response time. The present study suggests estimation of SO 2 in brain tissue using diffuse reflectance spectroscopy (DRS) for finding an analytical relation between measured spectra and the SO 2 for different blood concentrations. The P 3 diffusion approximation is used to generate a set of spectra simulating brain tissue for various levels of blood concentrations in order to estimate SO 2 . The algorithm is evaluated on optical phantoms mimicking white brain matter (blood volume of 0.5–2%) where pO 2 and temperature is controlled and on clinical data collected during brain surgery. The suggested method is capable of estimating the blood fraction and oxygen saturation changes from the spectroscopic signal and the hemoglobin absorption profile.