Gagnon Louis, Gauthier Claudine, Hoge Rick D, Lesage Frédéric, Selb Juliette, Boas David A
Institut de Génie Biomédical, Ecole Polytechnique de Montréal, C.P. 6079, succ. Centre-Ville, Montréal, Québec H3C 3A7, Canada.
J Biomed Opt. 2008 Sep-Oct;13(5):054019. doi: 10.1117/1.2982524.
We present in vivo measurements of baseline physiology from five subjects with a four-wavelength (690, 750, 800, and 850 nm) time-resolved optical system. The measurements were taken at four distances: 10, 15, 25, and 30 mm. All distances were fit simultaneously with a two-layered analytical model for the absorption and reduced scattering coefficient of both layers. The thickness of the first layer, comprising the skin, scalp, and cerebrospinal fluid, was obtained from anatomical magnetic resonance images. The fitting procedure was first tested with simulations before being applied to in vivo measurements and verified that this procedure permits accurate characterization of the hemoglobin concentrations in the extra- and intracerebral tissues. Baseline oxyhemoglobin, deoxyhemoglobin, and total hemoglobin concentrations and oxygen saturation were recovered from in vivo measurements and compared to the literature. We observed a noticeable intersubject variability of the hemoglobin concentrations, but constant values for the cerebral hemoglobin oxygen saturation.
我们展示了使用四波长（690、750、800和850纳米）时间分辨光学系统对五名受试者进行的基线生理学体内测量。测量在四个距离处进行：10、15、25和30毫米。所有距离均同时使用两层分析模型拟合，以确定两层的吸收系数和约化散射系数。包含皮肤、头皮和脑脊液的第一层厚度是从解剖磁共振图像中获得的。在将拟合程序应用于体内测量之前，首先通过模拟对其进行了测试，并验证了该程序能够准确表征脑外和脑内组织中的血红蛋白浓度。从体内测量中恢复了基线氧合血红蛋白、脱氧血红蛋白、总血红蛋白浓度和氧饱和度，并与文献进行了比较。我们观察到血红蛋白浓度在受试者之间存在明显差异，但脑血红蛋白氧饱和度的值恒定。
