Correlative studies in optical reflectance measurements of cerebral blood oxygenation

A numerical study is made of correlation development for measuring cerebral blood oxygen saturation (StO) noninvasively using optical reflectance ratio of dual wavelengths. The Monte Carlo (MC) method was used for simulating reflectance measurements in a model neck tissue, where the cerebral blood oxygenation was monitored through the blood flows in the common carotid artery (CCA) and jugular vein. Reflectance ratios between two wavelengths at 633 and 800 nm were obtained under different blood vessel conditions. The results revealed a quantifiable correlation between the reflectance ratio and the cerebral StO level. Correlations for each of the blood vessel parameters such as the location, size, and hemoglobin concentration of the CCA or jugular vein (JV) were developed.