| 摘要 |
The present invention generally relates to apparatus and methods for obtaining absolute values of concentrations of chromophores of a medium and/or absolute values of their ratios. In particular, the present invention relates to continuous wave spectroscopic optical systems and methods for determining the absolute values of deoxygenated and/or oxygenated hemoglobins and their ratios in a physiological medium. The optical system typically includes (1) a source module optically coupling with the medium and irradiating into the medium multiple sets of electromagnetic waves with different wave characteristics, (2) a detector module optically coupling with the medium and detecting electromagnetic waves, and (3) a processing module operatively coupling with the detector module, and determining the absolute values of the concentrations and the ratios thereof from multiple wave equations applied to the source and detector modules. The processing module is designed to obtain such absolute values by a method typically including the steps of (1) obtaining multiple sets of wave equations, (2) eliminating source-dependent and detector-dependent parameters therefrom to obtain a set of intermediate equations, (3) providing a correlation between medium-dependent and geometry-dependent parameters and the chromophore concentrations or ratios thereof, (4) incorporating the correlation into the set of intermediate equations, and (5) obtaining the absolute values of the chromophore concentrations and ratios thereof. |
