摘要 |
Apparatus for measuring total concentration of a chromophore having at least two functional states in tissue, including: a sensor for generating a set of absorbance values from tissue being analyzed at the first chromophore-absorbing wavelength, and for generating data representative of the functional state of the chromophore in the tissue being analyzed; memory connected to the sensor for storing absorbance values and relationship data, the relationship data being representative of lines of curves which characterize the relationship between second-derivative absorbance values at a first chromophore-absorbing wavelength and total concentration of the chromophore in tissue at constant functional state portion values; a processor connected to the memory for generating a first second-derivative absorbance value from the absorbance values, the processor further generating data representative of the total concentration of the chromophore in the tissue being analyzed as a function of the line or curve of constant functional state portion of the chromophore associated with the functional state portion data and the first second-derivative absorbance value. |