JPH067828B

The invention relates in particular to a process for determination of local dye concentrations in animal and human tissues. Light from two different wavelength regions (I, II), of which one (I) has a window for haemoglobin, is directed into the partial area of the tissue, and the reflectance (M10, M110) is determined. Then, in a further step, on the basis of the reflectance in the first wavelength region and at least one previously obtained tissue-type-specific standard basic reflectance curve for both wavelength regions, a personal tissue-specific standard basic reflectance curve (S110) is determined for the second wavelength region (II), and a value for the haemoglobin concentration (KHb1) is obtained on the basis of the determined personal tissue-specific standard basic reflectance curve (S110) and the measured reflectance (M110) in the second wavelength region (II).