Method for the spectroscopic determination of the oxygen saturation of blood in the presence of optical disturbance varibles

Abstract

The invention is directed to a method for the spectrometric determination of the oxygen saturation of blood in the presence of optical disturbance variables in which transmission measurements and reflection measurements are carried out in at least two wavelengths that are isosbestic for hemoglobin and oxyhemoglobin, and at least one other wavelength at which the extinction of hemoglobin and oxyhemoglobin differ. Corresponding auxiliary functions are defined in the measurement spectrum (M) and in the reference spectra of hemoglobin and oxyhemoglobin, at least two of the measurement values or two of the reference values for the isosbestic wavelengths lying on this auxiliary function. A corrected measurement spectrum (M″) is generated by means of the two auxiliary functions. The oxygen saturation is determined by comparing the changed data of this corrected measurement spectrum (M″) with the data of the reference spectra at the other wavelength.

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         4 . A method for determining the oxygen saturation of blood in the presence of optical disturbance variables, the method comprising:
 generating at least two transmission or reflection isosbestic measuring values at wavelengths that are isosbestic for hemoglobin and oxyhemoglobin;   generating at least one transmission or reflection non-isosbestic measuring value at a wavelength that is non-isosbestic hemoglobin and oxyhemoglobin;   using the two isosbestic measuring values to determine a corrected function of the optical disturbance; and   using the correction function to determine the oxygen saturation.   
     
     
         5 . A method for determining the oxygen saturation of blood in the presence of optical disturbance values, the method comprising:
 generating at least one transmission or reflection non-isosbestic measuring value for a non-isosbestic wavelength for hemoglobin and oxyhemoglobin;   wherein the non-isosbestic measuring value for hemoglobin and the non-isosbestic measuring value for oxyhemoglobin duffer as far as possible in the reference spectra.