Abstract: A method for estimating a local metabolic parameter of an area of tissue of a patient. The method receives light intensities from the area of tissue in question for at least three different wavelengths selected according to the absorptive power of different types of haemoglobin, on the basis of the absorbancy values calculated using the light intensities measured for the three wavelengths. The method determines a oxyhaemoglobin concentration and a deoxyhaemoglobin concentration and estimates at least one local metabolic parameter on the basis of the calculated oxyhaemoglobin and deoxyhaemo-globin concentrations.

Abstract: The invention relates to a method for estimating a local metabolic parameter of an area of tissue of a patient, said method comprising: receiving (10) light intensities from the area of tissue in question for at least three different wavelengths selected according to the absorptive power of different types of haemoglobin; on the basis of the absorbancy values calculated using the light intensities measured for the three wavelengths, determining (40) a oxyhaemoglobin concentration and a deoxyhaemoglobin concentration; and estimating (50) at least one local metabolic parameter on the basis of the calculated oxyhaemoglobin and deoxyhaemoglobin concentrations.