Patent ID: 6622095
Filing Date: 2003-09-16
Classification: A61B

Abstract:
An apparatus for determining concentrations of hemoglobins comprising:a light source for emitting lights of at least three different wavelengths, a first wavelength in a near-infrared wavelength region, a second wavelength in a red wavelength region, and a third wavelength in a red orange wavelength region; a light receiving means for receiving light emitted by the light source, transmitted through a living tissue or reflected by the living tissue; attenuation ratio processing means for processing attenuation ratios between the wavelengths in accordance with variations of received-light output signals in each of the wavelengths output from the light receiving means, the variations are caused by a pulsation of blood; and concentration ratio processing means for processing concentration ratios of at least oxyhemoglobin and methemoglobin based on the output signals from the attenuation ratio processing means.