Patent ID: 6415236
Filing Date: 2002-07-02
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 of 790 to 100 nm, a second wavelength in a red wavelength region of 640 to 675 nm, and a third wavelength in an orangy red wavelength region of 590 to 660 nm; light receiving means for receiving light emitted by said light source, transmitted through a living tissue or reflected by the living tissue; attenuation ratio processing means for processing attenuation ratios on said wavelengths based on variations of signals associated with said wavelengths output from said light receiving means, said variations are caused by a pulsation of blood; and concentration ratio processing means for processing concentration ratios of at least oxyhemoglobin, deoxyhemoglobin and carboxyhemoglobin based on the output signals from said attenuation ratio processing means.