Patent ID: 6339714
Filing Date: 2002-01-15
Classification: A61B

Abstract:
A method of measuring concentrations of a light-absorbing material in a living organism, comprising the steps of:a) directing light into the living organism at a chosen site; b) detecting light transmitted through or reflected from the living organism at one wavelength and determining its optical intensity at a time before a predetermined initial time; c) measuring the concentration of blood hemoglobin; d) injecting a defined amount of said light-absorbing material absorbing light at said wavelength into the circulatory system of the living organism at said initial time; e) detecting light transmitted through or reflected from the living organism at said wavelength and determining its optical intensity immediately after said initial time; f) calculating concentrations of said light-absorbing material by comparing the optical intensities of said one wavelength detected before and after said initial time and by utilizing the value of said concentration of blood hemoglobin; g) determining the concentration time curve of said light-absorbing material; h) to determine physiological parameters analyzing said concentration time curve.