Method for measuring glucose concentration in blood using infrared spectroscopy and instrument employing it

• US 7,974,669 B2
• Filed: 07/26/2005
• Issued: 07/05/2011
• Est. Priority Date: 07/30/2004
• Status: Expired due to Fees

• Current Assignee: National University Corporation Chiba University, National University Corporation (University of Fukui)
• Original Assignee: National University Corporation Chiba University
• Inventors: Kitamura, Akihide, Karatsu, Takashi, Nomura, Fumio
• Primary Examiner(s): Prouty; Rebecca E
• Assistant Examiner(s): Martin; Paul C
• Application Number:
  US11/572,960
• Publication Number:
  US 20090004682A1
• Time in Patent Office: 2,170 Days
• Field of Search: None
• US Class Current: 600/316
• CPC Class Codes: G01N 21/3577 for analysing liquids, e.g. polluted water

Abstract

The objective of the present invention is to provide a method and instrument for measuring glucose concentration in blood using infrared spectroscopy. Glucose concentration in blood is measured based on an integrated value obtained by measuring an absorption spectrum that includes the wavenumber range of 1020-1040 cm⁻¹, and by integrating the intensity of absorption of the wavenumber range of 1020-1040 cm⁻¹ within the absorption spectrum. Alternatively, a glucose concentration in blood is measured based on an integrated value through measuring an absorption spectrum including the wavenumber range of 1010-1050 cm^{31 1}; obtaining a second-derivative spectrum by calculating a second derivative of the absorption spectrum that includes the wavenumber range of 1010-1050 cm⁻¹ in the absorption spectrum; determining an integration range based on the second derivative spectrum; and then obtaining the integrated value by integrating the intensity of absorption based on this determined integration range.

Claims

1. A method for measuring a glucose concentration in blood, comprising the steps of:

measuring an absorption spectrum that includes a wavenumber range of 1020-1040 cm<sup>−

1</sup> by pressing a forefinger to an ATR prism and receiving the reflected light by said forefinger;

obtaining a second derivative spectrum by calculating the second derivative of said absorption spectrum for the wavenumber range 1020-1040 cm<sup>−

1</sup>;

determining, based on said second derivative spectrum, two peak points to be used as bases for an integration range, said two peak points being two upward peaks that surround a downward peak in the wavenumber range 1020-1040 cm<sup>−

1</sup> of said second derivative spectrum;

obtaining an integrated value by integrating the absorption intensity in said absorption spectrum using said integration range that corresponds to said determined two peak points; and

determining the glucose concentration in blood based on a relationship between pre-obtained integrated values and glucose concentrations, and said integrated value obtained from said absorption spectrum.