Method for providing general calibration for near infrared instruments for measurement of blood glucose

• US 5,576,544 A
• Filed: 01/22/1993
• Issued: 11/19/1996
• Est. Priority Date: 01/19/1989
• Status: Expired due to Term

• Current Assignee: Futrex, Inc.
• Original Assignee: Futrex, Inc.
• Inventors: Rosenthal, Robert D.
• Primary Examiner(s): Willis, Davis L.
• Assistant Examiner(s): HANIG, RICHARD E
• Application Number:
  US08/007,967
• Time in Patent Office: 1,397 Days
• Field of Search: 250/341, 250/339, 250/343, 356/39, 128/633
• US Class Current: 250/341.1
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: A61B 5/1495 Calibrating or testing of in-vivo probes
• CPC Class Codes: A61N 5/06 using light
• CPC Class Codes: G01N 21/274 Calibration, base line adjustment, drift correction
• CPC Class Codes: G01N 21/314 with comparison of measurements at specific and non-specific wavelengths dual wavelength spectrometry G01J3/427
• CPC Class Codes: G01N 21/359 using near infrared light
• CPC Class Codes: G01N 2201/129 Using chemometrical methods

Abstract

A method is disclosed for accurately providing general calibration of near-infrared quantitative analysis instruments for almost any individual user. The general calibration method comprises comparing an individual'"'"'s near-infrared spectrum to a plurality of near-infrared spectral clusters. Each near-infrared spectral cluster has a set of calibration constants associated therewith. The calibration constants of the spectral cluster most closely associated with the individual spectra are used to custom calibrate the near-infrared analysis measurement instrument.

Claims

1. A method for accurately calibrating a near-infrared analysis instrument for the measurement of a blood analyte, said method comprising:

(a) obtaining a near-infrared optical absorption measurement in a body part of an individual, wherein said near-infrared optical measurement is made using energy of between about 600 to 1000 nanometers;

(b) applying said optical measurement to an initial calibration means for calibrating said optical measurement over substantially the entire range of possible blood analyte concentrations and determining a first calibrated value;

(c) determining whether said first calibrated value falls into at least a first higher range of possible blood analyte concentrations or a first lower range of possible blood analyte concentrations, said first higher range and said first lower range comprises substantially non-overlapping portions of said entire range of possible blood analyte concentrations, said first higher range and said first lower range each comprising a second calibration means corresponding thereto;

(d) applying to said first calibrated value said second calibration means corresponding to said first higher range or said first lower range based on the determination whether said first calibrated value falls within said first higher range or said first lower range, and producing a second calibrated value representing the measurement of said blood analyte.

2. The method as set forth in claim 1, further comprising applying a third calibration means to said second calibrated value if said second calibrated value falls within a second lower range of blood analyte concentrations, producing a third calibrated value representing the measurement of said blood concentrations.

3. The method as set forth in claim 1, wherein said blood analyte is blood glucose levels.