Method and apparatus for using alternative site glucose determinations to calibrate and maintain noninvasive and implantable analyzers

• US 20050203358A1
• Filed: 05/04/2005
• Published: 09/15/2005
• Est. Priority Date: 03/08/2002
• Status: Abandoned Application

• Current Assignee: James R. Henderson, Kevin H. Hazen, Stephen L. Monfre, Thomas B. Blank, Timothy L Ruchti
• Original Assignee: James R. Henderson, Kevin H. Hazen, Stephen L. Monfre, Thomas B. Blank, Timothy L Ruchti
• Inventors: Henderson, James R., Ruchti, Timothy L., Monfre, Stephen L., Hazen, Kevin H., Blank, Thomas B.
• Application Number:
  US11/122,921
• Publication Number:
  US 20050203358A1
• Time in Patent Office: Days
• US Class Current: 600/331
• 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: G01N 21/274 Calibration, base line adjustment, drift correction
• CPC Class Codes: G01N 21/359 using near infrared light
• CPC Class Codes: G01N 21/49 within a body or fluid

Abstract

A method and apparatus for calibrating noninvasive or implantable glucose analyzers uses either alternative invasive glucose determinations or noninvasive glucose determinations for calibrating noninvasive or implantable glucose analyzers. Use of an alternative invasive or noninvasive glucose determination in the calibration allows minimization of errors due to sampling methodology, and spatial and temporal variations that are built into the calibration model. An additional embodiment uses statistical correlations between noninvasive and alternative invasive glucose determinations and traditional invasive glucose determinations to adjust noninvasive or alternative invasive glucose concentrations to traditional invasive glucose concentrations. The invention provides a means for calibrating on the basis of glucose determinations that reflect the matrix observed and the variable measured by the analyzer more closely. A glucose analyzer couples an invasive fingerstick meter to a noninvasive glucose analyzer for calibration, validation, adaptation, and safety check of the calibration model embodied in the noninvasive analyzer.

Claims

1. A method for calibration, comprising the steps of:

collecting spectra with a glucose analyzer from a first region on a subject'"'"'s body;

generating corresponding reference glucose concentrations from a second region on said subject'"'"'s body;

creating a first set of paired data points;

collecting a second set of reference signals from said first region;

correlating said second set of reference signals with said spectra;

creating a second set of paired data points;

determining difference in glucose concentrations between corresponding reference values from said first set of paired data points and said second set of paired data points; and

selecting a calibration set of paired spectra and reference glucose concentration from either said first set or said second set based on said difference.

2. The method of claim 1, wherein said signals comprise one of:

a set of alternative invasive signals;

a set of noninvasive signals; and

a set of implantable signals.

3. The method of claim 2, wherein said set of noninvasive signals comprise:

a set of near-infrared spectra;

4. The method of claim 3, wherein said set of near-infrared spectra are collected in a range of approximately 1150 to 1850 nm.

5. The method of claim 1, wherein said reference glucose concentrations comprise one of:

a reference set of traditional invasive glucose concentrations;

a reference set of alternative invasive glucose concentrations; and

a reference set of noninvasive glucose concentrations.

6. The method of claim 5, wherein said step of selecting comprises:

selecting said paired data points during a period of glucose stasis.

7. The method of claim 1, wherein said step of selecting data points comprises selecting differences of less than 10 percent.

8. The method of claim 1, further comprising the steps of:

perturbing circulation at said first site prior to collecting said signals to reduce said difference in glucose concentration.