Apparatus using reference measurement for calibration

• US 7,183,102 B2
• Filed: 05/04/2005
• Issued: 02/27/2007
• Est. Priority Date: 03/08/2002
• Status: Expired due to Fees

• Current Assignee: GLT Acquisition Corporation
• Original Assignee: Sensys Medical, Inc. (Sensys Medical Limited)
• Inventors: Henderson, James R., Ruchti, Timothy L., Monfre, Stephen L., Hazen, Kevin H., Blank, Thomas B.
• Primary Examiner(s): GITOMER, RALPH J
• Application Number:
  US11/122,669
• Publication Number:
  US 20050203364A1
• Time in Patent Office: 664 Days
• Field of Search: 435/287.1, 435/288.7, 250/341.5
• US Class Current: 435/287.1
• 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: 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 that uses either alternative invasive glucose determinations or noninvasive glucose determinations to calibrate 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. An apparatus for measuring a tissue analyte In vivo, comprising:

a first component for generating a noninvasive measurement of said tissue analyte;

a second component for generating an invasive reference measurement of said tissue analyte, said first and second components electromagnetically coupled; and

means for using said reference measurement to optimize calibration of said apparatus.

2. The apparatus of claim 1, wherein said tissue analyte comprises glucose.

3. The apparatus of claim 2, wherein said second component comprises one of:

an alternative invasive glucose analyzer; and

a traditional invasive glucose analyzer.

4. The apparatus of claim 2, further comprising:

memory means for storing any of said measurements.

5. The apparatus of claim 4, wherein said means for optimizing said calibration comprises:

computer program means for optimizing said calibration, said program means embodied in said memory means; and

a processing element configured to execute said program means.

6. The apparatus of claim 5, said program means comprising program means for using a second calibration to adjust any of:

said calibration; and

a bias correction.

7. The apparatus of claim 6, where said second calibration is used in any of:

a calibration assignment;

a validation;

a quality assurance procedure; and

a quality control procedure.

8. The apparatus of claim 3, wherein said first component comprises a near-infrared glucose analyzer.

9. The apparatus of claim 1, wherein said first component and said second component are integrated.

10. The apparatus of claim 1, wherein said first component and said second component are separate units.

11. The apparatus of claim 10, wherein said first component and said second component are wirelessly electromagnetically coupled.

12. The apparatus of claim 11, wherein said first component and said second component are wirelessly electromagnetically coupled through any of telemetry, infrared signals, and radiowaves.