Method for adjusting a blood analyte measurement

• US 6,825,044 B2
• Filed: 11/21/2002
• Issued: 11/30/2004
• Est. Priority Date: 11/21/2001
• Status: Expired due to Fees

• Current Assignee: OptiScan Biomedical Corporation
• Original Assignee: OptiScan Biomedical Corporation
• Inventors: Witte, Kenneth G., Gable, Jennifer H., Braig, James R., Zheng, Peng, Hall, W. Dale
• Primary Examiner(s): Snay, Jeffrey R.
• Application Number:
  US10/301,927
• Publication Number:
  US 20030143116A1
• Time in Patent Office: 740 Days
• Field of Search: 436/95, 436/164, 436/171, 422/82-5-, 250/252.1, 250/341.6, 250/341.8
• US Class Current: 436/164
• 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 5/1491 Heated applicators

Abstract

A device and method for determining analyte concentrations within a material sample are provided. A modulating temperature gradient is induced in the sample and resultant, emitted infrared radiation is measured at selected analyte absorbance peaks and reference wavelengths. The modulating temperature gradient is controlled by a surface temperature modulation. A transfer function relating the surface temperature modulation to a modulation of the measured infrared radiation is provided. Phase and magnitude differences in the transfer function are detected. These phase and magnitude differences, having a relationship to analyte concentration, are measured, correlated and processed to determine analyte concentration in the material sample. A method for adjusting an analyte measurement is provided. The method provides a hydration correction process for calibration and correction whereby analyte concentrations within the material sample may be determined. The hydration correction process is particularly suitable for determining blood analyte concentrations within human tissue.

Claims

1. A method of analyzing a material sample, said method comprising:

placing said material sample in operative engagement with an analyte detection system;

operating said analyte detection system according to an operation algorithm by which said analyte detection system computes a hydration correction coefficient based on changes in electromagnetic energy generated and emitted by at least one of said material sample and a test sample;

determines an estimated concentration of an analyte in said material sample; and

reduces the effect of a hydration level of said material sample on said estimated concentration.

2. The method of claim 1, further comprising inducing a periodically modulated thermal gradient in said material sample.

3. The method of claim 1, wherein said analyte detection system determines said estimated concentration based on a phase of electromagnetic energy emitted d by said material sample.

4. The method of claim 1, wherein said analyte detection system determines said estimated concentration based on a phase difference between multiple w wavelength-specific signals of electromagnetic energy emitted by said material sample.

5. A method of analyzing a material sample, said method comprising:

detecting non-reflected electromagnetic energy generated and emitted by at least one of said material sample and a test sample;

determining a hydration correction coefficient base on aid non-reflected electromagnetic energy;

placing said material sample in operative engagement with a analyte detection system;

determining an estimated concentration of an analyte in said material sample; and

reducing the effect of a hydration level of said material sample on said estimated concentration.

6. The method of claim 5, further comprising inducing a periodically modulated thermal gradient in said material sample.

7. The method of claim 5, wherein determining said estimated concentration comprises measuring a phase of electromagnetic energy emitted by said material sample.

8. The method of claim 5, wherein determining said estimated concentration comprises measuring a phase difference between multiple wavelength-specific signals of electromagnetic energy emitted by said material sample.

9. An analyte detection system comprising:

a detector array;

a processing circuit in communication with said detector array; and

a module executable by said processing circuit whereby said processing circuit computes a hydration correction coefficient based on internal electromagnetic emissions of least one of a material sample and a test sample;

computes an estimated concentration of an analyte in said material sample and reduces the effect of a hydration level of said material sample on said estimated concentration.

10. The system of claim 9, wherein said processing circuit computes said estimated concentration based on a phase of electromagnetic energy emitted by said material sample.

11. The system of claim 9, wherein said processing circuit computes said estimated concentration based on a phase difference between multiple wavelength-specific signals of electromagnetic energy emitted by said material sample.