APPARATUS AND METHOD FOR NON-INVASIVE MEASUREMENT OF THE CONCENTRATION OF A SUBSTANCE IN SUBJECT'S BLOOD

• US 20090204366A1
• Filed: 02/11/2008
• Published: 08/13/2009
• Est. Priority Date: 02/11/2008
• Status: Active Grant

• Current Assignee: GlucoVista, Inc.
• Original Assignee: GlucoVista, Inc.
• Inventors: Gerlitz, Jonathan
• Granted Patent: US 8,364,218 B2
• Time in Patent Office: Days
• US Class Current: 702/179
• 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

Abstract

A method determines the concentration of a substance in a subject'"'"'s blood. The method includes measuring an interaction of at least one light beam with a portion of the subject'"'"'s body. The method further includes calculating a value of an optically-measured parameter indicative of the interaction of the at least one light beam with the substance in the portion of the subject'"'"'s body. The method further includes measuring values of one or more temperature-indicative parameters corresponding to a temperature of the portion of the subject'"'"'s body. The method further includes accessing an empirical correlation of the optically-measured parameter and the one or more temperature-indicative parameters to concentrations of the substance in blood. The method further includes obtaining a concentration of the substance in the subject'"'"'s blood using the empirical correlation. The concentration corresponds to the value of the optically-measured parameter and the values of the one or more temperature-indicative parameters.

Claims

1. A method of determining the concentration of a substance in a subject'"'"'s blood, the method comprising:

measuring an interaction of at least one light beam with a portion of the subject'"'"'s body;

calculating a value of an optically-measured parameter indicative of the interaction of the at least one light beam with the substance in the portion of the subject'"'"'s body;

measuring values of one or more temperature-indicative parameters corresponding to a temperature of the portion of the subject'"'"'s body;

accessing an empirical correlation of the optically-measured parameter and the one or more temperature-indicative parameters to concentrations of the substance in blood; and

obtaining a concentration of the substance in the subject'"'"'s blood using the empirical correlation, wherein the concentration corresponds to the value of the optically-measured parameter and the values of the one or more temperature-indicative parameters.

2. The method of claim 1, wherein measuring the interaction of the at least one light beam comprises measuring an absorption of the at least one light beam by the portion of the subject'"'"'s body.

3. The method of claim 1, wherein measuring the interaction of the at least one light beam comprises measuring a transmittance of the at least one light beam through the portion of the subject'"'"'s body.

4. The method of claim 1, wherein measuring the interaction of the at least one light beam comprises measuring a reflection of the at least one light beam from the portion of the subject'"'"'s body.

5. The method of claim 1, wherein measuring the interaction of the at least one light beam comprises performing raman spectroscopy on the portion of the subject'"'"'s body.

6. The method of claim 1, wherein the one or more temperature-indicative parameters comprises at least one of a body temperature of the subject and an ambient temperature of the subject.

7. The method of claim 6, wherein the one or more temperature-indicative parameters comprises both a body temperature of the subject and an ambient temperature of the subject.

8. The method of claim 1, wherein the empirical correlation comprises a look-up table relating concentrations of the substance in a person'"'"'s blood to values of the optically-measured parameter and of the one or more temperature-indicative parameters.

9. The method of claim 1, wherein the empirical correlation comprises one or more formulae relating concentrations of the substance in a person'"'"'s blood to values of the optically-measured parameter and of the one or more temperature-indicative parameters.

10. The method of claim 1, wherein measuring values of the one or more temperature-indicative parameters is performed non-invasively.

11. A method of determining a correlation of a concentration of a substance in a person'"'"'s blood with a plurality of parameters, the method comprising:

invasively measuring values of the concentration of the substance in the blood of a plurality of people at a plurality of conditions, the plurality of people statistically representative of a larger population of people;

non-invasively optically measuring values of a parameter from the plurality of people at the plurality of conditions, wherein the value of the optically-measured parameter measured from a portion of a person'"'"'s body is indicative of the concentration of the substance in the person'"'"'s blood;

measuring values of one or more temperature-indicative parameters for the plurality of people at the plurality of conditions, the one or more temperature-indicative parameters corresponding to a temperature of the portion of the person'"'"'s body;

generating a correlation by correlating the measured values of the optically-measured parameter and the measured values of the one or more temperature-indicative parameters to the measured values of the concentration of the substance in the blood of the plurality of people.

12. The method of claim 11, wherein invasively measuring values of the concentration of the substance in blood comprises measuring glucose concentration of blood samples extracted from the plurality of people.

13. The method of claim 11, wherein the value of the optically-measured parameter measured from the portion of the person'"'"'s body is indicative of an absorption of light by the portion of the person'"'"'s body, a transmittance of light through the portion of the person'"'"'s body, a reflection of light from the portion of the person'"'"'s body, or a raman interaction of light with the portion of the person'"'"'s body.

14. The method of claim 11, wherein the one or more temperature-indicative parameters comprises at least one of a body temperature of the person and an ambient temperature of the person.

15. The method of claim 14, wherein the one or more temperature-indicative parameters comprises both a body temperature of the person and an ambient temperature of the person.

16. The method of claim 11, wherein the correlation is representative of an average individual.

17. The method of claim 11, further comprising preparing a look-up table comprising at least a portion of the correlation.

18. The method of claim 17, further comprising storing the look-up table in a computer-readable medium.

19. The method of claim 11, further comprising preparing one or more formulae comprising at least a portion of the correlation.

20. The method of claim 19, further comprising storing the formulae in a computer-readable medium.

21. The method of claim 11, wherein measuring values of the one or more temperature-indicative parameters is performed non-invasively.