Methods and device for non-invasive analyte measurement

• US 20040220457A1
• Filed: 05/02/2003
• Published: 11/04/2004
• Est. Priority Date: 05/02/2003
• Status: Active Grant

• Current Assignee: John F. Burd
• Original Assignee: Oculir, Inc.
• Inventors: Kramer, Charles E., Fraden, Jacob, Sell, William, Burd, John F., Krantz, Gary
• Granted Patent: US 6,968,222 B2
• Time in Patent Office: Days
• US Class Current: 600/310
• CPC Class Codes: A61B 3/10 Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters

Abstract

The present invention is related to optical non-invasive methods and instruments to detect the level of analyte concentrations in the tissue of a subject. The spectra of mid-infrared radiation emitted from a subject'"'"'s body are altered corresponding to the concentration of various compounds within the radiating tissue. In one aspect of the invention, an instrument floods a body surface of the subject, such as the subject'"'"'s eye, with radiation in the mid-infrared range and measures analyte concentrations based on mid-infrared radiation reflected back to the instrument.

Claims

1. A method comprising the steps:

a. exposing a body surface of a subject to mid-infrared radiation;

b. detecting mid-infrared radiation reflected from said body surface; and

,

c. determining a radiation signature of said reflected mid-infrared radiation to determine an analyte concentration in a tissue of said subject.

2. The method of claim 1, wherein said method is non-invasive and wherein said subject is a human.

3. The method of claim 1, wherein said analyte is selected from the group consisting of metabolic compounds or substances, carbohydrates, sugars, glucose, proteins, peptides, amino acids, fats, fatty acids, triglycerides, polysaccharides, alcohols, ethanol, toxins, hormones, vitamins, bacteria-related substances, fungus-related substances, virus-related substances, parasite-related substances, pharmaceutical compounds, non-pharmaceutical compounds, pro-drugs, drugs, and any precursor, metabolite, degradation product or surrogate marker.

4. The method of claim 3, wherein said analyte is glucose.

5. The method of claim 1, wherein said tissue is selected from the group consisting of skin, blood, body fluids, eye, interstitial fluid, ocular fluid, bone, muscle, epithelium, fat, hair, fascia, organs, cartilage, tendons, ligaments, and mucous membrane.

6. The method of claim 1, wherein the mid-infrared radiation of step a) is in a wavelength range of about 2.5 microns to about 25.0 microns.

7. The method of claim 1, wherein said detecting step further comprises selecting and detecting said mid-infrared radiation.

8. The method of claim 7, wherein said selecting of said reflected mid-infrared radiation further comprises filtering said reflected mid-infrared radiation.

9. The method of claim 1, wherein said detecting step and said determining steps further comprise using a microprocessor.

10. The method of claim 1, wherein said reflected mid-infrared radiation comprises infrared radiation having wavelengths between about 2.5 microns to about 25.0 microns.

11. The method of claim 10, wherein said reflected mid-infrared radiation is within the wavelengths between about 2.5 microns to about 11.0 microns.

12. An instrument comprising:

a. a radiation source capable of generating mid-infrared radiation;

b. a mid-infrared radiation wavelength detector for detecting said generated mid-infrared radiation reflected from a surface of a subject'"'"'s body; and

,

c. a display for alphanumeric or audio representations of an analyte concentration in a tissue of said subject.

13. The instrument of claim 12, further comprising a microprocessor for correlating said detected mid-infrared radiation with wavelengths corresponding to said analyte concentration and analyzing said wavelengths to calculate said analyte concentration in said tissue.

14. The instrument of claim 12, wherein said mid-infrared radiation detector is selected from the group consisting of a thermocouple, a thermistor, a microbolometer, and liquid nitrogen cooled MCT.

15. The instrument of claim 12, wherein said mid-infrared radiation wavelength detector further comprises a mid-infrared radiation selector.

16. The instrument of claim 15, wherein said selector further comprises a filter which is selected from the group consisting of absorption filters, interference filters, monochromators, linear and circular variable filters, and prisms.

17. The instrument of claim 12, wherein said display is an alphanumeric representation selected from the group consisting of a liquid crystal display (LCD), a plasma display panel (PDP), and a field emission display (FED).

18. The instrument of claim 12, wherein said display is an audio display comprising speakers.

19. The instrument of claim 18, wherein said audio display is provided with an audio source selected from a group consisting of recorded audio clips, speech synthesizers and voice emulation algorithms.

20. The instrument of claim 12, wherein said instrument further comprises an infrared spectrometer.

21. The instrument of claim 13, wherein said microprocessor further comprises a memory which is operatively coupled to said microprocessor.

22. The instrument of claim 12, wherein said instrument further comprises a communications interface, wherein said interface is selected from the group consisting of serial, parallel, USB (universal serial bus), FireWire, Ethernet, fiber optic, co-axial, and twisted pair cables.

35. A computer system for downloading and storing data, collected from an instrument according to claim 12 or 23, comprising:

a. a computer processor;

b. a memory which is operatively coupled to said computer processor;

c. a communications interface adapted to receive and send data within said computer processor; and

d. a computer program stored in said memory which executes in said computer processor.

36. A method of downloading and storing a subject'"'"'s measured analyte concentration, comprising the steps of:

a. measuring said analyte concentration using a non-invasive instrument of claim 12 or 23 having a communications interface;

b. connecting said non-invasive instrument through said communications interface to a computer system having a computer processor, a computer program which executes in said computer processor, and an analogous communications interface; and

c. downloading from said non-invasive instrument to said computer system said measured analyte concentrations.

23. An instrument comprising:

a. a radiation source of mid-infrared radiation within the range of about 2.5 to about 25.0 microns; and

b. a mid-infrared radiation detector for detecting said mid-infrared radiation transmitted through a tissue of a subject within a wavelength range of between about 8.0 to about 11.0 microns.

24. The instrument of claim 23, further comprising a microprocessor for correlating said transmitted mid-infrared radiation with a radiation signature corresponding to an analyte concentration and analyzing said radiation signature to calculate said analyte concentration in said tissue of said subject.

25. The instrument of claim 23, wherein said mid-infrared radiation detector is selected from the group consisting of a thermocouple, a thermistor, a microbolometer, and liquid nitrogen cooled MCT.

26. The instrument of claim 23, wherein said mid-infrared radiation detector further comprises a mid-infrared radiation selector.

27. The instrument of claim 26, wherein said selector further comprises a filter which is selected from the group consisting of absorption filters, interference filters, monochromators, linear and circular variable filters, and prisms.

28. The instrument of claim 23, further comprising a display selected from the group consisting of a liquid crystal display (LCD), a plasma display panel (PDP), and a field emission display (FED).

29. The instrument of claim 28, wherein said display is an audio display comprising speakers.

30. The instrument of claim 29, wherein said audio display is provided with an audio source selected from a group consisting of recorded audio clips, speech synthesizers and voice emulation algorithms.

31. The instrument of claim 23, wherein said instrument further comprises an infrared spectrometer.

32. The instrument of claim 24, wherein said microprocessor further comprises a memory which is operatively coupled to said microprocessor.

33. The instrument of claim 23, wherein said instrument further comprises a communications interface adapted to transmit data from said instrument to a computer system.

34. The instrument of claim 33, wherein said communications interface is selected from the group consisting of standard input/output, serial cable, parallel cable, USB (universal serial bus), FireWire, networking card, fiber optic, wireless, co-axial cables, and twisted pair cables.