Determination of a Measure of a Glycation End-Product or Disease State Using Tissue Fluorescence of Various Sites

• US 20070197880A1
• Filed: 02/15/2007
• Published: 08/23/2007
• Est. Priority Date: 04/04/2002
• Status: Active Grant

• Current Assignee: Veralight, Inc. (Britannia Life Sciences, Inc.)
• Original Assignee: Veralight, Inc. (Britannia Life Sciences, Inc.)
• Inventors: Johnson, Robert, Maynard, John, Ediger, Marwood, Robinson, M.
• Granted Patent: US 8,131,332 B2
• Time in Patent Office: Days
• US Class Current: 600/300
• CPC Class Codes: A61B 5/0071 by measuring fluorescence emission
• 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

Embodiments of the present invention provide an apparatus suitable for determining properties of in vivo tissue from spectral information collected from various tissue sites. An illumination system provides light at a plurality of broadband ranges, which are communicated to an optical probe. The optical probe can be a flexible probe in some embodiments, allowing ease of application. Light homogenizers and mode scramblers can be employed to improve the performance in some embodiments. The optical probe in some embodiments physically contacts the tissue, and in some embodiments does not physically contact the tissue. The optical probe receives light from the illumination system and transmits it to tissue, and receives light diffusely reflected in response to the broadband light, emitted from the in vivo tissue by fluorescence thereof in response to the broadband light, or a combination thereof. The optical probe can communicate the light to a spectrograph which produces a signal representative of the spectral properties of the light. An analysis system determines a property of the in vivo tissue from the spectral properties.

Claims

1. A method of determining a state of health of an individual, where “

state of health”

is any of (i) a disease state based on long-term changes (greater than one month duration) in tissue, (ii) a measure of chemical change based on long-term (greater than one month duration) glycemic control, (iii) a measure of glycation end-products in tissue, and (iv) a combination of the above, comprising;

a. Illuminating a portion of a tissue of the individual with excitation light;

b. Detecting light emitted from the tissue by fluorescence of a chemical within the tissue, where the tissue is not the lens of the eye;

c. Determining the state of health from the detected light and a model relating fluorescence and a state of health.

2. A method as in claim 1, wherein the tissue comprises the tissue on an extremity of the individual.

3. A method as in claim 2, wherein the tissue comprises the tissue on a leg of the individual.

4. A method as in claim 3, wherein the tissue comprises skin on the foot of the individual.

5. A method as in claim 3, wherein the tissue comprises skin on the upper leg of the individual.

6. A method as in claim 3, wherein the tissue comprises skin on the lower leg of the individual.

7. A method as in claim 2, wherein the tissue comprises the tissue on an arm of the individual.

8. A method as in claim 7, wherein the tissue comprises skin on the hand of the individual.

9. A method as in claim 7, wherein the tissue comprises skin on the upper arm of the individual.

10. A method as in claim 1, wherein the tissue comprises the tissue on the torso of the individual.

11. A method as in claim 10, wherein the tissue comprises skin on the neck of the individual.

12. A method as in claim 10, wherein the tissue comprises skin on the buttocks of the individual.

13. A method as in claim 1, wherein the tissue comprises the tissue on the head of the individual.

14. A method as in claim 13, wherein the tissue comprises the sclera of the eye of the individual.

15. A method as in claim 13, wherein the tissue comprises the oral mucosa of the individual.

16. A method as in claim 13, wherein the tissue comprises the earlobe of the individual.

17. A method as in claim 13, wherein the tissue comprises skin on the cheek of the individual.

18. A method as in claim 13, wherein the tissue comprises skin on the forehead of the individual.

19. A method as in claim 1, wherein the step of detecting light emitted from the tissue comprises placing a flexible probe in contact with the tissue.

20. A method as in claim 19, wherein the flexible probe comprises a bundle of input and output fiber optic cables that are arranged in a pattern at a surface of the probe that is placed in contact with the tissue.

21. A method as in claim 1, further comprising acquiring biologic information relating to the individual, and wherein determining a tissue state comprises determining the tissue state from the information, the detected light, and a model relating biologic information, fluorescence and tissue state.

24. A method as in claim 1, wherein determining the state of health from the detected light and a model relating fluorescence and a state of health comprises determining the state of health in part from a measure of intrinsic fluorescence of the tissue.

25. A method as in claim 1, wherein the step of detecting light emitted from the tissue comprises detecting light with a sampler that does not contact the tissue.

22. An apparatus for the determination of a state of health in an individual, where “

state of health”

is any of (i) a disease state based on long-term changes (greater than one month duration) in tissue, (ii) a measure of chemical change based on long-term (greater than one month duration) glycemic control, (iii) a measure of glycation end-products in tissue, and (iv) a combination of the above, comprising;

a. An illumination subsystem adapted to illuminate a portion of the tissue of the individual with excitation light, where the tissue is one or more of tissue on an extremity of the individual, tissue on the torso of the individual, or tissue on the head of the individual, and where the tissue is not the lens of the eye;

b. A detection subsystem adapted to detect light emitted from the tissue by fluorescence of a chemical within the tissue;

c. An analysis subsystem, comprising a model relating fluorescence property of the skin of an individual to a state of health.

23. An apparatus as in claim 22, wherein the detection subsystem comprises a flexible probe adapted to be placed in contact with the tissue.