Method and Apparatus for Non-Invasive Monitoring of Blood Substances Using Self-Sampled Tears

• US 20070043283A1
• Filed: 10/20/2006
• Published: 02/22/2007
• Est. Priority Date: 04/05/2002
• Status: Abandoned Application

• Current Assignee: Eyelab Group, LLC
• Original Assignee: Eyelab Group, LLC
• Inventors: Cui, Gang, Nam, Hakhyun, Flanders, Zvi, Kim, Jong, Meyerhoff, Mark, Gillespie, Donald, Cohan, Bruce, Cha, Geun
• Application Number:
  US11/551,458
• Publication Number:
  US 20070043283A1
• Time in Patent Office: Days
• US Class Current: 600/345
• CPC Class Codes: A61B 2562/0295 Strip shaped analyte sensors for apparatus classified in A61B5/145 or A61B5/157
• CPC Class Codes: A61B 5/1486 using enzyme electrodes, e.g. with immobilised oxidase
• CPC Class Codes: C12Q 1/006 for glucose
• CPC Class Codes: C12Q 1/32 involving dehydrogenase
• CPC Class Codes: C12Q 1/54 involving glucose or galactose
• CPC Class Codes: G01N 2001/1056 Disposable (single-use) samplers
• CPC Class Codes: G01N 2001/149 Capillaries; Sponges
• CPC Class Codes: G01N 2035/0465 Loading or unloading the conveyor
• CPC Class Codes: G01N 27/3272 Test elements therefor, i.e. disposable laminated substrates with electrodes, reagent and channels optical biosensors G01N33/52
• CPC Class Codes: G01N 33/528 Atypical element structures, e.g. gloves, rods, tampons, toilet paper
• CPC Class Codes: Y10T 436/144444 Glucose

Abstract

A method and apparatus for non-invasively determining the concentration of a substance in blood, such as glucose, include a sample portion arranged for contacting an eye region of a user to obtain a tear fluid sample, a sensor in communication with the sample portion for generating a signal related to the tear substance concentration, and a processor in communication with the sensor for determining a blood substance concentration corresponding to the tear substance concentration.

Claims

1. An apparatus for determining the concentration of a substance in blood, the apparatus comprising:

a housing;

a test probe arranged to be received within the housing, the test probe arranged to engage an eye region of a user to obtain a tear fluid sample while the test probe is received within the housing;

a sensor disposed within the housing in communication with the test probe for generating a signal related to the tear substance concentration; and

a processor disposed within the housing in communication with the sensor for determining a blood substance concentration corresponding to the tear substance concentration.

2. The apparatus according to claim 1, wherein the substance includes glucose.

3. The apparatus according to claim 2, wherein the sensor is operable to detect glucose concentrations less than about 20 mg/dL with a resolution of at least 5 mg/dL.

4. The apparatus according to claim 1, wherein the test probe is arranged to allow self-sampling of the tear fluid sample by a user.

5. The apparatus according to claim 1, wherein the test probe includes an inlet extending outwardly therefrom.

6. The apparatus according to claim 5, wherein the inlet includes a capillary member or a wicking membrane.

7. The apparatus according to claim 1, wherein a volume of the tear fluid sample held by the test probe is less than about 0.5 μ

L.

8. The apparatus according to claim 1, wherein the test probe is removable from the housing.

9. The apparatus according to claim 1, further comprising a display screen in communication with the processor for displaying the blood substance concentration.

10. The apparatus according to claim 1, further comprising memory in communication with the processor for storing the blood substance concentration.

11. The apparatus according to claim 1, wherein the housing is generally pen-shaped.

12. The apparatus according to claim 1, wherein the test probe includes an enzyme for reacting with the substance in the tear fluid sample.

13. The apparatus according to claim 12, wherein the enzyme includes glucose dehydrogenase.

14. The apparatus according to claim 12, wherein the test probe includes an electrode system provided therein, the apparatus further comprising a power source for applying a voltage to the electrode system to induce an electrochemical reaction of the enzyme and the substance, and wherein the sensor detects a current resulting from the electrochemical reaction and the processor determines a tear substance concentration from the detected current.

15. The apparatus according to claim 1, wherein the apparatus is configured to allow the electronic transfer of substance concentration data.

16. An apparatus for determining glucose concentration in a tear fluid sample, the apparatus comprising:

a housing;

a test probe arranged to be received within the housing, the test probe arranged to engage an eye region of a user to obtain a tear fluid sample while the test probe is received within the housing;

a sensor disposed within the housing in communication with the test probe for generating a signal related to the glucose concentration in the tear fluid sample; and

a processor in communication with the sensor for processing the signal to determine the tear glucose concentration.

17. An apparatus for determining glucose concentration in blood, the apparatus comprising:

a housing;

a test probe arranged to be received within the housing, the test probe having an inlet arranged to engage an eye region of a user to obtain a tear fluid sample while the test probe is received within the housing, the test probe having an enzyme provided therein for initiating a reaction with the tear fluid sample, wherein a volume of the tear fluid sample held by the test probe is less than about 0.5 μ

L;

a sensor disposed within the housing in communication with the test probe for detecting a signal generated by the reaction;

a processor in communication with the sensor for determining a tear glucose concentration from the detected signal and correlating the determined tear glucose concentration with a blood glucose concentration; and

means for providing an output indicative of the blood glucose concentration.

18. The apparatus according to claim 17, wherein the test probe is arranged to allow self-sampling of the tear fluid sample by a user.

19. The apparatus according to claim 17, wherein the housing is generally pen-shaped.

20. The apparatus according to claim 17, wherein the sensor is operable to detect glucose concentrations less than about 20 mg/dL with a resolution of at least 5 mg/dL.

21. The apparatus according to claim 17, wherein the enzyme includes glucose dehydrogenase.

22. The apparatus according to claim 17, wherein the test probe includes pyrrolo-quinoline-quinone as a coenzyme.

23. The apparatus according to claim 17, wherein the test probe includes an electron transfer mediator.

24. The apparatus according to claim 23, wherein the electron transfer mediator includes a ruthenium complex.

25. The apparatus according to claim 23, wherein the test probe includes a base plate, a cover plate, and a spacer disposed between and joining the base and cover plates, the base and cover plates including a converse-type electrode system, the apparatus further comprising a power source for applying a voltage to the electrode system to induce an electrochemical reaction of the enzyme and the electron transfer mediator with glucose in the tear fluid sample and generate a current related to tear glucose concentration.

26. The apparatus according to claim 25, wherein the processor determines a tear glucose concentration from the generated current and multiplies the tear glucose concentration by a calibration factor to determine the corresponding blood glucose concentration.

27. The apparatus according to claim 17, further comprising a speaker in communication with the processor.

28. The apparatus according to claim 17, wherein the apparatus is configured to allow the electronic transfer of glucose concentration data.