Non-invasive blood glucose measurement system and method using optical refractometry

• US 6,442,410 B1
• Filed: 06/09/2000
• Issued: 08/27/2002
• Est. Priority Date: 06/10/1999
• Status: Expired due to Fees

• Current Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Original Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Inventors: Steffes, Paul G.
• Primary Examiner(s): Winakur, Eric F.
• Assistant Examiner(s): KREMER, MATTHEW J
• Application Number:
  US09/590,495
• Time in Patent Office: 809 Days
• Field of Search: 600/309-310, 600/318, 600/316, 600/319, 600/322-326
• US Class Current: 600/319
• CPC Class Codes: A61B 3/103 for determining refraction, e.g. refractometers, skiascopes
• 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 for determining blood glucose levels by measuring the glucose concentration in the ocular aqueous humor using optical refractometry by passing laser light the aqueous ocular humor, measuring the laser light'"'"'s optical refractivity, and comparing the refractivity with known data, the comparison yielding the blood glucose level.

Claims

1. A method for determining a mammal'"'"'s blood glucose level based on ocular refractive correction, said method comprising the steps of:

measuring the ocular refractive correction of the mammal;

relating the measured ocular refractive correction of the mammal to the mammal'"'"'s blood glucose level by comparing the measured ocular refractive correction to a database of known ocular refractive corrections and blood glucose concentrations.

2. The method of claim 1, wherein the mammal is a human.

3. The method of claim 2, including the further steps of:

measuring the ocular refractive correction at least a second time; and

averaging the measured ocular refractive corrections to obtain a value.

4. The method of claim 2, wherein said step of measuring the ocular refractive correction is performed using a traditional lens set.

5. The method of claim 2, wherein said step of measuring the ocular refractive correction is performed using an automatic refractometer.

6. The method of claim 2, further including the initial step of measuring the ocular refractive correction at a plurality of known blood glucose levels.

7. The method of claim 2, further including the step of interpolating a blood glucose value correlated to the measured ocular refractive correction in relation to a plurality of data from said database.

8. The method of claim 2, wherein said measuring step includes the step of shielding an eye from external light.

9. An apparatus for determining a mammal'"'"'s blood glucose level, said apparatus comprising:

a refractometer for measuring ocular refractive correction, said refractometer outputting data indicative of the ocular refractive correction; and

a processor adapted to receive said data indicative of the ocular refractive correction from said refractometer, said processor being operative to correlate said data to a correlated blood glucose level, said processor outputting a signal indicative of said correlated blood glucose level.

10. The apparatus of claim 9, wherein the mammal is a human.

11. The apparatus of claim 10, further comprising a display adapted to display the correlated blood glucose level.

12. A method for determining blood glucose concentrations based on ocular refractive correction, said method comprising the steps of:

measuring the ocular refractive correction needed to correct a mammal'"'"'s vision; and

comparing the ocular refractive correction with predetermined ocular refractive corrections correlated to predetermined blood glucose concentrations.

13. The method of claim 12, wherein the ocular refractive correction is measured with an automatic refractometer.

14. The method of claim 13, wherein the mammal is human.

15. The method of claim 12, wherein the ocular refractive correction is measured in diopters.

16. A method of monitoring changes in blood glucose concentration, said method comprising the steps of:

calibrating a patient'"'"'s blood glucose concentration with the patient'"'"'s ocular refractive correction;

measuring the patient'"'"'s ocular refractive correction; and

interpolating the patient'"'"'s blood glucose concentration based on the calibration.

17. A method of monitoring changes in blood glucose concentration, said method comprising the steps of:

taking a first ocular refractive correction measurement of a patient;

taking a first blood glucose concentration measurement from the patient;

taking a second ocular refractive correction measurement and a second blood glucose measurement from the patient after inducing a change in the patient'"'"'s blood glucose concentration;

correlating the ocular refractive correction measurements with the corresponding blood glucose concentrations;

taking a third ocular refractive correction measurement of the patient; and

interpolating the blood glucose concentration corresponding to the third ocular refractive correction measurement.