Optical non-invasive blood monitoring system and method

• US 7,486,976 B1
• Filed: 07/25/2006
• Issued: 02/03/2009
• Est. Priority Date: 07/25/2006
• Status: Active Grant

• Current Assignee: Edward Belotserkovsky
• Original Assignee: Edward Belotserkovsky
• Inventors: Belotserkovsky, Edward
• Primary Examiner(s): Winakur; Eric F
• Assistant Examiner(s): Berhanu; Etsub D
• Application Number:
  US11/492,451
• Time in Patent Office: 924 Days
• Field of Search: 600/309, 600/310, 600/316, 600/322, 600/323
• US Class Current: 600/310
• CPC Class Codes: A61B 5/05 Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves impedance plethysmography A61B5/0295; measuring movement of the entire body or parts thereof A61B5/11; detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof A61B5/24
• 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
• CPC Class Codes: A61B 5/681 Wristwatch-type devices

Abstract

A simple noninvasive technique that is capable of very accurate and fast blood analyte, e.g., glucose, level monitoring is provided. Fluctuation in the levels of glucose and other analytes affect the refractive index of blood and extra cellular fluid in biological tissue. Given that the propagation speed of light through a medium depends on its refractive index, continuous monitoring of analyte levels in tissue is achieved by measuring characteristics of the tissue that can be correlated to the refractive index of the tissue. For instance, the frequency or number of optical pulse revelations that are transmitted through an individual'"'"'s tissue of known thickness within a certain time period can be correlated to an individual'"'"'s blood glucose level.

Claims

1. A device for noninvasive measurement of the levels of at least one analyte in a subject that comprises:

means for irradiating the subject through tissue with electromagnetic radiation;

means for detecting the radiation that passes through the tissue;

means for calculating the speed at which the electromagnetic radiation passes through the tissue; and

means for correlating the calculated speed of the electromagnetic radiation to the concentration of the at least one analyte in the subject.

2. The device of claim 1 wherein the means for irradiating the subject emits pulses of radiation and the means for detecting the radiation measures the number of pulses of radiation that passes through the tissue during a defined time period which is referred as the pulse circulation frequency measurement.

3. The device of claim 2 wherein the means for correlating the calculated speed of the electromagnetic radiation to the concentration of the at least one analyte in the subject calculates the changes, if any, of the pulse circulation frequency being measured.

4. The device of claim 1 wherein the means for irradiating the subject emits pulses of radiation and the means for detecting the radiation measures the time period required for a defined number of pulses of radiation to pass through the tissue which is referred to as the time interval measurement.

5. The device of claim 4 wherein the means for correlating the calculated speed of the electromagnetic radiation to the concentration of the at least one analyte in the subject calculates the changes, if any, of the time interval being measured.

6. The device of claim 1 further comprising means for dispensing a medical formulation in response to a determination of the concentration of the at least one analyte in the subject.

7. The device of claim 1 wherein the at least one analyte is selected from the group consisting of glucose, cholesterol, triglycerides, urea, protein, and mixtures thereof.

8. The device of claim 1 wherein said at least one analyte is glucose.

9. The device of claim 1 wherein the concentration of two or more analytes are measured and the means for irradiating the subject emits electromagnetic radiation at two or more different wavelengths.

10. The device of claim 1 wherein the means for irradiating the subject through tissue with electromagnetic radiation comprises means for irradiating the subject with electromagnetic radiation at different wavelengths and the device further comprises means for detecting the radiation at different wavelengths in order to compensate for variations in conditions other than the concentration of the analyte or analytes being measured.

11. The device of claim 1 wherein the means for irradiating the subject comprises means for supporting the device such that the electromagnetic radiation passes through a defined thickness of the tissue.

12. A device for noninvasive measurement of the levels of glucose in a subject that comprises:

means for irradiating the subject through tissue with electromagnetic radiation having a wavelength such that the speed of the electromagnetic radiation traversing through the tissue is sensitive to the glucose concentration in the tissue;

means for detecting the radiation that passes through the tissue;

means for calculating the speed at which the electromagnetic radiation passes through the tissue; and

means for correlating the calculated speed of the electromagnetic radiation to the concentration of glucose in the subject.

13. The device of claim 12 wherein the means for irradiating the subject emits pulses of radiation and the means for detecting the radiation measures the number of pulses of radiation that passes through the tissue during a defined time period, which is referred as the pulse circulation frequency being measured.

14. The device of claim 13 wherein means for correlating the calculated speed of the electromagnetic radiation to the concentration of the glucose in the subject calculates the changes, if any, of the pulse circulation frequency measurement.

15. The device of claim 12 wherein the means for irradiating the subject emits pulses of radiation and the means for detecting the radiation measures the time period required for a defined number of pulses of radiation to pass through the tissue which is referred to as the time interval measurement.

16. The device of claim 15 wherein the means for correlating the calculated speed of the electromagnetic radiation to the concentration of glucose in the subject calculates the changes, if any, of the time interval being measured.

17. The device of claim 12 further comprising means for dispensing an insulin formulation in response to a determination of the concentration of the glucose in the subject.

18. A noninvasive method of monitoring the levels of at least one analyte in a subject that comprises:

(a) irradiating the subject through tissue of known thickness with electromagnetic radiation;

(b) detecting the radiation that passes through the tissue in a transmissive mode;

(c) calculating the speed at which the electromagnetic radiation passes through the tissue; and

(d) correlating the calculated speed of the electromagnetic radiation to the concentration of the at least one analyte in the subject.

19. The method of claim 18 wherein step (a) comprises directing pulses of radiation through the tissue and step (b) comprises detecting the number of pulses that passes through the tissue during a defined time period, which is referred as the pulse circulation frequency measurement.

20. The method of claim 19 wherein step (d) comprises calculating the changes, if any, of the pulse circulation frequency being measured.

21. The method of claim 18 wherein step (a) comprises directing pulses of radiation and step (b) comprises measuring the time period required for a defined number of pulses of radiation to pass through the tissue which is referred to as the time interval measurement.

22. The method of claim 21 wherein step (d) comprises calculating the changes, if any, of the time interval being measured.

23. The method of claim 18 further comprising the step of dispensing a medical formulation in response to a determination of the concentration of the at least one analyte in the subject.

24. The method of claim 18 wherein the at least one analyte is selected from the group consisting of glucose, cholesterol, triglycerides, urea, protein, and mixtures thereof.

25. The method of claim 18 wherein said at least one analyte is glucose.

26. The method of claim 18 wherein the concentration of two or more different analytes are measured and step (a) comprises irradiating the subject with electromagnetic radiation at two or more different wavelengths.

27. The method of claim 18 wherein step (a) comprises irradiating the subject through tissue with electromagnetic radiation at different wavelengths in order to compensate for variations in conditions other than the concentration of the analyte or analytes being monitored.