Non-invasive tissue glucose level monitoring

• US 6,505,059 B1
• Filed: 04/06/1999
• Issued: 01/07/2003
• Est. Priority Date: 04/06/1998
• Status: Expired due to Fees

• Current Assignee: The General Hospital Corporation (Mass General Brigham, Inc.)
• Original Assignee: The General Hospital Corporation (Mass General Brigham, Inc.)
• Inventors: Kollias, Nikiforos, Freeman, Jenny E., Tian, Wei Dong
• Primary Examiner(s): WINAKUR, ERIC FRANK
• Application Number:
  US09/287,486
• Time in Patent Office: 1,372 Days
• Field of Search: 600/316, 600/322, 600/310, 600/476, 600/317, 356/301, 604/890.1, 604/891.1, 604/66
• US Class Current: 600/316
• 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

Instruments and methods for performing non-invasive measurements of analyte concentrations and for monitoring, analyzing and regulating tissue status, such as tissue glucose levels.

Claims

1. A non-invasive glucose monitoring instrument comprising:

a radiation source capable of directing radiation to a portion of a tissue surface of a body wherein said source emits radiation at a wavelength that excites a target such that the excited target provides a glucose level indication of the patient wherein said target is a tissue component;

a radiation detector positioned to receive fluorescent radiation emitted from an excited target; and

a processing circuit operatively connected to the radiation detector that translates emitted radiation to a measurable signal to obtain said glucose level indication.

2. The instrument of claim 1 wherein the -radiation source is an ultraviolet light source.

3. The instrument of claim 1 further including a flexible-fiber optic arm that is capable of directing said radiation to the target.

4. The instrument of claim 3 wherein the probe comprises a glass or quartz fiber.

5. The instrument of claim 1 wherein the portion of the tissue surface is a portion of the skin of a patient.

6. The instrument of claim 5 wherein the portion of skin irradiated is less than about 1 square cm.

7. The instrument of claim 5 wherein the portion of skin irradiated is about 0.2 square cm.

8. The instrument of claim 5 wherein the portion of-skin is pigmented.

9. The instrument of claim 1 wherein the excitation wavelength is about 295 nm.

10. The instrument of claim 1 wherein the excitation wavelength is between about 335-340 nm.

11. The instrument of claim 1 wherein the target is a structural matrix component.

12. The instrument of claim 1 wherein the target is a collagen cross-link.

13. The instrument of claim 1 wherein the target is a pepsin-digestible or a collagenase-digestible collagen cross-link.

14. The instrument of claim 1 wherein the target is tryptophan.

15. The instrument of claim 1 wherein the radiation source is operative to emit radiation at between about 285 and 305 nm and the radiation detector is operative to detect radiation at between about 315 and 420 nm.

16. The instrument of claim 1 wherein the radiation source is operative to emit radiation at between about 330 and 345 nm and the radiation detector is operative to detect radiation at between about 370 and 410 nm.

17. The instrument of claim 1 which weighs less than about 0.5 kilograms.

18. The instrument of claim 1 further comprising a display operatively connected to the processing circuit that is operative to display said glucose level indication.

19. The instrument of claim 1 further comprising an insulin pump responsive to the processing circuit that is operative to administer insulin to a patient at a rate that corresponds to the glucose level signal.

20. The instrument of claim 19 wherein the detector, processing circuit, insulin pump and the patient form part of a servo loop.

21. The instrument of claim 1 further comprising an alarm means operationally coupled to the processing circuit wherein the alarm means is activated when the glucose level indication exceeds a first predetermined value, falls below a second predetermined value or varies more than 20% from a third predetermined value.

22. The instrument of claim 1 further comprising a normalizing detector responsive to another target that provides normalizing information to said processing circuit to normalize the glucose level indication.

23. The instrument of claim 1 further comprising normalizing means which provides normalizing information to said processing circuit to normalize the glucose level indication.

24. The instrument of claim 1 further comprising means for measuring scattering.

25. The instrument of claim 24 wherein the means for measuring scattering comprises an illuminating means that emits radiation at an angle greater than 60 degrees to said target.

26. The instrument of claim 24 wherein the means for measuring scattering comprises an illuminating means which emits radiation at between about 330 to 420 nm.

27. The instrument of claim 1 further comprising a portable housing and wherein the radiation source, the radiation detector and the processing circuit are disposed in the housing.

28. The instrument of claim 27 further comprising a battery compartment disposed in the housing and a pair of battery contacts operatively connected to the radiation source, the radiation detector. and the processing circuit.

29. The instrument of claim 1 further comprising an attachment means for attaching the radiation source to the patient.

30. The instrument of claim 1 further comprising a transmitter.

31. A disposable non-invasive glucose monitoring instrument comprising:

a radiation source capable of directing radiation to a portion of a tissue surface of a body wherein said source emits radiation at a wavelength that excites a target such that the excited target provides a glucose level indication of the patient wherein said target is a tissue component;

a radiation detector positioned to receive fluorescent radiation emitted from an excited target; and

a processing circuit operatively connected to the radiation detector that translates emitted radiation to a measurable signal to obtain said glucose level indication.

32. A non-invasive method of detecting a glucose level comprising:

exciting a non-glucose target wherein the excited target is indicative of a glucose level of a patient and said target is a tissue component;

detecting an amount of fluorescent radiation emitted by the target; and

determining said glucose level from the amount of radiation detected.

33. The method of claim 32 wherein the target is excited with electromagnetic radiation.

34. The method of claim 32 wherein the radiation is ultraviolet radiation.

35. The method of claim 33 wherein the radiation is at a wavelength of about 295 nm.

36. The method of claim 32 wherein the radiation is at a wavelength of about 335-340 nm.

37. The method of claim 32 wherein the target is a collagen cross-link.

38. The method of claim 32 wherein the target is a pepsin digestible or a collagenase digestible collagen cross-link.

39. The method of claim 32 wherein the target is tryptophan.

40. The method of claim 32 wherein the radiation detected from the excited target is between about 340 and 400 nm.

41. The method of claim 32 further comprising adjusting the glucose level of the patient in response to the glucose level determined.

42. The method of claim 32 further comprising administering insulin to the patient.

43. The method of claim 42 wherein insulin is administered with a biodelivery system. .

44. The method of claim 43 wherein the biodelivery system includes an insulin pump.

45. The method of claim 32 wherein the glucose level is remotely transmitted to a monitor or servo mechanism.

46. The method of claim 32 further comprising normalizing the glucose level determined.

47. The method of claim 32 further comprising actuating an alarm in response to the glucose level when said glucose level exceeds a predetermined first level, falls below a predetermined second level or varies more than 20% from a predetermined third level.

48. The method of claim 32 further comprising measuring scattering and adjusting the glucose level.

49. A non-invasive glucose monitoring instrument comprising:

an ultraviolet light source capable of directing radiation to a portion of a tissue surface of a body wherein said source emits radiation at a wavelength that excites a target such that the excited target provides a glucose level indication of the patient;

a radiation detector positioned to receive radiation emitted from an excited target; and

a processing circuit operatively connected to the radiation detector that translates emitted radiation to a measurable signal to obtain said glucose level indication.

50. The non-invasive glucose monitoring instrument of claim 49 wherein the target is located in a dermal region or an epidermal region of said body.

51. The non-invasive glucose monitoring instrument of claim 49 wherein the target is selected from the group consisting of a structural matrix component, a dermal matrix component, an epidermal matrix component, collagen, glycated collagen, glycosaminoglycans, elastin, glycosylated substances in a tissue, a pepsin-digestible cross link, a collagenase-digestible cross link, tryptophan and combinations thereof.

52. The non-invasive glucose monitoring instrument of claim 49 wherein the target emits radiation at between 315-420 nanometers.

53. A non-invasive glucose monitoring instrument comprising:

a radiation source capable of directing radiation to a portion of a tissue surface of a body wherein said source emits radiation at a wavelength that excites a target such that the excited target provides a glucose level indication of the patient wherein the target is selected from the group consisting of a structural matrix component, a dermal matrix component, an epidermal matrix component, collagen, glycated collagen, glycosaminoglycans, elastin, glycosylated substances in a tissue, a pepsin-digestible cross link, a collagenase-digestible cross link, tryptophan and combinations thereof;

a radiation detector positioned to receive radiation emitted from an excited target; and

a processing circuit operatively connected to the radiation detector that translates emitted radiation to a measurable signal to obtain said glucose level indication.

54. The non-invasive glucose monitoring instrument of claim 53 wherein the target emits radiation at between about 315-420 nanometers.

55. The non-invasive glucose monitoring instrument of claim 53 wherein the radiation source is an ultraviolet light source.

56. A non-invasive method of detecting a glucose level comprising:

exciting a non-glucose target with an ultraviolet light source wherein the excited target is indicative of a glucose level of a patient;

detecting an amount of radiation emitted by the target; and

determining said glucose level from the amount of radiation detected.

57. The method of claim 56 wherein the target emits radiation at between about 315-420 nanometers.

58. The method of claim 56 wherein the target is selected from the group consisting of a structural matrix component, a dermal matrix component, an epidermal matrix component, collagen, glycated collagen, glycosaminoglycans, elastin, glycosylated substances in a tissue, a pepsin-digestible cross link, a collagenase-digestible cross link, tryptophan and combinations thereof.

59. A non-invasive method of detecting a glucose level comprising:

exciting a non-glucose target wherein the excited target is indicative of a glucose level of a patient and the target is selected from the group consisting of a structural matrix component, a dermal matrix component, an epidermal matrix component, collagen, glycated collagen, glycosaminoglycans, elastin, glycosylated substances in a tissue, a pepsin-digestible cross link, a collagenase-digestible cross link, tryptophan and combinations thereof;

detecting an amount of radiation emitted by the target; and

determining said glucose level from the amount of radiation detected.

60. The method of claim 59 wherein the target emits radiation at between about 315-420 nanometers.

61. The method of claim 59 wherein the target is selected from the group consisting of a structural matrix component, a dermal matrix component, an epidermal matrix component, collagen, glycated collagen, glycosaminoglycans, elastin, glycosylated substances in a tissue, a pepsin-digestible cross link, a collagenase-digestible cross link, tryptophan and combinations thereof.

62. The method of claim 59 wherein the non-glucose target is excited with ultraviolet light.

63. A non-invasive method of detecting a glucose level of a patient comprising:

exciting a fluorophore in vivo with electromagnetic radiation wherein the excited fluorophore provides an indication of said glucose level;

detecting an amount of radiation emitted by the fluorophore; and

determining said glucose level from the amount of radiation detected.

64. The method of claim 63 wherein the fluorophore emits radiation at between about 315-420 nanometers.

65. The method of claim 63 wherein the fluorophore is selected from the group consisting of a structural matrix component, a dermal matrix component, an epidermal matrix component, collagen, glycated collagen, glycosaminoglycans, elastin, glycosylated substances in a tissue, a pepsin-digestible cross link, a collagenase-digestible cross link, tryptophan and combinations thereof.

66. The method of claim 63 wherein the electromagnetic radiation comprises ultraviolet light.