Non-invasive system for the determination of analytes in body fluids

• US 7,299,079 B2
• Filed: 02/11/2003
• Issued: 11/20/2007
• Est. Priority Date: 02/11/2002
• Status: Active Grant

• Current Assignee: Ascensia Diabetes Care Holdings AG (PHC Holdings Corporation)
• Original Assignee: Bayer Healthcare LLC (Bayer AG)
• Inventors: Rebec, Mihailo V., Smous, James E., Tan, Hu-Wei, Brown, Steven D.
• Primary Examiner(s): WINAKUR, ERIC FRANK
• Application Number:
  US10/361,895
• Publication Number:
  US 20040092804A1
• Time in Patent Office: 1,743 Days
• Field of Search: 600/310, 600/316, 600/322, 600/473, 250/338.1, 250/341.3
• US Class Current: 600/316
• 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
• CPC Class Codes: A61B 5/1495 Calibrating or testing of in-vivo probes
• CPC Class Codes: A61B 5/726 using Wavelet transforms
• CPC Class Codes: G01N 21/274 Calibration, base line adjustment, drift correction
• CPC Class Codes: G01N 21/359 using near infrared light
• CPC Class Codes: G01N 2201/067 Electro-optic, magneto-optic, acousto-optic elements

Abstract

A system for determining the concentration of an analyte in at least one body fluid in body tissue, the system comprising an infrared light source, a body tissue interface, a detector, and a central processing unit. The body tissue interface is adapted to contact body tissue and to deliver light from the infrared light source to the contacted body tissue. The detector is adapted to receive spectral information corresponding to infrared light transmitted through the portion of body tissue being analyzed and to convert the received spectral information into an electrical signal indicative of the received spectral information. The central processing unit is adapted to compare the electrical signal to an algorithm built upon correlation with the analyte in body fluid, the algorithm adapted to convert the received spectral information into the concentration of the analyte in at least one body fluid.

Claims

1. A system for determining the concentration of an analyte in at least one body fluid in body tissue, the system comprising:

an infrared light source;

a body tissue interface adapted to contact body tissue and to deliver light from the infrared light source to the contacted body tissue, the body tissue interface comprising a clamping device having two plates for contacting the body tissue;

a detector adapted to receive spectral information corresponding to infrared light transmitted through the portion of body tissue being analyzed and to convert the received spectral information into an electrical signal indicative of the received spectral information;

a central processing unit adapted to compare the electrical signal to an algorithm built upon correlation with the analyte in body fluid, the algorithm adapted to convert the received spectral information into the concentration of the analyte in at least one body fluid; and

a load cell for measuring an amount of pressure applied to the body tissue by the clamping device.

2. The system of claim 1 wherein the tissue is compressed approximately five to ten percent by the clamping device.

3. The system of claim 1 wherein the body tissue interface comprises a clamping device having two plates for contacting the body tissue, at least one of the two plates including a temperature control element for controlling the temperature of the body tissue contacted by the clamping device.

4. The system of claim 3 wherein the temperature control element is a thermal electric device.

5. The system of claim 3 wherein the temperature control element is adapted to control the temperature of the contacted body tissue to a temperature ranging between about 50°

F. and 105°

F.

6. The system of claim 5 wherein the temperature control element is adapted to control the temperature of the contacted body tissue to a temperature ranging between about 99°

F. and 101°

F.

7. The system of claim 1 wherein the detector is an extended Indium Gallium Arsenate detector.

8. The system of claim 1 wherein the wavelength ranges between approximately 1400 nanometers and 2500 nanometers.

9. The system of claim 1 wherein the at least one body fluid is plasma.

10. The system of claim 1 wherein the at least one body fluid is interstitial fluid.

11. The system of claim 1 wherein the at least one body fluid includes intercellular fluid.

12. The system of claim 1 wherein the at least one body fluid is intracellular fluid.

13. The system of claim 1 wherein the analyte is glucose.

14. The system of claim 1 wherein the detector comprises a diode array and further includes a grating for filtering the infrared light transmitted through the body tissue.

15. The system of claim 1 further comprising an acoustic optical tunable filter for receiving the transmitted infrared light and outputting predetermined wavelength bands of the transmitted light to the detector.

16. The system of claim 1 further comprising an acoustic optical tunable filter for receiving the infrared light from the infrared light source and outputting a monochromatic beam of light to the body tissue interface.

17. The system of claim 16 further comprising a reference detector adapted to receive a portion of the monochromatic light output by the acoustic optical tunable filter and to convert the received light into a reference electrical signal.

18. The system of claim 1 wherein the wavelength ranges between approximately 750 nanometers and 2500 nanometers.

19. A method for determining the concentration of an analyte in at least one body fluid in body tissue, the method comprising the acts of:

contacting body tissue to be analyzed;

compressing the contacted body tissue;

controlling the temperature of the body tissue such that the body tissue is maintained at a substantially uniform temperature;

directing infrared light into the body tissue;

detecting infrared light transmitted through the body tissue;

analyzing the detected transmitted light using an algorithm built upon correlation with the analyte in the body fluid, the algorithm being adapted to convert the detected transmitted light into the concentration of the analyte in at least one body fluid;

determining the concentration of the analyte in at least one body fluid; and

further comprising measuring an amount of pressure applied to the body tissue being analyzed.

20. The method of claim 19 wherein controlling the temperature further comprises controlling the temperature with a thermal electrical device.

21. The method of claim 19 wherein the controlling the temperature further comprises controlling the body tissue to a temperature ranging between about 50°

F. and about 105°

F.

22. The method of claim 21 wherein the controlling the temperature further comprises controlling the body tissue to a temperature ranging between about 99°

F. and about 101°

F.

23. The method of claim 19 wherein detecting further comprises detecting the transmitted light with an extended Indium Gallium Arsenate detector.

24. The method of claim 19 wherein directing infrared light further comprises selectively directing narrow bandwidths of infrared light.

25. The method of claim 19 wherein directing infrared light further comprises directing monochromatic light onto the body tissue.

26. The method of claim 25 wherein the directing of monochromatic light further comprises directing a beam of monochromatic light having a wavelength ranging between approximately 750 nanometers and approximately 11,000 nanometers.

27. The method of claim 26 wherein the wavelength ranges between approximately 1400 nanometers and 11,000 nanometers.

28. The method of claim 27 wherein the wavelength ranges between approximately 1400 nanometers and 2500 nanometers.

29. The method of claim 19 wherein directing further comprises:

directing the infrared light to an acoustic optical tunable filter; and

outputting a monochromatic beam of light from the acoustic optical tunable filter onto the contacted body tissue.

30. The method of claim 29 further comprising detecting a portion of monochromatic light output by the acoustic optical tunable filter with a reference detector.

31. The method of claim 30 further comprising:

modulating the monochromatic beam of light output by the acoustic optical tunable filter;

demodulating the monochromatic light received by the reference detector; and

demodulating the detected transmitted light.

32. The method of claim 19 wherein the at least one body fluid is plasma.

33. The method of claim 19 wherein the at least one body fluid is interstitial fluid.

34. The method of claim 19 wherein the at least one body fluid is intercellular fluid.

35. The method of claim 19 wherein the at least one body fluid is intracellular fluid.

36. The method of claim 19 wherein the analyte is glucose.

37. A method for determining the concentration of an analyte in at least one body fluid in body tissue, the method comprising the acts of:

contacting body tissue to be analyzed;

compressing the contacted body tissue;

directing infrared light into the body tissue;

detecting infrared light transmitted through the body tissue;

measuring pressure applied to the body tissue being analyzed;

measuring temperature of the body tissue;

analyzing the detected transmitted light using an algorithm built upon correlation with the analyte in the body fluid, the algorithm being adapted to convert the detected transmitted light into the concentration of the analyte in at least one body fluid; and

determining the concentration of the analyte in at least one body fluid using the measured pressure and temperature to correct for spectral information.

38. The method of claim 37 wherein directing infrared light further comprises selectively directing narrow bandwidths of infrared light.

39. The method of claim 37 wherein directing infrared light further comprises directing monochromatic light onto the body tissue.

40. The method of claim 39 wherein the directing of monochromatic light further comprises directing a beam of monochromatic light having a wavelength ranging between approximately 750 nanometers and approximately 11,000 nanometers.

41. The method of claim 40 wherein the wavelength ranges between approximately 1400 nanometers and 11,000 nanometers.

42. The method of claim 41 wherein the wavelength ranges between approximately 1400 nanometers and 2500 nanometers.

43. The method of claim 37 wherein directing further comprises:

directing the infrared light to an acoustic optical tunable filter; and

outputting a monochromatic beam of light from the acoustic optical tunable filter onto the contacted body tissue.

44. The method of claim 43 further comprising detecting a portion of monochromatic light output by the acoustic optical tunable filter with a reference detector.

45. The method of claim 44 further comprising:

modulating the monochromatic beam of light output by the acoustic optical tunable filter;

demodulating the monochromatic light received by the reference detector; and

demodulating the detected transmitted light.

46. The method of claim 37 wherein the analyte is glucose.

47. A method for determining the concentration of an analyte in at least one body fluid in body tissue, the method comprising the acts of:

contacting body tissue to be analyzed;

compressing the contacted body tissue;

directing infrared light into the body tissue;

detecting infrared light transmitted through the body tissue;

measuring pressure applied to the body tissue being analyzed;

analyzing the detected transmitted light using an algorithm built upon correlation with the analyte in the body fluid, the algorithm being adapted to convert the detected transmitted light into the concentration of the analyte in at least one body fluid; and

determining the concentration of the analyte in at least one body fluid using the measured pressure to correct for spectral information.

48. The method of claim 47 wherein directing infrared light further comprises selectively directing narrow bandwidths of infrared light.

49. The method of claim 47 wherein directing infrared light further comprises directing monochromatic light onto the body tissue.

50. The method of claim 49 wherein the directing of monochromatic light further comprises directing a beam of monochromatic light having a wavelength ranging between approximately 750 nanometers and approximately 11,000 nanometers.

51. The method of claim 50 wherein the wavelength ranges between approximately 1400 nanometers and 11,000 nanometers.

52. The method of claim 51 wherein the wavelength ranges between approximately 1400 nanometers and 2500 nanometers.

53. The method of claim 47 wherein directing further comprises:

directing the infrared light to an acoustic optical tunable filter; and

outputting a monochromatic beam of light from the acoustic optical tunable filter onto the contacted body tissue.

54. The method of claim 53 further comprising detecting a portion of monochromatic light output by the acoustic optical tunable filter with a reference detector.

55. The method of claim 54 further comprising:

modulating the monochromatic beam of light output by the acoustic optical tunable filter;

demodulating the monochromatic light received by the reference detector; and

demodulating the detected transmitted light.

56. The method of claim 47 wherein the wavelength ranges between approximately 750 nanometers and 2500 nanometers.

57. The method of claim 47 wherein the analyte is glucose.