Instrument

• US 7,018,843 B2
• Filed: 11/07/2001
• Issued: 03/28/2006
• Est. Priority Date: 11/07/2001
• Status: Active Grant

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Diagnostics Operations Incorporated (Roche Holding AG)
• Inventors: Heller, Zindel Herbert
• Primary Examiner(s): WALLENHORST, MAUREEN
• Application Number:
  US10/046,030
• Publication Number:
  US 20030096420A1
• Time in Patent Office: 1,602 Days
• Field of Search: 436/63, 436/70, 436/95, 436/149, 436/150, 422/68.1, 422/73, 422/82.01, 422/67, 435/14
• US Class Current: 436/95
• CPC Class Codes: G01N 27/3274 Corrective measures, e.g. error detection, compensation for temperature or hematocrit, calibration coding of calibration information G01N33/48771
• CPC Class Codes: G01N 33/5094 for blood cell populations red blood cells G01N33/80
• CPC Class Codes: Y10T 436/144444 Glucose

Abstract

A method and apparatus for performing a first measurement on a biological fluid or control, which first measurement varies with both the concentration of a first component and at least one of the presence and concentration of a second component. The method and apparatus perform a second measurement on the biological fluid or control, which second measurement varies primarily only with the at least one of the presence and concentration of the second component to develop an indication of the at least one of the presence and concentration of the second component. The first and second measurements may be made sequentially or simultaneously. The method and apparatus then remove an amount representative of the indicated presence or concentration of the second component from the concentration of the first component indicated by the first measurement.

Claims

1. A method for determining the concentration of glucose in blood, a blood fraction or a control, the blood, blood fraction or control including red blood cells or red blood cell fractions which affect the determination of the concentration of glucose, the method including performing a first measurement on the blood, blood fraction or control which first measurement varies with both the concentration of glucose and at least one of the presence and concentration of red blood cells or red blood cell fractions, which first measurement comprises a measurement of a time-varying function i₁ (t) having the general form

i₁(t)=M/sqrt(t)+B

where t is time from initiating the measurement, M is the slope of a graph of the function and B is a value the function approaches as t becomes very large, performing a second measurement on the blood, a blood fraction or control which second measurement has the form of a time-varying function i₂(t), where t is time, t<

some arbitrarily established time, i₂(t) varying primarily only with the at least one of the presence and concentration of red blood cells or red blood cell fractions to develop an indication of the at least one of the presence and concentration of red blood cells or red blood cell fractions, and removing an amount representative of the indicated presence or concentration of red blood cells or red blood cell fractions from the concentration of glucose indicated by the first measurement to provide the concentration of glucose in the blood, blood fraction or control.

2. The method of claim 1 wherein the first measurement is of a hematocrit-sensitive measure of glucose concentration.

3. The method of claim 1 further including contacting the blood, blood fraction or control with a reactant before performing the first measurement.

4. The method of claim 3 wherein the second measurement is of a largely glucose-insensitive measure of hematocrit.

5. The method of claim 4 wherein the first measurement is of a hematocrit-sensitive measure of glucose concentration.

6. The method of claim 3 wherein the first and second measurements exhibit an interdependence between the concentration of glucose and the concentration of red blood cells or red blood cell fractions.

7. The method of claim 6 wherein the second measurement is of a largely glucose-insensitive measure of hematocrit.

8. The method of claim 7 wherein the first measurement is of a hematocrit-sensitive measure of glucose concentration.

9. The method of claim 1 wherein the first and second measurements exhibit an interdependence between the concentration of glucose and the concentration of red blood cells or red blood cell fractions.

10. The method of claim 9 wherein the second measurement is of a largely glucose-insensitive measure of hematocrit.

11. The method of claim 10 wherein the first measurement is of a hematocrit-sensitive measure of the glucose concentration.

12. Apparatus for determining the concentration of glucose in blood, a blood fraction or a control, the blood, blood fraction or control including red blood cells or red blood cell fractions which affect the determination of the concentration of glucose, the apparatus including a device that performs a first measurement on the blood, blood fraction or control which first measurement varies with both the concentration of glucose and at least one of the presence and concentration of red blood cells or red blood cell fractions, the device performing measurements of a time-varying function i₁(t) having the general form

i₁(t)=M/sqrt(t)+B

where t is time from initiating the measurement, M is the slope of a graph of the function and B is a value the function approaches as t becomes very large, the device further performing a second measurement of a time-varying function i₂(t) of the blood, blood fraction or control, where t is time, t<

some arbitrarily established time, which second measurement varies primarily only with the at least one of the presence and concentration of red blood cells or red blood cell fractions to develop an indication of the at least one of the presence and concentration of red blood cells or red blood cell fractions, the device further removing an amount representative of the indicated presence or concentration of red blood cells or red blood cell fractions from the concentration of glucose indicated by the first measurement.

13. The apparatus of claim 12, the device performing the first measurement on the blood, blood fraction or control which first measurement varies with both the concentration of glucose and the concentration of blood cells in blood, a blood fraction or a control.

14. The apparatus of claim 13, the device performing the second measurement on the blood, blood fraction or control which second measurement varies primarily only with the concentration of blood cells in the blood, blood fraction or control.

15. The apparatus of claim 14, wherein the second measurement is a largely glucose-insensitive measure of hematocrit.

16. The apparatus of claim 15, wherein the first measurement is a hematocrit-sensitive measure of glucose concentration.

17. The apparatus of claim 12, further including a reactant for contacting the blood, blood fraction or control or control before performing the first measurement.

18. The apparatus of claim 17, the device performing the first measurement on the blood, blood fraction of control which first measurement varies with both the concentration of glucose and the concentration of blood cells in blood, a blood fraction or a control.

19. The apparatus of claim 18, the device performing the second measurement on the blood, blood fraction or control which second measurement varies primarily only with the concentration of blood cells in the blood, blood fraction or control.

20. The apparatus of claim 19, wherein the second measurement is a largely glucose-insensitive measure of hematocrit.

21. The apparatus of claim 20, wherein the first measurement is a hematocrit-sensitive measure of glucose concentration.

22. The apparatus of claim 17, wherein the first and second measurements exhibit an interdependence between the concentration of glucose and the concentration of red blood cells or red blood cell fractions.

23. The apparatus of claim 22, the device performing the first measurement on the blood, blood fraction or control which first measurement varies with both the concentration of glucose and the concentration of blood cells in blood, a blood fraction or a control.

24. The apparatus of claim 23, the device performing the second measurement on the blood, blood fraction or control which second measurement varies primarily only with the concentration of blood cells in the blood, blood fraction or control.

25. The apparatus of claim 24, wherein the second measurement is a largely glucose-insensitive measure of hematocrit.

26. The apparatus of claim 25, wherein the first measurement is a hematocrit-sensitive measure of glucose concentration.

27. The apparatus of claim 12, wherein the first and second measurements exhibit an interdependence between the concentration of glucose and the concentration of red blood cells or red blood cell fractions.

28. The apparatus of claim 27, the device performing the first measurement on the blood, blood fraction or control which first measurement varies with both the concentration of glucose and the concentration of blood cells in blood, a blood fraction or a control.

29. The apparatus of claim 28, the device performing the second measurement on the blood, blood fraction or control which second measurement varies primarily only with the concentration of blood cells in the blood, blood fraction or control.

30. The apparatus of claim 29, wherein the second measurement is a largely glucose-insensitive measure of hematocrit.

31. The apparatus of claim 30, wherein the first measurement is a hematocrit-sensitive measure of glucose concentration.

32. A method for determining the concentration of glucose in blood, a blood fraction or a control, the blood, blood fraction or control including red blood cells or red blood cell fractions which affect the determination of the concentration of glucose, the method including performing a first measurement of a time-varying function i₁(t) of the blood, blood fraction or control, i1(t) varying with both the concentration of glucose and at least one of the presence and concentration of red blood cells or red blood cell fractions, i₁(t) having the general form

i₁(t)=M/sqrt(t)+B

where t is time from initiating the measurement, M is the slope of a graph of the function and B is a value the function approaches as t becomes very large, performing a second measurement on the blood, blood fraction or control which second measurement also varies with the at least one of the presence and concentration of red blood cells or red blood cell fractions to develop an indication of the at least one of the presence and concentration of red blood cells or red blood cell fractions, and removing an amount representative of the indicated presence or concentration of red blood cells or red blood cell fractions from the concentration of glucose indicated by the first measurement to provide the concentration of glucose in the blood, blood fraction or control.

33. The method of claim 32 wherein the second measurement is of a largely glucose-insensitive measure of hematocrit.

34. The method of claim 33 wherein the first measurement is of a hematocrit-sensitive measure of glucose concentration.

35. The method of claim 32 further including contacting the blood, blood fraction or control with a reactant before performing the first measurement.

36. The method of claim 35 wherein the second measurement is of a largely glucose-insensitive measure of hematocrit.

37. The method of claim 36 wherein the first measurement is of a hematocrit-sensitive measure of glucose concentration.

38. The method of claim 35 wherein the first and second measurements exhibit an interdependence between the concentration of glucose and the concentration of red blood cells or red blood cell fractions.

39. The method of claim 38 wherein the second measurement is of a largely glucose-insensitive measure of hematocrit.

40. The method of claim 39 wherein the first measurement is of a hematocrit-sensitive measure of glucose concentration.

41. The method of claim 32 wherein the first and second measurements exhibit an interdependence between the concentration of glucose and the concentration of red blood cells or red blood cell fractions.

42. The method of claim 41 wherein the second measurement is of a largely glucose-insensitive measure of hematocrit.

43. The method of claim 42 wherein the first measurement is of a hematocrit-sensitive measure of the glucose concentration.

44. Apparatus for determining the concentration of a glucose in blood, a blood fraction or a control, the blood, blood fraction or control including red blood cells or red blood cell fractions which affect the determination of the concentration of glucose, the apparatus including a device that performs a first measurement of a time-varying function i₁(t) of the blood, blood fraction or control, i₁(t) varying with both the concentration of glucose and at least one of the presence and concentration of red blood cells or red blood cell fractions, i₁(t) having the general form

i₁(t)=M/sqrt(t)+B

where t is time from initiating the measurement, M is the slope of a graph of the function and B is a value the function approaches as t becomes very large, the device further performing a second measurement on the blood, a blood fraction or control which second measurement varies primarily only with the at least one of the presence and concentration of red blood cells or red blood cell fractions to develop an indication of the at least one of the presence and concentration of red blood cells or red blood cell fractions, and the device further removing an amount representative of the indicated presence or concentration of red blood cells or red blood cell fractions from the concentration of glucose indicated by the first measurement.

45. The apparatus of claim 44, the device being a device for performing the first measurement on the blood, blood fraction or control which first measurement varies with both the concentration of glucose and the concentration of blood cells in blood, a blood fraction or a control.

46. The apparatus of claim 45, the device performing the second measurement on the blood, blood fraction or control which second measurement varies primarily only with the concentration of blood cells in the blood, blood fraction or control.

47. The apparatus of claim 46, wherein the second measurement is a largely glucose-insensitive measure of hematocrit.

48. The apparatus of claim 47, wherein the first measurement is a hematocrit-sensitive measure of glucose concentration.

49. The apparatus of claim 44 further including a reactant for contacting the blood, a blood fraction or control before performing the first measurement.

50. The apparatus of claim 49, the device performing the first measurement on the blood, blood fraction or control which first measurement varies with both the concentration of glucose and the concentration of blood cells in blood, a blood fraction or a control.

51. The apparatus of claim 50, the device performing the second measurement on the blood, blood fraction or control which second measurement varies primarily only with the concentration of blood cells in the blood, blood fraction or control.

52. The apparatus of claim 51, wherein the second measurement is a largely glucose-insensitive measure of hematocrit.

53. The apparatus of claim 52, wherein the first measurement is a hematocrit-sensitive measure of glucose concentration.

54. The apparatus of claim 49, wherein the first and second measurements exhibit an interdependence between the concentration of glucose and the concentration of red blood cells or red blood cell fractions.

55. The apparatus of claim 54, the device performing the first measurement on the blood, blood fraction or control which first measurement varies with both the concentration of glucose and the concentration of red blood cells or red blood cell fractions in blood, a blood fraction or a control.

56. The apparatus of claim 55, the device performing the second measurement on the blood, blood fraction or control which second measurement varies primarily only with the concentration of red blood cells or red blood cell fractions in the blood, blood fraction or control.

57. The apparatus of claim 56, wherein the second measurement is a largely glucose-insensitive measure of hematocrit.

58. The apparatus of claim 57, wherein the first measurement is a hematocrit-sensitive measure of glucose concentration.

59. The apparatus of claim 44, wherein the first and second measurements exhibit an interdependence between the concentration of glucose and the concentration of red blood cells or red blood cell fractions.

60. The apparatus of claim 59, the device performing the first measurement on the blood, blood fraction or control which first measurement varies with both the concentration of glucose and the concentration of red blood cells or red blood cell fractions in blood, a blood fraction or a control.

61. The apparatus of claim 60, the device performing the second measurement on the blood, blood fraction or control which second measurement varies primarily only with the concentration of red blood cells or red blood cell fractions in the blood, blood fraction or control.

62. The apparatus of claim 61, wherein the second measurement is a largely glucose-insensitive measure of hematocrit.

63. The apparatus of claim 62, wherein the first measurement is a hematocrit-sensitive measure of glucose concentration.