INSTRUMENT

• US 20080293082A1
• Filed: 08/04/2008
• Published: 11/27/2008
• Est. Priority Date: 11/07/2001
• Status: Active Grant

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Zindel Herbert Heller
• Inventors: Heller, Zindel Herbert
• Granted Patent: US 7,923,258 B2
• Time in Patent Office: Days
• US Class Current: 435/14
• 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 a first, medically significant component of a biological fluid or a control, the biological fluid or control including a second component which affects the determination of the concentration of the first component, the method including performing a first measurement of a time-varying function i₁(t) on the biological fluid or control which first measurement varies with both the concentration of the first component and at least one of the presence and concentration of the second component, 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 biological fluid 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 the second component to develop an indication of the at least one of the presence and concentration of the second component, and removing 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.

2. The method of claim 1 wherein the biological fluid is blood or a blood fraction.

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

4. The method of claim 3 wherein the biological fluid is blood or a blood fraction.

5. The method of claim 3 wherein the first component is glucose.

6. The method of claim 3 wherein the second component is blood cells.

7. The method of claim 3 wherein the first and second measurements exhibit an interdependence between the concentration of the first component and the concentration of the second component.

8. The method of claim 7 wherein the biological fluid is blood or a blood fraction.

9. The method of claim 7 wherein the first component is glucose.

10. The method of claim 7 wherein the second component is blood cells.

11. The method of claim 1 wherein the first and second measurements exhibit an interdependence between the concentration of the first component and the concentration of the second component.

12. The method of claim 11 wherein the biological fluid is blood or a blood fraction.

13. The method of claim 11 wherein the first component is glucose.

14. The method of claim 11 wherein the second component is blood cells.

15. Apparatus for determining the concentration of a first, medically significant component of a biological fluid or a control, the biological fluid or control including a second component which affects the determination of the concentration of the first component, the apparatus including a device for performing a first measurement of a time-varying function i₁(t) on the biological fluid or control which first measurement varies with both the concentration of the first component and at least one of the presence and concentration of the second component, 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 biological fluid 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 the second component to develop an indication of the at least one of the presence and concentration of the second component, and the device further removing 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.

16. The apparatus of claim 15 wherein the device determines the concentration of a first, medically significant component of blood, a blood fraction or a control.

17. The apparatus of claim 15 further including a reactant for contacting the biological fluid or control before performing the first measurement.

18. The apparatus of claim 17 wherein the device determines the concentration of a first, medically significant component of blood, a blood fraction or a control.

19. The apparatus of claim 17 wherein the device performs first and second measurements which exhibit an interdependence between the concentration of the first component and the concentration of the second component.

20. The apparatus of claim 19 wherein the device determines the concentration of a first, medically significant component of blood, a blood fraction or a control.

21. The apparatus of claim 15 wherein the device performs first and second measurements which exhibit an interdependence between the concentration of the first component and the concentration of the second component.

22. The apparatus of claim 21 wherein the device determines the concentration of a first, medically significant component of blood, a blood fraction or a control.

23. A method for determining the concentration of a first, medically significant component of a biological fluid or a control, the biological fluid or control including a second component which affects the determination of the concentration of the first component, the method including performing a first measurement of a time-varying function i₁(t) of the biological fluid or control, i₁(t) varying with both the concentration of the first component and at least one of the presence and concentration of the second component, 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 biological fluid or control which second measurement also varies 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, and removing 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.

24. The method of claim 23 wherein the biological fluid is blood or a blood fraction.

25. The method of claim 23 further including contacting the biological fluid or control with a reactant before performing the first measurement.

26. The method of claim 25 wherein the biological fluid is blood or a blood fraction.

27. The method of claim 25 wherein the first component is glucose.

28. The method of claim 25 wherein the second component is blood cells.

29. The method of claim 25 wherein the first and second measurements exhibit an interdependence between the concentration of the first component and the concentration of the second component.

30. The method of claim 29 wherein the biological fluid is blood or a blood fraction.

31. The method of claim 30 wherein the first component is glucose.

32. The method of claim 30 wherein the second component is blood cells.

33. The method of claim 23 wherein the first and second measurements exhibit an interdependence between the concentration of the first component and the concentration of the second component.

34. The method of claim 33 wherein the biological fluid is blood or a blood fraction.

35. The method of claim 33 wherein the first component is glucose.

36. The method of claim 33 wherein the second component is blood cells.

37. Apparatus for determining the concentration of a first, medically significant component of a biological fluid or a control, the biological fluid or control including a second component which affects the determination of the concentration of the first component, the apparatus including a device for performing a first measurement of a time-varying function i₁(t) of the biological fluid or control, i₁(t) varying with both the concentration of the first component and at least one of the presence and concentration of the second component, 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 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, and the device further removing 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.

38. The apparatus of claim 37 wherein the device determines the concentration of a first, medically significant component of blood, a blood fraction or a control.

39. The apparatus of claim 37 further including a reactant for contacting the biological fluid or control before performing the first measurement.

40. The apparatus of claim 39 wherein the device determines the concentration of a first, medically significant component of blood, a blood fraction or a control.

41. The apparatus of claim 40 wherein the device performs 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.

42. The apparatus of claim 39 wherein the device performs first and second measurements which exhibit an interdependence between the concentration of the first component and the concentration of the second component.

43. The apparatus of claim 42 wherein the device determines the concentration of a first, medically significant component of blood, a blood fraction or a control.

44. The apparatus of claim 43 wherein the device performs 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.

45. The apparatus of claim 37 wherein the device performs first and second measurements which exhibit an interdependence between the concentration of the first component and the concentration of the second component.

46. The apparatus of claim 45 wherein the device determines the concentration of a first, medically significant component of blood, a blood fraction or a control.

47. The apparatus of claim 46 wherein the device performs 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.