SYSTEM AND METHODS FOR DETERMINATION OF ANALYTE CONCENTRATION USING TIME RESOLVED AMPEROMETRY

• US 20120234700A1
• Filed: 12/20/2011
• Published: 09/20/2012
• Est. Priority Date: 07/26/2007
• Status: Active Grant

• Current Assignee: Trividia Health, Inc. (Sinocare, Inc.)
• Original Assignee: Nipro Diagnostics, Inc.
• Inventors: Deng, David
• Granted Patent: US 8,574,424 B2
• Time in Patent Office: Days
• US Class Current: 205/792
• CPC Class Codes: A61B 2562/0295 Strip shaped analyte sensors for apparatus classified in A61B5/145 or A61B5/157 disposable multilayered or laminated electrodes G01N27/307; details of handling chemical test elements G01N33/4875
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/1486 using enzyme electrodes, e.g. with immobilised oxidase
• CPC Class Codes: A61B 5/1495 Calibrating or testing of in-vivo probes
• CPC Class Codes: G01N 27/3273 Devices therefor, e.g. test element readers, circuitry details not specific to biochemical electrodes G01N33/4875
• CPC Class Codes: Y10S 435/817 Enzyme or microbe electrode

Abstract

A method for determining a concentration of an analyte is disclosed. The method includes applying a potential excitation to a fluid sample containing an analyte and determining if a current decay curve associated with the fluid sample has entered an analyte depletion stage. The method also includes measuring a plurality of current values associated with the fluid sample during the analyte depletion stage and calculating an analyte concentration based on at least one of the plurality of current values.

Claims

1-30. -30. (canceled)

31. A method for determining a concentration of an analyte in a fluid sample, the steps comprising:

applying a potential excitation to the fluid sample;

measuring a first current during a first time-segment following application of the potential excitation, wherein a first set of calibration data is derived from the first time-segment and a second set of calibration data is derived from a second time-segment that follows at least part of the first time-segment;

determining if the first measured current is within a first target range associated with the first time-segment, wherein the first target range is different to a second target range associated with the second time-segment; and

calculating a final concentration of the analyte based on the first measured current and the first set of calibration data if the first measured current is within the first target range.

32. The method of claim 31, wherein calculating the final concentration of the analyte includes inputting the first measured current into at least one of an iterative algorithm, an interpolative algorithm, a line-plot, and an extrapolative algorithm.

33. The method of claim 31, wherein the first set of calibration data includes at least one of a plurality of calibration curves, a lookup table, a data array, and a mathematical equation.

34. The method of claim 31, wherein the first time-segment is less than about two to about ten seconds and the second time-segment is more than about two to about ten seconds.

35. The method of claim 34, wherein the first time-segment is less than about four seconds and the second time-segment is more than about four seconds.

36. The method of claim 31, wherein at least part of the calibration data is determined using at least one of empirical data and predicted data.

37. The method of claim 31, wherein the first and second sets of calibration data are associated with different levels of hematocrit.

38. The method of claim 37, wherein the different levels of hematocrit include at least one of a high level greater than about 42%, a physiological level of about 42%, and a low level less than about 42%.

39. The method of claim 31, further comprising:

measuring a second current during the second time-segment;

determining if the second measured current is within the second target range; and

calculating a final concentration of the analyte based on the second measured current and the second set of calibration data if the second measured current is within the second target range.

40. The method of claim 39, further comprising:

measuring a third current during a third time-segment following at least part of the second time-segment; and

calculating a final concentration of the analyte based on the third measured current and a third set of calibration data derived from the third time-segment.

41. A system for analyzing an analyte in a fluid sample, comprising:

a set of electrodes configured to apply a potential excitation to a fluid sample containing an analyte;

a memory system configured to store a first set of calibration data derived from a first time-segment and a second set of calibration data derived from a second time-segment that follows at least part of the first time-segment;

processor configured to;

measure a first current during the first time-segment following application of the potential excitation;

determine if the first measured current is within a first target range associated with the first time-segment; and

calculate a final concentration of the analyte based on the first measured current and the first set of calibration data if the first measured current is within the first target range.

42. The system of claim 41, wherein the processor is further configured to:

measure a second current during the second time-segment;

determine if the second measured current is within the second target range; and

calculate a final concentration of the analyte based on the second measured current and the second set of calibration data if the second measured current is within the second target range.

43. The system of claim 42, wherein the processor is further configured to:

measure a third current during a third time-segment following at least part of the second time-segment; and

calculate a final concentration of the analyte based on the third measured current and a third set of calibration data derived from the third time-segment.

44. The system of claim 41, wherein the analyte includes glucose and the fluid sample includes blood.

45. The system of claim 41, wherein the fluid sample includes an enzyme of at least one of glucose oxidase and glucose dehydrogenase and a mediator of at least one of potassium ferricyanide and ruthenium hexamine.

46. The system of claim 41, wherein the set of electrodes are contained within in a test strip.

47. The system of claim 41, wherein the memory system and the processor are contained within a meter.

48. A non-transitory computer readable media, wherein the media comprises a plurality of instructions configured to direct a processor to:

measure a first current during a first time-segment following application of a potential excitation, wherein the potential excitation is applied to a fluid sample containing an analyte, a first set of calibration data is derived from the first time-segment, and a second set of calibration data is derived from a second time-segment that follows at least part of the first time-segment;

determine if the first measured current is within a first target range associated with the first time-segment, wherein the first target range is different to a second target range associated with the second time-segment; and

calculate a final concentration of the analyte based on the first measured current and the first set of calibration data if the first measured current is within the first target range.

49. The computer readable media of claim 48, wherein the processor is further configured to:

measure a second current during the second time-segment;

determine if the second measured current is within the second target range; and

calculate a final concentration of the analyte based on the second measured current and the second set of calibration data if the second measured current is within the second target range.

50. The computer readable media of claim 49, wherein the processor is further configured to:

measure a third current during a third time-segment following at least part of the second time-segment; and

calculate a final concentration of the analyte based on the third measured current and a third set of calibration data derived from the third time-segment.