Temperature-Adjusted Analyte Determination For Biosensor System

• US 20110039286A1
• Filed: 07/20/2010
• Published: 02/17/2011
• Est. Priority Date: 02/27/2006
• Status: Active Grant

• Current Assignee: Ascensia Diabetes Care Holdings AG (PHC Holdings Corporation)
• Original Assignee: Bayer Healthcare LLC (Bayer AG)
• Inventors: Wu, Huan-Ping, Nelson, Christine D.
• Granted Patent: US 8,148,162 B2
• Time in Patent Office: Days
• US Class Current: 435/14
• CPC Class Codes: A61B 2560/0252 using ambient temperature
• 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: G01N 27/26 by investigating electrochemical variables; by using electrolysis or electrophoresis
• 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: G16B 40/10 Signal processing, e.g. from mass spectrometry [MS] or from PCR
• CPC Class Codes: G16B 99/00 Subject matter not provided for in other groups of this subclass
• CPC Class Codes: Y10T 436/10 Composition for standardization, calibration, simulation, stabilization, preparation or preservation; processes of use in preparation for chemical testing
• CPC Class Codes: Y10T 436/104998 Glucose, ketone, nitrate standard or control
• CPC Class Codes: Y10T 436/12 Condition responsive control
• CPC Class Codes: Y10T 436/144444 Glucose

Abstract

A biosensor system determines analyte concentration from an output signal generated by an oxidation/reduction reaction of the analyte. The biosensor system adjusts a correlation for determining analyte concentrations from output signals at one temperature to determining analyte concentrations from output signals at other temperatures. The temperature-adjusted correlation between analyte concentrations and output signals at a reference temperature may be used to determine analyte concentrations from output signals at a sample temperature.

Claims

1. A method for determining an analyte concentration in a sample of a biological fluid, comprising:

determining a sample temperature of the sample;

generating an output signal in response to a redox reaction of an analyte in the sample;

adjusting a correlation between analyte concentrations and output signals at a reference temperature in response to temperature, where the correlation between the analyte concentrations and the output signals at the reference temperature is adjusted to calculate analyte concentrations in response to output signals at another temperature; and

after adjusting the correlation, determining the analyte concentration in the sample from the temperature-adjusted correlation and the output signals at the other temperature.

2. The method of claim 1, further comprising adjusting the correlation in response to a normalized temperature function of slope and a normalized temperature function of intercept.

3. The method of claim 1, where the temperature-adjusted correlation between analyte concentrations and output signals is represented as follows:

4. The method of claim 3, where the normalized temperature function for slope comprises a regression analysis of normalized slopes.

5. The method of claim 4, where the normalized temperature function for slope, f(T), is represented as follows:

f(T)=a₂T²+a₁T+a₀,

where T is the sample temperature and a₂, a₁, and a₀ are coefficients of a regression analysis representing the normalized slopes.

6. The method of claim 3, where the normalized temperature function for intercept comprises a regression analysis of normalized intercepts.

7. The method of claim 6, where the normalized temperature function for intercept, g(T) is represented as follows:

g(T)=b₂T²+b₁T+b₀,

where T is the sample temperature and b₂, b₁, and b₀ are coefficients of a regression analysis representing the normalized intercepts.

8. The method of claim 1, further comprising generating the output signal in response to an electrochemical process.

9. The method of claim 1, where the output signal comprises light.

10. The method of claim 1, where the output signal comprises an electrical signal.

11. The method of claim 1, further comprising generating the output signal in response to pulsed input signals.

12. The method of claim 1, where the analyte comprises glucose and the biological fluid comprises whole blood.

13-23. -23. (canceled)

24. A biosensor for determining an analyte concentration in a biological fluid, comprising:

a measuring device having a processor connected to a sensor interface and a temperature sensor;

a sensor strip having a sample interface on a base, where the sample interface is adjacent to a reservoir formed by the base; and

where the processor adjusts a correlation between analyte concentrations and output signals at a reference temperature in response to a sample temperature from the temperature sensor, and

where after the processor adjusts the correlation, the processor determines an analyte concentration in a sample of a biological fluid in the reservoir of the sensor strip from the temperature-adjusted correlation and an output signal from the sample interface.

25. The biosensor of claim 24, where the processor adjusts the correlation in response to a normalized temperature function of slope and a normalized temperature function of intercept.

26. The biosensor of claim 24 where the temperature-adjusted correlation of a reference temperature is represented as follows:

27. The biosensor of claim 26, where the normalized temperature function for slope, f(T), is represented as follows:

f(T)=a₂T²+a₁T+a₀,

where T is the sample temperature and a₂, a₁, and a₀ are coefficients of a regression analysis representing the normalized slopes.

28. The biosensor of claim 26, where the normalized temperature function for intercept, g(T) is represented as follows:

g(T)=b₂T²+b₁T+b₀,

where T is the sample temperature and b₂, b₁, and b₀ are coefficients of a regression analysis representing the normalized intercepts.

29. The biosensor of claim 24, where the output signal comprises light.

30. The biosensor of claim 24, where the output signal comprises an electrical signal.

31. The biosensor of claim 24, where the output signal is responsive to pulsed input signals.

32. The biosensor of claim 24, where the analyte comprises glucose and the biological fluid comprises whole blood.

33. A method for determining an analyte concentration in a sample of a biological fluid, comprising:

measuring a sample temperature of the sample;

determining if the sample temperature is too high or too low in relation to predetermined temperature threshold values;

generating an output signal in response to a redox reaction of an analyte in the sample;

selecting a slope value and an intercept value from values previously determined at a reference temperature;

adjusting the selected slope value and the selected intercept value in response to the measured sample temperature to provide an adjusted slope value and an adjusted intercept value; and

calculating an analyte concentration from the output signal and the adjusted slope and intercept values.

34. The method of claim 33, where the slope adjustment is represented as follows:

S_T=S*(a₂*T₁²+a₁*T₁+a₀), where S_T is the adjusted slope value, S is the selected slope value, a₀, a₁, and a₂ are slope temperature function coefficients, and T₁ is the measured sample temperature.

35. The method of claim 34, where the slope temperature function coefficients are from Table II.

36. The method of claim 33, where the intercept adjustment is represented as follows:

Int_T=Int*(b₂*T₁²+b₁*T₁+b₀), where Int_T is the adjusted intercept value, Int is the selected intercept value, b₀, b₁, and b₂ are intercept temperature function coefficients, and T₁ is the measured sample temperature.

37. The method of claim 36, where the intercept temperature function coefficients are from Table II.

38. The method of claim 33, where the too high temperature is 50°

C. and the too low temperature is 5°

C.

39. The method of claim 33, where the analyte concentration calculation is represented as follows: