Temperature-adjusted analyte determination for biosensor systems

• US 8,445,290 B2
• Filed: 03/06/2012
• Issued: 05/21/2013
• 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.
• Primary Examiner(s): Wallenhorst, Maureen
• Application Number:
  US13/413,028
• Publication Number:
  US 20120215460A1
• Time in Patent Office: 441 Days
• Field of Search: 436/8, 436/14, 436/63, 436/95, 436/147, 436/149, 436/150, 436/164, 422/68.1, 422/82.01, 422/82.02, 422/82.05, 422/82.09, 422/82.12, 422/400, 73/10.1, 73/10.2, 435/14, 708/205
• US Class Current: 436/147
• 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 output signals at a reference temperature and analyte concentrations, to a temperature-adjusted correlation between output signals at the sample temperature and analyte concentrations, in response to the sample temperature; and

after adjusting the correlation, determining the analyte concentration in the sample from the temperature-adjusted correlation and the output signals at the sample 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. The method of claim 1, where determining a sample temperature of the sample comprises measuring the sample temperature, calculating the sample temperature from the output signal, or measuring an ambient temperature and assuming the sample temperature to be the same or similar to the ambient temperature.

14. 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; and

a sensor strip having a reservoir for a liquid sample, and a sample interface in communication with the sensor interface;

where the processor adjusts a correlation between output signals at a reference temperature and analyte concentrations, to a temperature-adjusted correlation between output signals at a sample temperature and analyte concentrations, 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.

15. The biosensor of claim 14, where the processor adjusts the correlation in response to a normalized temperature function of slope and a normalized temperature function of intercept.

16. The biosensor of claim 14 where the temperature-adjusted correlation is represented as follows:

17. The biosensor of claim 16, 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 normalized slopes.

18. The biosensor of claim 16, 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 normalized intercepts.

19. The biosensor of claim 14, where the output signal comprises light.

20. The biosensor of claim 14, where the output signal comprises an electrical signal.

21. The biosensor of claim 14, where the output signal is responsive to pulsed input signals.

22. The biosensor of claim 14, where the analyte comprises glucose and the biological fluid comprises whole blood.

23. The biosensor of claim 14, where the sample temperature is determined by measuring the sample temperature, by calculating the sample temperature from the output signal, or by measuring an ambient temperature and assuming the sample temperature to be the same or similar to the ambient temperature.