Underfill recognition system for a biosensor

• US 8,668,819 B2
• Filed: 10/22/2010
• Issued: 03/11/2014
• Est. Priority Date: 11/10/2009
• Status: Active Grant

• Current Assignee: Ascensia Diabetes Care Holdings AG (PHC Holdings Corporation)
• Original Assignee: Bayer Healthcare LLC (Bayer AG)
• Inventors: Wu, Huan-Ping, Perry, Joseph E., Trippel, Christine, Maurer, Eric
• Primary Examiner(s): Van, Luan
• Assistant Examiner(s): Kessel, Maris R
• Application Number:
  US12/910,449
• Publication Number:
  US 20110108440A1
• Time in Patent Office: 1,236 Days
• Field of Search: 20440301-40315, 205/775, 205/777.5, 205/792, 73/10.2
• US Class Current: 205/775
• CPC Class Codes: G01N 27/327 Biochemical electrodes , e.g. electrical or mechanical details for in vitro measurements
• 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 27/4163 checking the operation of, or calibrating, the measuring apparatus G01N27/3274, G01N27/4175 and G01N33/0006 take precedence

Abstract

A biosensor with an underfill recognition system assesses whether to analyze a sample for one or more analytes in response to the volume of the sample. The underfill recognition system applies polling and test excitation signals to the sample. The polling signals generate one or more polling output signals, which maybe used to detect when a sample is present and to determine whether the sample has sufficient volume for analysis. The test excitation signal generates one or more test output signals, which may be used to determine one or more analyte concentrations in the sample.

Claims

1. A method for assessing the volume of a sample in a biosensor, comprising:

applying a regular polling sequence, where the regular polling sequence substantially eliminates irreversible alteration of the concentration of at least one analyte in the sample during the application of the regular polling sequence;

detecting the presence of the sample;

then applying an extended polling sequence having at least one different extended input pulse, where the extended polling sequence substantially eliminates irreversible alteration of the concentration of the at least one analyte in the sample during the application of the extended polling sequence;

detecting whether a sample volume is sufficient for analysis of the at least one analyte in the sample; and

applying a test excitation signal when the sample volume is sufficient for analysis of the at least one analyte in the sample, where the test excitation signal irreversibly alters the concentration of the at least one analyte in the sample during the application of the test excitation signal.

2. The method of claim 1, further comprising determining the concentration of the at least one analyte in the sample.

3. The method of claim 1, where the regular and extended polling sequences and the test excitation signal are part of a gated amperometry electrochemical analysis.

4. The method of claim 1, the test excitation signal having at least one test input pulse with a test amplitude that is essentially the same as a regular amplitude of at least one regular input pulse of the regular polling sequence.

5. The method of claim 1, further comprising detecting at least one of a selected volume and a range of volumes.

6. The method of claim 1, where a last pulse in the extended polling sequence is a different extended pulse.

7. The method of claim 1,

the regular polling sequence having at least one regular input pulse;

and

the extended polling sequence having at least one similar extended input pulse, where the at least one similar extended input pulse has an extended amplitude that is essentially the same as a regular amplitude of the at least one regular input pulse, and

where the at least one different extended pulse has another extended amplitude that is not the same as the regular amplitude of the at least one regular input pulse.

8. The method of claim 1,

the regular polling sequence having at least one regular input pulse;

and

the extended polling sequence having at least one cycle, where each cycle has at least one similar extended input pulse and at least one different extended input pulse.

9. The method of claim 8, where the at least one similar extended input pulse has an extended amplitude that is essentially the same as a regular amplitude of the at least one regular input pulse, and where the at least one different extended pulse has another extended amplitude that is not the same as the regular amplitude of the at least one regular input pulse.

10. The method of claim 8, where a last pulse in each cycle is a different extended pulse.

11. The method of claim 1, further comprising:

counting a delay period when sample volume is insufficient; and

detecting whether a sample volume is sufficient for analysis of the at least one analyte in the sample after the delay period.

12. The method of claim 1, further comprising indicating when the sample volume is insufficient for analysis of the at least one analyte in the sample.

13. The method of claim 12, further comprising:

stopping the test excitation signal when the sample volume is insufficient for analysis of the at least one analyte in the sample;

requesting a user to add more sample;

applying another regular polling sequence, where the another regular polling sequence substantially eliminates irreversible alteration of the concentration of the at least one analyte in the sample during the application of the another regular polling sequence;

detecting the presence of a larger sample;

applying another extended polling sequence having at least one different extended input pulse to the larger sample, where the another extended polling sequence substantially eliminates irreversible alteration of the concentration of the at least one analyte in the sample during the application of the another extended polling sequence; and

detecting whether the larger sample has a sample volume sufficient for analysis of the at least one analyte in a sample.

14. The method of claim 1, further comprising improving at least one of a sample output signal and a volume output signal with at least one mediator.

15. The method of claim 14, where the at least one mediator includes a two electron transfer mediator.

16. A method for assessing the volume of a sample in a biosensor, comprising:

applying a regular polling sequence, where the regular polling sequence substantially eliminates irreversible alteration of the concentration of at least one analyte in the sample during the application of the regular polling sequence;

detecting when at least one regular output pulse reaches at least one sample threshold;

applying an extended polling sequence, where the extended polling sequence substantially eliminates irreversible alteration of the concentration of the at least one analyte in the sample during the application of the extended polling sequence;

detecting when at least one different extended output pulse reaches at least one volume threshold;

indicating when a sample volume is insufficient for analysis of the at least one analyte in the sample; and

then applying a test excitation signal when the sample volume is sufficient for analysis of at least one analyte in the sample, where the test excitation signal irreversibly alters the concentration of the at least one analyte in the sample during the application of the test excitation signal.

17. The method of claim 16, where a last pulse in the extended polling sequence is a different extended pulse.

18. The method of claim 16, further comprising:

applying at least one similar extended input pulse with an extended amplitude that is essentially the same as a regular amplitude of the at least one regular input pulse; and

applying at least one different extended pulse with another extended amplitude that is not the same as the regular amplitude of the at least one regular input pulse.

19. The method of claim 18, further comprising applying a test excitation signal having at least one test input pulse with a test amplitude that is essentially the same as the regular amplitude of the at least one regular input pulse.

20. The method of claim 16, the extended polling sequence having at least one cycle, where each cycle has at least one similar extended input pulse and at least one different extended input pulse.

21. The method of claim 20, where the at least one similar extended input pulse has an extended amplitude that is essentially the same as a regular amplitude of the at least one regular input pulse, and where the at least one different extended pulse has another extended amplitude that is not the same as the regular amplitude of the at least one regular input pulse.

22. The method of claim 20, where a last pulse in each cycle is a different extended pulse.

23. The method of claim 16, further comprising:

detecting an initial extended output pulse that does not reach at least one or more volume thresholds;

counting a delay period from the initial extended output pulse; and

detecting a later extended output pulse after the delay period that does reach one or more volume thresholds.

24. The method of claim 16, further comprising:

stopping the test excitation signal when the sample volume is insufficient for analysis of the at least one analyte in the sample;

requesting a user to add more sample

applying another regular polling sequence to a larger sample, where the another regular polling sequence substantially eliminates irreversible alteration of the concentration of the at least one analyte in the sample during the application of the another regular polling sequence;

detecting when at least one regular output pulse from the larger sample reaches at least one sample threshold;

applying another extended polling sequence to the larger sample, where the another extended polling sequence substantially eliminates irreversible alteration of the concentration of the at least one analyte in the sample during the application of the another extended polling sequence; and

detecting when at least one different extended output pulse from the larger sample reaches at least one volume threshold.

25. The method of claim 16, further comprising improving at least one of a sample output signal and a volume output signal with at least one mediator.

26. The method of claim 25, where the at least one mediator comprises a two electron transfer mediator.

27. The method of claim 16, further comprising determining the concentration of at least one analyte in a sample.

28. The method of claim 27, where the regular and extended polling sequences and the test excitation signal are part of a gated amperometry electrochemical analysis.