Underfill Recognition System for a Biosensor

• US 20110108440A1
• Filed: 10/22/2010
• Published: 05/12/2011
• 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: Perry, Joseph E., Trippel, Christine, Wu, Huan-Ping, Maurer, Eric
• Granted Patent: US 8,668,819 B2
• Time in Patent Office: Days
• US Class Current: 205/792
• 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;

detecting the presence of a sample;

applying an extended polling sequence having at least one different extended input pulse; and

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

2. The method of claim 1, further comprising applying a test excitation signal when the sample volume is sufficient for analysis of the at least one analyte in the sample.

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

4. The method of claim 2, where the regular and extended polling sequences and the test excitation signal are part of a gated amperometry electrochemical analysis.

5. The method of claim 2, 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.

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

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

9. 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.

10. The method of claim 9 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.

11. The method of claim 9, where a last pulse in each cycle is a different extended pulse.

12. The method of claim 1, further comprising:

counting a delay period when sample volume insufficient; and

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

13. 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.

14. The method of claim 13, further comprising:

stopping the test excitation signal;

requesting a user to add more sample

applying 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; and

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

15. 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.

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

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

applying a regular polling sequence;

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

applying an 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 at least one analyte in the sample; and

applying a test excitation signal when the sample volume is sufficient for analysis of at least one analyte in the sample.

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

19. The method of claim 17, 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.

20. The method of claim 19, 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.

21. The method of claim 17, 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.

22. The method of claim 21, 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.

23. The method of claim 21, where a last pulse in each cycle is a different extended pulse.

24. The method of claim 17, further comprising:

detecting an initial extended output pulse that does not reach at least one 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.

25. The method of claim 17, further comprising:

stopping the test excitation signal;

requesting a user to add more sample

applying another regular polling sequence to a larger sample;

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

applying an extended polling sequence to the larger sample;

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

applying a test excitation signal to the larger sample when the sample volume is sufficient for analysis of at least one analyte in a sample

26. The method of claim 17, further comprising improving at least one of a sample output signal and a volume output signal with at least one mediator.

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

28. The method of claim 17, further comprising determining the concentration of at least one analyte in a sample.

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

30. A biosensor with an underfill recognition system, comprising:

a sensor strip having a sample interface on a base, where the sample interface is in electrical communication with a working electrode and a counter electrode, the working and counter electrodes positioned in a reservoir formed by the base; and

a measuring device having a processor connected to a sensor interface, where the sensor interface has a signal generator, and where the sensor interface has electrical communication with the sample interface; and

where the processor directs the signal generator to apply a regular polling sequence,

where the processor detects the presence of a sample,

where the processor directs the signal generator to apply an extended polling sequence,

where the processor detects whether a sample volume is sufficient for analysis of at least one analyte in the sample,

where the processor directs the signal generator to apply a test excitation signal when a sample volume is sufficient for analysis of at least one analyte in the sample, and

where the processor determines the concentration of at least one analyte in a sample in response to a test output signal.

31-47. -47. (canceled)