Systems, Methods, and Devices Including Amperometric and Voltammetric Duty Cycles

• US 20120298507A1
• Filed: 07/19/2012
• Published: 11/29/2012
• Est. Priority Date: 07/10/2008
• Status: Active Grant

• Current Assignee: Ascensia Diabetes Care Holdings AG (PHC Holdings Corporation)
• Original Assignee: Bayer Healthcare LLC - Diabetes Care
• Inventors: Wu, Huan-Ping
• Granted Patent: US 8,871,070 B2
• Time in Patent Office: Days
• US Class Current: 204/406
• CPC Class Codes: G01N 27/3271 Amperometric enzyme electrodes for analytes in body fluids, e.g. glucose in blood amperometry per se G01N27/49; aspects concerning the enzyme reagent C12Q1/001
• CPC Class Codes: G01N 27/3272 Test elements therefor, i.e. disposable laminated substrates with electrodes, reagent and channels optical biosensors G01N33/52
• 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: G01N 27/48 using polarography, i.e. measuring changes in current under a slowly-varying voltage

Abstract

A sensor system including devices and methods for determining the concentration of an analyte in a sample is described. Input signals including amperometric and voltammetric duty cycles of excitations and relaxations may provide a shorter analysis time and/or improve the accuracy and/or precision of the analysis. The disclosed system may reduce analysis errors, thus improving measurement performance, by adjusting the potential and/or scan rate in response to output currents obtained from voltammetric scans. The disclosed system also may determine the concentration of more than one ionizable species in the sample by adjusting the potential and/or scan rate in response to output currents obtained from voltammetric scans. The multiple, determined concentrations may be used to determine the concentration of multiple analytes or to correct the concentration determined for an analyte, thus improving the measurement performance of the system.

Claims

1. A measurement device for determining the concentration of an analyte in a sample, comprising:

a signal interface including at least two contacts; and

electrical circuitry establishing electrical communication between the at least two contacts and a signal generator, where the electrical circuitry has a processor in electrical communication with the signal generator and a storage medium,

where the processor is operable to apply an input signal from the signal generator to the at least two contacts,

where the input signal includes a first duty cycle having an amperometric excitation and a first relaxation, and where

the input signal includes a second duty cycle having a voltammetric excitation and a second relaxation,

where the processor is operable to detect an output signal at the at least two contacts, the output signal including output currents responsive to the voltammetric excitation,

where the processor is operable to adjust a potential of the amperometric excitation in response to the output currents responsive to the voltammetric excitation, and

where the processor is operable to correlate a portion of the output signal with a concentration of at least one analyte in the sample.

2. The device of claim 1, the processor operable to correlate a portion of the output signal including at least one output current responsive to the amperometric excitation with the concentration of the at least one analyte in the sample.

3. The device of claim 1, the processor operable to apply the voltammetric excitation as a linear scan.

4. The device of claim 1, the processor operable to adjust a voltammetric scan rate in response to the output currents responsive to the voltammetric excitation.

5. The device of claim 1, the processor operable to identify a first contributing ionizable species by applying a derivative data treatment stored in the storage medium to the output currents responsive to the voltammetric excitation.

6. The device of claim 1, the processor operable to adjust the potential of the amperometric excitation to reduce output currents responsive to a second contributing ionizable species in relation to output currents responsive to a first contributing ionizable species in the output signal.

7. The device of claim 6, the processor further operable to compare a portion of the output signal including at least one output current responsive to the first contributing ionizable species with a portion of the output signal including at least one output current responsive to the second contributing ionizable species to provide a concentration of the second contributing ionizable species.

8. The device of claim 6, the processor operable to identify the first contributing ionizable species from the output currents responsive to the voltammetric excitation, from a derivative data treatment stored in the storage medium.

9. The device of claim 6, where the second contributing ionizable species is an interferent.

10. The device of claim 1, the processor operable to correlate a portion of the output signal including at least one current responsive to a first contributing ionizable species with the concentration of the at least one analyte in the sample.

11. The device of claim 10, the processor operable to reduce non-linearity of the output currents responsive to the first contributing ionizable species by adjusting the potential.

12. The device of claim 1, the processor operable to apply the voltammetric excitation as an acyclic scan having a forward excitation and a reverse excitation.

13. The device of claim 12, the processor further operable to identify a first contributing ionizable species by determining a ratio of the output currents responsive to the forward excitation of the acyclic scan, from a ratio data treatment stored in the storage medium.

14. The device of claim 1, where the input signal the processor is operable to apply further includes a third duty cycle having an acyclic scan and a third relaxation, and

the processor is further operable to adjust a potential of the acyclic scan in response to the output currents responsive to the voltammetric excitation,

where the adjusting reduces output currents responsive to a second contributing ionizable species in relation to output currents responsive to a first contributing ionizable species in the output signal.

15. The device of claim 14, the processor further operable to compare a portion of the output signal including at least one output current responsive to a first contributing ionizable species with a portion of the output signal including at least one output current responsive to a second contributing ionizable species to provide a concentration of the second contributing ionizable species.

16. A measurement device for determining the concentration of an analyte in a sample, comprising:

a signal interface including at least two contacts; and

electrical circuitry establishing electrical communication between the at least two contacts and a signal generator, where the electrical circuitry has a processor in electrical communication with the signal generator and a storage medium,

where the processor is operable to apply an input signal from the signal generator to the at least two contacts,

where the input signal includes

a first duty cycle having an amperometric excitation and a first relaxation,

a second duty cycle having a voltammetric excitation and a second relaxation, and

a third duty cycle having an acyclic scan and a third relaxation,

where the processor is operable to detect an output signal at the at least two contacts, the output signal including output currents responsive to the voltammetric excitation,

where the processor is operable to adjust a potential of the acyclic scan of the third duty cycle in response to the output currents responsive to the voltammetric excitation, and

where the processor is operable to correlate a portion of the output signal with a concentration of at least one analyte in the sample.

17. The device of claim 16, the processor operable to correlate a portion of the output signal including at least one output current responsive to the amperometric excitation with the concentration of the at least one analyte in the sample.

18. The device of claim 16, the processor operable to correlate a portion of the output signal including at least one output current responsive to the acyclic scan with the concentration of the at least one analyte in the sample.

19. The device of claim 16, the processor operable to apply the voltammetric excitation as a linear scan.

20-29. -29. (canceled)

30. A measurement device for determining the concentration of an analyte in a sample, comprising:

a signal interface including at least two contacts; and

electrical circuitry establishing electrical communication between the at least two contacts and a signal generator, where the electrical circuitry has a processor in electrical communication with the signal generator and a storage medium,

where the processor is operable to apply an input signal from the signal generator to the at least two contacts, where the input signal includes a first duty cycle having a voltammetric excitation and a first relaxation, and where the input signal includes a second duty cycle having an acyclic scan and a second relaxation,

where the processor is operable to detect an output signal at the at least two contacts, the output signal including output currents responsive to the voltammetric excitation and output currents responsive to the acyclic scan,

where the processor is operable to adjust a scan range of the acyclic scan in response to the output currents responsive to the voltammetric excitation, and

where the processor is operable to correlate a portion of the output signal with a concentration of at least one analyte in the sample.

31-39. -39. (canceled)

40-41. -41. (canceled)