Reference electrode error trap determined from a specified sampling time and a pre-determined sampling time

• US 9,423,374 B2
• Filed: 01/26/2015
• Issued: 08/23/2016
• Est. Priority Date: 01/26/2015
• Status: Active Grant

• Current Assignee: Cilag Gmbh International (Johnson & Johnson)
• Original Assignee: LifeScan Scotland Limited (Johnson & Johnson)
• Inventors: Mackintosh, Stephen, Smith, Antony
• Primary Examiner(s): NOGUEROLA, ALEXANDER STEPHAN
• Application Number:
  US14/605,501
• Publication Number:
  US 20160216226A1
• Time in Patent Office: 575 Days
• US Class Current: 1/1
• 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 27/3274 Corrective measures, e.g. error detection, compensation for temperature or hematocrit, calibration coding of calibration information G01N33/48771

Abstract

Various embodiments for a method that allow for a more accurate analyte concentration with a biosensor by determining at least one physical characteristic of the sample and determining whether a counter or reference electrode is causing an error by monitoring the working electrodes and flagging an error if the signal outputs of the working electrodes do not meet certain thresholds.

Claims

1. An analyte measurement system with electrode error determination, the system comprising:

a test strip including;

a substrate;

a plurality of electrodes connected to respective electrode connectors with a reagent disposed proximate the plurality of the electrodes, the plurality of electrodes comprising;

physical characteristic sensing electrodes;

a first working electrode and a second working electrode; and

a reference electrode; and

an analyte meter including;

a housing;

a test strip port connector configured to connect to the respective electrode connectors of the test strip; and

a microprocessor in electrical communication with the test strip port connector to apply electrical signals or measure electrical signals from the plurality of electrodes, wherein the microprocessor is configured to;

(a) apply a first signal to the physical characteristic sensing electrodes of the plurality of electrodes to determine a physical characteristic of a fluid sample;

(b) apply a second signal between the first working electrode and the reference electrode, and between the second working electrode and the reference electrode to determine an analyte concentration of the fluid sample;

(c) measure a signal output proximate a specified sampling time point from each of the first and second working electrodes;

(d) measure another signal output proximate a predetermined sampling time point from each of the first and second working electrodes;

(e) calculate a first differential between a signal output of the first working electrode measured at the specified sampling time point and a signal output of the first working electrode measured at the predetermined sampling time point;

(f) calculate a second differential between a signal output of the second working electrode measured at the specified sampling time point and a signal output of the second working electrode measured at the predetermined sampling time point;

(g) evaluate whether any one of the first differential and second differential is less than a predetermined threshold to determine an error; and

(h) in the event one of the first and second differentials is less than a bias threshold then annunciate the error.

2. The system of claim 1, in which the plurality of electrodes are commonly disposed in a chamber provided on the substrate.

3. The system of claim 2, in which the plurality of electrodes is disposed on the same plane defined by the substrate.

4. The system of claim 2, in which the reagent is disposed proximate the first and second working electrodes and no reagent is disposed on the physical characteristic sensing electrodes.

5. The system of claim 1, in which the error is annunciated when both the first and second differential thresholds are less than the predetermined threshold.

6. The system of claim 1, in which the predetermined threshold comprises about 100 nanoamperes.