Method of reducing the effect of direct interference current in an electrochemical test strip

• US 20050114062A1
• Filed: 10/29/2004
• Published: 05/26/2005
• Est. Priority Date: 10/31/2003
• Status: Abandoned Application

• Current Assignee: LifeScan Scotland Limited (Johnson & Johnson)
• Original Assignee: LifeScan Scotland Limited (Johnson & Johnson)
• Inventors: Leiper, Elaine, Marshall, Robert, Whyte, Lynsey, Baskeyfield, Damian Edward Haydon, Davies, Oliver William Hardwicke
• Application Number:
  US10/977,292
• Publication Number:
  US 20050114062A1
• Time in Patent Office: Days
• US Class Current: 702/104
• 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: A61B 5/150022 for capillary blood or interstitial fluid
• CPC Class Codes: A61B 5/150282 for piercing elements, e.g. blade, lancet, canula, needle
• CPC Class Codes: A61B 5/150358 Strips for collecting blood, e.g. absorbent optical reagent test strips G01N21/8483; chemical reagent test strips G01N33/4875, G01N33/52
• CPC Class Codes: A61B 5/150435 Specific design of proximal end
• CPC Class Codes: A61B 5/150503 Single-ended needles hollow piercing element tip design A61B5/150396, needle sets for catheters A61M25/06, needles for bringing media into the body A61M5/32
• CPC Class Codes: C12Q 1/001 Enzyme electrodes
• CPC Class Codes: C12Q 1/006 for glucose
• 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: Y02A 90/10 Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Abstract

This invention describes a method of reducing the effect of interfering compounds in a bodily fluid when measuring an analyte using an electrochemical sensor. In particular, the present method is applicable to electrochemical sensors where the sensor includes a substrate, first and second working electrodes, and a reference electrode and either the first and second or only the second working electrode include regions which are bare of reagent. In this invention, an algorithm is described with mathematically corrects for the interference effect using the test strip embodiments of the present invention.

Claims

1. A method of reducing interferences in an electrochemical sensor comprising:

measuring a first current at a first working electrode, said first working electrode being covered by a reagent layer;

measuring a second current at a second working electrode, wherein said reagent layer partially covers said second working electrode, said second working electrode having a covered area and an uncovered area; and

calculating a corrected current value representative of a glucose concentration using a ratio of said covered area to said uncovered area of said second working electrode.

2. The method of claim 1, wherein said corrected current value is calculated using the equation:

3. A method of reducing interferences in an electrochemical sensor comprising:

measuring a second current at a first working electrode, wherein said reagent layer partially covers said first working electrode, said first working electrode having a first covered area and a first uncovered area;

measuring a second current at a second working electrode, wherein said reagent layer partially covers said second working electrode, said second working electrode having a second covered area and a second uncovered area; and

calculating a corrected current value representative of a glucose concentration using a ratio of said covered area to said uncovered area of said first and said second working electrodes.

4. The method of claim 3, wherein said corrected current value is calculated using the equation: