Systems and methods of discriminating between a control sample and a test fluid using capacitance

• US 9,575,027 B2
• Filed: 11/22/2013
• Issued: 02/21/2017
• Est. Priority Date: 09/30/2010
• Status: Active Grant

• Current Assignee: LifeScan IP Holdings, LLC
• Original Assignee: Cilag Gmbh International (Johnson & Johnson)
• Inventors: Chatelier, Ronald C., Hodges, Alastair M.
• Primary Examiner(s): Van, Luan
• Assistant Examiner(s): ROSENWALD, STEVEN ERIC
• Application Number:
  US14/087,527
• Publication Number:
  US 20140151245A1
• Time in Patent Office: 1,187 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: C12Q 1/005 involving specific analytes or enzymes including groups of enzymes, e.g. oxydases; C12Q1/004 takes precedence
• CPC Class Codes: G01N 27/28 Electrolytic cell components
• 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 33/48707 by electrical means G01N33/49, G01N33/493 take precedence

Abstract

Methods for distinguishing between an aqueous non-blood sample (e.g., a control solution) and a blood sample are provided herein. In one aspect, the method includes using a test strip in which multiple current transients are measured by a meter electrically connected to an electrochemical test strip. The current transients are used to determine if a sample is a blood sample or an aqueous non-blood sample based on characteristics of the sample (e.g., amount of interferent present, reaction kinetics, and/or capacitance). The method can also include calculating a discrimination criteria based upon these characteristics. Various aspects of a system for distinguishing between a blood sample and an aqueous non-blood sample are also provided herein.

Claims

1. A method for distinguishing between a blood sample and an aqueous non-blood sample, the method comprising:

(a) introducing a sample into an electrochemical cell, the electrochemical cell comprising;

(i) two electrodes in a spaced apart relationship; and

(ii) a reagent;

(b) applying a first test potential, having a first polarity, between the electrodes, and measuring cell current;

(c) measuring a capacitance of the electrochemical cell;

(d) summing at least two current values measured during the first test potential to generate a first reference value;

(e) calculating a capacitance index (C_av/C_m) related to the measured capacitance (C_m), said capacitance index comprising a ratio of a pre-determined average capacitance of electrochemical cells of the same type (C_av) and the measured capacitance;

(f) using the capacitance index and the first reference value to distinguish between a blood sample and an aqueous non-blood sample.

2. The method of claim 1, further comprising calculating a second reference value related to reaction kinetics;

and using the capacitance index, the first reference value, and the second reference value to distinguish between a blood sample and an aqueous non-blood sample.

3. The method of claim 1, wherein the aqueous non-blood sample comprises a control solution.