Method and apparatus for assay of electrochemical properties

• US 9,164,054 B2
• Filed: 10/01/2014
• Issued: 10/20/2015
• Est. Priority Date: 08/21/2003
• Status: Active Grant

• Current Assignee: Agamatrix Incorporated (AgaMatrix Holdings LLC d/b/a WaveForm Diabetes)
• Original Assignee: Agamatrix Incorporated (AgaMatrix Holdings LLC d/b/a WaveForm Diabetes)
• Inventors: Iyengar, Sridhar G., Harding, Ian
• Primary Examiner(s): NOGUEROLA, ALEXANDER STEPHAN
• Application Number:
  US14/503,529
• Publication Number:
  US 20150083610A1
• Time in Patent Office: 384 Days
• US Class Current: 1/1
• 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 5/1495 Calibrating or testing of in-vivo probes
• CPC Class Codes: C12Q 1/001 Enzyme electrodes
• CPC Class Codes: C12Q 1/004 mediator-assisted
• CPC Class Codes: C12Q 1/006 for glucose
• CPC Class Codes: G01N 27/26 by investigating electrochemical variables; by using electrolysis or electrophoresis
• 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 27/4168 Oxidation-reduction potential, e.g. for chlorination of water water analysis G01N33/18

Abstract

The presence of a select analyte in the sample is evaluated in an an electrochemical system using a conduction cell-type apparatus. A potential or current is generated between the two electrodes of the cell sufficient to bring about oxidation or reduction of the analyte or of a mediator in an analyte-detection redox system, thereby forming a chemical potential gradient of the analyte or mediator between the two electrodes After the gradient is established, the applied potential or current is discontinued and an analyte-independent signal is obtained from the relaxation of the chemical potential gradient. The analyte-independent signal is used to correct the analyte-dependent signal obtained during application of the potential or current. This correction allows an improved measurement of analyte concentration because it corrects for device-specific and test specific factors such as transport (mobility) of analyte and/or mediator, effective electrode area, and electrode spacing (and as a result, sample volume), without need for separate calibration values. The analysis can be performed using disposable test strips in a hand held meter, for example for glucose testing.

Claims

1. In a method for the electrochemical determination of an analyte in a sample, the improvement comprising

determining an analyte-dependent electrochemical signal from analysis of the sample;

determining an analyte-independent electrochemical potential signal from analysis of the sample, said analyte-independent signal containing information about device-specific and test specific factors, and

correcting the analyte-dependent signal based on the analyte-independent signal to provide an improved measurement of analyte without need for separate calibration values.