Method for determination of analyte concentrations and related apparatus

• US 9,846,140 B2
• Filed: 01/05/2016
• Issued: 12/19/2017
• Est. Priority Date: 04/15/2005
• 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: Diamond, Steven, Harding, Ian, Iyengar, Sridhar G., Wei, Baoguo
• Primary Examiner(s): Ball, J. Christopher
• Application Number:
  US14/988,264
• Publication Number:
  US 20160209357A1
• Time in Patent Office: 714 Days
• CPC Class Codes: C12Q 1/006 for glucose
• CPC Class Codes: G01N 27/307 Disposable laminated or multilayered electrodes G01N27/3272 takes precedence
• 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 27/4161 measuring the voltage and using a constant current supply, e.g. chronopotentiometry
• CPC Class Codes: G01N 27/4166 measuring a particular property of an electrolyte
• CPC Class Codes: G01N 33/48707 by electrical means G01N33/49, G01N33/493 take precedence

Abstract

A method is provided for determining analyte concentrations, for example glucose concentrations, that utilizes a dynamic determination of the appropriate time for making a glucose measurement, for example when a current versus time curve substantially conforms to a Cottrell decay, or when the current is established in a plateau region. Dynamic determination of the time to take the measurement allows each strip to operate in the shortest appropriate time frame, thereby avoiding using an average measurement time that may be longer than necessary for some strips and too short for others.

Claims

1. A method for determining an analyte in a sample comprising the steps of:

introducing a sample to be evaluated into an electrochemical test strip having working and counter electrodes;

applying a potential between the electrodes sufficient to generate a diffusion-limited current when analyte is present in the sample;

dynamically determining a time, t_peak, as the time when diffusion limiting current at the counter electrode is established;

sampling the current value at a time, t_meas, wherein t_meas is a multiple of t_peak, and

generating an indication of analyte in the sample based on the sampled current value at time t_meas.

2. The method of claim 1, wherein the multiple is in the range of 1.2 to 1.4.

3. The method of claim 2, wherein the multiple is between 1.25 and 1.35.

4. The method of claim 1, wherein the multiple is in the range of 1.5 to 5.

5. The method of claim 4, wherein the multiple is between 3.8 and 4.7.

6. A method for determining an analyte in a sample comprising the steps of:

introducing a sample to be evaluated into an electrochemical test strip having working and counter electrodes;

applying a potential between the electrodes sufficient to generate a diffusion-limited current when analyte is present in the sample;

dynamically determining a time, t_peak, as the time when diffusion limiting current at the counter electrode is established;

sampling the current value at a time, t_meas, wherein t_meas is determined by adding a defined period of time to t_peak, and

generating an indication of analyte in the sample based on the sampled current value at time t_meas.

7. The method of claim 6, wherein the defined period of time is 1.5 to 2 seconds.

8. The method of claim 6, wherein the defined period of time is 6 to 10 seconds.