SYSTEM AND METHOD FOR MEASURING AN ANALYTE IN A SAMPLE

• US 20150101928A1
• Filed: 12/19/2014
• Published: 04/16/2015
• Est. Priority Date: 01/17/2008
• Status: Active Grant

• Current Assignee: Cilag Gmbh International (Johnson & Johnson)
• Original Assignee: Lifescan Incorporated (Duv Holding Corporation)
• Inventors: Chatelier, Ronald C., Hodges, Alastair M., Nandagopalan, Santhanagopalan
• Granted Patent: US 9,739,749 B2
• Time in Patent Office: Days
• US Class Current: 204/401
• 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: G01N 27/4163 checking the operation of, or calibrating, the measuring apparatus G01N27/3274, G01N27/4175 and G01N33/0006 take precedence

Abstract

Methods of determining a corrected analyte concentration in view of some error source are provided herein. The methods can be utilized for the determination of various analytes and/or various sources of error. In one example, the method can be configured to determine a corrected glucose concentration in view of an extreme level of hematocrit found within the sample. In other embodiments, methods are provided for identifying various system errors and/or defects. For example, such errors can include partial-fill or double-fill situations, high track resistance, and/or sample leakage. Systems are also provided for determining a corrected analyte concentration and/or detecting some system error.

Claims

1. A system for determining a processing or system error, the system comprising:

a test strip having a first electrode and a second electrode defining an electrochemical cell that is sized and configured to receive a sample, and

a test meter configured to generate at least one pre-determined voltage between the electrodes for a predetermined amount of time and at least one resulting current of the sample during the pre-determined time, the test meter including a processor for receiving a set of data, the data including at least one applied voltage and at least one resulting current, wherein the processor is configured to utilize the set of data to determine a processing or system error.

2. The system according to claim 1, wherein the test meter is configured to apply a first test voltage for a first period of time between the first electrode and second electrode sufficient to oxidize a reduced mediator at the second electrode and a second test voltage between the first and second electrode sufficient to oxidize the reduced mediator at the first electrode, the test meter being further configured to measure a first test current and a second test current occurring during the second test interval wherein the processor is configured to determine whether the test strip has a defect using an equation based on the first test current and second test current.

3. The system according to claim 2, wherein the equation comprises a ratio between the first test current and the second test current.

4. The system according to claim 3, wherein the equation comprises a ratio between the first test current and the difference between the first test current and the second test current.

5. The system according to claim 2, wherein the defect is a high track resistance between a connection point on the test meter and either the first or second electrode of the test strip.

6. The system according to claim 1, wherein the test meter is configured to apply a first test voltage for a first period of time between the first electrode and second electrode sufficient to oxidize a reduced mediator at the second electrode and a second test voltage between the first and second electrode sufficient to oxidize the reduced mediator at the first electrode, the test meter being further configured to measure a first test current, a second test current, a third test current and a fourth test current that occur during the second test interval, wherein the processor is configured to calculate a first logarithm of a first ratio based on the first test current and the second test current, a second logarithm of a second ratio based on the third test current and the fourth test current and determining whether the test strip has a defect using an equation based on the first logarithm and the second logarithm.

7. The system according to claim 6, wherein the equation comprises a third ratio based on the first and second ratios.

8. The system according to claim 7, wherein the test meter is configured to generate an error message indicating a defective test strip if the third ratio is less than a predetermined threshold.

9. The system according to claim 6, wherein the defect is a leakage of fluid between a spacer and the first electrode of the test strip.

10. The system according to claim 6, wherein a reagent layer is disposed on the first electrode so that a portion of the reagent layer is between the spacer and the first electrode.

11. The system according to claim 2, wherein the test meter is configured to apply a first test voltage for a first period of time between the first electrode and second electrode sufficient to oxidize a reduced mediator at the second electrode and a second test voltage between the first and second electrode sufficient to oxidize the reduced mediator at the first electrode, the test meter being further configured to measure a first test current, a second test current and a third test current, the processor being programmed to determine whether an error was performed using an equation based on the second test current and a summation of the absolute value of the first test current and the absolute value of the third test current.

12. The system according to claim 1, wherein the system error is indicative of a double dosing event.

13. The system according to claim 1, wherein the system error is indicative of a late start event.

14. The system according to claim 1, wherein the system error is indicative of a false start of a test on the test strip.

15. The system according to claim 1, wherein the analyte is glucose.