System and method for measuring an analyte in a sample
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.
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 further having a reagent layer, including a mediator, disposed on the first electrode, and
a test meter having a processor programmed with instructions 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 predetermined voltage and at least one resulting current, wherein the processor is programmed with instructions to utilize the set of data to determine a processing or system error, and in which the processor is programmed with instructions 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 processor being further programmed with instructions to measure a first test current and a second test current occurring during the second test interval wherein the processor is further programmed with instructions to determine whether the test strip has a defect using an equation based on the first test current and second test current.
2. The system according to claim 1 , wherein the equation comprises a ratio between the first test current and the second test current.
3. The system according to claim 2 , wherein the equation comprises a ratio between the first test current and the difference between the first test current and the second test current.
4. The system according to claim 1 , 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.
5. The system according to claim 1 , wherein the test meter is further configured, using the processor, 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 programmed with instructions 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.
6. The system according to claim 5 , wherein the equation comprises a third ratio based on the first and second ratios.
7. The system according to claim 6 , wherein the processor of the test meter is programmed with instructions to generate an error message indicating a defective test strip if the third ratio is less than a predetermined threshold.
8. The system according to claim 5 , wherein the defect is a leakage of fluid between a spacer and the first electrode of the test strip.
9. The system according to claim 5 , 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.
10. The system according to claim 1 , wherein the processor of the test meter is further programmed to measure a first test current, a second test current and a third test current, the processor being further 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.
11. The system according to claim 1 , wherein the system error is indicative of a double dosing event.
12. The system according to claim 1 , wherein the system error is indicative of a late start event.
13. The system according to claim 1 , wherein the system error is indicative of a false start of a test on the test strip.
14. The system according to claim 1 , wherein the analyte is glucose.