Method for Improving Measurement Accuracy and Devices and Systems Related Thereto

Abstract

The present disclosure relates to methods and devices for providing accurate measurement of a property of a sample. The method comprises obtaining a plurality of independent measurements of the property. The plurality of values of the property of the sample obtained by the plurality of independent measurements is compared to determine whether one or more of the values is an outlier.

1 . A meter for measuring an interferent value of a sample, the meter configured for insertion of a sensor comprising a sample chamber comprising a first electrode, a second electrode, and a third electrode, and comprising:
 a memory and a processor for executing instructions stored in a memory of the instrument, the instructions comprising instructions for:
 determining fill-time by measuring time elapsed between detecting a signal between the first electrode and the second electrode and another signal between the first electrode and the third electrode,
 wherein the fill-time is related to the interferent value in the sample; 
 
 measuring a first signal at the second electrode after the sample chamber is substantially filled with the sample,
 wherein the first signal is substantially independent of the analyte concentration and is related to interferent value in the sample; 
 
 measuring a second signal at the third electrode, wherein the second signal is related to interferent value in the sample; 
 deriving, by using the processor executing instructions stored in the memory, a first interferent value, a second interferent value and a third interferent value of the property using the fill-time, the first signal, and the second signal, respectively; 
 comparing the first, second, and third interferent values to determine whether one of the values is an outlier; and 
 calculating a single interferent value of the property based on at least two of the first, second, and third interferent values that are in agreement 
   wherein the interferent is acetaminophen, uric acid, or ascorbic acid.   
     
     
         2 . The meter of  claim 1 , wherein when the first, second, and third interferent values are in agreement, the calculating comprises calculating a single interferent value from the first, second, and third interferent values. 
     
     
         3 . The meter of  claim 1 , wherein the sensor comprises an enzyme responsive to an analyte and a redox mediator, the instructions comprise instructions for measuring an analyte related signal at the second electrode after determining the fill-time; determining concentration of the analyte using the analyte related signal; and correcting the concentration of the analyte. 
     
     
         4 . The meter of  claim 1 , wherein the first and second signals are selected from the group consisting of voltage, current, resistance, capacitance, charge, conductivity, or combination thereof. 
     
     
         5 . A system for determining concentration of an analyte in a sample, the system comprising
 an analyte measurement instrument and an analyte sensor, the analyte sensor comprising a sample chamber comprising a first electrode, a second electrode, and a third electrode; an enzyme responsive to the analyte and a redox mediator;
 the analyte measurement instrument comprising a processor for executing instructions stored in a memory of the instrument, the instructions comprising instructions for:
 determining fill-time by measuring time elapsed between detecting a signal between the first electrode and the second electrode and another signal between the first electrode and the third electrode, wherein the fill-time is related to an interferent value of the sample; 
 measuring a first signal at the second electrode after the sample chamber is substantially filled with the sample, wherein the first signal is substantially independent of the analyte concentration and is related to interferent value of the sample; 
 measuring an analyte related signal at the second electrode after measuring the first signal; 
 measuring a second signal at the third electrode after measuring the analyte related signal, wherein the second signal is related to interferent value of the sample; 
 deriving first, second, and third interferent values of the sample using the fill-time the first signal, and the second signal; 
 comparing the first, second, and third interferent values of the sample; calculating a single interferent value based on at least two of the first, second and third interferent values when the at least two of the first, second, and third interferent values are in agreement; 
 determining concentration of the analyte; and 
 correcting the concentration of the analyte according to the single interferent value; 
 
   wherein the interferent is acetaminophen, uric acid, or ascorbic acid.   
     
     
         6 . The system of  claim 5 , wherein the calculating a single hematocrit value comprises calculating a single hematocrit value based on the first, second and third hematocrit values when the first, second, and third hematocrit values of the sample are in agreement. 
     
     
         7 . The system of  claim 5 , wherein the first and second signals are selected from the group consisting of voltage, current, resistance, impedance, capacitance, or combination thereof. 
     
     
         8 . The system of  claim 5 , wherein the analyte is glucose. 
     
     
         9 . The system of  claim 8 , wherein the enzyme comprises glucose dehydrogenase or glucose oxidase. 
     
     
         10 . The system of  claim 8 , wherein the glucose dehydrogenase is nicotinamide dinucleotide glucose dehydrogenase (NAD-GDH), pyrrole quinoline quinone glucose dehydrogenase (PQQ-GDH), or flavin-adenine dinucleotide glucose dehydrogenase (FAD-GDH). 
     
     
         11 . The system of  claim 5 , wherein the analyte is β-hyroxybutyrate. 
     
     
         12 . The system of  claim 11 , wherein the enzyme is hydroxybutyrate dehydrogenase. 
     
     
         13 . The system of  claim 5 , wherein the first, second, and third electrodes are coplanar. 
     
     
         14 . The system of  claim 5 , wherein one of the first, second, and third electrodes is in facing configuration with the other two electrodes. 
     
     
         15 . The system of  claim 5 , wherein the electrodes are arranged such that the sample contacts the first electrode before contacting the third electrode. 
     
     
         16 . The system of  claim 5 , wherein the electrodes are arranged such that the sample contacts the second electrode before contacting the third electrode. 
     
     
         17 . A system for determining analyte concentration of a sample, the system comprising an analyte sensor and a meter, the analyte sensor comprising a sample chamber comprising a reference/counter electrode, a working electrode, a trigger electrode, an enzyme responsive to the analyte, and a redox mediator;
 the meter comprising a processor for executing instructions stored in a memory of the meter, the instructions comprising instructions for:
 determining fill-time by measuring time elapsed between detecting a signal between the reference/counter electrode and the working electrode and another signal between the reference/counter electrode and the trigger electrode, wherein the fill-time is related to an interferent value of the sample; 
 disconnecting the reference/counter electrode from the working electrode and from the trigger electrode after the sample chamber is substantially filled with the sample; 
 reconnecting the reference/counter electrode to the working electrode and the trigger electrode; 
 measuring a first signal at the working electrode, wherein the first signal is substantially independent of the analyte concentration and is related to the interferent value of the sample; 
 measuring an analyte related signal at the working electrode after measuring the first signal; 
 measuring a second signal at the trigger electrode after measuring the analyte related signal, wherein the second signal is related to the interferent value of the sample; 
 deriving first, second, and third interferent values of the sample using the fill-time, the first signal, and the second signal; 
 comparing the first, second, and third interferent values of the sample; calculating a single interferent value based on at least two of the first, second and third interferent values when the at least two of the first, second, and third interferent values are in agreement; 
 determining concentration of the analyte; and correcting the concentration of the analyte according to the single interferent value; 
   wherein the interferent is acetaminophen, uric acid, or ascorbic acid.   
     
     
         18 . The meter of  claim 17 , wherein the first signal is peak interfacial charging current and the second signal is integrated current. 
     
     
         19 . The meter of  claim 17 , wherein the analyte is glucose. 
     
     
         20 . The meter of  claim 17 , wherein the reference/counter electrode, the working electrode and the trigger electrode are coplanar.