Abstract: Testing of the performance of an electrochemical meter used to measure the presence of an analyte in a biological sample, particularly glucose in whole blood, includes introducing a control solution containing a predetermined amount of the analyte and a predetermined amount of an internal reference compound. The internal reference compound is selected such that it is oxidized at a potential greater than that used to oxidize the analyte, thereby making it possible to distinguish the control solution from a biological sample.

Abstract: An indexer adapted to index a test sensor from a test-sensor cartridge. The indexer includes an indexer face having a first aperture formed generally through the center thereof. The indexer further includes a retention pin extending through the first aperture and a flexible pawl positioned near an edge of the indexer face. The indexer is adapted to be rotated in a first direction and a second generally opposite direction about the retention pin. The flexible pawl is configured to bend when the indexer is rotated in the second direction. The flexible pawl is configured to assist in rotating the test-sensor cartridge.

Abstract: A sensor system including devices and methods for determining the concentration of an analyte in a sample is described. Input signals including amperometric and voltammetric duty cycles of excitations and relaxations may provide a shorter analysis time and/or improve the accuracy and/or precision of the analysis. The disclosed system may reduce analysis errors, thus improving measurement performance, by adjusting the potential and/or scan rate in response to output currents obtained from voltammetric scans. The disclosed system also may determine the concentration of more than one ionizable species in the sample by adjusting the potential and/or scan rate in response to output currents obtained from voltammetric scans. The multiple, determined concentrations may be used to determine the concentration of multiple analytes or to correct the concentration determined for an analyte, thus improving the measurement performance of the system.

Abstract: A biosensor with an underfill recognition system assesses whether to analyze a sample for one or more analytes in response to the volume of the sample. The underfill recognition system applies polling and test excitation signals to the sample. The polling signals generate one or more polling output signals, which maybe used to detect when a sample is present and to determine whether the sample has sufficient volume for analysis. The test excitation signal generates one or more test output signals, which may be used to determine one or more analyte concentrations in the sample.

Abstract: The present invention relates to improved electrochemical biosensor strips and methods for determining the concentration of an analyte in a sample. By selectively measuring a measurable species residing in a diffusion barrier layer, to the substantial exclusion of the measurable species residing exterior to the diffusion barrier layer, measurement errors introduced by sample constituents, such as red blood cells, and manufacturing variances may be reduced.

Abstract: The present invention relates to electrochemical sensor strips and methods of determining the concentration of an analyte in a sample or improving the performance of a concentration determination. The electrochemical sensor strips may include at most 8 ?g/mm2 of a mediator. The strips, the strip reagent layer, or the methods may provide for the determination of a concentration value having at least one of a stability bias of less than ±10% after storage at 50° C. for 4 weeks when compared to a comparison strip stored at ?20° C. for 4 weeks, a hematocrit bias of less than ±10% for whole blood samples including from 20 to 60% hematocrit, and an intercept to slope ratio of at most 20 mg/dL. A method of increasing the performance of a quantitative analyte determination also is provided.

Abstract: An instrument adapted to determine an analyte concentration of a fluid sample using a test sensor is disclosed. The instrument comprises a display adapted to display information to a user, a user-interface mechanism adapted to allow the user to interact with the instrument, a first test-sensor cartridge, and a body portion including at least a first opening and a second opening formed therein. The first opening is adapted to receive a test sensor from the first test-sensor cartridge. The second opening is adapted to store at least one additional test-sensor cartridge.

Abstract: A biosensor (102) for determining the presence or amount of a substance in a sample and methods of use of the biosensor (102) are provided. The biosensor (102) for receiving a user sample to be analyzed includes a mixture for electrochemical reaction with an analyte. The mixture includes an enzyme, a mediator and an oxidizable species as an internal reference.

Abstract: The present invention relates to electrochemical sensor strips and methods of determining the concentration of an analyte in a sample or improving the performance of a concentration determination. The electrochemical sensor strips may include at most 8 ?g/mm2 of a mediator. The strips, the strip reagent layer, or the methods may provide for the determination of a concentration value having at least one of a stability bias of less than ±10% after storage at 50° C. for 4 weeks when compared to a comparison strip stored at ?20° C. for 4 weeks, a hematocrit bias of less than ±10% for whole blood samples including from 20 to 60% hematocrit, and an intercept to slope ratio of at most 20 mg/dL. A method of increasing the performance of a quantitative analyte determination also is provided.

Abstract: A method of indexing and excising a test sensor from a test-sensor cartridge including rotating an indexer in a first direction such that a flexible pawl thereon is positioned between a first and second notch of the test-sensor cartridge. Rotating the indexer in a first direction, but not in a second generally opposite direction, likewise rotates the cartridge. The method further includes rotating the indexer in the second direction such that the flexible pawl is positioned between the second notch and a third notch, and an aperture of the indexer face is generally aligned with a first cavity of the test-sensor cartridge. The method further includes moving an excise mechanism such that a push rod extends through the second aperture and through the first cavity until the first test sensor is excised through an opposing end of the first cavity into a read position.

Abstract: A biosensor (102) for determining the presence or amount of a substance in a sample and methods of use of the biosensor (102) are provided. The biosensor (102) for receiving a user sample to be analyzed includes a mixture for electrochemical reaction with an analyte. The mixture includes an enzyme, a mediator and an oxidizable species as an internal reference.

Abstract: A biosensor has an abnormal output detection system that determines whether an output signal from the redox reaction of an analyte has a normal or abnormal shape or configuration. The abnormal output detection system improves the accuracy and precision of the biosensor in determining whether an output signal has a shape or configuration that may not provide an accurate and/or precise analysis of a biological fluid. The biosensor generates an output signal in response to the redox reaction of the analyte. The biosensor normalizes the output signal and compares the normalized output signal with one or more control limits. The biosensor may generate an error signal when the normalized output signal is not within the control limits.

Abstract: Testing of the performance of an electrochemical meter used to measure the presence of an analyte in a biological sample, particularly glucose in whole blood, includes introducing a control solution containing a predetermined amount of the analyte and a predetermined amount of an internal reference compound. The internal reference compound is selected such that it is oxidized at a potential greater than that used to oxidize the analyte, thereby making it possible to distinguish the control solution from a biological sample.

Abstract: A microdeposition pin having a contact surface with at least one concave edge for creating microarrays and the like. The microdeposition pin may be used either alone or with a plurality of microdeposition pins in conjunction with a holder. The concave edge of the pin is especially adapted for helping to control the spreading of a deposited material. By selectively controlling the spread of the reagent composition from the microdeposition pin, the flow of the reagent composition from the deposition target area may be reduced. Sensor strips having raised substrate features with limited or no spreading of the reagent composition beyond the target area are disclosed.

Abstract: A biosensor with an underfill recognition system assesses whether to analyze a sample for one or more analytes in response to the volume of the sample. The underfill recognition system applies polling and test excitation signals to the sample. The polling signals generate one or more polling output signals, which maybe used to detect when a sample is present and to determine whether the sample has sufficient volume for analysis. The test excitation signal generates one or more test output signals, which may be used to determine one or more analyte concentrations in the sample.

Abstract: A sensor system including devices and methods for determining the concentration of an analyte in a sample is described. Input signals including amperometric and voltammetric duty cycles of excitations and relaxations may provide a shorter analysis time and/or improve the accuracy and/or precision of the analysis. The disclosed system may reduce analysis errors, thus improving measurement performance, by adjusting the potential and/or scan rate in response to output currents obtained from voltammetric scans. The disclosed system also may determine the concentration of more than one ionizable species in the sample by adjusting the potential and/or scan rate in response to output currents obtained from voltammetric scans. The multiple, determined concentrations may be used to determine the concentration of multiple analytes or to correct the concentration determined for an analyte, thus improving the measurement performance of the system.

Abstract: The present invention relates to electrochemical sensor strips and methods of determining the concentration of an analyte in a sample or improving the performance of a concentration determination. The electrochemical sensor strips may include at most 8 ?g/mm2 of a mediator. The strips, the strip reagent layer, or the methods may provide for the determination of a concentration value having at least one of a stability bias of less than ±10% after storage at 50° C. for 4 weeks when compared to a comparison strip stored at ?20° C. for 4 weeks, a hematocrit bias of less than ±10% for whole blood samples including from 20 to 60% hematocrit, and an intercept to slope ratio of at most 20 mg/dL. A method of increasing the performance of a quantitative analyte determination also is provided.

Abstract: A biosensor system including the underfill management system determines the analyte concentration in a sample from the at least one analytic output signal value. The underfill management system includes an underfill recognition system and an underfill compensation system. The underfill recognition system determines whether the test sensor initially is substantially full-filled or underfilled, indicates when the sample volume is underfilled so that additional sample may be added to the test sensor, and starts or stops the sample analysis in response to the sample volume. The underfill recognition system also may determine the initial degree of underfill. After the underfill recognition system determines the initial fill state of the test sensor, the underfill compensation system compensates the analysis based on the initial fill state of the test sensor to improve the measurement performance of the biosensor system for initially underfilled test sensors.

Abstract: The present invention relates to improved electrochemical biosensor strips and methods for determining the concentration of an analyte in a sample. By selectively measuring a measurable species residing in a diffusion barrier layer, to the substantial exclusion of the measurable species residing exterior to the diffusion barrier layer, measurement errors introduced by sample constituents, such as red blood cells, and manufacturing variances may be reduced.

Abstract: Error may be introduced into an analysis by both the biosensor system used to perform the analysis and by errors in the output signal measured by the measurement device of the biosensor. For a reference sample, system error may be determined through the determination of relative error. However, during an analysis of a test sample with the measurement device of the biosensor system, true relative error cannot be known. A pseudo-reference concentration determined during the analysis may be used as a substitute for true relative error. The closer the analysis-determined pseudo-reference analyte concentration is to the reference analyte concentration of the test sample, the more accurate and/or precise the analyte concentration determined by the measurement device using an anchor parameter during compensation. The present invention provides an improvement in the accuracy and/or precision of the analysis determined pseudo-reference concentration through progressive approximation.