Electrochemical Sensor Antioxidant Interference Detection
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Solution Overview
Problem
Current electrochemical methods for measuring analyte concentrations in fluidic samples, such as glucose, are affected by antioxidants like ascorbate, leading to falsely elevated readings, which can cause hypoglycemia or death in diabetic patients, and lack effective quality checks for reagent failures.
Innovation Solution
The method involves using a test sequence with DC blocks, including slow-ramped bi-polar potential waveforms and continuous unipolar pulsed excitation, to provide specific information about the redox mediator status, allowing discrimination between acceptable and clinically unacceptable antioxidant levels and detecting reagent layer failures, thereby preventing erroneous analyte concentration reporting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If electrochemical measurement methods are used to measure analyte concentration, then convenience and speed are improved, but measurement precision deteriorates due to antioxidant interference
Solution Approach 1:
The test sequence is divided into multiple blocks (DC blocks with slow-ramped bi-polar potential waveforms, AC blocks with multi-frequency square wave voltammetry) that separately measure different electrochemical responses. This segmentation allows the system to isolate antioxidant interference from analyte signal, enabling both rapid measurement and accurate discrimination of interfering substances.
Solution Approach 2:
The patent uses redox mediators as intermediary substances that facilitate the electrochemical reaction between the analyte and electrode. By monitoring the redox mediator status through specific DC blocks, the system can detect antioxidant interference that affects the mediator, thereby identifying when measurements may be inaccurate without sacrificing measurement speed.
2Device complexity
If simple electrochemical measurement is used, then device complexity is reduced, but reliability deteriorates due to inability to detect interferents and reagent failures
Solution Approach 1:
The electrochemical test sequence is designed to perform multiple functions within a single integrated system: it measures analyte concentration, detects antioxidant interferents, monitors redox mediator status, and identifies reagent failures. This multi-functionality is achieved through a unified test sequence with different blocks that can be executed sequentially without requiring separate devices or complex additional hardware.
Solution Approach 2:
The system incorporates feedback mechanisms where the results from DC blocks (monitoring redox mediator status) and AC blocks (detecting interferents) are used to validate the analyte measurement. If interferents or reagent failures are detected, the system can flag or reject the measurement result, providing automatic quality assurance that enhances reliability without requiring manual intervention or complex external validation systems.
3Measurement precision
If DC blocks with slow-ramped bi-polar potential waveforms are added to detect antioxidants, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent combines the antioxidant detection function with the existing analyte measurement process by integrating DC blocks into the same test sequence used for glucose measurement. The slow-ramped bi-polar potential waveforms are applied in sequence with other measurement blocks, allowing the system to extract multiple pieces of information (analyte concentration, antioxidant levels, redox mediator status) from a single integrated test sequence rather than requiring separate measurement procedures.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach ensures patient safety by accurately differentiating between antioxidant interference and reliable analyte measurements, reducing false positives and identifying reagent issues, thus providing a more reliable analyte concentration and preventing harmful medical responses.
Implementation Method 1
electrochemically measuring analytes in fluidic samples
Implementation Method 2
measuring the response information to the test sequence, wherein the at least one DC block provides specific information about a status of a redox mediator
Implementation Method 3
providing a test sequence including at least one DC block... wherein the at least one DC block is a slow-ramped bi-polar potential waveform
Implementation Method 4
using information relating to a redox mediator status derived from at least one DC block to discriminate between antioxidant levels at which the analyte prediction bias of an electrochemical system is acceptable and antioxidant levels at which the analyte prediction bias is clinically unacceptable
Data Source
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AI summary
Methods are disclosed for measuring an analyte concentration in a fluidic sample. Such methods further allow one to provide an error code or correct and/or compensate for interferents such as an antioxidant before providing an analyte concentration. The measurement methods utilize information obtained from test sequences having at least one DC block, such as a slow-ramped bi-polar waveform, where a closed circuit condition is maintained during the DC block. The methods use information relating to status of a redox mediator feature during the electrochemical analysis to provide an antioxidant failsafe if the antioxidant is interfering with the analyte concentration. Also disclosed are devices, apparatuses and systems incorporating the various measurement methods.