Underfill Management System for Biosensor Accuracy

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Solution Overview

Problem

Conventional biosensor systems face challenges in accurately determining analyte concentrations from underfilled test sensors, particularly when the sensors are initially underfilled and subsequently refilled, as they fail to compensate for errors arising from varying sample fill rates and addition profiles, leading to inaccurate glucose measurements.

Innovation Solution

An electrochemical biosensor system employing an underfill management system that uses regular and extended polling sequences to detect the presence and degree of underfill, applying a slope compensation equation to correct for errors, ensuring accurate glucose analyte concentration determination even when the sensor is initially underfilled and subsequently filled.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional biosensor systems analyze samples without underfill detection, then the device complexity is reduced, but measurement precision deteriorates due to inaccurate analyte concentration determination from underfilled sensors

Engineering Contradiction:
Improveanalyte concentration determination accuracyVSAvoidsystem structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system performs preliminary detection of underfill conditions by applying polling input signals before the main electrochemical analysis. This preliminary action identifies when the test sensor is underfilled and triggers appropriate compensation or error handling, preventing inaccurate measurements from compromising results.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from polling output signals to determine the fill state of the test sensor. Based on this feedback, the system adjusts the analysis procedure by applying compensation equations or requesting additional sample, thereby maintaining measurement precision despite varying fill conditions.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If the system applies compensation equations for underfill conditions, then measurement precision improves, but device complexity increases due to additional processing requirements

Engineering Contradiction:
Improveglucose reading accuracyVSAvoidsignal processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system changes parameters in the electrochemical signal based on detected underfill conditions. By applying slope compensation equations that adjust the signal characteristics according to the degree of underfill, the system corrects measurement errors without requiring complete system redesign.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system applies compensation only when underfill conditions are detected, rather than continuously processing complex corrections. This partial application of compensation logic maintains precision when needed while minimizing unnecessary processing complexity during normal operation.

Inventive Principle:
Principle #16Partial or excessive action

3Measurement precision

If the system uses extended polling sequences to detect underfill, then measurement precision improves, but loss of time increases due to additional detection steps

Engineering Contradiction:
Improvesample fill state detection accuracyVSAvoidanalysis time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system uses periodic polling sequences to detect underfill conditions efficiently. By applying multiple polling input signals at regular intervals and analyzing the resulting output signals, the system determines fill state without requiring continuous or excessively long detection periods, thus balancing precision with time efficiency.

Inventive Principle:
Principle #19Periodic action

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

The system significantly improves measurement performance by reducing errors and increasing accuracy, with a higher percentage of glucose readings falling within a ±15% percent bias limit, enhancing the reliability of glucose monitoring in biosensors.

Implementation Method 1

the analyte concentration is determined from an electrical signal generated by an electrochemical oxidation/reduction or redox reaction of a measurable species

Methodology Applied
Scientific EffectRedox reactions: Redox Reactions

Implementation Method 2

Mediators assist in the transfer of an electron from a first species to a second species. For example, a mediator may assist in the transfer of an electron from the redox reaction between the analyte and the oxidoreductase to or from the surface of the working electrode

Methodology Applied
Scientific EffectElectron transfer:

Data Source

PatentEP2577303B1Underfill management system for a biosensor
Publication Date: 2022.08.03 ASCENSIA DIABETES CARE HLDG AG
  • EP2577303B1 patent drawingFigure 1A~1B
  • EP2577303B1 patent drawingFigure 2A~2B
  • EP2577303B1 patent drawingFigure 3A~3B

AI summary

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.