Glucose Test Strip Electrode Segmentation for Hematocrit Correction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing electrochemical glucose test strips are affected by hematocrit variations in blood samples, leading to inaccurate glucose readings due to interference from red blood cells, which current strategies struggle to fully correct.

Innovation Solution

An analyte measurement system that includes a test strip with multiple electrodes and a microprocessor-controlled meter, which applies specific electrical signals to determine physical characteristics of the sample, such as hematocrit, and adjusts the sampling time to correct for these variations, ensuring accurate glucose concentration measurement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If hematocrit correction strategies are implemented, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improveglucose reading accuracyVSAvoidtest strip structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The test strip is segmented into multiple functional electrode regions: a first working electrode for primary glucose measurement, a second working electrode for hematocrit determination, and a reference electrode. This segmentation allows simultaneous measurement of both glucose and hematocrit to enable correction algorithms that improve accuracy without requiring complex mechanical structures.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The electrochemical test strip is designed with multi-functionality by incorporating multiple working electrodes that serve different purposes: one for glucose detection and another for hematocrit measurement. This universal design allows a single device to perform both measurements, enabling the system to compensate for hematocrit effects and improve glucose reading accuracy without adding separate devices or complex mechanisms.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If multiple electrodes are added to correct hematocrit effects, then measurement precision improves, but manufacturing complexity increases

Engineering Contradiction:
Improveglucose concentration measurement accuracyVSAvoidtest strip fabrication
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

Multiple electrode functions are merged into a single integrated test strip structure. The first working electrode, second working electrode, and reference electrode are all incorporated into one strip during a single manufacturing process, eliminating the need for separate assembly steps and reducing manufacturing complexity despite the increased functional requirements.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention changes the electrical parameters of the test strip by incorporating multiple electrodes with different configurations and reagent compositions. This allows the system to measure both glucose and hematocrit simultaneously, improving measurement precision while maintaining ease of manufacture through standardized electrochemical manufacturing processes.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If hematocrit measurement and correction is implemented, then reliability of glucose monitoring improves, but device complexity increases

Engineering Contradiction:
Improveblood glucose monitoring accuracyVSAvoidsignal processing system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system uses feedback by measuring hematocrit levels through the second working electrode and using this information to correct the glucose measurement from the first working electrode. This feedback mechanism allows the system to automatically compensate for hematocrit effects, improving reliability while keeping the processing algorithm relatively simple and integrated into the meter.

Inventive Principle:
Principle #23Feedback

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 provides accurate glucose readings by effectively accounting for hematocrit-induced biases, reducing errors and improving the reliability of blood glucose monitoring.

Implementation Method 1

The plurality of electrodes comprises: physical characteristic sensing electrodes spaced apart from and not in contact with the reagent; a first working electrode and a second working electrode; and a reference electrode

Methodology Applied
Scientific EffectElectrical Conductivity: Conduction (electrical)

Implementation Method 2

The reactions that can occur in a glucose test strip are summarized below in Equations 1 and 2. As illustrated in Equation 1, glucose is oxidized to gluconic acid by the oxidized form of glucose oxidase (GO (ox) )

Methodology Applied
Scientific EffectElectrochemical reaction: Redox Reactions

Implementation Method 3

In particular, the transfer of electrons across the electrical interface results in the flow of a test current (2 moles of electrons for every mole of glucose that is oxidized)

Methodology Applied
Scientific EffectElectron transfer: Electrical Resistance

Data Source

PatentEP3250916B1Reference electrode error trap determined from a specified sampling time and a pre-determined sampling time
Publication Date: 2021.04.21 LIFESCAN SCOTLAND
  • EP3250916B1 patent drawingFigure 1A
  • EP3250916B1 patent drawingFigure 1B
  • EP3250916B1 patent drawingFigure 2A

AI summary

Various embodiments for a method that allow for a more accurate analyte concentration with a biosensor by determining at least one physical characteristic of the sample and determining whether a counter or reference electrode is causing an error by monitoring the working electrodes and flagging an error if the signal outputs of the working electrodes do not meet certain thresholds.