Biosensor Test Strip Hematocrit Correction Algorithm

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current biosensors face challenges in accurately measuring blood glucose levels due to the interfering effects of hematocrit and humidity, with existing methods requiring long correction times and lacking accuracy, especially when differentiating between capillary and venous blood.

Innovation Solution

A method that uses a biosensor system with a test strip, voltage generator, and microcontroller unit to determine the type of blood and calculate hematocrit values based on electric current measurements, applying correction algorithms to accurately adjust glucose level readings and account for humidity effects, eliminating the need for additional instruments and reagents.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional hematocrit correction methods are used, then measurement accuracy is improved, but correction time is significantly prolonged

Engineering Contradiction:
Improveglucose level measurement accuracyVSAvoidcorrection time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies preliminary action by measuring hematocrit level immediately when blood is applied to the test strip, before the glucose measurement is completed. This allows the correction algorithm to be prepared in advance, eliminating the need for prolonged correction time while maintaining measurement accuracy. The hematocrit measurement is performed concurrently with the initial measurement phase rather than as a separate subsequent step.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If additional instruments are used to measure hematocrit, then measurement accuracy is improved, but device complexity increases

Engineering Contradiction:
Improvehematocrit measurement accuracyVSAvoidnumber of instruments
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies universality by designing the test strip to perform multiple functions: it simultaneously measures both glucose level and hematocrit level using the same physical structure and reagent composition. The test strip contains reagents that respond to both analytes, eliminating the need for separate hematocrit measurement instruments and reducing overall device complexity while maintaining measurement accuracy.

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

Solution Approach 2:

The patent merges the hematocrit measurement function with the glucose measurement function into a single integrated test strip system. Both measurements are performed using the same blood sample application, same electrical circuit, and same processing timeline, combining what would traditionally require separate instruments into one unified device.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of manufacture

If conventional test strips are used, then manufacturing simplicity is maintained, but test strip stability is reduced

Engineering Contradiction:
Improvetest strip manufacturing simplicityVSAvoidtest strip stability
Core Design Contradiction:
Ease of manufactureVSDuration of action of stationary object

Solution Approach 1:

The patent applies composite materials by formulating the test strip with a specific composite reagent system that includes multiple chemical components working together. The reagent composition is designed to provide both glucose measurement capability and hematocrit measurement capability while maintaining enhanced stability. This composite approach allows the test strip to resist degradation and maintain performance over time without requiring complex manufacturing processes.

Inventive Principle:
Principle #40Composite materials

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 significantly improves the accuracy of blood glucose level measurements by minimizing hematocrit and humidity effects, providing stable and cost-effective results with prolonged test strip stability.

Implementation Method 1

measuring the conductivity of diluted blood correlated to the total amount of red blood cells and thus hematocrit value

Methodology Applied
Scientific EffectElectrical Conductivity: Conduction (electrical)

Implementation Method 2

measuring the current by amperometry

Methodology Applied
Scientific EffectAmperometry:

Implementation Method 3

applying 500 mV of potential difference sufficient to oxidize a reactant on a test strip to generate current

Methodology Applied
Scientific EffectOxidation: Oxidation

Data Source

PatentEP2193367B1Method for correcting erroneous results of measurement in biosensors and apparatus using the same
Publication Date: 2019.01.23 PHILOSYS
  • EP2193367B1 patent drawingFigure 1~2
  • EP2193367B1 patent drawingFigure 3~4
  • EP2193367B1 patent drawingFigure 5

AI summary

Disclosed herein is a method of correcting erroneous measurement results in a biosensor. The method includes the steps of: (a) applying a first voltage from a voltage generator 12 to a test strip 10 when a blood sample is applied on the test strip 10, and measuring an electric current generated from the test strip within one second of applying the first voltage by a microcontroller unit (MCU), and then calculating a hematocrit value of the blood sample using the measured electric current value! (b) applying a second voltage from the voltage generator to the test strip after calculating the hematocrit value of the blood sample, and measuring an electric current generated from the test strip within a predetermined time of applying the second voltage, and then calculating a glucose level using the measured electric current value; and (c) correcting the glucose level in (b) by using the calculated hematocrit value in (a).