Thermistor Sensor Temperature Compensation in Biosensors

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing blood glucose monitoring systems using thermistor-based temperature sensors face inaccuracies due to slow thermal equilibration, leading to erroneous glucose readings, and there is a need for a system to differentiate between disequilibrated meters and damaged sensors using estimated and measured temperatures.

Innovation Solution

A biosensor system that compares estimated and measured temperatures to determine the suitability of the temperature input for glucose concentration calculations, selecting one over the other based on their difference to ensure accurate readings and detect potential sensor malfunctions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If thermistor-based temperature measurement is used, then temperature can be measured, but the measurement is inaccurate when the meter has not equilibrated to the environment

Engineering Contradiction:
Improvetemperature measurement accuracyVSAvoidthermal equilibration time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs preliminary action by estimating the temperature using electrochemical reactions before the thermistor completes thermal equilibration. The estimation algorithm uses the relationship between electrochemical reaction rates and temperature to provide an immediate temperature estimate, allowing glucose measurement to proceed without waiting for thermal equilibrium.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The electrochemical reaction serves as an intermediary to indirectly determine temperature. Instead of directly measuring temperature with the thermistor during the equilibration period, the system uses the temperature-dependent electrochemical reaction as a mediator to infer the temperature, bypassing the need for direct thermal contact measurement during the transition period.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If estimated temperature is used, then glucose calculation can proceed immediately, but damaged sensors may produce erroneous temperature estimates

Engineering Contradiction:
Improveglucose measurement speedVSAvoidtemperature estimation accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system implements feedback by continuously monitoring the consistency between the estimated temperature and the thermistor temperature reading. When the meter is disequilibrated, the estimated temperature provides accurate glucose calculation. When equilibrated, the thermistor reading should match, providing feedback validation. Discrepancies trigger error detection to identify damaged sensors.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically switches between using estimated temperature and thermistor temperature based on the equilibration state. During disequilibration, the estimated temperature is used for immediate glucose calculation. After equilibration, the system transitions to using the thermistor reading, creating a dynamic adaptation strategy that optimizes both speed and reliability at different stages.

Inventive Principle:
Principle #15Dynamics

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 improves the accuracy of glucose readings by selecting the appropriate temperature input and detecting sensor malfunctions, reducing the risk of inaccurate results from disequilibrated or damaged sensors, thereby enhancing the reliability of blood glucose monitoring.

Implementation Method 1

A measured temperature is determined from a thermistor based temperature sensor

Methodology Applied
Scientific EffectThermistor: Thermistor

Implementation Method 2

An estimated temperature is determined from a temperature estimation algorithm

Methodology Applied
Scientific EffectTemperature estimation algorithm:

Data Source

PatentEP3972493B1Compensation system and method for thermistor sensing in an analyte biosensor
Publication Date: 2024.10.16 ASCENSIA DIABETES CARE HLDG AG
  • EP3972493B1 patent drawingFigure 1
  • EP3972493B1 patent drawingFigure 2A
  • EP3972493B1 patent drawingFigure 2B

AI summary

An analyte concentration sensor system is disclosed that selects a temperature for input to an analyte concentration estimation algorithm. The analyte concentration estimation algorithm is executed by an analyte meter that analyzes a sample in a test sensor. A thermistor based temperature sensor is configured to measure temperature. An estimated temperature is obtained via a temperature estimation algorithm. The difference between the estimated temperature and the measured temperature is determined. One of the estimated temperature or the measured temperature is selected based on the estimated temperature, the measured temperature and the absolute difference between the estimated temperature and the measured temperature. In addition, a malfunction in the test sensor may be determined based on the estimated temperature, the measured temperature and the absolute difference between the estimated temperature and the measured temperature.