Handheld Analyte Meter Charging Control for Thermal Lockout Accuracy

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Solution Overview

Problem

Handheld blood glucose meters with rechargeable batteries face self-heating issues during charging, leading to inaccurate temperature measurements that can prevent or allow blood glucose tests incorrectly, due to unpredictable thermal conditions caused by modulating charging current.

Innovation Solution

Implementing recharging controls that select a maximum charging current prior to charging, based on the battery temperature and the capacity of the charging source, using two temperature sensors to differentiate between battery and test element temperatures, thereby stabilizing thermal conditions and preventing false lock-out conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If modulating charging current during recharging session, then charging efficiency is improved, but temperature control becomes difficult and causes inaccurate temperature measurements

Engineering Contradiction:
Improvecharging efficiencyVSAvoidtemperature measurement accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent divides temperature monitoring into two separate functions: one temperature sensor monitors battery temperature for charging control, while another temperature sensor monitors test element temperature for measurement accuracy. This segmentation allows independent optimization of charging efficiency and measurement precision without interference.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a controller as an intermediary that receives temperature data from both sensors and makes intelligent decisions about charging current modulation. The controller mediates between the conflicting requirements of charging efficiency and temperature measurement accuracy by adjusting charging parameters based on real-time temperature feedback from both locations.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Use of energy by moving object

If using rechargeable battery to reduce power consumption, then energy efficiency is improved, but self-heating occurs during charging that affects temperature stability

Engineering Contradiction:
Improvepower consumptionVSAvoidtemperature stability
Core Design Contradiction:
Use of energy by moving objectVSTemperature

Solution Approach 1:

The patent performs preliminary temperature assessment by monitoring battery temperature before and during charging sessions. Based on this preliminary data, the system pre-adjusts charging parameters or implements cooling measures before self-heating significantly impacts test element temperature, thereby maintaining temperature stability throughout the charging process.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements a feedback mechanism where temperature sensors continuously monitor both battery and test element temperatures, and this temperature feedback is used by the controller to dynamically adjust charging current. This closed-loop control prevents excessive self-heating while maintaining efficient charging, thus preserving temperature stability.

Inventive Principle:
Principle #23Feedback

3Adaptability or versatility

If increasing meter capability with color displays and wireless communications, then functionality is improved, but power consumption increases requiring rechargeable batteries

Engineering Contradiction:
Improvemeter capabilityVSAvoidpower consumption
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent implements dynamic power management where the controller adjusts charging parameters based on real-time conditions including battery temperature, charge state, and power consumption patterns. This dynamic approach allows the system to optimize the balance between advanced functionality and power consumption, enabling efficient recharging of the rechargeable battery that powers the enhanced meter features.

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 reduces the risk of preventing valid blood glucose measurements due to high lock-out conditions and avoids incorrect tests due to masked low lock-out conditions, ensuring accurate analyte testing by maintaining stable thermal conditions during recharging.

Implementation Method 1

a first temperature sensor to measure a first temperature inside the housing

Methodology Applied
Scientific EffectTemperature sensing: Thermistor

Implementation Method 2

a second temperature sensor to measure a second temperature inside the housing that more closely reflects the reaction temperature

Methodology Applied
Scientific EffectTemperature sensing: Thermistor

Implementation Method 3

a rechargeable battery and a battery charger to recharge the rechargeable battery

Methodology Applied
Scientific EffectElectrochemical energy storage and conversion: Battery (electricity)

Implementation Method 4

During recharging, the charging current and electrochemical reactions cause the battery to self-heat or warm

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP3145391B1Handheld analyte meter with recharging control for improved analyte testing
Publication Date: 2023.11.01 F HOFFMANN LA ROCHE & CO AG
  • EP3145391B1 patent drawingFigure 1~2
  • EP3145391B1 patent drawingFigure 3
  • EP3145391B1 patent drawingFigure 4

AI summary

Handheld analyte meters are provided that have a measurement module, a rechargeable battery and a charging control to select a maximum charging current to regulate self-heating during recharging that can interfere with analyte tests. Prior to beginning a charging session, the charging control selects the maximum charging current that does not change during the charging session based capacity of a charging source along with a first temperature measured near the battery that is compared with a first temperature range. By selecting the maximum charging current in this manner, the risk of the measurement module preventing a test under high lock-out conditions and the risk of the measurement module allowing a test when low lock-out conditions that are masked is reduced. Methods also are provided for using/operating such devices.