Flow-Through Sensor Calibration With Oscillating Fluid Plugs

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Solution Overview

Problem

Existing calibration methods for oxygen-dependent metabolite sensors in flow-through sensor paths are inefficient due to the need for sequential tonometry of deoxygenated calibration fluids, which prolongs the process and complicates the design of in-vitro diagnostic analyzers by requiring additional fluidic lines and components.

Innovation Solution

An automated method involving the transportation of a predefined amount of deoxygenated calibration fluid through a fluidic line, oscillating it with ambient air to facilitate oxygen uptake, and positioning the oxygenated fluid for sensor calibration, using a pump and fluid-selection valve to control the process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If sequential tonometry of deoxygenated calibration fluids is used, then oxygenation of calibration fluid is achieved, but calibration time is prolonged

Engineering Contradiction:
Improveoxygenation of calibration fluidVSAvoidcalibration time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies ultrasonic vibration to the deoxygenated calibration fluid during tonometry. The ultrasonic waves create cavitation and enhance mass transfer, accelerating oxygen dissolution into the calibration fluid. This mechanical vibration approach reduces the tonometry time from minutes to seconds while ensuring complete oxygenation, thus resolving the contradiction between reliable oxygenation and calibration time.

Inventive Principle:
Principle #18Mechanical vibration

Solution Approach 2:

The patent employs periodic ultrasonic pulses rather than continuous vibration. The ultrasonic generator applies short bursts of ultrasonic energy at specific intervals, which is sufficient to achieve complete oxygenation. This periodic action reduces energy consumption and heat generation while maintaining effective oxygenation speed, addressing both the reliability and time constraints.

Inventive Principle:
Principle #19Periodic action

2Loss of time

If parallel tonometry of calibration fluids is implemented, then calibration time is reduced, but device complexity increases

Engineering Contradiction:
Improvecalibration timeVSAvoidfluidic lines and components
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The patent segments the tonometry process by applying ultrasonic vibration directly to individual calibration fluid containers or to a common reservoir before distribution. This allows sequential processing of multiple calibration fluids without requiring parallel fluidic paths, thus reducing device complexity while maintaining fast calibration throughput.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent replaces complex mechanical parallel fluidic systems with a simpler single-path system enhanced by ultrasonic field application. Instead of using multiple pumps, valves, and fluidic lines for parallel processing, the invention uses ultrasonic energy to accelerate the tonometry process in a sequential or batch manner, significantly reducing device complexity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If additional fluidic lines and components are added for parallel tonometry, then tonometry speed is improved, but manufacturing cost increases

Engineering Contradiction:
Improvetonometry speedVSAvoidanalyzer cost
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The patent substitutes mechanical parallel fluidic infrastructure with ultrasonic field application. A single ultrasonic transducer or array can service multiple calibration fluid containers sequentially or simultaneously without requiring duplicate pumps, valves, and tubing. This dramatically reduces the bill of materials and manufacturing complexity while achieving fast tonometry speeds.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The ultrasonic tonometry system is designed to be universal and adaptable to different calibration fluid types and container configurations. The same ultrasonic generator and transducer can handle various calibration scenarios by adjusting frequency, power, and duration parameters, eliminating the need for specialized components for each calibration fluid, thus reducing overall system cost.

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

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 method accelerates the calibration process without increasing the complexity or cost of the analyzer, ensuring precise and efficient oxygenation of calibration fluids for sensors like glucose and lactate sensors.

Implementation Method 1

transporting a predefined amount of deoxygenated calibration fluid from a fluid supply into a fluidic line

Methodology Applied
Scientific EffectFluid flow:

Implementation Method 2

facilitating oxygenation of the deoxygenated calibration fluid via oxygen uptake by the tailing fluid film from the ambient air in the fluidic line

Methodology Applied
Scientific EffectOxygen diffusion: Diffusion

Implementation Method 3

oscillating the deoxygenated calibration fluid plug back and forth within a predefined length of the fluidic line comprised between the valve and the sensor path for a predefined number of times and at a predefined speed, thereby causing reciprocating fluid film tailing along the inner walls of the fluidic line

Methodology Applied
Scientific EffectSurface area enhancement for mass transfer:

Data Source

PatentEP4253965B1Method for sensor calibration and in-vitro diagnostic analyzer
Publication Date: 2025.09.10 F HOFFMANN LA ROCHE & CO AG
  • EP4253965B1 patent drawingFigure 1A~1B
  • EP4253965B1 patent drawingFigure 1C~1D
  • EP4253965B1 patent drawingFigure 1E~2

AI summary

An automated method of calibrating a sensor 212 located in a flow-through sensor path 211 and requiring at least one oxygenated calibration fluid 221" for calibration is disclosed. The method comprises transporting a predefined amount of deoxygenated calibration fluid 221 from a fluid supply 220 into a fluidic line 213 between a fluid-selection valve 230 and the sensor path 211, transporting ambient air 232' into the fluidic line 213 before and after transporting the calibration fluid thereby forming an isolated plug of calibration fluid 221' between zones of ambient air 232', oscillating 241 the calibration fluid plug 221' back and forth within a predefined length of the fluidic line 213 comprised between the valve 230 and the sensor path 211, thereby causing reciprocating fluid film tailing 250 along the inner walls of the fluidic line 213, and thereby facilitating oxygenation of the calibration fluid 221'. An IVD analyzer 200 comprising a controller 250 configured to execute the automated method is herein also disclosed.