Automated Analyzer Discharge Speed Control for Uniform Mixing

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Solution Overview

Problem

Existing automated analyzers face challenges in uniformly stirring blood coagulation samples and reagents without foaming, especially when viscosity varies, leading to non-uniform reactions and measurement inaccuracies.

Innovation Solution

An automated analyzer is configured with a pressure sensor to adjust discharge speed based on viscosity, using a dispensing mechanism to stir the sample and reagent without external stirring methods, ensuring uniform mixing and avoiding foaming.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If stirring is performed by discharge pressure without external stirring mechanisms, then device complexity is reduced, but mixing uniformity deteriorates

Engineering Contradiction:
Improvestirring mechanism complexityVSAvoidmixing uniformity
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The dispensing mechanism performs dual functions: both dispensing the reagent and stirring the reaction solution. The discharge pressure generated during reagent dispensing is utilized to create stirring motion, eliminating the need for separate stirring mechanisms. This self-service approach reduces device complexity while maintaining effective mixing through the inherent motion of the dispensing process

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The dispensing mechanism is designed to serve multiple purposes: reagent delivery, reaction initiation, and stirring. By making the dispensing mechanism universal, the system eliminates dedicated stirring components, reducing overall device complexity while ensuring that the same mechanism that delivers the reagent also provides the necessary mixing action

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

2Speed

If discharge pressure is increased to improve stirring, then mixing speed is improved, but foaming increases

Engineering Contradiction:
Improvestirring speedVSAvoidfoaming
Core Design Contradiction:
SpeedVSObject-generated harmful factors

Solution Approach 1:

The dispensing mechanism operates in dynamic phases: an initial high-speed phase for rapid reagent delivery and stirring, followed by a deceleration phase that prevents excessive pressure buildup. This dynamic control allows the system to achieve effective stirring speed while avoiding the sustained high pressure that would cause foaming, by adjusting the discharge profile over time

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The dispensing process employs periodic motion with varying discharge rates. The mechanism delivers the reagent in a controlled periodic fashion, creating stirring action during the discharge phase while allowing pressure to equalize during the pause phase. This periodic action prevents continuous high pressure that would generate foam, while still achieving adequate mixing during the active discharge periods

Inventive Principle:
Principle #19Periodic action

3Device complexity

If stirring is performed by discharge pressure alone, then device structure is simplified, but measurement precision deteriorates due to non-uniform mixing

Engineering Contradiction:
Improvestirring device structureVSAvoidblood coagulation measurement precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The system incorporates feedback control where the dispensing parameters are adjusted based on the specific reagent and sample characteristics. The control mechanism monitors the dispensing process and modifies the discharge pressure and speed profile to ensure optimal mixing for each specific measurement, thereby maintaining measurement precision despite using a simplified stirring approach

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The dispensing mechanism allows for parameter changes in discharge pressure, speed, and volume based on the specific measurement requirements. By adjusting these parameters, the system optimizes the stirring effect for different reagent types and sample viscosities, ensuring uniform mixing and accurate measurements without requiring complex mechanical stirring devices

Inventive Principle:
Principle #35Parameter changes

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 allows for accurate and reproducible blood coagulation measurements by preventing foaming and ensuring uniform stirring, even with varying sample and reagent ratios and viscosities.

Implementation Method 1

a pressure sensor to adjust discharge speed based on viscosity

Methodology Applied
Scientific EffectPressure sensor detection: Piezoresistive Effect

Implementation Method 2

stirring is performed by a pressure generated when a sample or a reagent is discharged

Methodology Applied
Scientific EffectPressure-generated stirring: Turbulence

Data Source

PatentEP2937700B1Automated analyzer
Publication Date: 2020.03.11 HITACHI HIGH TECH CORP
  • EP2937700B1 patent drawingFigure 1
  • EP2937700B1 patent drawingFigure 2
  • EP2937700B1 patent drawingFigure 3~4

AI summary

There is a concern that in the case of performing stirring by the discharge pressure of a reagent or a sample, a mixing ratio of the sample to the reagent varies, and therefore, stirring cannot be sufficiently performed at a constant discharge speed, and thus, a reaction occurs non-uniformly. On the other hand, if the discharge speed is increased excessively, foaming occurs, resulting in disturbing the measurement of a change in light intensity. A control section causes one dispensing mechanism of either a reagent dispensing mechanism or a sample dispensing mechanism to first discharge a predetermined amount of a liquid into the reaction container, and then, with respect to the cases where the amount of a liquid to be discharged by the other dispensing mechanism is larger or smaller than the amount of the liquid in the reaction container, causes the other dispensing mechanism to discharge the liquid such that the discharge speed in the case where the amount of the liquid to be discharged is larger is decreased relative to the discharge speed in the case where the amount of the liquid to be discharged is smaller.