Reagent Aspiration Pressure Sensing in Automatic Analyzers

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Solution Overview

Problem

Existing automatic analyzers face difficulties in accurately detecting aspiration abnormalities when the amount of reagent used for analysis is small, leading to potential erroneous detections due to small pressure sensor output differences.

Innovation Solution

The automatic analyzer includes a dispensing mechanism that aspirates and discharges predetermined amounts of reagent, using a pressure sensor to measure pressure, and adjusts the reagent aspiration amount based on a threshold value to ensure accurate abnormality detection, even when the reagent amount is small.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a small pressure threshold value is used to detect aspiration abnormalities when reagent amount is small, then detection sensitivity is improved, but measurement precision deteriorates due to difficulty in distinguishing normal states

Engineering Contradiction:
Improveaspiration abnormality detection accuracyVSAvoiddetection reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The invention changes the parameter of reagent aspiration amount dynamically based on the detected reagent amount. When the reagent amount is small, the system increases the aspiration amount to a predetermined level to amplify the pressure signal difference, making abnormality detection more reliable. This parameter change resolves the contradiction by adjusting the operating conditions to maintain detection accuracy across different reagent volumes.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention applies partial excessive action by aspirating more reagent than the actual required amount when the detected amount is small. This excessive aspiration creates a larger pressure difference signal that improves detection reliability, while the excess reagent is then discarded or returned to the container. This resolves the measurement precision issue by temporarily exceeding the minimum required action to achieve detectable signal changes.

Inventive Principle:
Principle #16Partial or excessive action

2Measurement precision

If the reagent aspiration amount is increased to improve pressure signal difference, then detection accuracy is improved, but reagent consumption increases

Engineering Contradiction:
Improveaspiration abnormality detection accuracyVSAvoidreagent consumption
Core Design Contradiction:
Measurement precisionVSLoss of substance

Solution Approach 1:

The invention applies dynamics by making the aspiration amount adjustable based on real-time detection of the reagent amount. The control unit dynamically changes the aspiration amount from the actual required amount to a predetermined larger amount when the detected amount is small. This dynamic adjustment resolves the contradiction by optimizing the aspiration amount for each specific situation, ensuring detection accuracy while minimizing unnecessary reagent consumption.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the parameter of aspiration amount based on the detected reagent amount. When the reagent amount is small, the system changes the aspiration amount to a predetermined level that ensures sufficient pressure signal difference. This parameter change allows the system to maintain detection accuracy without consistently consuming excessive reagent, as the increased aspiration only occurs when necessary.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If a fixed pressure threshold value is used for all reagent amounts, then device complexity is reduced, but measurement precision deteriorates when reagent amount is small

Engineering Contradiction:
Improvecontrol system complexityVSAvoidaspiration abnormality detection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The invention applies dynamics by making the aspiration amount adjustable based on real-time detection of the reagent amount. The control unit dynamically changes the aspiration amount from the actual required amount to a predetermined larger amount when the detected amount is small. This dynamic adjustment resolves the contradiction by optimizing the aspiration amount for each specific situation, ensuring detection accuracy while minimizing unnecessary reagent consumption.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention applies preliminary action by detecting the reagent amount before the actual dispensing operation. Based on this preliminary detection, the control unit pre-adjusts the aspiration amount to ensure that sufficient pressure signal difference will be generated during the subsequent aspiration phase. This preliminary action allows the system to maintain measurement precision without requiring complex real-time adjustments during the actual dispensing process.

Inventive Principle:
Principle #10Preliminary action

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 precise detection of aspiration abnormalities, reducing erroneous detections and maintaining determination accuracy even with small reagent volumes.

Implementation Method 1

a pressure sensor configured to measure pressure in the dispensing mechanism

Methodology Applied
Scientific EffectPressure measurement:

Data Source

PatentEP4715391A1Automatic analysis device
Publication Date: 2026.03.25 HITACHI HIGH TECH CORP
  • EP4715391A1 patent drawingFigure 1
  • EP4715391A1 patent drawingFigure 2
  • EP4715391A1 patent drawingFigure 3

AI summary

Provided is an automatic analyzer capable of accurately detecting an abnormality during aspiration even when an amount of a reagent used for analysis is small. An automatic analyzer includes: a dispensing mechanism configured to dispense a reagent from a reagent container to a reaction container; a control unit configured to control the dispensing mechanism to aspirate an amount of the reagent used for analysis, the amount including at least a second predetermined amount in addition to a first predetermined amount, then discharge the second predetermined amount of the reagent to the reagent container, and then discharge the first predetermined amount of the reagent to the reaction container; and a pressure sensor configured to measure pressure in the dispensing mechanism. The control unit determines whether the reagent is normally aspirated based on a measurement value of the pressure sensor when the dispensing mechanism aspirates the reagent. When the first predetermined amount is equal to or larger than a first predetermined amount threshold value that is predetermined in advance, the second predetermined amount is a constant value regardless of the first predetermined amount. When the first predetermined amount is smaller than the first predetermined amount threshold value, the second predetermined amount is larger than the constant value.