Automatic Analyzer Aspiration Control for Small-Sample Fault Detection

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Solution Overview

Problem

Existing automatic analyzers struggle to accurately detect abnormalities during aspiration when the amount of sample used for analysis is small, leading to potential erroneous detections due to small differences in pressure sensor outputs.

Innovation Solution

The automatic analyzer includes a dispensing unit that aspirates a sample in a third predetermined amount greater than the first predetermined amount used for analysis, discharges a second predetermined amount to a different site, and then discharges the first predetermined amount to a reaction vessel, with a detection unit to analyze pressure waveforms for faulty aspiration and clogging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If the amount of sample used for analysis is small, then reagent consumption is reduced, but the difference between pressure sensor outputs becomes small leading to erroneous detection

Engineering Contradiction:

Improvereagent consumptionVSAvoidabnormality detection accuracy

Core Design Contradiction:

Loss of substanceVSMeasurement precision

Solution Approach 1:

The system performs a preliminary aspiration of a third predetermined amount (greater than the first predetermined amount) before the actual analysis. This preliminary action provides sufficient pressure waveform data for accurate abnormality detection while the excess sample is subsequently discharged to a predetermined site different from the sample vessel, ensuring the analysis uses only the required first predetermined amount.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The aspiration process is divided into multiple segments: first aspirating a third predetermined amount for abnormality detection, then discharging a second predetermined amount to a predetermined site different from the sample vessel, and finally discharging the first predetermined amount to the reaction vessel for analysis. This segmentation allows the detection phase to use a larger volume for accurate pressure waveform analysis while the analysis phase uses only the minimal required volume.

Inventive Principle:

Principle #1Segmentation

2Measurement precision

If the threshold for abnormality detection is changed based on the amount of liquid aspirated, then detection accuracy improves for different volumes, but device complexity increases

Engineering Contradiction:

Improveabnormality detection accuracyVSAvoidcontrol system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

Instead of changing the threshold based on aspirated volume, the system changes the aspiration volume parameter itself. By aspirating a third predetermined amount (larger than the first predetermined amount) for detection purposes, the pressure waveform difference becomes sufficiently large to use a fixed threshold for abnormality detection, avoiding the need for dynamic threshold adjustment.

Inventive Principle:

Principle #35Parameter changes

3Measurement precision

If a larger amount of sample is aspirated for abnormality detection, then detection accuracy improves, but reagent consumption increases

Engineering Contradiction:

Improveabnormality detection accuracyVSAvoidreagent consumption

Core Design Contradiction:

Measurement precisionVSLoss of substance

Solution Approach 1:

The system extracts the abnormality detection function from the sample destined for analysis. By discharging the second predetermined amount to a predetermined site different from the sample vessel (such as a waste container), the system separates the detection sample from the analysis sample, ensuring that only the minimal first predetermined amount is consumed for actual analysis while sufficient volume is available for detection.

Inventive Principle:

Principle #2Taking out (Extraction)

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 detection of abnormalities during aspiration, even with small sample amounts, reducing erroneous detections and reagent consumption by canceling plans to dispense samples with abnormalities.

Implementation Method 1

a detection unit that detects a pressure waveform in the dispensing unit

Methodology Applied

Scientific EffectPressure sensor detection:

Data Source

PatentEP4718077A1Automated analysis device and analysis method therefor

Publication Date: 2026.04.01 HITACHI HIGH TECH CORP

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AI summary

There is provided an automatic analyzer that is capable of highly accurately detecting an abnormality at the time of aspiration even though the amount of a sample used for analysis is small. An automatic analyzer according to the present invention includes: a dispensing unit that aspirates a sample from a sample vessel that houses the sample; a control unit that controls the dispensing unit such that the dispensing unit aspirates the sample in a third predetermined amount greater than a first predetermined amount that is an amount of the sample used for analysis, the dispensing unit discharges the sample in a second predetermined amount to a predetermined site different from the sample vessel, and the dispensing unit discharges the sample in the first predetermined amount to a reaction vessel used for analysis; a detection unit that detects a pressure waveform in the dispensing unit; and a determining unit that determines faulty aspiration and/or clogging, based on a first waveform that is the pressure waveform when the dispensing unit aspirates the sample, the faulty aspiration being in a state in which the dispensing unit insufficiently aspirates the sample, the clogging being a state in which the sample is clogged in the dispensing unit.