Autoanalyzer Probe Speed Control for Sample Dispensing Precision

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Solution Overview

Problem

In autoanalyzers, the precision of sample dispensing deteriorates when the same sample is dispensed multiple times due to air layer thinning and pressure transmission medium dilution, leading to reduced accuracy and contamination risks.

Innovation Solution

The autoanalyzer controls the probe's elevation speed during sample dispensing, allowing it to enter the sample container at a slower speed in subsequent dispensing operations, reducing shock and preventing air layer thinning, and allocates operation time to ensure precise dispensing of the same sample multiple times.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the sample dispensing probe enters the sample container at high speed for rapid dispensing operations, then the productivity is improved, but the air layer is thinned and the pressure transmission medium mixes with the dummy examined sample, causing deterioration in measurement precision

Engineering Contradiction:
Improvedispensing operation speedVSAvoidsample dispensing precision
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The probe elevation speed is made variable rather than constant. The control unit adjusts the elevation speed based on the dispensing operation number - using higher speeds for initial operations and reducing speed for subsequent operations to prevent air layer thinning and maintain measurement precision while preserving overall productivity

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The elevation speed parameter is changed dynamically based on the dispensing operation count. The control unit modifies the probe elevation speed parameter - reducing it from the first dispensing operation onwards to prevent shock and maintain the air layer, thereby preventing pressure transmission medium dilution while keeping the system efficient

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If the probe elevation speed is reduced to prevent air layer thinning and maintain precision, then the measurement precision is improved, but the analysis cycle time increases

Engineering Contradiction:
Improvesample dispensing precisionVSAvoidanalysis cycle time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system dynamically adjusts probe elevation speed based on the dispensing operation number. The control unit implements different speed profiles for first versus subsequent operations, reducing speed only when necessary to prevent air layer thinning, thereby maintaining precision without unnecessarily extending the entire analysis cycle

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system performs preliminary high-speed dispensing operations when the air layer is still intact, and only reduces speed when the air layer becomes thin during repeated operations. This preliminary action approach maximizes productivity during stable conditions while preventing precision deterioration only when needed

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 enhances the precision and reduces contamination risks during multiple dispensing operations of the same sample, maintaining high accuracy and preventing sample mix-ups.

Implementation Method 1

the sample dispensing probe sucks the examined sample in a sample container via a pressure transmission medium such as water inserted in the sample dispensing probe

Methodology Applied
Scientific EffectPressure transmission medium: Pressure Gradient

Implementation Method 2

a liquid surface of the examined sample is detected by a detector when the sample dispensing probe enters the examined sample in the sample container

Methodology Applied
Scientific EffectLight detection: Absorption Spectroscopy

Data Source

PatentEP1978367B1Autoanalyzer and method of up-and-down moving of probe
Publication Date: 2019.06.26 TOSHIBA MEDICAL SYST CORP
  • EP1978367B1 patent drawingFigure 1
  • EP1978367B1 patent drawingFigure 2
  • EP1978367B1 patent drawingFigure 3~4

AI summary

An autoanalyzer includes a measurement unit (20) which measures a reaction liquid produced by an interaction between a reagent and an examined sample contained in a reaction container, a sample probe (9) which sucks the examined sample from a sample container and discharges the examined sample to the reaction container, a probe elevating arm (10) which elevates the sample probe with respect to the sample container, and a control unit (32) which controls the probe elevating arm so that a speed at which the sample probe enters a liquid surface of the examined sample to perform an n-th suction operation (n ≥ 2) of the examined sample is slower than a speed at which the sample probe enters the liquid surface of the examined sample to perform a first suction operation of the examined sample.