Automatic Analyzer Bubble Detection Pressure Sensor Control
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Solution Overview
Problem
Existing automatic analyzers face challenges in accurately dispensing liquids like reagents and specimens due to bubble detection issues, leading to air suction and variations in dispensing amounts, which increases user workload and delays sample return without effectively reducing costs.
Innovation Solution
An automatic analyzer equipped with a pressure sensor to determine normal or abnormal suction, a cumulative count of air suction events, and a controller to manage the dispensing process, allowing continued suction until a predetermined allowable cumulative number is reached, then canceling requests and switching to the next sample, thereby reducing user burden and ensuring early sample return.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a liquid level detection mechanism is provided to detect contact of the nozzle with the liquid level, then the suction of the solution starts from below the liquid level preventing air suction, but bubbles on the solution surface are falsely detected as the liquid level causing air suction and variation in dispensing amount
Solution Approach 1:
The patent applies feedback by using a pressure sensor to detect pressure changes during suction and comparing them with reference data to determine whether air suction has occurred. This feedback mechanism allows the system to automatically detect bubble presence and adjust the suction process accordingly, resolving the contradiction between reliable liquid level detection and precise suction amount by continuously monitoring and adjusting based on actual suction conditions
Solution Approach 2:
The patent replaces the mechanical liquid level detection method with a pressure-based detection system. Instead of relying on mechanical contact detection that is susceptible to bubble interference, the system uses pressure sensors to detect pressure changes in the suction line, providing a more reliable and bubble-resistant method for determining liquid level and suction status
2Reliability
If the user checks bubbles manually before sample mounting, then air suction can be avoided, but user workload increases and samples with bubbles may still be processed in high-volume facilities
Solution Approach 1:
The patent implements self-service by enabling the system to automatically detect bubbles and manage the suction process without user intervention. The pressure sensor continuously monitors suction conditions, automatically identifies when bubbles are present, and controls the suction process to avoid air suction, freeing the user from manual bubble checking while maintaining high reliability
Solution Approach 2:
The system uses feedback from the pressure sensor to automatically adjust the suction process in real-time. When bubbles are detected through pressure changes, the system automatically modifies suction parameters or stops the process, eliminating the need for user intervention and maintaining consistent quality without increasing workload
3Reliability
If air suction abnormality is detected and the specimen is discharged for user checking, then bubble elimination can be performed, but throughput decreases and sample return is delayed
Solution Approach 1:
The patent applies partial action by implementing a cumulative count mechanism that allows a certain number of air suction abnormalities to be tolerated before discharging the sample. Instead of immediately discharging upon first detection, the system permits a predetermined cumulative number of occurrences, reducing unnecessary sample discharge and maintaining higher throughput while still ensuring quality through the cumulative monitoring approach
4Manufacturing precision
If the suction operation is repeated when bubbles are detected, then dispensing accuracy is improved, but the allowable cumulative number threshold may be too high causing unnecessary repetitions
Solution Approach 1:
The patent changes the parameter of tolerance by introducing a cumulative count threshold that dynamically determines when to repeat the suction operation. Instead of a fixed immediate rejection policy, the system adjusts its behavior based on the cumulative frequency of abnormalities, allowing flexibility in the balance between precision and efficiency without overly complex control logic
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 user efficiency, reduces workload, and prevents throughput reduction by re-executing suction operations with detected bubbles, ensuring quick user intervention when the cumulative air suction abnormality reaches a set limit without incurring additional costs.
Implementation Method 1
a pressure sensor that measures a change of an internal pressure of a probe provided at the liquid dispensing mechanism
Data Source
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AI summary
An automatic analyzer that can re-execute bubble detection even when bubbles are detected on a liquid level and that can reduce user's work burden without cost increase is realized. The automatic analyzer includes: a liquid dispensing mechanism 15 that performs suction of a liquid; a pressure sensor 26 that measures a change of an internal pressure of a probe provided at the liquid dispensing mechanism 15; a determination section 623 that determines whether the suction of the liquid by the probe 16 is normal suction or air suction abnormality; an analysis section; a storage section 624 that stores a cumulative number of times of air suction abnormality per liquid and an allowable cumulative number for the cumulative number of times of air suction abnormality; and a controller 60 that exercises operation control over the liquid dispensing mechanism 15, the determination section 623, and the analysis section. The controller exercises control such that the cumulative number of times of air suction abnormality is updated and the updated cumulative number is stored in the storage section 624 even if the air suction abnormality occurs unconsecutively in a course of an operation of the suction of the liquid by the probe 16 in response to the number of measurement items for the same liquid, such that the planned operation of the suction is continued until the updated cumulative number reaches the allowable cumulative number, and such that a planned request for the measurement item is cancelled and the operation of the suction is started at another liquid planned next when the updated cumulative number reaches the allowable cumulative number.