Probe Wear Checking for Accurate Liquid Dispensing
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Solution Overview
Problem
Existing dispensing devices fail to ensure accurate dispensing when using probes that have worn tips, leading to reduced accuracy due to variations in probe contact with reaction vessels during specimen ejection.
Innovation Solution
A dispensing device equipped with a probe, sensor, and drive unit that measures the change in probe length by detecting contact with a reference surface, allowing for timely replacement and adjustment of the probe's lowering amount to maintain accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the probe is repeatedly used to penetrate the plug of the sealed specimen container, then the penetration performance is maintained, but the probe length shortens and dispensing accuracy deteriorates
Solution Approach 1:
The system performs preliminary measurement of the probe length before dispensing operations. By measuring the probe length in advance using a sensor that detects the position where the probe tip contacts the reaction vessel bottom, the system can calculate the required lowering amount to compensate for probe wear, thereby maintaining dispensing accuracy throughout the probe's service life
Solution Approach 2:
The system dynamically adjusts the lowering amount parameter of the probe based on measured length changes. By changing the lowering amount parameter according to the actual probe length (which decreases with wear), the system ensures that the probe tip consistently reaches the correct position for accurate dispensing despite probe degradation
2Ease of operation
If the probe lowering amount is not adjusted for wear, then the operation is simple, but the dispensing accuracy varies due to probe length shortening
Solution Approach 1:
The system performs self-measurement of the probe length automatically without requiring manual intervention. The sensor autonomously detects the probe tip position by detecting light blockage when the probe contacts the reaction vessel bottom, and the control unit automatically calculates and applies the compensation amount, making the system self-adjusting while maintaining operational simplicity
Solution Approach 2:
The system implements a feedback mechanism where the measured probe length information is fed back to the control unit, which then adjusts the lowering amount parameter accordingly. This closed-loop feedback ensures that dispensing accuracy is maintained throughout the probe's usage life without complex manual adjustments
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
The solution enables accurate probe replacement timing and maintains dispensing precision by correcting the probe's lowering amount based on wear, ensuring consistent specimen delivery.
Implementation Method 1
a sensor configured to detect contact of a tip of the probe
Data Source
AI summary
An object of the invention is to provide a dispensing device and a probe state checking method capable of grasping an appropriate replacement time of a probe while reducing a decrease in dispensing accuracy. Therefore, according to the invention, in a dispensing device including: a probe configured to aspirate and eject a liquid; a sensor configured to detect contact of a tip of the probe; a drive unit configured to drive the probe in an up-down direction; and a control unit configured to control the drive unit, the control unit performs a checking operation of checking a change in a length of the probe by lowering the probe by the drive unit until contact with a predetermined reference surface forming a part of the dispensing device is detected.