Dispensing Syringe Correction for Probe Height Variations
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Solution Overview
Problem
Automatic analyzers face inaccuracies in sample and reagent dispensing due to variations in liquid level heights within containers, leading to differences in aspiration heights and subsequent discharge quantities, which affect measurement reliability, especially in trace amounts.
Innovation Solution
The implementation of a correction data calculation method that adjusts the dispensing syringe operation based on the calculated difference in equivalent air volume and sample-aspirating probe height, ensuring consistent discharge quantities regardless of container configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If the amount of sample dispensed is decreased to save reagent consumption, then reagent consumption is reduced, but dispensing accuracy deteriorates
Solution Approach 1:
The patent changes the parameter of dispensing volume to trace amounts (nanoliter scale) while implementing compensation mechanisms. The system uses correction data calculation based on equivalent air volume differences to maintain accuracy even when dispensing extremely small amounts of reagent, thus resolving the contradiction between reduced reagent consumption and maintained dispensing accuracy
Solution Approach 2:
The patent implements a feedback mechanism where the actual dispensing amount is measured and compared with the target amount, and correction data is calculated based on the difference. This feedback loop allows the system to compensate for variations in dispensing accuracy even when dispensing trace amounts, thereby maintaining reliability while reducing reagent consumption
2Ease of operation
If the liquid level sensing function is used to control probe stopping position, then probe tip cleaning is facilitated, but discharge quantity varies due to aspiration height differences
Solution Approach 1:
The patent introduces an intermediary correction data calculation mechanism that mediates between the liquid level sensing function and the discharge quantity. The system calculates correction data based on equivalent air volume differences caused by varying aspiration heights, and applies this correction to compensate for discharge quantity variations, thus resolving the contradiction between ease of probe cleaning and discharge quantity consistency
Solution Approach 2:
The patent performs preliminary action by calculating correction data in advance based on the relationship between aspiration height and discharge quantity. This pre-calculated correction data is then applied during actual dispensing operations to ensure consistent discharge quantities regardless of variations in probe stopping positions, thereby resolving the contradiction between probe cleaning ease and discharge consistency
Data Source
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AI summary
This invention provides an automatic analyzer adapted to enhance sample/reagent dispensing accuracy, regardless of a difference in sample/reagent dispensing height of a dispensing probe. When the amount of sample in a sample container is small, tip height "h1" of a sample dispensing probe 17 positioned immediately after it has aspirated the sample decreases below tip height "h'" of the sample dispensing probe 17 positioned immediately before it discharges the sample. The sample in this state takes a concave shape at the tip of the sample dispensing probe 17 positioned immediately before it discharges the sample. When the amount of sample in a sample container is large, tip height "h2" of the sample dispensing probe 17 positioned immediately after it has aspirated the sample increases above the tip height "h'" and the sample takes a convex shape at the tip of the sample dispensing probe 17 positioned immediately before it discharges the sample. The difference in the sample-aspirating tip height of the sample dispensing probe 17 appears as a difference in a discharge quantity of the sample. Highly accurate and highly reliable data measurements can be performed by detecting the sample-aspirating tip height of the sample dispensing probe 17 and correcting a discharge quantity of the sample appropriately as the amount of driving of a fixed-volume dispensing syringe 25, according to the detected tip height.