Syringe Piston Seal Width Matching for Blood Volume Precision
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Solution Overview
Problem
Current syringes lack visual differentiation between general volume indicators and recommended volume indicators, leading to uncertainty in aligning the piston seal, which can result in imprecise blood volumes and affect the accuracy of subsequent analysis procedures.
Innovation Solution
A syringe design featuring distinct visual indicators on the housing and piston, with the first visual indicator matching the width of the piston seal to provide clear optical feedback on aligning the piston for the recommended blood volume, ensuring precise blood aspiration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If all volume indicators are made with the same thin width to convey precision, then manufacturing precision is maintained, but ease of operation deteriorates because users cannot easily distinguish the recommended volume indicator
Solution Approach 1:
The patent applies local quality by making the first visual indicator (target volume indicator) have a different width than the additional visual indicators (general volume markers). Specifically, the first visual indicator has a greater width to make it stand out and easily distinguishable, while the additional indicators maintain a thinner profile. This localized differentiation resolves the contradiction by allowing visual distinction without requiring all indicators to be uniformly thick.
2Ease of manufacture
If volume indicators are made substantially different in thickness compared to the piston seal, then ease of manufacture is improved, but measurement precision deteriorates because users are uncertain how to align the piston seal with the volume indicator
Solution Approach 1:
The patent applies asymmetry by making the first visual indicator's width substantially equal to the piston seal's width, creating a symmetric visual relationship between these two elements. This symmetry provides a clear alignment reference for users - when the first visual indicator and piston seal are aligned, they appear as a continuous visual element. This resolves the measurement precision issue while maintaining manufacturing simplicity through the use of standard indicator widths.
3Measurement precision
If the first visual indicator has the same width as the piston seal, then measurement precision is improved by providing clear alignment reference, but device complexity increases due to additional width specification requirements
Solution Approach 1:
The patent applies local quality by applying the equal-width specification only to the first visual indicator and piston seal, while the additional visual indicators can have different widths. This localized application of the design principle provides clear alignment reference where needed without requiring complex specifications across all indicators, thus limiting the increase in device complexity.
Data Source
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AI summary
The present invention provides a syringe for obtaining a target volume of a liquid, in particular blood. The syringe provides a piston with a seal having a width that is identical to the volume line indicating the target full volume of the syringe. This offers a precise and an intuitive way for the end user to understand how much blood is recommended to be drawn from the patient. In exemplary embodiments these visual indicators have the same colour and a desired amount of interruptions of the line of the volume scale are provided.