Syringe Plunger Barrel Discontinuous Thread Volume Control
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Solution Overview
Problem
Conventional syringes lack a mechanism for precise control over fluid volume transfer and dosage, particularly in transitioning between engaged and disengaged configurations, which affects the accuracy and ease of use in medical procedures.
Innovation Solution
The syringe design incorporates a plunger and barrel with discontinuous threads, allowing for rotational engagement and disengagement, providing tactile feedback and controlled fluid transfer by adjusting the pitch and arc length of thread features, enabling precise volume adjustments and improved user interaction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional syringes use continuous threads for plunger engagement, then the syringe structure is simple, but the control over fluid volume transfer and dosage precision is insufficient
Solution Approach 1:
The continuous thread is segmented into discontinuous thread features with gaps, allowing the plunger to be engaged or disengaged from the barrel at specific positions. This segmentation enables precise control over fluid volume transfer by allowing the operator to select specific engagement positions corresponding to different volume markings, thereby improving dosage precision without requiring complex adjustment mechanisms.
Solution Approach 2:
The thread structure transitions from a fixed continuous engagement to a dynamic engaged/disengaged state. The discontinuous threads allow the plunger to switch between being mechanically coupled to the barrel (engaged) and being separable (disengaged), providing dynamic control over the fluid transfer process and enabling precise dosage selection.
2Ease of operation
If the plunger is continuously engaged with the barrel, then fluid transfer is controlled, but the ease of adjusting volume and transitioning between configurations is reduced
Solution Approach 1:
The discontinuous thread features create distinct engaged and disengaged positions, allowing the operator to easily transition between volume configurations by simply rotating the plunger to different engagement positions. The gaps in the threads facilitate easy disengagement and re-engagement at different volume markings, improving operational ease while maintaining fluid seal reliability when engaged.
3Measurement precision
If discontinuous threads are used for precise volume control, then dosage precision is improved, but the force required to translate the plunger increases in engaged configuration
Solution Approach 1:
The discontinuous thread features are designed with specific pitch and arc length parameters that optimize the balance between engagement strength and translation force. The segmented structure allows for precise volume measurement through controlled engagement positions while the gap design reduces the cumulative friction and mechanical resistance compared to continuous threads, thereby managing the force required for plunger translation.
4Ease of operation
If the thread features have larger pitch and arc length, then the ease of rotation and volume adjustment is improved, but the precision of volume control is reduced
Solution Approach 1:
The thread features are designed with optimized pitch and arc length parameters that balance rotation ease with volume control precision. By carefully selecting these geometric parameters, the design allows for smooth rotational adjustment while maintaining sufficient resolution for precise volume measurement, resolving the trade-off between operational ease and measurement precision.
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 design enhances the precision and user experience by allowing controlled fluid transfer and dosage, providing audible and tactile feedback, and ensuring accurate volume measurements during medical procedures.
Implementation Method 1
The plunger can have a plunger thread face that can include a discontinuous external thread. The barrel and/or the barrel nut can have a barrel thread face that can include a discontinuous internal thread.
Data Source
AI summary
A syringe is disclosed. The syringe comprises a plunger and a barrel. The plunger can be rotated relative to the barrel to lock, unlock and/or translate the components relative to each other.