Pre-filled Syringe with Air Bubble Discharge Grooves
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional pre-filled syringes face challenges in easily expelling air bubbles during injection and can experience uneven dissolution of medicines when shaken, leading to discomfort and inefficiency in medicine delivery.
Innovation Solution
A pre-filled syringe design featuring a barrel partitioned by gaskets with a nozzle part that includes a concave liquid flow passage with a widening width, allowing for easy air bubble expulsion and preventing uneven dissolution through a spiral communication passage between chambers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the front end stopper and base end stopper have smooth faces perpendicular to the axis of the tubular body, then the structure is simple and easy to manufacture, but air bubbles remaining in the liquid medicine are difficult to expel to the outside
Solution Approach 1:
The stopper faces are made smooth in most areas for ease of manufacture, but air bubble discharge grooves are locally formed at specific positions (front end and rear end of the stopper face) to enable air bubble expulsion. This local modification maintains manufacturing simplicity while solving the air bubble problem.
Solution Approach 2:
Instead of making the stopper face completely smooth and relying on other mechanisms for air bubble expulsion, the invention inverts the approach by directly forming discharge grooves on the stopper face itself, making the stopper surface the active element for air bubble discharge.
2Volume of stationary object
If the inner diameter of the tubular body is increased to provide larger storage capacity, then the storage capacity is improved, but air bubbles are even more difficult to expel from the injection needle
Solution Approach 1:
The discharge grooves are positioned at the front end and rear end of the stopper face, creating localized air escape pathways that are effective regardless of the overall tubular body size. This allows large capacity syringes to still effectively discharge air bubbles.
Solution Approach 2:
The discharge grooves extend in the radial direction from the stopper face, creating a three-dimensional air escape path that allows air bubbles to be discharged from multiple positions and angles, making the discharge mechanism effective independent of the tubular body's inner diameter.
3Stability of the object's composition
If the pre-filled syringe is designed as a two-chamber type with partition by intermediate gasket, then the stability during conservation is improved, but uneven dissolution of medicine occurs when shaken
Solution Approach 1:
The intermediate gasket provides a stable partition structure during conservation, while the bypass structure creates localized communication pathways that enable uniform mixing when shaken, resolving the contradiction between stability and dissolution uniformity.
Solution Approach 2:
The system transitions from a static sealed two-chamber structure during storage to a dynamic connected structure during use. The bypass allows the two chambers to communicate when pressure changes occur during shaking, enabling uniform dissolution while maintaining separation during storage.
4Manufacturing precision
If the liquid flow passage has a narrow opening to maintain precision, then the injection precision is improved, but air bubbles adhere to the stopper face and are difficult to expel
Solution Approach 1:
The liquid flow passage is segmented into two distinct parts: a narrow opening for precise injection control and wider discharge grooves for effective air bubble expulsion. This segmentation allows each function to be optimized independently without compromise.
Solution Approach 2:
Different regions of the flow passage have different dimensional characteristics - the main injection opening remains narrow for precision, while the discharge grooves provide wider pathways specifically for air bubble removal, allowing both functions to coexist.
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
Facilitates the easy discharge of air bubbles during injection without compromising convenience or storage stability, ensuring uniform dissolution of medicines and smooth operation even with larger inner diameters.
Implementation Method 1
a concave liquid flow passage with a widening width, through which a liquid medicine can pass
Implementation Method 2
a barrel whose front end and base end are open, a base end gasket in a base end side in the barrel and fluid-tightly slidable in the barrel, a front end gasket in a front end side in the barrel
Implementation Method 3
preventing uneven dissolution through a spiral communication passage between chambers
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A pre-filled syringe including a barrel (1), a base end gasket (4) which is fluid-tightly slidable in the barrel (1), a front end gasket (8) which is fluid-tightly slidable in the barrel (1), and a nozzle part (2) provided in a front end of the barrel (1), wherein the nozzle part (2) includes a front end gasket accommodation part (23) which is capable of accommodating the front end gasket (8), and a liquid flow passage (21) extending in an axial direction in an inner periphery wall, through which a liquid medicine can pass when the front end gasket (23) is accommodated in the front end gasket accommodation part (23), and a sectional area of a front end of the liquid flow passage (21) is smaller than a sectional area of a base end.