Vacuum Connection for Drug Delivery Device Needle Retraction
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Solution Overview
Problem
Existing drug delivery devices, particularly safety syringes with retractable needles, face challenges in mechanically connecting the plunger and needle assembly without complex snap-lock mechanisms, which complicate the retraction process and increase the risk of injury.
Innovation Solution
A drug delivery device utilizing a vacuum connection between the proximal end of the needle assembly and the distal end of the plunger, where flexible and deformable connecting elements form a strong vacuum seal without the need for snap mechanisms, allowing for efficient retraction of the needle into the body unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a snap-lock mechanism is used to connect the plunger and needle assembly, then the mechanical connection strength is improved, but the device complexity increases
Solution Approach 1:
The patent replaces the mechanical snap-lock connection system with a vacuum-based connection system. The plunger and needle assembly are connected through vacuum pressure differential rather than mechanical interlocking, thereby eliminating the complexity of snap mechanisms while maintaining connection strength.
Solution Approach 2:
The patent employs vacuum pressure (pneumatic principle) to create the connection between the plunger and needle assembly. By establishing a pressure differential through vacuum, the system achieves reliable mechanical connection without requiring complex snap-lock structures.
2Reliability
If a key-lock principle is formed on the inner sides of the plunger and needle assembly, then the connection reliability is improved, but the ease of manufacture deteriorates
Solution Approach 1:
The patent substitutes the key-lock mechanical principle with a vacuum connection system. Instead of forming complex key-lock features on the inner surfaces of the plunger and needle assembly, the invention uses vacuum pressure to create a reliable connection, significantly simplifying the manufacturing process.
3Object-affected harmful factors
If a retractable needle mechanism is implemented, then the user safety is improved, but the device complexity increases
Solution Approach 1:
The patent replaces complex mechanical retraction mechanisms with a vacuum-based retraction system. The needle assembly is retracted into the body unit by utilizing vacuum pressure differential, eliminating the need for complex springs, latches, or motorized mechanisms while maintaining effective needle retraction for user safety.
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 vacuum connection enables safe and efficient retraction of the needle assembly into the body unit, reducing the risk of injury and simplifying the design by eliminating complex mechanical connections, thus enhancing user safety and device usability.
Implementation Method 1
the proximal end of the needle assembly and the distal end of the plunger are configured such that they can get into a vacuum connection
Data Source
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Figure 3a~3b
Figure 4a~4b
AI summary
Drug delivery device, comprising a body unit having a first opening and a second opening, a plunger arranged such that its distal end is positioned inside the body unit, wherein the plunger is moveable in the distal direction with respect to the body unit, a needle assembly, with a proximal end and a distal end comprising a needle, wherein the proximal end of the needle assembly and the distal end of the plunger are configured such that they can get into a vacuum connection.