Cap Assembly Ejector Mechanism for Drug Delivery Needle Safety
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Solution Overview
Problem
Drug delivery devices, particularly pen-type injectors, face challenges in user safety and ease of use, especially for physically infirm or visually impaired individuals, due to the risk of needlestick injuries during assembly and disassembly of needle assemblies, which complicates the process and increases production costs.
Innovation Solution
A cap assembly with an ejector unit that allows for the safe and easy assembly and disassembly of needle assemblies from the cartridge holder, featuring a cylindrical cap body with a receptacle for the needle assembly, a radially inwardly protruding pin, and a circumferential groove for snap-fit engagement, reducing direct contact with the needle and enabling secure attachment and detachment without requiring manual handling of the needle hub.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a removable needle assembly is used to enable easy needle replacement, then ease of operation is improved, but the risk of needlestick injuries increases due to manual handling of the needle hub
Solution Approach 1:
The cap assembly serves as an intermediary tool between the user and the needle assembly. It provides a protected interface for attaching and detaching the needle hub from the cartridge holder, eliminating the need for direct manual handling of the needle hub while enabling easy needle replacement.
Solution Approach 2:
The cap assembly is designed to perform the assembly and disassembly operations automatically through its mechanical structure. The user simply needs to attach the cap assembly to the cartridge holder, and the needle assembly is automatically secured or released without requiring manual manipulation of the needle hub.
2Ease of operation
If the needle assembly is easily detachable to simplify disposal, then ease of operation is improved, but reliability decreases due to potential misalignment or incomplete detachment
Solution Approach 1:
The needle assembly is extracted from the cartridge holder through the cap assembly mechanism. The cap assembly provides a controlled extraction path that ensures complete detachment while maintaining ease of operation. The needle hub is fully removed from the cartridge holder through the cap's internal structure.
Solution Approach 2:
The cap assembly is pre-configured with the necessary mechanical features (such as alignment guides and release mechanisms) that enable reliable detachment before the user performs the operation. The structure is designed in advance to ensure proper alignment and complete separation of the needle assembly from the cartridge holder.
3Adaptability or versatility
If multiple separate components are used for needle assembly and protection, then adaptability is improved, but device complexity increases
Solution Approach 1:
The cap assembly merges multiple functions into a single integrated component: it provides protection for the needle hub, serves as a tool for attaching the needle assembly to the cartridge holder, and acts as a tool for detaching the needle assembly. This consolidation reduces the number of separate parts while maintaining adaptability.
Solution Approach 2:
The cap assembly is designed as a universal component that performs multiple functions: protection during storage and transport, assembly assistance when attaching the needle hub, and disassembly assistance when removing the needle hub. This multi-functionality eliminates the need for separate specialized components.
Data Source
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AI summary
Cartridge holder assembly for Drug Delivery Devices The present invention relates to a cap assembly for a drug delivery device, comprising: a cap body (12) adapted to releasably engage with a housing (46) of the drug delivery device and being further adapted to receive a needle assembly (40) to be releasably interconnected with said housing (46), an ejector unit (14) movably arranged on the cap body (12) at least along the body's long axis and having mechanical transmission means (18) adapted to transfer axial movement of the ejector unit (14) to the needle assembly (40) for ejecting the needle assembly (40) from the cap body (12).