Medication Pen Needle Shield with Interlocking Projections
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Solution Overview
Problem
Existing needle safety devices for medication delivery pens are complex, expensive, and prone to failure, and often lack patient visual confirmation of needle priming before use.
Innovation Solution
A manually-actuatable shield mechanism is introduced, which is axially displaceable and locks into a safety position to enclose the used needle, featuring projections on the hub and tubular portion that interengage to prevent unintended movement, allowing for easy removal and disposal while minimizing needle stick risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a complex shielding mechanism with multiple parts is used, then needle protection is improved, but device complexity and cost increase
Solution Approach 1:
The shield is integrated with the hub as a single unit, eliminating the need for separate shielding components. The shield forms an integral part of the hub structure, reducing part count while maintaining protective function. This merging approach resolves the contradiction by providing reliable needle protection without increasing device complexity.
Solution Approach 2:
The shield automatically performs protective function through its integrated design with the hub. The shield's structure allows it to self-engage and self-lock without requiring additional actuating mechanisms or external components. This self-service capability provides reliable protection while minimizing device complexity.
2Loss of information
If a manually-actuatable shield is used, then patient visual confirmation of needle priming is improved, but ease of operation may be reduced
Solution Approach 1:
The shield is designed to be manually movable between retracted and extended positions, allowing dynamic adjustment based on operational needs. During priming, the shield can be retracted to allow visual confirmation. During disposal, it extends to provide protection. This dynamic design resolves the contradiction by providing visual confirmation when needed while maintaining ease of operation through simple manual actuation.
Solution Approach 2:
The shield is pre-positioned in a retracted state during priming to allow visual confirmation before injection. This preliminary positioning ensures patients can observe needle priming. After priming, the shield can be extended for protection during disposal. This preliminary action resolves the contradiction by ensuring visual confirmation is available when most critical.
3Reliability
If a shield with locking mechanism is used, then reliability of needle enclosure is improved, but device complexity increases
Solution Approach 1:
The locking mechanism is integrated into the shield-hub assembly and operates automatically through the relative movement between components. The interengaging projections and recesses create self-locking action when the shield is extended, providing reliable needle enclosure without requiring separate locking components or complex actuation mechanisms. This self-service locking resolves the contradiction by ensuring reliable enclosure while minimizing device complexity.
Solution Approach 2:
The locking mechanism is merged with the shield and hub structures themselves. The projections on the shield and corresponding recesses in the hub form an integrated locking system that arises from the basic components rather than being added as separate elements. This merging approach provides reliable needle enclosure while avoiding additional device complexity.
4Device complexity
If a simple shield design is used, then device complexity is reduced, but reliability of needle protection may be compromised
Solution Approach 1:
The shield is formed as an integral part of the hub structure, eliminating the need for separate shielding components. This merging provides reliable needle protection through the unified structure while minimizing device complexity by reducing part count. The integrated design ensures the shield cannot be easily separated from the hub, providing reliable protection.
Solution Approach 2:
The integrated shield-hub structure provides self-locking through interengaging features built into the basic components. This self-service mechanism ensures reliable needle protection without requiring additional complex components. The simple yet effective design resolves the contradiction by providing reliable protection through intelligent integration rather than additional complexity.
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 solution provides a cost-effective, reliable, and user-friendly mechanism for safely enclosing the needle after use, reducing the risk of inadvertent skin penetration and allowing for easy needle changes, while maintaining visual confirmation of priming.
Implementation Method 1
the at least one projection on the hub is deflectibly urged passed the at least one projection on the tubular portion
Data Source
AI summary
A medication delivery pen assembly having a pen body and a needle assembly with a hub connected to the pen body, a needle cannula extending through the hub with a distal end sharpened for insertion into a patient, and a shield having a tubular portion telescopingly disposed about at least a portion of the hub. The tubular portion includes an internal surface, at least one projection extending inwardly from the internal surface, and the hub having at least one externally extending projection. The shield is axially displaceable relatively along the hub distally from a first position, where the distal end of the needle cannula is exposed, to a second position, where the distal end of the needle cannula is enclosed by the shield. Upon the shield being displaced to the second position, the at least one projection on the hub is deflectibly urged passed the at least one projection on the tubular portion so that subsequent distal-to-proximal movement of the shield relative to the hub is hindered by interengagement of the projections. The needle cannula may be directly affixed to the pen body with the hub being formed unitarily with, rigidly affixed to, or removably affixed to the pen body.