Auto Injector Needle Shielding Mechanism
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Solution Overview
Problem
Existing auto injectors either require complex manual operations for needle shielding and medicament delivery or are difficult to manufacture, lacking a user-friendly and automated sequence for medicament delivery with proper needle protection before and after use.
Innovation Solution
An auto injector with a housing that includes a needle mounting site, a movable needle shield, and a driver mechanism to automate the needle shielding process, ensuring the needle is protected during mounting, use, and disposal, with a locking mechanism to prevent accidental exposure and facilitate easy manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If manual operations are used for needle shielding and medicament delivery, then device complexity is reduced, but ease of operation deteriorates due to complex manual steps required
Solution Approach 1:
The needle shield is pre-positioned in a retracted locked position before needle mounting. The locking mechanism is pre-configured to automatically release upon needle insertion, eliminating the need for manual shielding operations and automating the protection sequence before use.
Solution Approach 2:
The device performs automatic needle shielding through self-contained mechanisms. The needle shield driver automatically advances the shield to cover the needle after injection, and the locking mechanism automatically engages and disengages based on operational state, reducing manual intervention requirements.
2Ease of operation
If automated needle shielding is implemented, then ease of operation improves, but device complexity increases due to additional mechanisms
Solution Approach 1:
The locking mechanism and needle shield driver are integrated into a unified system. The driver is anchored to the fixed part of the housing and connects to the needle shield, combining the shielding function with the structural framework rather than adding separate independent mechanisms.
Solution Approach 2:
The needle shield serves multiple functions: it protects the needle before injection, covers the needle after injection, and works in conjunction with the locking mechanism to prevent accidental exposure. The locking mechanism both secures the shield in retracted position and releases it automatically during operation.
3Reliability
If needle shield is kept in retracted position during mounting, then ease of operation improves, but safety deteriorates due to risk of inadvertent needle contact
Solution Approach 1:
The locking mechanism prevents the needle shield from moving forward during needle mounting by maintaining it in the retracted locked position. This preliminary protective action ensures the needle remains covered and inaccessible during the vulnerable mounting phase, preventing accidental contact before the device is ready for use.
Solution Approach 2:
The needle shield is pre-positioned in a protected retracted state with automatic locking before needle mounting occurs. This preliminary protective configuration ensures safety during the mounting operation without requiring manual intervention to maintain the protective state.
4Ease of operation
If needle shield is automatically advanced after injection, then ease of operation improves, but device complexity increases due to automated sequencing mechanisms
Solution Approach 1:
The needle shield driver is pre-configured to automatically advance the needle shield to cover the needle after injection. The driver mechanism is anchored to the fixed part of the housing and connected to the needle shield, creating a self-actuating system that performs the shielding action without manual intervention following the injection process.
Data Source
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AI summary
The present invention relates to an auto injector, e.g. a disposable auto injector, that can be safely operated for automatic injection of a dose of medication by the recipient of the medication, having a housing for accommodation of a container with at least one compartment for accommodation of a medicament to be injected and a needle mounting site for user mounting of a needle covered by a needle cap before injection, and a needle shield that is accommodated in the housing in a retracted position before mounting of the needle and that is configured to be automatically moved forward to a protruded position by a needle shield driver upon mounting of the needle and removal of the needle cap.