Pre-filled Syringe Safety Device with Deflectable Arm Guide
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Solution Overview
Problem
Existing safety devices for pre-filled syringes often require multiple components and user effort to activate needle safety, which can lead to accidental needle pricks and discomfort during injections, especially for self-administered injections.
Innovation Solution
A safety device with a hollow support body and a slidable needle shield guided by a deflectable flexible arm and guide pin within a guide track, allowing for automatic needle protection without the need for user activation, minimizing friction and part count for cost-effective, single-use disposable solutions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a manual needle shield operation is used, then the device structure can be simple, but the risk of accidental needle pricks increases and user comfort deteriorates
Solution Approach 1:
The needle shield automatically moves to cover the needle after injection without requiring manual operation. The spring mechanism and guide track enable the shield to self-activate, eliminating the need for user effort while maintaining safety and comfort
Solution Approach 2:
The needle shield is pre-positioned to cover the needle before injection. The automatic retraction mechanism is pre-configured with spring force and guide track geometry to ensure the shield returns to cover the needle immediately after injection, preventing accidental pricks
2Extent of automation
If multiple components are used in the safety device, then the automation of needle protection can be improved, but the device complexity increases
Solution Approach 1:
The guide pin and flexible arm are integrated into a single deflectable component. This merging reduces the number of separate parts while maintaining the automatic guidance function that enables automated needle protection
Solution Approach 2:
The deflectable flexible arm with guide pin serves multiple functions: it guides the needle shield movement, provides friction compensation through deflection, and enables automatic activation. This multi-functionality reduces overall device complexity while maintaining automation
3Ease of operation
If external parts rotate during injection, then the needle shield can be guided, but friction with the patient's skin increases causing discomfort or pain
Solution Approach 1:
The guidance function is separated from the external rotating parts. The guide pin moves within the guide track along the central axis, decoupling the guidance mechanism from any rotational movement of external components that would contact the patient's skin
Solution Approach 2:
The guide pin acts as an intermediary element that transfers the guidance function internally. It moves within the guide track to control needle shield position without requiring external parts to rotate or contact the patient's skin, eliminating friction-induced discomfort
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 safe and convenient needle protection during and after injections, reducing the risk of accidental needle sticks and material fatigue, while ensuring easy use and extended shelf-life, suitable for both self-administered and healthcare professional use.
Implementation Method 1
The deflectable flexible arm extends essentially parallel to a central axis of the safety device... As the flexible arm is deflectable in a lateral direction, a relative rotation of any external parts like the needle shield and the support body is unnecessary to guide the guide pin along the guide track
Implementation Method 2
The guide pin is moved within and along the guide track when the needle shield is slid relative to the support body... friction between these rotating external parts and the skin of the patient is uncomfortable and may even cause pain to the patient
Data Source
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AI summary
A safety device (1) for a pre-filled syringe (2) comprises a hollow support body (1.2) to retain the pre-filled syringe (2) therein, a hollow needle shield (1.1) that is slidable relative to the support body (1.2) and guiding means for guiding the movement of the needle shield (1.1.) relative to the support body (1.2). The guiding means comprise a deflectable flexible arm (1.1.4), a guide pin (1.1.3) and a guide track (1.2.2). The deflectable flexible arm extends essentially parallel to a central axis (A) of the safety device (1). The guide pin (1.1.3) extends radial from the flexible arm (1.1.4). The guide track (1.2.2) guides the guide pin (1.1.3) within and along the guide track (1.2.2) when the needle shield (1.1) is slid relative to the support body (1.2).