Syringe Safety Device with Rotating Collar and Spring Retraction
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Solution Overview
Problem
Existing safety devices for pre-filled syringes do not adequately prevent accidental needle stick injuries, particularly during and after injections, as they often require complex movements or additional interactions to activate safety features, and may not ensure the needle is fully protected from exposure.
Innovation Solution
A safety device with a rotating collar and guide pin mechanism that automatically retracts the pre-filled syringe after a single injection stroke, using a spring for energy and a flexible needle shield to ensure the needle is never exposed, and providing audible feedback for mechanism activation, preventing re-use and ensuring needle safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a needle shield is manually moved or moved by a relaxing spring to surround the needle, then needle safety is provided, but the device requires complex movements or additional interactions to activate safety features
Solution Approach 1:
The safety device automatically activates the needle shielding function through the spring mechanism without requiring manual intervention. The spring stores energy during injection and automatically triggers the shield to surround the needle after injection, making the system self-protecting and eliminating complex user operations.
Solution Approach 2:
The spring is pre-charged with energy during the injection process itself. This preliminary action of storing energy during the useful phase (injection) enables the automatic activation of the safety feature (needle shielding) after injection, eliminating the need for separate activation steps.
2Reliability
If the pre-filled syringe is retracted into the body after injection, then needle safety is improved, but the device may not ensure the needle is fully protected from exposure
Solution Approach 1:
The safety device combines the syringe holder and needle shielding functions into a single integrated structure. The holder itself forms the protective shield that surrounds the needle, eliminating the need for separate retraction mechanisms and ensuring the needle is always protected within the holder structure.
3Reliability
If a locking mechanism with cam profile and locking member is used, then the shield is locked in position, but the device complexity increases
Solution Approach 1:
The invention extracts the complex cam profile and rotational locking member mechanisms from the design. Instead, it uses a simplified linear spring-loaded system where the holder directly engages with the syringe barrel, achieving reliable positioning without complex mechanical components.
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 device effectively prevents accidental needle stick injuries by automatically retracting the syringe and shielding the needle after use, providing enhanced safety for both users and patients, and extending the device's shelf-life through partial spring charging.
Implementation Method 1
using a spring for energy
Implementation Method 2
flexible needle shield to ensure the needle is never exposed
Data Source
Figure 1
Figure 2~3
Figure 4~5C
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), a retaining collar (1.5) and a rotating collar (1.4) arranged within the support body (1.2). The retaining collar (1.5) is releasably mounted to the support body (1.2). The rotating collar(1.4) is slidable along an axial length of the support body(1.2) and rotatable around a central axis (A) of the safety device (1). The retaining collar (1.5) is movable with respect to the support body (1.2) in a proximal direction when the retaining collar (1.5) is released from being mounted to the support body (1.2) by the rotating collar (1.4).