Pre-filled Syringe Safety Device with Automatic Needle Retraction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing safety devices for pre-filled syringes do not adequately prevent accidental needle stick injuries after injection, and there is a need for a mechanism that automatically shields the needle to prevent reuse and infection.

Innovation Solution

A safety device with a telescoping needle shield and retention and locking mechanism that automatically retracts the needle into a shield after use, using resilient arms and a spring mechanism to ensure the needle is safely covered, preventing accidental exposure and reuse.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a manual needle shield is used, then the device complexity is reduced, but the reliability of preventing accidental needle stick injuries is insufficient

Engineering Contradiction:
Improveprevention of accidental needle stick injuriesVSAvoidcomplexity of safety mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The safety device automatically activates the needle shield through a self-service mechanism. The resilient arm is deflectable by the plunger during injection, which automatically triggers the shield to move into the blocked position, eliminating the need for manual operation and ensuring reliable protection without requiring user intervention.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces complex electronic or multi-component mechanical safety systems with a simple resilient arm mechanism. The deflectable resilient arm converts the mechanical motion of the plunger into automatic shield activation, achieving high reliability with minimal device complexity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If an automatic spring mechanism is used to retract the needle shield, then the reliability of needle protection is improved, but the device complexity increases

Engineering Contradiction:
Improveautomatic needle retractionVSAvoidspring mechanism components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the spring mechanism directly with the needle shield assembly, integrating the resilient arm as an integral part of the shield structure. This combination eliminates separate components and reduces overall device complexity while maintaining automatic retraction functionality and reliability.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If the needle shield is made larger to ensure complete coverage, then the protection effectiveness is improved, but the ease of operation deteriorates

Engineering Contradiction:
Improveneedle coverageVSAvoidhandling of injection device
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The needle shield is designed as a dynamic component that moves between retracted and blocked positions. The telescopic design allows the shield to extend only when needed for protection, maintaining a compact form during injection operations. This dynamic adjustment ensures complete needle coverage while preserving ease of handling during the injection process.

Inventive Principle:
Principle #15Dynamics

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 effectively prevents accidental needle stick injuries and ensures the needle is safely shielded after use, reducing the risk of infection and allowing for mass production with a compact design that is economically viable.

Implementation Method 1

a spring arranged with the needle shield as one piece and arranged within the needle shield so as to shield the spring from being influenced from the exterior, wherein the spring is deflected when the needle shield is moved from the first advanced position to the retracted position and moves the needle shield automatically to the second advanced position

Methodology Applied
Scientific EffectElastic energy storage and release: Elasticity

Data Source

PatentEP3744372B1A safety device for a pre-filled syringe and an injection device
Publication Date: 2023.04.26 SANOFI AVENTIS DEUT GMBH
  • EP3744372B1 patent drawingFigure 1
  • EP3744372B1 patent drawingFigure 2
  • EP3744372B1 patent drawingFigure 3

AI summary

According to the invention, a safety device (1) for a pre-filled syringe (2) with an injection needle (2.1) comprises - a support body (1.2) adapted to mount the pre-filled syringe (2), - a needle shield (1.1) slidably arranged with respect to the support body (1.2), - a retention and locking means (M) for retaining and locking the needle shield (1.1) with respect to the support body (1.2) in a first and a second advanced position (PA1, PA2) and in a retracted position (PR). The needle shield (1.1) comprises an annular flange (1.1.1) adapted to rest on the skin of the patient receiving an injection. The retention and locking means (M) are arranged at a distal end of the safety device (1).