Needle Shield Sleeve Mechanism for Safer Dose Injection

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Solution Overview

Problem

Administering injections presents risks and challenges for users and healthcare professionals, with a need for improved medicament delivery devices that enhance safety and ease of use.

Innovation Solution

A medicament delivery device featuring a body, a container carrier, and a sleeve with biased legs and springs, allowing for controlled needle insertion and retraction, along with a cap for needle protection and user guidance, providing tactile and visual feedback for dose administration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a needle safety system is added to prevent needle stick injuries, then safety is improved, but device complexity increases

Engineering Contradiction:
ImprovesafetyVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The device is divided into distinct functional segments: a body housing, a movable carrier for the medicament container, and a protective sleeve. Each segment performs a specific function - the carrier holds and positions the container, while the sleeve provides safety protection. This segmentation allows the safety function to be added without completely redesigning the entire device architecture.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The protective sleeve is nested within the body housing, and the carrier is nested within the body as well. The sleeve can slide over the carrier to cover the needle when not in use. This nesting arrangement allows multiple safety and functional features to be integrated in a compact configuration without significantly increasing the overall device footprint or complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Reliability

If a protective sleeve is added to cover the needle, then safety is improved, but ease of operation deteriorates

Engineering Contradiction:
ImprovesafetyVSAvoidease of operation
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The protective sleeve is designed to be movable rather than fixed. It can slide along the carrier to expose the needle when needed and cover it when not in use. This dynamic design allows the safety feature to be activated only when required, maintaining ease of operation during actual medicament administration while providing protection at other times.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The device incorporates tactile feedback mechanisms through springs and stops that provide sensory cues to the user during operation. When the sleeve reaches its extended or retracted positions, mechanical stops provide tactile feedback confirming the sleeve's position, making it easier for users to understand the device state without visual confirmation.

Inventive Principle:
Principle #23Feedback

3Reliability

If spring biases and axial stops are added for controlled movement, then reliability is improved, but device complexity increases

Engineering Contradiction:
ImprovereliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The springs are designed to automatically bias the carrier and sleeve to their proper positions without requiring external actuation or complex control mechanisms. The first spring biases the carrier within the body, and the second spring biases the sleeve relative to the carrier. These self-service spring mechanisms provide reliable controlled movement through simple elastic forces rather than complex motorized or pneumatic systems.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The device uses mechanical stops to define specific positional parameters for the carrier and sleeve. The axial stops limit the travel distance of the carrier, while the sleeve stops limit the sleeve's movement relative to the carrier. By changing the physical parameters (positions) through simple mechanical constraints rather than complex control systems, reliable controlled movement is achieved with minimal added complexity.

Inventive Principle:
Principle #35Parameter changes

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

Enhances user safety by hiding the needle during operation, ensuring proper needle insertion depth, and allowing for multiple dose administration with visual and tactile feedback, thus improving the overall injection process.

Implementation Method 1

a sleeve spring biasing the sleeve relative to the container carrier. The sleeve spring biases the sleeve toward the first protrusion.

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

a container spring biasing the carrier relative to the body.

Methodology Applied
Scientific EffectSpring: Spring

Data Source

PatentEP4223334B1Medicament delivery device
Publication Date: 2026.05.20 SANOFI AVENTIS DEUT GMBH
  • EP4223334B1 patent drawingFigure 1
  • EP4223334B1 patent drawingFigure 2
  • EP4223334B1 patent drawingFigure 3

AI summary

Described is a medicament delivery device (1) comprising a body (2), a container carrier (7) slidably disposed in the body (2), and a sleeve (6) slidably coupled to the container carrier (7).