Autoinjector Force Reduction for Pre-Filled Syringe Protection

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Solution Overview

Problem

Existing autoinjectors risk damaging pre-filled syringes due to high forces applied during activation, which can lead to structural damage.

Innovation Solution

Incorporating a force reduction member between the autoinjector body and the pre-filled syringe to absorb and reduce the forces applied, potentially using a spring element or deformable structures to decelerate the syringe and minimize peak stresses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a large gap is provided between the engaging part of the autoinjector and the stopper to enable flexible system with different fill volumes, then the engaging part can accelerate unimpeded and reach high velocity, but this results in very high forces being applied to the pre-filled syringe upon impact, potentially damaging it

Engineering Contradiction:

Improveflexibility to incorporate different pre-filled syringe fill volumesVSAvoiddamage risk to pre-filled syringe from high impact forces

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

A force reduction member is introduced as an intermediary element between the engaging part of the autoinjector and the pre-filled syringe. This member includes a deformable connection element that can elastically deform to absorb impact energy, thereby mediating the force transmission and reducing peak forces applied to the pre-filled syringe during activation

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The force reduction member is pre-configured with elastic deformation capability to provide cushioning before the impact occurs. The deformable connection element is designed to yield elastically during the impact event, absorbing energy that would otherwise be transmitted directly to the pre-filled syringe, thus protecting it from damage

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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 force reduction member effectively lowers the forces acting on the syringe, reducing the risk of damage and ensuring safe and reliable operation of the autoinjector.

Implementation Method 1

said force reduction member is capable of reducing a force acting on said force reduction members by internal deformation

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Implementation Method 2

The force reduction member may also be configured to aid in decelerating a syringe of the autoinjector by providing a spring feature to increase a distance over which deceleration occurs

Methodology Applied

Scientific EffectSpring mechanism: Spring

Data Source

PatentEP4603119A1autoinjector

Publication Date: 2025.08.20 MEDMIX SWITZERLAND AG

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Figure 4a~4g

AI summary

The present invention relates to an autoinjector (12) comprising a body (34) having a proximal end (300) and a distal end (310), with the body (34) being configured to receive a pre-filled syringe (170) having a needle (172) arranged at a proximal end (300) and a flange (174) arranged at a distal end (310); wherein the body (34) is configured to receive the pre-filled syringe (170); wherein the body (34) further comprises a force reduction member (120) arranged between the body (34) and the pre-filled syringe (170).