Medicament Delivery Device Biasing Element Tolerance Management

Solution Overview

Problem

Medicament delivery devices with movable medicament containers face issues due to tolerance variations, leading to play between the container and the housing, which can cause rattling noises, compromise sterility, and increase the risk of breakage during handling or accidental drops.

Innovation Solution

A medicament delivery device with a medicament container holder and a biasing element, such as a tubular wall with slots, that provides a biasing force to minimize movement and dampen forces, ensuring secure containment and reducing the risk of breakage, while allowing for intuitive and straightforward operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the medicament container is not rigidly mounted within the housing, then tolerance variations between parts are accommodated, but the container moves inside the housing causing rattling noises and potential sterility compromise

Engineering Contradiction:

Improveaccommodation of tolerance variationsVSAvoidsterility maintenance

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The biasing element is pre-loaded to continuously apply a retaining force to the medicament container, preventing movement before it can compromise sterility. This preliminary action ensures the container is always held in its proper position relative to the housing, eliminating rattling noises and preventing accidental needle exposure

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The biasing element provides a dynamic retaining force that adapts to tolerance variations between parts. Instead of a rigid fixed position, the system uses elastic deformation of the biasing element to accommodate dimensional variations while maintaining continuous contact and retention of the medicament container

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If the medicament container is not rigidly mounted within the housing, then tolerance variations between parts are accommodated, but the container moves inside the housing causing rattling noises

Engineering Contradiction:

Improveaccommodation of tolerance variationsVSAvoidrattling noises

Core Design Contradiction:

Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The biasing element is pre-loaded to continuously apply a retaining force to the medicament container, preventing movement before it can generate rattling noises. This preliminary action ensures the container is always held in its proper position relative to the housing, eliminating rattling noises

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The biasing element provides a dynamic retaining force that adapts to tolerance variations between parts. Instead of a rigid fixed position, the system uses elastic deformation of the biasing element to accommodate dimensional variations while maintaining continuous contact and retention of the medicament container

Inventive Principle:

Principle #15Dynamics

3Reliability

If the medicament container is rigidly mounted within the housing, then movement is prevented, but manufacturing complexity increases due to rigid fixation requirements

Engineering Contradiction:

Improvecontainer position stabilityVSAvoidrigid fixation structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The biasing element provides a dynamic retaining force that adapts to tolerance variations between parts. Instead of a rigid fixed position, the system uses elastic deformation of the biasing element to accommodate dimensional variations while maintaining continuous contact and retention of the medicament container

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The biasing element changes its elastic parameters (deformation) to accommodate tolerance variations. By using an elastic element with appropriate stiffness characteristics, the system achieves reliable retention without requiring complex rigid fixation structures, simplifying the overall device design

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

The biasing element effectively minimizes container movement and dampens forces, preventing breakage and maintaining sterility, thus enhancing user experience and device reliability by reducing rattling noises and ensuring safe operation.

Implementation Method 1

a biasing element arranged to bias the medicament container in the proximal direction in the medicament container holder

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

The biasing element effectively minimizes container movement and dampens forces, preventing breakage

Methodology Applied

Scientific EffectDamping: Damping

Data Source

PatentUS11547809B2Medicament delivery device

Publication Date: 2023.01.10 SHL MEDICAL AG

AI summary

A medicament delivery device is presented having a medicament container having an attached medicament delivery member; a housing where the medicament container is movable between a retracted and an extended position in which the medicament delivery member extends from the housing; a drive unit that advances the medicament container from its retracted position to its extended position to expel the contents through the medicament delivery member; and a medicament container holder for carrying the medicament container as it is advanced, the medicament container holder having a proximal end through which the medicament delivery member extends and a holding member releasably connected to the drive unit and attached to the medicament container holder. The holding member has a biasing element having a resilient structure in the form of a tubular wall provided with slots extending in the generally circumferential direction arranged to bias the medicament container in the proximal direction in the medicament container holder.