Medication Delivery Device Automatic Piston Rod Resetting

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Solution Overview

Problem

Existing medication delivery devices face challenges in easily resetting the drive mechanism when replacing cartridges, often requiring users to align components manually, which can be difficult for those with impaired vision or dexterity, and may result in pressurization of the cartridge contents, affecting accuracy.

Innovation Solution

A medication delivery device design featuring a dosing mechanism where the piston rod is driven back into the device body without user interaction, with a guiding mechanism that prevents cartridge bung movement during cartridge replacement, ensuring no pressurization of the medication before dosing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual alignment of drive mechanism components is required during cartridge replacement, then the drive mechanism can be reset, but the operation becomes difficult for users with impaired vision or dexterity

Engineering Contradiction:
Improveease of resetting drive mechanismVSAvoidcomplexity of manual alignment requirement
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The drive mechanism is designed to reset automatically through the engagement of engagement means between the cartridge holder and housing. The piston rod is driven back into the device body by the cartridge itself during insertion, eliminating the need for manual alignment or user interaction with the drive mechanism components.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The guiding means is positioned in advance during cartridge insertion to automatically guide the piston rod into the correct position. The engagement means are pre-configured to automatically engage and drive the piston rod back without requiring user intervention during the cartridge replacement process.

Inventive Principle:
Principle #10Preliminary action

2Ease of manufacture

If the cartridge bung moves during cartridge replacement, then the cartridge can be installed, but pressurization of the medication occurs affecting dosing accuracy

Engineering Contradiction:
Improveease of cartridge installationVSAvoidprecision of dosing accuracy
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The insertion process is divided into two distinct phases: first, the cartridge holder is inserted into the housing with the guiding means in a non-guiding position allowing free movement; second, upon full insertion, the guiding means automatically moves to the guiding position to constrain the piston rod. This segmentation prevents premature pressurization while ensuring proper installation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The guiding means transitions dynamically from a non-constraining position during insertion to a constraining guiding position once the cartridge is fully installed. This dynamic positioning allows the cartridge bung to move freely during installation but prevents movement during operation, eliminating pressurization issues.

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If direct user interaction with the drive mechanism is required for resetting, then the mechanism can be repositioned, but the possibility of damage through contamination increases

Engineering Contradiction:
Improveease of resetting operationVSAvoidrisk of contamination damage
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The drive mechanism resets through automatic engagement of the engagement means between the cartridge holder and housing. The piston rod is driven back by the mechanical engagement during cartridge insertion, eliminating the need for users to touch or interact with the drive mechanism components, thereby preventing contamination damage.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The engagement means act as an intermediary mechanism that transfers the resetting function from direct user interaction to automatic mechanical engagement. The cartridge holder and housing engagement automatically drives the piston rod back without requiring user contact with the drive mechanism, reducing contamination risk.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 allows for easy and accurate resetting of the device without direct user interaction with the drive mechanism, minimizing medication loss and ensuring precise dosing, even for users with impaired vision or dexterity.

Implementation Method 1

The first engagement means and the second engagement means are moveable into engagement by a movement of the medication receptacle which ends in a rotational movement without axial movement of the medication receptacle with respect to the housing

Methodology Applied
Scientific EffectThreading: Screw

Data Source

PatentEP2274030B2Medication delivery device
Publication Date: 2020.03.18 SANOFI AVENTIS DEUT GMBH
  • EP2274030B2 patent drawingFigure 1a
  • EP2274030B2 patent drawingFigure 1b
  • EP2274030B2 patent drawingFigure 1c

AI summary

The invention refers to a medication delivery device (1) comprising a housing (3) having a proximal and a distal end, a medication receptacle (2) designed to be engaged with the distal end of the housing (3) by engagement of first engagement means (5) with second engagement means (4) and a dosing mechanism. The dosing mechanism includes a piston rod (17) which is moveable in a distal direction for medication delivery and a drive device for moving the piston rod (17) in the distal direction for medication delivery. The medication receptacle (2) comprises an actuation means (70) for bringing and holding a guiding means (11) in a guiding position in which the guiding means (11) guides the piston rod (17) for medication delivery. The first engagement means (5) and the second engagement means (4) are moveable into engagement by a movement of the medication receptacle (2) which ends in a rotational movement without axial movement of the medication receptacle (2) with respect to the housing (3), the actuation means (70) thereby bringing the guiding means (11) in the guiding position.