Locking Band Mechanism for Drug Delivery Dose Limit

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Solution Overview

Problem

Existing drug delivery devices lack a simple and secure means to set and maintain a maximum dosable limit, posing risks of overdose, especially for users with visual impairments or dementia, as they often require multiple devices for different medications and may confuse dose settings.

Innovation Solution

A maximum settable dose feature incorporating a movable dose setting component and a locking band that transitions from an unlocked to a locked configuration after the initial dose is set, using a trigger mechanism or spring biasing to prevent exceeding the preset dose, ensuring a permanent stop for subsequent injections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a user can freely adjust the dose setting component for each injection, then the device provides flexibility for different dosing requirements, but the risk of accidental overdose increases especially for visually impaired or cognitively compromised users

Engineering Contradiction:
Improvedosing flexibilityVSAvoidoverdose risk
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The maximum dose is pre-set by a healthcare professional or user before the patient begins using the device. The locking band is initially in an unlocked state, allowing the dose setting component to be adjusted to a predetermined maximum value. Once set, the locking mechanism engages to prevent further adjustment, ensuring patients cannot exceed the safe dose limit while maintaining flexibility for legitimate dosing variations within the preset maximum.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The locking band acts as an intermediary mechanical element between the dose setting component and the user. It physically blocks rotation of the dose setting component beyond the preset maximum, serving as a passive safety barrier that does not require active user intervention to function. This intermediary mechanism translates the preset maximum dose into a physical constraint that prevents overdose.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a permanent maximum dose stop is implemented, then patient safety is improved, but the device complexity increases due to additional locking mechanisms

Engineering Contradiction:
Improvepatient safetyVSAvoidmechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locking band is constructed as a thin, flexible band that can elastically deform during the locking and unlocking process. This flexibility allows the band to be slipped over the dose setting component during manufacturing or initial setup, then engage with friction or deformation to create a secure lock. The thin-film construction minimizes the space required and reduces overall mechanism complexity while maintaining reliable locking functionality.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The locking mechanism transitions from a static fixed-stop design to a dynamic system where the locking band can change state between locked and unlocked configurations. The band is designed to be flexible enough to allow intentional unlocking by a healthcare professional or user, yet rigid enough when locked to provide a firm stop. This dynamic capability allows the same mechanism to serve both safety and maintenance functions.

Inventive Principle:
Principle #15Dynamics

3Reliability

If the locking band requires a trigger mechanism to unlock, then accidental unlocking is prevented, but the ease of operation decreases for users needing to adjust the maximum dose

Engineering Contradiction:
Improveaccidental preventionVSAvoidadjustment ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The trigger mechanism is localized to a specific access point on the device, separate from the normal dose setting operation. The trigger requires a specific action (such as pressing a button, sliding a tab, or rotating a specific portion) that is distinct from the routine dose adjustment motion. This localization ensures that accidental triggering is unlikely during normal use, while intentional unlocking by trained users remains straightforward through the dedicated trigger action.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2437826B1Dosing mechanism for a drug delivery device
Publication Date: 2019.10.09 SANOFI AVENTIS DEUT GMBH
  • EP2437826B1 patent drawingFigure 1~2
  • EP2437826B1 patent drawingFigure 2a~3
  • EP2437826B1 patent drawingFigure 4

AI summary

A maximum settable dose feature is disclosed that is set by a user or health care professional one time that prevents future injections from exceeding the desired maximum dose. The feature includes a locking band (5) initially in an unlocked configuration, which transforms to a locked configuration when activated after setting a desired maximum dose. The feature can include a trigger mechanism (6, 11) to transform the locking band (5) to the locked configuration.