Drug Delivery Trigger-Rod Locking for Accidental Release Prevention
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Solution Overview
Problem
Existing drug delivery devices, such as auto-injectors, lack a reliable mechanism to prevent accidental medicament delivery and often require complex assembly processes.
Innovation Solution
A drug delivery device with a housing, a rotatable rod, and a movable trigger member that requires a specific sequence of movements to switch from an unprimed to a primed state, ensuring safe and controlled medicament delivery by blocking accidental rotation or axial movement of the rod until the device is ready for use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a blocking feature is added to prevent accidental rod rotation, then safety against accidental medicament delivery is improved, but device complexity increases
Solution Approach 1:
The blocking feature is integrated into the trigger member itself, merging the safety blocking function with the existing trigger component. This eliminates the need for a separate blocking mechanism and reduces overall device complexity while maintaining safety functionality.
Solution Approach 2:
The trigger member serves multiple functions: it activates the drive unit for medicament delivery, prevents accidental rod rotation through its blocking feature, and controls the priming state transitions. This multi-functionality reduces the need for additional components.
2Ease of operation
If additional drive features are added to the rod for state switching, then control over delivery operation is improved, but device complexity and assembly difficulty increase
Solution Approach 1:
The blocking feature is extracted from the rod and placed on the trigger member instead. This simplifies the rod design by removing additional drive features while maintaining the same control functionality through the trigger member's blocking feature.
3Ease of manufacture
If the device structure is simplified to reduce assembly complexity, then ease of manufacture is improved, but safety against accidental delivery may worsen
Solution Approach 1:
The safety blocking function is merged into the trigger member, which is already a necessary component for activating the drive unit. This integration maintains safety functionality while avoiding the need for additional separate components that would complicate assembly.
4Ease of operation
If the rod is made rotatable for state switching, then ease of operation is improved, but risk of accidental rotation and delivery increases
Solution Approach 1:
The blocking feature on the trigger member provides preliminary prevention against accidental rod rotation by physically blocking the rotation path until the trigger is intentionally activated. This anti-action is in place before any accidental rotation could occur.
Solution Approach 2:
The rod is designed to be rotatable only when the blocking feature is disengaged, which occurs dynamically during intentional trigger activation. The rotational freedom is conditional and controlled, allowing ease of operation when needed while preventing accidental rotation.
Data Source
AI summary
A drug delivery device includes a housing, a blocking feature rotationally secured relative to the housing, a drive unit, a rod operatively coupled to the drive unit and arranged to move distally relative to the housing when the rod is released, and a movable trigger member. The rod is rotatable relative to the housing and has an unprimed state and a primed state. In the unprimed state, the blocking feature is arranged to block a rotation of the rod into the release position, and in the primed state, a trigger member feature is arranged to block rotation of the rod into the release position. The trigger member is arranged to move relative to the housing to release the rod. To switch from the unprimed state into the primed state, the trigger member moves and a movement is converted into an axial movement of the rod relative to the blocking feature.