Autoinjector Delayed Signal Mechanism
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Solution Overview
Problem
Existing medicament delivery devices face challenges in providing reliable audible, tactile, and visible confirmation of complete medicament delivery due to tight manufacturing tolerances, leading to potential human errors and increased costs.
Innovation Solution
A medicament delivery device with a pre-tensioned drive mechanism and a signal generating mechanism that includes a delay mechanism using a friction enhancing element to ensure reliable audible and tactile signals after the injection sequence is complete, allowing safe removal of the device from the delivery site.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If tight manufacturing tolerances are used to ensure simultaneous plunger termination and member disengagement, then reliable confirmation of complete delivery is achieved, but manufacturing and assembling costs increase
Solution Approach 1:
The signal generating member is disengaged from the drive mechanism before the plunger rod completes its displacement, allowing the signal to be generated in advance of actual delivery completion. This preliminary action eliminates the need for tight tolerances to synchronize signal generation with plunger termination, as the signal is intentionally generated early to account for the delay mechanism and ensure reliable confirmation without requiring precise simultaneous disengagement.
2Ease of manufacture
If the signal generating member is released before plunger displacement terminates to compensate for tolerances, then manufacturing costs are reduced, but the user may remove the device prematurely causing interruption of medicament delivery
Solution Approach 1:
A delay mechanism is introduced as an intermediary between the signal generating member and the user feedback system. This delay mechanism holds the signal generating member in a positioned state after initial disengagement, preventing premature signal generation. The delay mechanism acts as a buffer that reconciles the early disengagement (which reduces manufacturing costs) with the need to prevent premature user action (which protects delivery accuracy), allowing cost-effective manufacturing while maintaining delivery reliability.
3Measurement precision
If tight tolerances are required for simultaneous plunger termination and member disengagement, then accurate delivery confirmation is achieved, but device complexity increases
Solution Approach 1:
The delay mechanism serves as an intermediary component that decouples the timing of member disengagement from the timing of signal generation. Instead of requiring precise simultaneous events, the delay mechanism provides a controlled time buffer that simplifies the mechanical design. This intermediary approach reduces device complexity by eliminating the need for precision-synchronized disengagement while maintaining accurate delivery confirmation through the delayed signal.
4Manufacturing precision
If multiple components are manufactured to very tight tolerances to ensure complete delivery, then delivery accuracy is improved, but manufacturing time and costs increase
Solution Approach 1:
The signal generating member is disengaged preliminarily before plunger completion, and a delay mechanism is pre-configured to control the timing of signal generation. This preliminary disengagement approach allows standard manufacturing tolerances to be used, as the system is designed to accommodate the time delay rather than requiring precise synchronization. Consequently, manufacturing precision requirements are relaxed while delivery accuracy is maintained through the controlled delay, significantly improving manufacturing efficiency.
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 provides a cost-effective and reliable method for confirming complete medicament delivery, reducing the risk of human errors and manufacturing costs by using a simple design with a friction enhancing element to delay the signal generation, ensuring accurate and intuitive user feedback.
Implementation Method 1
a friction enhancing element arranged to act between the signal generating element and the drive mechanism
Data Source
AI summary
The present invention relates to a medicament delivery device comprising: a housing; a drive mechanism arranged to act on a plunger rod; a release mechanism interactively connected to the drive mechanism for releasing the drive mechanism from a pre-tensioned state; and a signal generating mechanism for generating an audible and/or tactile and/or visual signal indicating that a medicament has been completely delivered. The signal generating mechanism is operably connected to said drive mechanism such that it is arranged movable in a longitudinal direction in relation to said drive mechanism. Said drive mechanism is arranged with a signal release mechanism capable of activating said signal generating mechanism at a certain longitudinal position of said drive mechanism after its release, for generating an audible and/or tactile and/or visual signal. Said signal generating mechanism comprises a signal delay mechanism.