Injection Device Drive-Lock Mechanism for Jam-Free Medicament Delivery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current injection devices face challenges in delivering large medicament doses efficiently, leading to poor patient compliance due to prolonged delivery times and friction-related jamming issues, which hinder achieving the desired pharmacokinetic profile and accurate dosing.
Innovation Solution
An injection device featuring a drive spring and a drive-lock mechanism with a latch mechanism and retraction collar that reliably engages and disengages the plunger rod, minimizing friction and allowing for efficient medicament delivery by transitioning from a drive-locked to a drive-unlocked position, enabling the drive spring to expel medicament and then release its force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the drive spring continuously engages the plunger rod to maintain consistent drive force, then the reliability of medicament delivery is improved, but friction causes jamming and device failure
Solution Approach 1:
The drive-lock mechanism transitions between two dynamic states: engaged (during medicament delivery) and disengaged (after delivery). The latch mechanism dynamically adjusts the connection between drive spring and plunger rod, allowing the system to adapt its friction characteristics based on operational phase, thereby maintaining reliability while preventing jamming
Solution Approach 2:
The drive-lock mechanism is designed to deliberately discard the engagement between drive spring and plunger rod after medicament delivery completes. The latch mechanism releases the plunger rod from the drive spring's drive force, allowing the plunger rod to be recovered or reset for the next injection cycle, preventing cumulative friction damage
2Reliability
If the drive spring maintains continuous contact with the plunger rod throughout the injection process, then consistent drive force is achieved, but the device complexity increases due to friction management requirements
Solution Approach 1:
The latch mechanism extracts the friction management function from the continuous drive system. By separating the engagement control (latch) from the drive force transmission (spring to plunger rod), the system achieves consistent drive force during injection while simplifying friction management to a discrete on/off control mechanism rather than continuous friction management
3Quantity of substance
If the plunger rod travels a long distance to deliver large medicament doses, then the dosing volume is improved, but the delivery time increases causing poor patient compliance
Solution Approach 1:
The drive spring is pre-compressed to store elastic potential energy before injection. This preliminary energy storage allows the drive spring to exert strong force throughout the entire plunger rod travel distance, maintaining high delivery speed even for large volume injections, thereby reducing total delivery time and improving patient compliance
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 ensures reliable and efficient medicament delivery, reducing the likelihood of device jamming and improving patient compliance by maintaining a consistent drive force throughout the injection process while allowing for easy decoupling of the drive spring after delivery, facilitating smooth retraction of the medicament container.
Implementation Method 1
a drive spring disposed within the housing. The drive spring has a distal end and a proximal end opposite the distal end along the longitudinal axis
Data Source
AI summary
An injection device includes a housing and a drive spring within the housing. The drive spring has a distal end and a proximal end opposite the distal end along the longitudinal axis. The drive spring defines an interior cavity. A plunger is disposed at least partially within a medicament container and a plunger rod is engaged with the plunger. A drive-lock mechanism includes a latch mechanism at least partially received within the interior cavity. The lock mechanism includes at least one engagement portion that releasably engages the plunger rod. A retraction collar is engaged with the latch mechanism that moves from a drive-locked position, which prevents unlocking of the drive-lock mechanism, to a drive-unlocked position relative to the retraction collar, in which decoupling of the drive-lock mechanism is permitted. A method of manufacturing the injection device is also described.