Autoinjector Blocking Means Prevents Accidental Activation
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Solution Overview
Problem
Autoinjectors with small round flanges fail to prevent accidental activation during drop tests due to their reduced dimensions, which allow the medical container to move proximally and trigger the injection mechanism, leading to unintended activation.
Innovation Solution
Incorporating blocking means such as a friction-fit ring or spacer ring that secures the medical container in place, preventing proximal movement and ensuring the autoinjector remains in a deactivated state during drops or accidental falls.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a small round flange is used to avoid interference with the safety shield mechanism, then the autoinjector can accommodate the safety shield mechanism properly, but the medical container cannot abut against the abutment protrusions to prevent proximal movement during drop tests
Solution Approach 1:
A blocking means is introduced as an intermediary component between the medical container and the activation component. This blocking means prevents the medical container from directly abutting the activation component during drop tests, thereby preventing accidental activation while maintaining compatibility with small round flanges and safety shield mechanisms
2Reliability
If abutment protrusions are used to stop proximal movement of the medical container, then the medical container is secured in place, but the design becomes incompatible with small round flanges due to their reduced dimensions
Solution Approach 1:
The blocking means serves as a mediator that enables the use of small round flanges while still providing the necessary restriction on proximal movement. Instead of relying on the flange itself to abut the activation component, the blocking means intercepts the movement path, allowing small round flanges to be used without compromising security
3Adaptability or versatility
If the medical container is allowed to move proximally inside the housing during drop tests, then the autoinjector can accommodate various flange types, but the activation component may be triggered inadvertently by the filled medical container
Solution Approach 1:
The blocking means acts as a protective intermediary that prevents the medical container from directly interacting with the activation component during drop tests. This allows the autoinjector to accommodate different flange types while blocking the harmful pathway that would lead to inadvertent triggering
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 effectively prevents the medical container from displacing the holder and triggering the injection mechanism, maintaining the autoinjector in a deactivated condition even when dropped cap upward, thus avoiding inadvertent activation.
Implementation Method 1
The blocking means include a friction-fit ring which is secured to a locking element configured to lock the needle cover in the second extended position, and the friction-fit ring defines a central opening for frictionally engaging the barrel such that proximal movement of the barrel is prevented
Data Source
AI summary
The autoinjector has a proximal end and, a longitudinal axis A, and a housing configured to receive a medical container having a barrel defining a reservoir for containing a medical product, and said barrel having a distal end provided with a needle and an opened proximal end configured to receive a plunger rod for pushing a stopper arranged inside the barrel. A needle cover is coupled to and movable with respect to said housing between a first extended position, a retracted position, and a second extended position wherein the needle cover moves back in the distal direction to shield the needle. An injection mechanism is configured to move the plunger rod distally inside the barrel in order to expel the medical product contained inside the barrel. A holder is movable with respect to the housing between a passive position wherein the holder does not trigger the injection mechanism and an active position wherein the holder triggers the injection mechanism. The autoinjector includes blocking means configured to prevent the medical container from moving proximally inside the housing, such that the medical container cannot displace the holder towards the active position if the autoinjector falls down onto a floor, proximal end first.