Medicament Delivery Device Cap Blocking Mechanism
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Solution Overview
Problem
Medicament delivery devices face challenges in preventing unintentional activation, particularly during handling or accidental drops, which can lead to premature medicament release and contamination risks.
Innovation Solution
A medicament delivery device design featuring a removable cap with blocking formations that limit relative movement between the release member and the cartridge assembly, maintaining the device in a starting configuration until intentionally activated, and incorporating an aseptic seal and venting system to equalize pressures and prevent seal failure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the release member is spaced from the sealing element in the starting configuration, then the medicament remains sealed in the cartridge, but the device is vulnerable to unintentional activation during handling or accidental drops
Solution Approach 1:
A cap assembly is introduced as an intermediary component between the user's hand and the release member. The cap contains blocking formations that physically prevent the release member from moving into the activated configuration, thereby mediating the interaction between handling and activation prevention.
Solution Approach 2:
The blocking formations in the cap assembly apply a preliminary counteracting force against any potential activation movements. Before unintentional activation can occur, the cap's blocking formations preemptively block the release member's path, counteracting drops or mishandling that would otherwise cause premature activation.
2Reliability
If the cap includes blocking formations to prevent unintentional activation, then activation safety is improved, but the device structure becomes more complex
Solution Approach 1:
The cap assembly serves multiple functions simultaneously: it provides blocking formations for safety, defines a chamber for the distal end of the release member, and incorporates venting features for pressure equalization. This multi-functionality reduces the need for separate components, thereby limiting the increase in overall device complexity.
3Reliability
If the release member chamber is sealed to maintain sterility, then contamination is prevented, but pressure gradients may cause seal failure
Solution Approach 1:
The seal in the release member chamber is designed to be flexible rather than rigid. This flexible seal can deform to accommodate pressure differences, preventing seal failure while maintaining the sterile barrier. The venting feature works in conjunction with this flexible seal to equalize pressures.
Solution Approach 2:
A venting feature acts as an intermediary pressure equalization mechanism. It allows controlled pressure balancing between the sealed release member chamber and the external environment, mediating the pressure gradient that would otherwise cause seal failure while maintaining sterility through the vent's design.
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 reduces the risk of unintentional activation and maintains sterility of the medicament and needle until use, ensuring safe handling and preventing seal failure due to pressure gradients.
Implementation Method 1
incorporating an aseptic seal and venting system to equalize pressures and prevent seal failure
Data Source
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AI summary
A medicament delivery device is disclosed, comprising a cartridge assembly that comprises a cartridge having a medicament chamber for containing a medicament, a sealing element for sealing a distal end of the medicament chamber and a coupling element attached to the cartridge. The device also includes a sealing element release member, a cannula for delivery of the medicament, and a removable cap. The device is switchable from a starting configuration in which the release member is spaced from the sealing element to an activated configuration in which the release member cooperates with the sealing element to connect the medicament chamber to the cannula. A proximal end of the release member is sealed in a release member chamber defined in part by the sealing element and in part by the coupling element. To prevent accidental activation of the device, the cap comprises at least one blocking formation that cooperates with the coupling element for limiting relative movement between the release member and the cartridge assembly in at least one direction, thereby to keep the device in the starting configuration when the cap is in place.