Medicament Mixing Assembly Threaded Locking Mechanism
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Solution Overview
Problem
Medicament delivery devices with mixing capabilities face challenges in preventing accidental exposure of delivery members and improper mixing due to lack of secure mechanisms for mixing and triggering processes.
Innovation Solution
A mix and triggering assembly with a housing structure, rotator sleeve, and triggering member that requires rotational effort to initiate mixing, preventing irrotational axial movement and ensuring the delivery member is covered before mixing, and includes a plunger rod to mix freeze-dried medicament with liquid by increasing pressure and using bypass channels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the delivery member cover is allowed to move axially without rotation, then the device is easier to operate, but accidental exposure of the delivery member may occur
Solution Approach 1:
The triggering member is designed to dynamically change its engagement state with the thread structure. During normal operation, it is disengaged to allow free axial movement. When rotational force is applied, it engages with the thread structure to lock axial movement, preventing accidental exposure while maintaining ease of operation during intended use
Solution Approach 2:
The system changes the mechanical state parameter of the triggering member between two positions: engaged with the thread structure (preventing axial movement) and disengaged (allowing axial movement). This parameter change is triggered by rotational force, creating a reliable safety mechanism that responds to user intent
2Reliability
If the triggering member is prevented from axial movement by threaded connection, then accidental triggering is prevented, but the mixing operation becomes more complex
Solution Approach 1:
The triggering member combines multiple functions into a single component: it acts as both a safety lock (when engaged with the thread structure) and a mixing actuator (when rotated). The rotator sleeve similarly combines the roles of rotational driver and axial mover, eliminating the need for separate mechanisms and reducing overall device complexity
Solution Approach 2:
The threaded connection structure serves multiple purposes: it prevents accidental axial movement during storage and transport, enables controlled axial movement during mixing when rotated, and provides a mechanical interface for the triggering member. This multi-functionality reduces the need for additional safety mechanisms
3Reliability
If the rotator sleeve and triggering member are screwed towards the distal end for mixing, then secure mixing is achieved, but the mixing process takes more time
Solution Approach 1:
The system is pre-configured with the rotator sleeve and triggering member in a ready-to-mix position where they are axially locked but rotationally free. The user only needs to apply rotational force to initiate mixing, rather than first assembling or positioning components. This preliminary preparation reduces the actual mixing time while maintaining secure operation
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
Ensures secure and controlled mixing of medicaments by requiring deliberate effort for mixing initiation, preventing accidental exposure and ensuring accurate mixing and dosing, thereby enhancing user safety and device reliability.
Implementation Method 1
The medicament container holder is configured to receive a greater portion of the proximal end portion of the plunger rod during this motion, increasing the pressure in the distal chamber. This causes the plunger to move towards the proximal end of the housing structure
Data Source
Figure 1
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Figure 4~5
AI summary
A mix and triggering assembly (20) for a medicament delivery device (1), comprising: a housing structure (3) having a proximal end (3a) and a distal end (3b), a delivery member cover (5), a rotator sleeve (11), and a triggering member (13) configured to be rotatably locked with the rotator sleeve (11) and the delivery member cover (5), the triggering member (13) being configured to move axially relative to the rotator sleeve (11), wherein the delivery member cover (5), the rotator sleeve (11) and the triggering member (13) are configured to be received by the housing structure (3), the delivery member cover (5) being configured to extend from the proximal end (3a) of the housing structure (3), wherein the delivery member cover (5), the rotator sleeve (11) and the triggering member (13) are rotatably arranged relative to the housing structure (3), wherein the housing structure (3) has a thread structure and the rotator sleeve (11) and the triggering member (13) are configured to be in a threaded connection with the thread structure in a ready to mix position of the triggering member (13), preventing irrotational axial movement of the triggering member (13) relative to the housing structure (3) towards the distal end (3b) of the housing structure (3), wherein rotation of the delivery member cover (5) relative to the housing structure (3) causes the rotator sleeve (11) and the triggering member (13) to be screwed from the ready to mix position towards the distal end (3b) of the housing structure (3) until the triggering member (13) reaches a dose setting position, in which the triggering member (13) is configured to be released from engagement with the thread structure (3c), enabling irrotational axial movement of the triggering member (13) further towards the distal end (3b) of the housing structure (3).