Safety Injection Device Locking Clip Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing medical injection systems for self-administration often fail to ensure proper needle insertion depth and may trigger the injection step prematurely, leading to wasted drug composition and inconvenience for patients.
Innovation Solution
An injection device with a locking clip mechanism that engages the plunger rod only when the needle is fully inserted, featuring a needle shield that covers the needle until a predetermined depth is reached, and a deflecting member to ensure safe disposal after use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a simplified operation combining several steps into a single movement is used, then ease of operation is improved, but reliability deteriorates due to premature injection triggering
Solution Approach 1:
The needle shield must be retracted in advance before the injection can occur. The locking clip is pre-configured to block the plunger rod, and only after the needle shield is fully retracted (indicating proper needle insertion) does the locking clip release, allowing the injection to proceed. This preliminary action ensures that needle insertion is completed before drug delivery begins.
Solution Approach 2:
The locking clip acts as an intermediary mechanism between the needle shield and the plunger rod. It translates the position of the needle shield into a corresponding state of the plunger rod, ensuring that the injection cannot occur unless the needle shield is properly retracted. This intermediary component provides a mechanical linkage that enforces the correct sequence of operations.
2Object-affected harmful factors
If the injection needle is hidden or covered by the medical injection system, then safety is improved, but ease of operation deteriorates due to difficulty in ensuring proper insertion depth
Solution Approach 1:
The needle shield includes visual indicators such as color-coded zones or markings that change position as the shield is retracted. These visual cues provide immediate feedback to the user about the insertion depth, making it easy to confirm when the needle has reached the appropriate depth without exposing the needle during the process.
Solution Approach 2:
The system provides mechanical feedback through the locking clip mechanism and visual feedback through indicators on the needle shield. When the needle shield is properly retracted, the locking clip releases and visual indicators show the correct position, giving the user confidence that proper insertion depth has been achieved before injection begins.
3Reliability
If a locking mechanism is added to prevent premature injection, then reliability is improved, but device complexity increases
Solution Approach 1:
The locking clip mechanism is integrated with the existing needle shield and plunger rod components rather than being a separate system. The locking clip uses the movement of the needle shield itself to trigger the release mechanism, combining the safety function with the existing operational components. This merging approach adds reliability without proportionally increasing overall device complexity.
Solution Approach 2:
The locking clip is designed to automatically engage and disengage based on the position of the needle shield. The mechanism is self-actuating, using the mechanical movement of components already present in the device to control the locking and releasing actions, rather than requiring separate control systems or additional user inputs.
4Object-affected harmful factors
If the needle shield covers the injection needle permanently, then safety is improved, but productivity deteriorates due to inability to administer injection
Solution Approach 1:
The needle shield transitions from a static protective covering to a dynamic component that moves between covered and retracted positions. The shield is designed to be movable along the needle axis, allowing it to provide protection during storage and handling, then retract to allow injection, and finally return to cover the needle after use. This dynamic behavior enables both safety and productivity.
Solution Approach 2:
The needle shield undergoes periodic movement through distinct phases: initially covering the needle for safety, then retracting to enable injection, and finally returning to the covered position after injection completion. This periodic action ensures that the needle is protected during non-use periods while being accessible during the injection phase, balancing safety and productivity requirements.
Data Source
Figure 1~2
Figure 3~5
Figure 6~7B
AI summary
An injection device for injecting a substance into a body, comprising: a barrel (100) provided with the substance a stopper (103) in sliding engagement inside the barrel (100) and an injection needle (101); a plunger rod (110) coupled to the stopper (103) and moveable in order to inject the substance, a locking clip (150) fixed relative to the barrel (100) and provided with at least two jaws (151) engaging the plunger rod (110) so as to prevent an injection movement of the plunger rod (110) with regard to the barrel (100), and a needle shield (130) comprising a triggering portion (134), said needle shield (130) being configured in sliding engagement with respect to the injection needle (101), wherein the triggering portion (134) is configured to open the locking clip (150) when the needle shield (130) moves from an initial position to a retracted position.