Needle Shield Removal Mechanism for Low-Force Injection Caps
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Solution Overview
Problem
Existing injection devices require significant force to remove the cap, making it difficult for elderly or infirm patients to expose the needle for medicament administration.
Innovation Solution
An injection device with a pivotable actuator member and translating member mechanism that facilitates easier removal of the needle shield by leveraging the actuator's pivotal movement, reducing the required force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the cap is held onto the body with sufficient force to prevent accidental removal, then the needle is kept sterile and injury is prevented, but it becomes difficult for patients to intentionally remove the cap prior to injection
Solution Approach 1:
The actuator member transitions from a static locking position to a dynamic actuated position, changing the mechanical state of the needle shield retention. The spring member provides dynamic force that can be overcome by the actuator, allowing the system to switch between locked and unlocked states easily
Solution Approach 2:
The actuator member serves as an intermediary mechanism between the user's manual input and the needle shield retention system. By pivoting the actuator, force is transmitted through the translating member to overcome the spring force and release the needle shield, providing an easy-to-operate interface
2Ease of operation
If a simple cap removal mechanism is used, then ease of operation is improved, but sufficient force to hold the cap and prevent accidental removal is not achieved
Solution Approach 1:
The spring member acts as a counterweight providing continuous retaining force on the needle shield, opposing the removal direction. This spring force ensures the needle shield remains securely held during storage and transport, while the actuator mechanism provides the means to overcome this counteracting force when needed
Solution Approach 2:
The mechanism operates in distinct phases: a prolonged retention phase where the spring holds the needle shield secure, and a brief actuation phase where the pivotable actuator overcomes the spring force. This periodic action between retention and release states ensures both safety and ease of use
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 mechanism allows easier and more accessible removal of the needle shield, particularly beneficial for elderly or infirm patients, by utilizing leverage and pivotal movement to reduce the force needed.
Implementation Method 1
by leveraging the actuator's pivotal movement, reducing the required force
Data Source
Figure 1A~1B
Figure 2~3
Figure 4~5
AI summary
The present invention relates to an injection device. The injection device comprises a body for holding a syringe that has a needle at one end and a cap that is removably attached to the body. The cap has a needle shield to cover said needle. The injection device further comprises an actuator member and a translating member. The actuator member is pivotally coupled to one of the cap or body. The translating member is connected to the actuator member and is configured such that pivotal movement of the actuator member relative to said one of the cap or body causes movement of the translating member relative to the body to urge the needle shield away from the body.