Safety Needle Cannula Deformation Mechanism
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Solution Overview
Problem
Existing safety needles face challenges in constructing a cost-effective, automated assembly process without damaging the cannula and preventing microdeformations during injection, while ensuring the cannula is permanently deformed after use to prevent reuse and user contact.
Innovation Solution
A safety needle design featuring a cannula holder with a cup-shaped body, a compression spring, and a deforming member with a ratchet mechanism that rotates to deform the cannula after use, using a single spring and eccentric ledges to minimize cannula interaction during assembly and injection, ensuring the cannula is securely deformed and protected.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a moving protective element is used to expose the cannula during injection, then the cannula can be properly exposed for drug administration, but the protective element may come into contact with and damage the cannula end during assembly or operation
Solution Approach 1:
A protective sleeve is introduced as an intermediary element between the moving protective element and the cannula. The sleeve covers the cannula during assembly and operation, preventing direct contact that could cause damage or microdeformations, while still allowing the protective element to move freely to expose the cannula tip when needed for injection.
2Reliability
If multiple springs and resilient elements are used to ensure cannula deformation and protection, then the safety and deformation reliability improve, but the device complexity and manufacturing cost increase
Solution Approach 1:
The invention extracts and eliminates unnecessary resilient elements from the system. Instead of using multiple springs and resilient elements to achieve cannula deformation and protection, the design employs a single compression spring working in conjunction with the moving protective element and protective sleeve, significantly reducing device complexity while maintaining reliability.
3Reliability
If the protective element continuously covers the cannula, then safety and prevention of contact are improved, but the cannula cannot be exposed for proper drug administration
Solution Approach 1:
The protective element is designed with dynamic movement capability. During assembly and non-use periods, the protective element remains in the retracted position, allowing the protective sleeve to continuously cover the cannula for safety. During injection, the protective element moves to the extended position, dynamically exposing the cannula tip while the sleeve maintains coverage to prevent damage.
4Reliability
If the cannula is permanently deformed after use, then prevention of reuse and user contact is improved, but the construction of the deformation mechanism becomes more complex
Solution Approach 1:
The deformation mechanism is designed to be self-activating through the natural operation of the injection device. The single compression spring, when released during the injection cycle, automatically deforms the cannula without requiring additional actuators or complex control mechanisms. The protective sleeve and moving protective element work together to ensure the deformation occurs at the appropriate moment, simplifying the overall construction while achieving reliable permanent deformation.
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 simplifies manufacturing, reduces construction complexity, and ensures the cannula is permanently deformed and protected, preventing reuse and user contact, while maintaining ease of assembly and user comfort by avoiding cannula vibrations during injection.
Implementation Method 1
a compression spring (50) having a first extremity (51) bearing on the cup-shaped body (8) of the cannula holder (2) and a second extremity (53) inserted into a first enlarged extremity part (54) of the protective element (55), said spring (50) being capable of exerting a thrust force on said protective element (55)
Implementation Method 2
a deforming member or ratchet (68) having a body (69) capable of rotating between cavity (60A) of said protective element (55) to deform cannula (15)
Implementation Method 3
said deforming member or ratchet (68) having ledges (78) capable of interacting with corresponding recesses (38) made internally in outer jacket (4) and inner sleeve (28), their interaction bringing about said rotation
Data Source
AI summary
A safety needle having a rigid outer structure within which there is a cannula holding element of being movably coupled to an injector pen for a drug is provided. The cannula holding element supports a cannula having a first extremity and a second extremity for administration of the drug. A moving protective element associated with the rigid structure, covers the second extremity of the cannula after administration, with provision being made for a deforming member capable of deforming the cannula after administration of the drug so that the second extremity of the cannula remains within the protective element. The deforming member is associated with the protective element and is capable of rotating autonomously with respect thereto after administration of the drug to deform the cannula.