Auto-Injector With Decoupling Arms for Complete Dose Delivery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing auto-injectors face challenges such as user discomfort due to high injection forces and hand trembling, risk of incomplete doses, and complexity in manual devices, while auto-injectors often require multiple springs leading to increased weight and cost.
Innovation Solution
An auto-injector using a single compression spring for needle insertion, dose delivery, and retraction, with a simplified mechanism that includes a retraction sleeve and decoupling arms to ensure complete dose delivery and safe needle retraction, featuring a safety button to prevent accidental operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple springs are used in auto-injectors for needle insertion, dose delivery, and retraction, then the injection functions are achieved, but the weight and cost of the device increase
Solution Approach 1:
The patent combines multiple spring functions (needle insertion, dose delivery, and retraction) into a single compression spring mechanism. The compression spring is coupled to both the needle assembly and the syringe plunger, allowing one spring to perform what traditionally required multiple separate springs, thereby reducing device weight and complexity while maintaining reliable injection functionality.
Solution Approach 2:
The single compression spring is designed to serve multiple functions: it drives needle insertion, delivers the medicament dose, and enables syringe retraction. This multi-functional spring replaces the traditional multi-spring system, reducing the number of components and overall device weight while achieving all necessary injection operations.
2Reliability
If multiple springs are used in auto-injectors for needle insertion, dose delivery, and retraction, then the injection functions are achieved, but the manufacturing cost increases
Solution Approach 1:
The patent combines multiple spring functions (needle insertion, dose delivery, and retraction) into a single compression spring mechanism. The compression spring is coupled to both the needle assembly and the syringe plunger, allowing one spring to perform what traditionally required multiple separate springs, thereby reducing device weight and complexity while maintaining reliable injection functionality.
Solution Approach 2:
The single compression spring is designed to serve multiple functions: it drives needle insertion, delivers the medicament dose, and enables syringe retraction. This multi-functional spring replaces the traditional multi-spring system, reducing the number of components and overall device weight while achieving all necessary injection operations.
3Device complexity
If a single compression spring is used for needle insertion and retraction, then device weight and complexity are reduced, but ensuring complete dose delivery and safe retraction becomes more challenging
Solution Approach 1:
The patent introduces a decoupling mechanism that acts as an intermediary between the compression spring and the syringe plunger. This decoupling mechanism ensures that the spring's retraction force is properly transmitted to the plunger, preventing premature disengagement and ensuring complete dose delivery while maintaining the simplicity of the single-spring design.
Solution Approach 2:
The compression spring is pre-loaded to a specific compression level during assembly, which preliminarily sets the force parameters for both injection and retraction operations. This pre-compression ensures that when the single spring is released, it provides sufficient and controlled force to deliver the complete dose and safely retract the needle, eliminating the need for multiple springs.
4Device complexity
If a single compression spring is used for needle insertion and retraction, then device weight and complexity are reduced, but operational safety against accidental operation becomes more difficult to ensure
Solution Approach 1:
The patent segments the operation control into distinct functional zones: a trigger mechanism for initiating injection, a decoupling mechanism for controlling spring release, and a safety button for preventing accidental activation. This segmentation allows the simple single-spring mechanism to be controlled through multiple interlocked stages, ensuring operational safety without increasing mechanical complexity.
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 provides a reliable, lightweight, and cost-effective auto-injector that ensures complete dose delivery and safe needle retraction, reducing user discomfort and operational complexity.
Implementation Method 1
spring means capable of, upon activation: pushing the needle from a covered position inside the housing into an advanced position through the orifice and past the proximal end
Data Source
AI summary
An auto-injector for administering a dose of a liquid medicament includes an elongate housing arranged to contain a syringe with a hollow needle and a stopper for sealing the syringe and displacing the medicament, the housing having a distal end and a proximal end with an orifice intended to be applied against an injection site. The syringe is slidably arranged with respect to the housing. A spring capable of, upon activation: pushing the needle from a covered position inside the housing into an advanced position through the orifice and past the proximal end (P), operating the syringe to supply the dose of medicament (M), and retracting the syringe with the needle into the covered position. After delivering the medicament, an activator arranged to lock the spring in a pressurized state prior to manual operation and capable of, upon manual operation, releasing the spring for injection.