Auto-Injector Needle Guard and Indicator Mechanism
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Solution Overview
Problem
Existing auto-injectors require manual operation and lack features for preventing needle stick injuries and indicating injection progress, especially when used for self-administration of drugs with varying viscosities.
Innovation Solution
A modular auto-injector design with a cartridge, power source, and needle assembly that includes a biased needle guard for safety and an indicator system to monitor injection progress, allowing for easy assembly and reassembly, and accommodating different needle configurations for subcutaneous, intramuscular, or intra-dermal injections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If manual operation is used in existing auto-injectors, then device complexity is reduced, but ease of operation deteriorates for self-administration
Solution Approach 1:
The device enables self-service operation through automatic injection execution. The processor automatically controls the plunger rod to advance and retract, and the needle guard automatically covers the needle after injection, allowing the user to simply activate the device without manual manipulation of injection components.
Solution Approach 2:
The patent replaces manual mechanical operation with an automated control system. A processor receives activation input and automatically controls the plunger rod movement and needle guard positioning, substituting human manual operations with electronic control and automated mechanical actuation.
2Reliability
If needle guard is not provided, then device complexity is reduced, but object-affected harmful factors increase due to needle stick injuries
Solution Approach 1:
The needle guard is positioned to automatically cover the needle after injection completes. This preliminary action occurs as part of the automated retraction sequence, where the processor controls the needle guard to move into the covering position before the user can accidentally contact the needle.
Solution Approach 2:
The device converts the potentially harmful exposed needle into a safe configuration through automated guarding. The same automated control system that manages injection also manages needle coverage, turning the risk of needle stick injury into a controlled safety feature that automatically engages.
3Loss of information
If injection progress indication is not provided, then device complexity is reduced, but loss of information occurs regarding injection completion
Solution Approach 1:
The device provides feedback on injection progress through an indicator mechanism. The processor monitors the plunger rod position and activates visual or tactile indicators to communicate injection status to the user, ensuring information about completion is provided without requiring complex user interpretation.
4Ease of operation
If automated injection is implemented, then ease of operation is improved, but device complexity increases
Solution Approach 1:
The device segments functions into distinct modular components: a processor for control, a plunger rod mechanism for drug delivery, a needle guard for safety, and an indicator system for feedback. This segmentation allows each component to be optimized independently while working together under automated control.
Solution Approach 2:
The processor serves multiple functions: it controls plunger rod advancement, manages needle guard positioning, monitors injection progress, and activates indicators. This multi-functionality consolidates control logic into a single component, reducing overall system complexity despite the automated capabilities.
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 modular design automates the injection process, prevents needle stick injuries, and provides clear indication of injection completion, enhancing user safety and flexibility for various drug types, including viscous solutions and biologics, while allowing for sterilization and easy module interchangeability.
Implementation Method 1
A biased means that pushes against the movable plunger or stopper of the cartridge thus pressurizing the drug contents
Implementation Method 2
A needle guard is connected to the casing, being biased outwards by a spring or the like such that the needle is always covered by the needle guard
Data Source
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AI summary
The present invention is an auto-injector for the administration and self-administration of drugs by subcutaneous, intramuscular or intra-dermal injection and for drug solutions or suspensions. The auto-injector may comprise three modules for ease of assembly, the modules principally including a standard cartridge module with stopper and septum, a power source and indicator module that pushes against the cartridge stopper pressurizing contents, an injection progress indicator and a needle shuttle comprising of two needles, one needle being the injection needle and one needle being the septum needle. A needle guard ensures that the needle is always covered thus hiding the needle before and after the injection and that prevents needle stick injuries after use.