Retractable Syringe Dual Locking Mechanism and Fluid Delivery
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Solution Overview
Problem
Current retractable syringes face challenges in ensuring safety and efficiency while maintaining low manufacturing costs, particularly in mass production, and fail to adequately prevent syringe re-use and needle stick injuries.
Innovation Solution
A retractable syringe design featuring a plunger with dual locking mechanisms, a biasing member for automatic needle retraction, and a needle assembly with self-centering and adhesive guide channels, which includes a lock to prevent re-use and needle exposure after fluid delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If retractable syringes are designed with locking mechanisms to prevent re-use and needle stick injury, then safety is improved, but device complexity increases
Solution Approach 1:
The locking mechanism is divided into two independent locking members: a first locking member that locks the plunger member to the plunger outer, and a second locking member that locks the plunger outer to the barrel. This segmentation allows each locking member to be simpler in design while collectively providing robust safety functionality.
Solution Approach 2:
The locking members are designed to automatically engage at predetermined positions during the injection process. The first locking member engages after needle retraction, and the second locking member engages at the end of fluid delivery, preventing any manual manipulation without requiring complex control systems.
2Reliability
If dual locking members are added to prevent syringe re-use, then reliability is improved, but manufacturing cost increases
Solution Approach 1:
The syringe is designed as a single-use disposable device with integrated locking mechanisms that are cost-effective to manufacture. The locking members are simple mechanical components that can be produced economically at scale, ensuring that the added safety functionality does not significantly increase manufacturing costs.
3Reliability
If automatic needle retraction is implemented using a biasing member, then safety is improved, but device complexity increases
Solution Approach 1:
The biasing member (spring) is pre-loaded during assembly to automatically retract the needle after injection without requiring additional power sources, motors, or complex control systems. The spring simply releases its stored energy to drive the retraction mechanism, providing self-powered safety functionality.
4Productivity
If fluid conduits are integrated into the plunger seal for efficient fluid delivery, then productivity is improved, but manufacturing precision requirements increase
Solution Approach 1:
The fluid conduits are integrated directly into the plunger seal component, merging the sealing function and fluid delivery function into a single part. This eliminates the need for separate fluid channels in the barrel or additional connecting components, reducing the number of precision alignment requirements while maintaining efficient fluid delivery.
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 design provides a user-friendly, safe, and efficient syringe that minimizes re-use and needle stick risks, with cost-effective mass production capabilities and reduced fluid wastage, ensuring effective locking mechanisms and efficient fluid delivery.
Implementation Method 1
the plunger further comprises a biasing member, wherein the plunger member and plunger outer co-operate to releasably maintain said biasing member in an initially energized state. Suitably, retraction of said retractable needle is facilitated by a release of energy from said biasing member.
Data Source
AI summary
A plunger, a needle assembly and a retractable syringe comprising same are provided. The plunger comprises a plunger member and a plunger outer having a lock spring that prevents or impedes movement of the plunger member after needle retraction. The plunger further comprises another locking member for engaging the barrel to prevent or impede further movement of the plunger outer after delivery of fluid contents. The plunger member has a plunger seal which engages a retractable needle of the needle assembly for retraction. The retractable needle comprises a cannula and needle body with a plurality of fluid channels that co-operate with a fluid conduit of the plunger seal to efficiently direct fluid to the cannula. A needle retainer comprises a plurality of barbed arms releasably coupled to the needle body, whereby an ejector with tabs facilitates release of the retractable needle from the needle retainer to allow compressed spring-driven retraction.