Universal Safety Syringe Automatic Needle Retraction
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Solution Overview
Problem
Current syringes used for injection and removal of fluids pose risks of needle sticks and microbial transmission due to contamination, with existing safety devices requiring user activation, potentially exposing healthcare workers to hazards and lacking tamper-proof mechanisms, especially in developing countries where re-use and inadequate disposal are prevalent.
Innovation Solution
A universal safety syringe design that automatically retracts the needle upon completion of injection, self-disables to prevent re-use, and securely locks the needle inside the barrel, eliminating the need for sharps containers and ensuring passive operation without user intervention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If existing safety devices (sheaths, hinged devices, sliding devices) are used to cover needles after use, then needle protection is improved, but user activation is required which may expose healthcare workers to hazards and hands must be positioned near the exposed sharp end
Solution Approach 1:
The syringe automatically retracts the needle into the barrel after injection completion without requiring user activation. The retraction mechanism is triggered automatically when the plunger reaches its forward limit position, eliminating the need for manual operation and keeping hands away from the needle throughout the process.
Solution Approach 2:
The patent replaces manual mechanical activation with an automatic mechanical trigger system. A trigger member is actuated by the plunger's movement to release the needle holder, allowing spring-driven retraction to occur automatically without user intervention.
2Object-affected harmful factors
If retractable needle syringes are used with spring mechanisms, then needle retraction is achieved, but the rubber stopper or plug must be cut or displaced which requires voluntary user action and transmits impact to the needle point while still in the patient's body
Solution Approach 1:
The patent extracts the cutting/displacing operation from the retraction trigger mechanism. Instead of requiring the rubber stopper to be cut or displaced, the trigger member is actuated by the plunger's forward movement alone, eliminating the harmful impact transmission to the needle point while maintaining automatic retraction.
3Object-affected harmful factors
If retractable needle syringes are used, then needle retraction is achieved, but there is danger of aerosol and microbial spread to others during the retraction process when the needle is taken out of the patient's body
Solution Approach 1:
The patent implements rapid automatic retraction that occurs immediately when the plunger reaches its forward limit. The needle is quickly retracted into the barrel without prolonged exposure, minimizing the time window for aerosol and microbial spread while the healthcare worker's hands remain positioned safely away from the needle.
4Object-affected harmful factors
If retractable needle syringes are used, then needle retraction is achieved, but the devices are not tamper proof and the contaminated needle can escape and cause needle stick injury and microbial transmission
Solution Approach 1:
The patent nests the needle holder and needle within the barrel, with the needle holder being retractable into the barrel's interior. The trigger mechanism and spring are also contained within the barrel, creating a nested configuration that prevents the needle from escaping and ensures all components remain contained during operation and disposal.
Solution Approach 2:
The patent employs a dynamic trigger mechanism that automatically actuates when the plunger reaches its forward limit position. The trigger member moves from a locked to an unlocked position, releasing the needle holder for spring-driven retraction. This automatic dynamic response ensures reliable operation without manual intervention and prevents tampering.
5Object-affected harmful factors
If retractable needle syringes are used, then needle retraction is achieved, but they require disposal in sharps containers which is expensive and not available in many countries
Solution Approach 1:
The patent nests the needle holder and needle within the barrel, with the needle holder being retractable into the barrel's interior. The trigger mechanism and spring are also contained within the barrel, creating a nested configuration that prevents the needle from escaping and ensures all components remain contained during operation and disposal.
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 syringe effectively prevents needle sticks and microbial transmission by ensuring the needle is never exposed after use, reducing healthcare costs and improving safety globally, even in regions with limited sharps disposal infrastructure.
Implementation Method 1
a spring surrounding the needle holder and compressed between the needle holder and the distal end of the barrel for retracting the needle holder and the needle
Data Source
AI summary
A syringe comprises a generally-cylindrical, hollow barrel with a hollow nozzle at a distal end thereof. A plunger with an open channel is slidably mounted in the barrel. A needle holder with a needle mounted at one end thereof is arranged in the plunger channel, and movable between an advanced position, whereat the needle projects from a distal end of the nozzle for injection, and a retracted position, whereat the needle is enclosed within the barrel when the injection is complete. A spring retainer is arranged in the barrel. A spring is positioned within the spring retainer, urging the needle holder toward the retracted position. A latch latches the needle holder to the spring retainer thereby maintaining the spring in compression. The latch is releasable in response to the plunger moving to its fully advanced position, whereby the needle holder is released, allowing the spring to expand and thereby move the needle holder to the retracted position.