Auto-Disable Prefilled Syringe With Radial Plunger Spring
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Solution Overview
Problem
Existing prefilled syringes are susceptible to misuse due to their design, leading to the risk of infection and high costs associated with preventing reuse, despite efforts to address this issue.
Innovation Solution
A plunger rod with a radial spring mechanism and a separable design from the syringe barrel, allowing for efficient disposal and recycling, and a plunger stopper that prevents reuse by ensuring it cannot be pulled back.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional prefilled syringes are designed with minimal dead space and high quality glass to assure complete drug release, then the syringe performance is improved, but the syringe becomes susceptible to reuse and misuse
Solution Approach 1:
The syringe is divided into two separate components: a reusable barrel containing the drug and a disposable plunger rod with the spring mechanism. This segmentation allows the barrel to maintain its integrity for complete drug release while the plunger rod is discarded after single use, preventing reuse and misuse.
Solution Approach 2:
The plunger rod is designed as a disposable component that is discarded after single use. This eliminates the risk of reuse and misuse while maintaining the reliability of the barrel system. The plunger rod includes a spring mechanism that provides the necessary force for injection and then is discarded to prevent any attempt at reuse.
2Object-affected harmful factors
If measures are taken to prevent syringe reuse, then the infection risk is reduced, but the manufacturing cost increases significantly
Solution Approach 1:
By segmenting the syringe into a reusable barrel and disposable plunger rod, the cost of preventing reuse is distributed. The barrel, which contains the expensive drug, is reused multiple times, while only the relatively inexpensive plunger rod is discarded. This significantly reduces the overall manufacturing cost compared to making the entire syringe disposable.
Solution Approach 2:
The plunger rod is designed as a cheap disposable component that prevents reuse. Its low cost allows it to be discarded after single use without significantly impacting the overall manufacturing cost, while effectively preventing infection risk through reuse.
3Ease of operation
If the plunger rod is connected to the plunger stopper to ensure proper force transmission, then the injection function is improved, but the plunger stopper can be pulled back enabling reuse
Solution Approach 1:
The plunger rod is segmented from the plunger stopper, with the plunger stopper remaining fixed in the barrel while the plunger rod can be removed. This segmentation allows proper force transmission during injection through the spring mechanism, while the separable design prevents the plunger stopper from being pulled back, eliminating reuse.
4Productivity
If the plunger rod is made as a separate removable component, then the disposal and recycling efficiency is improved, but the manufacturing complexity increases
Solution Approach 1:
The plunger rod is designed as a separate removable component that can be easily separated from the barrel. This segmentation improves disposal and recycling efficiency by allowing the plunger rod to be discarded separately from the reusable barrel. The manufacturing complexity is managed through standardized connection interfaces and simple assembly procedures.
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 effectively prevents reuse of the syringe while maintaining manufacturing costs similar to conventional syringes, reducing infection risks and improving disposal efficiency.
Implementation Method 1
The plunger rod further comprises a radial spring mechanism, adapted to interact with an inner surface of the barrel
Implementation Method 2
the plunger rod is made of a thermoplastic polymer having a Young's modulus within the interval 500 MPa to 2000 MPa
Data Source
AI summary
A syringe may include a barrel with a needle. A plunger stopper may be disposed within the barrel, and displaceable along an axis of the barrel. A plunger rod may be provided with an elongated rod, and adapted to be inserted into the barrel. The plunger rod may be adapted to transmit force to the plunger stopper. A radial spring mechanism may be provided on the elongated rod, and may interact with an inner surface of the barrel. The radial spring mechanism may be located radially outward from a center portion of the elongated rod. The center portion of the elongated rod may extend through the radial spring mechanism. The plunger stopper may be adapted to receive force from the plunger rod. The plunger rod may not be connected to the plunger stopper, such that the plunger stopper cannot be pulled back by the plunger rod.