Safety Needle Assembly for Single-Handed Retraction and Flushing
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Solution Overview
Problem
Existing medical needle assemblies for vascular access systems face challenges such as inadvertent needle sticks and blood backflow during removal, which are cumbersome and cosmetically undesirable, and require complex flushing techniques that often need two hands to perform.
Innovation Solution
A medical safety needle assembly with a slidable needle design and a connection hub that allows single-handed removal and positive flushing, featuring a handle and attachment elements for easy manipulation and a low profile to minimize exposure above the skin.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a Huber needle is used to minimize needle height above skin, then the needle extends minimally above the skin, but the force to remove the needle is high due to radial compression by the elastomeric septum
Solution Approach 1:
The needle is designed with a bend that allows it to flex dynamically during insertion and removal. The bend enables the needle to deform under radial compression from the elastomeric septum, reducing the force required for removal while maintaining the low-profile configuration when inserted.
Solution Approach 2:
The needle geometry is modified by introducing a bend that changes the mechanical parameters of the needle. This bend alters the stress distribution and deformation characteristics, allowing the needle to accommodate radial compression with lower removal forces while maintaining minimal extension above the skin.
2Loss of time
If the needle is removed early from the vascular access port, then the procedure is completed quickly, but blood draws into the distal end of the catheter causing thrombus formation risk
Solution Approach 1:
The system enables preliminary flushing action to be performed before needle removal. By providing a mechanism to inject flushing solution through the needle hub before extraction, the system prepares the catheter lumen to prevent blood backflow and thrombus formation, allowing safe early removal.
3Ease of operation
If a regular hypodermic needle is inserted into the elastomeric septum, then insertion is simple, but there is an elevated risk that the needle may core particles from the septum
Solution Approach 1:
The needle tip is designed with specific local qualities including a Huber tip configuration with a bend that creates a slit rather than a core when penetrating the elastomeric septum. This localized design modification at the tip prevents particle coring while maintaining ease of insertion through the septum.
4Reliability
If safety devices with wings are used to prevent inadvertent needle sticks, then needle stick risk is reduced, but the device extends significantly above the skin and is cosmetically undesirable
Solution Approach 1:
The safety shield is designed to nest over the needle in a compact configuration. When retracted, the shield folds or collapses to minimize extension above the skin, providing safety functionality while maintaining a cosmetically acceptable low profile similar to the Huber needle configuration.
Data Source
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AI summary
Medical safety needle assembly comprising a medical needle (14) having a distal and a proximal end and a stem extending there between, the needle having a tip at its distal end, the proximal end of the needle being connected to a tubing (15) with a connection hub for connecting the tubing (15) to a syringe (30), the connection being able to resist tensile loads, and a base plate (10) the needle (14) extending slidably through the base plate (10) and having an inserted position with the needle tip extending in distal direction from the base plate (10) and a retracted position with the needle tip being in a position inside a cavity of the base plate, characterized in that the needle comprises a first attachment element at its proximal side of the base plate (10), and the connection hub comprises a second attachment element (31) being able to engage with the first attachment element in order to pull the needle (14) through the base (10) plate into its retracted position.