Needle Guard Arms Biasing for Retraction Safety
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Solution Overview
Problem
Healthcare workers face risks of accidental needle sticks and disease transmission due to the exposure of used needles during withdrawal and disposal, as existing needle safety systems do not adequately address the low friction and resistance issues during needle retraction, making them vulnerable to needle sticks.
Innovation Solution
The proposed needle safety assembly features a needle guard with a proximal wall and two arms that are biased away from the needle in a ready position, supported by a ring-shaped or projection-based support, which minimizes contact with the needle during retraction and automatically covers the needle tip upon a change in profile engaging the proximal wall, reducing resistance and preventing accidental sticks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the needle guard contacts the needle during retraction to ensure safety, then the protective function is improved, but the friction and resistance increase making retraction difficult
Solution Approach 1:
The needle guard is divided into multiple functional segments: a body portion that guides the needle, and separate arm portions that can independently engage with the needle. This segmentation allows different parts to perform different functions - the body provides guidance with minimal friction while the arms provide protective engagement when needed.
Solution Approach 2:
The needle guard employs dynamic arms that can change their position and engagement state during needle retraction. The arms are biased away from the needle in the ready position but can engage with the needle during retraction through interaction with the change in profile, providing adaptive protection that activates only when needed rather than continuous contact.
2Reliability
If the needle guard is designed to automatically cover the needle tip, then the safety function is improved, but the device complexity increases
Solution Approach 1:
The needle guard is designed to be self-actuating during needle retraction. The arms automatically engage with the needle through interaction with the change in profile on the needle shaft, and the needle itself drives the protective action during retraction. This eliminates the need for external actuators, motors, or complex control mechanisms while achieving automatic needle tip coverage.
Solution Approach 2:
The change in profile on the needle acts as an intermediary element that mediates between the needle retraction motion and the arm engagement. This simple geometric feature on the needle shaft translates the retraction motion into automatic arm engagement, providing a simple mechanism for complex protective function without adding significant structural complexity.
3Ease of operation
If the arms are biased away from the needle in ready position, then the friction during insertion is reduced, but the reliability of automatic engagement during retraction may be compromised
Solution Approach 1:
The arms are pre-biased away from the needle in the ready position to minimize friction during insertion and maintain sterility. However, the geometry of the change in profile on the needle is designed to automatically trigger arm engagement during retraction, ensuring reliable protective function is activated at the appropriate moment without requiring additional actuation.
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 significantly reduces the risk of accidental needle sticks by minimizing contact between the needle guard and the needle during retraction, enhancing safety for healthcare workers by ensuring the needle tip is protected once the change in profile engages the proximal wall, thus preventing inadvertent exposure.
Implementation Method 1
a resilient needle guard having two arms biased away from the needle
Data Source
Figure 1
Figure 2A~2B
Figure 3
AI summary
A safety needle assembly having a first hub (104) attached to a flexible tube (102) and a second hub (108) attached to a needle (106) projecting through the flexible tube. A needle guard (122) is positioned in an interior cavity of the first hub. The needle guard has a proximal wall (130) having an opening (132) and two arms (134,136) each with an end and wherein the two ends ((138,140) spaced from and biased toward the needle in a ready position. In a particular example, a support (126) is located inside the cavity of the first hub and wherein the two ends of the two arms on the needle guard rest on the support in the ready position.