Subcutaneous Infusion Device Hub Ribs for Needle Stability
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Solution Overview
Problem
Conventional subcutaneous infusion devices face challenges with delivering highly viscous medicinal substances due to excessive pressure buildup and clogging, as well as instability and breakage of needles during use, especially when administering medicines with high viscosity and high flow rates.
Innovation Solution
The medical fluid delivery device features a 24G needle with a thin tubular wall and a mid-region slightly bent at a predetermined radius, along with a hub design that includes asymmetric top ribs to prevent wing twisting and sliding, and diagonally disposed bottom ribs to stabilize the hub and reduce movement, thereby minimizing flow resistance and enhancing needle stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional needle design is used, then the device structure is simple, but the needle is prone to breakage and kinking when delivering highly viscous substances at high flow rates
Solution Approach 1:
The needle is divided into distinct functional segments: a straight insertion portion for piercing the skin, a bent delivery portion for subcutaneous fluid delivery, and a support region with increased rigidity to prevent kinking. This segmentation allows each part to be optimized for its specific function while maintaining overall reliability.
Solution Approach 2:
The needle has non-uniform structural properties along its length, with the support region featuring increased wall thickness or reinforcement to provide localized kinking resistance. The bent portion has specific curvature radius optimized for both insertion and delivery functions, while the tip remains sharp for penetration.
2Ease of operation
If the needle diameter is reduced for smaller gauge needles, then the device is more comfortable for users, but the needle is not supported firmly and causes breakage during use
Solution Approach 1:
The needle features localized structural reinforcement at the support region with increased wall thickness or material density, while maintaining a thinner wall in the delivery portion for comfort. This allows small gauge needles (e.g., 28G-30G) to provide both comfort and sufficient support stability during use.
Solution Approach 2:
The needle may utilize composite material structures combining different materials with complementary properties - such as a core material for strength and a outer coating for smoothness and flexibility. This allows optimization of both comfort and support stability in thin-walled small gauge needles.
3Reliability
If the hub is made with foldable gripping wings for secure needle holding, then the needle insertion is stabilized, but the wings may slide against each other during insertion making it challenging
Solution Approach 1:
The gripping wings feature asymmetric geometry with different angles, widths, or surface textures on each wing. This asymmetric design provides secure needle holding while the specific geometric configuration allows the wings to move smoothly relative to each other during insertion without excessive friction or sliding.
Solution Approach 2:
The hub design includes pre-formed gripping surfaces and geometric features that are optimized for the insertion motion sequence. The wings are positioned and shaped to engage the needle shaft at the appropriate moment during insertion, providing security without requiring forceful manipulation.
4Productivity
If conventional subcutaneous infusion devices are used, then the device structure is simple, but excessive delivery pressure builds up and clogging occurs when delivering highly viscous substances
Solution Approach 1:
The needle delivery portion features a specific curvature radius that optimizes fluid flow dynamics. The bent geometry with controlled radius reduces flow resistance by preventing sharp angular transitions, allowing highly viscous substances to flow smoothly at high rates without excessive pressure buildup or clogging.
Solution Approach 2:
The needle geometry parameters are optimized for viscous fluid delivery, including specific wall thickness, bending radius, and tip angles that reduce flow resistance. The hub and needle interface geometry is also designed to minimize turbulence and pressure drops during high flow rate delivery of viscous substances.
Data Source
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AI summary
A medical delivery device is provided for delivering a medicinal substance into a user's body. A foldable hub (18) has a left wing (20) and a right wing (22), where the hub is attached at one end to a tube (16), and at an opposite end to a needle (28). At least one first rib (32) is disposed on the left wing and at least one second rib (34) is disposed on the right wing. When the wings are folded back away from the needle and pinched together, the first and second ribs prevent twisting and/or sliding of the wings relative to each other during an insertion of the needle into a user's skin, thereby preventing a breakage of the needle due to undesirable movement of the wings.