Tapered Dilator for Catheter Advancement and Flashback Detection
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Solution Overview
Problem
Existing venipuncture methods face challenges in using large diameter catheters with smaller diameter needles, which can be painful and delay the observation of blood flashback, leading to potential misplacement of the needle.
Innovation Solution
A needle and catheter assembly with a tapered dilator element that transitions from a smaller needle diameter to a larger catheter diameter, allowing for reduced needle size and rapid blood flashback detection through a dedicated port, minimizing patient discomfort and procedural delays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a large diameter needle is used to advance a large diameter catheter, then the catheter can be properly introduced into the vein, but the patient experiences increased pain and discomfort
Solution Approach 1:
The device is divided into separate functional components: a smaller gauge needle for vein penetration, a tapered dilator element for gradual tissue expansion, and a large diameter catheter for fluid delivery. This segmentation allows each component to be optimized for its specific function while avoiding the need to use a large gauge needle that would cause patient pain.
Solution Approach 2:
The tapered dilator element serves as an intermediary component between the small needle and the large catheter. It gradually expands the tissue tract created by the needle, enabling the larger catheter to be introduced through a smaller needle opening without causing excessive pain or tissue damage.
2Ease of operation
If a long needle is used to advance the catheter, then the catheter can reach the vein, but there is a delay in observing blood flashback indicating proper placement
Solution Approach 1:
The flashback detection function is extracted from the needle tip and relocated to a flashback chamber positioned closer to the hub of the needle assembly. This allows blood to be visualized much sooner after vein entry, reducing the detection delay while maintaining the ability to access veins at appropriate depths.
Solution Approach 2:
The flashback observation point is moved from the distal end of the needle (far from the user) to a proximal location near the hub (close to the user). This spatial repositioning in another dimension of the assembly allows for timely visual confirmation of vein entry without requiring the user to observe the distant needle tip.
3Object-affected harmful factors
If the needle cross-sectional area is reduced for patient comfort, then patient pain is reduced, but the catheter cannot be properly advanced through the needle
Solution Approach 1:
The dilator element features a varying cross-sectional area along its length, with the distal portion having a smaller diameter that matches the needle opening for easy insertion, and the proximal portion having a larger diameter that matches the catheter outer diameter for proper catheter advancement. This local variation in geometry allows the device to satisfy both constraints.
Solution Approach 2:
The dilator element's cross-sectional dimensions are changed progressively along its length, transitioning from a small diameter at the distal end to a large diameter at the proximal end. This parameter change enables the dilator to pass through the small needle opening and then expand to accommodate the larger catheter.
Data Source
AI summary
Intravenous access is achieved by introducing a catheter over an access needle which is initially present in the catheter. A tapered dilating element is positioned over the needle and provides a transition between the needle and a larger catheter lumen. The access needle is hollow and has a port which allows blood to flash back through a lumen of the catheter so that flashback can be observed on a catheter hub or the catheter itself