Deflectable Access Sheath With Side Ports For Viscous Material Delivery
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Solution Overview
Problem
Existing medical injection devices face challenges in delivering relatively viscous therapeutic materials to tortuous vascular pathways due to insufficient flow capacity and navigation difficulties in the vasculature.
Innovation Solution
A medical device comprising an access sheath with deflectable side ports and a needle assembly, where the main cannula provides a large flow area for viscous materials, and the needles extend through side ports to facilitate delivery, allowing for improved navigation and volumetric flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional needles are used to deliver therapeutic materials, then the injection process is simple, but the flow capacity is insufficient for viscous materials
Solution Approach 1:
The needle assembly is nested within the access sheath, with the main cannula containing multiple needles that can extend through side ports. This nested configuration allows multiple needles to be stored compactly within the sheath while enabling their deployment when needed, thereby increasing flow capacity without proportionally increasing overall device complexity.
Solution Approach 2:
The needle assembly is segmented into multiple individual needles arranged around the main cannula, rather than using a single large needle. This segmentation allows the therapeutic material to flow through multiple parallel pathways, significantly increasing the total flow capacity for viscous materials while maintaining a manageable structural complexity.
2Adaptability or versatility
If a straight needle path is used, then the injection device is simple to construct, but it cannot navigate tortuous vascular pathways
Solution Approach 1:
The access sheath incorporates a deflection section that can be actively actuated to bend at angles, transforming the sheath from a rigid straight tube to a dynamically adjustable catheter. This allows the sheath to navigate tortuous vascular pathways by being steered into position, while the remaining portion of the sheath can remain relatively simple in structure.
Solution Approach 2:
The access sheath is segmented into distinct functional sections: a relatively simple proximal section, a deflection section with active bending capability, and a distal section with side ports. This segmentation allows the complex navigation function to be localized to the deflection section while keeping other parts of the sheath structurally simpler.
3Productivity
If a single large bore needle is used, then the flow area is maximized, but the device cannot provide multiple delivery points
Solution Approach 1:
The needle assembly is segmented into multiple individual needles (typically three) arranged around the main cannula, with each needle capable of extending through side ports at different locations. This segmentation provides multiple delivery points for therapeutic material injection, while the collective flow capacity of all needles together matches or exceeds that of a single large bore needle.
Solution Approach 2:
Instead of increasing the diameter of a single needle in one dimension, the solution distributes flow capacity across multiple needles arranged in a radial pattern around the main cannula. This dimensional arrangement allows the system to achieve high volumetric flow while simultaneously providing multiple spatial delivery points along the length of the access sheath.
Data Source
Figure 1A
Figure 1B~1C
Figure 1D
AI summary
Medical device (10) for delivering therapeutic material to a patient. The device comprises an access sheath (12) having a proximal section (18) extending to a distal section (20). A working lumen (22) is formed in the proximal and distal sections. The distal section has a plurality of side ports (48) formed therethrough in fluid communication with the working lumen. The distal section has a deflection section (42) actuatable to bend at an angle for positioning the side ports in the patient. A needle assembly (14) is configured to move within the working lumen between a retracted position and an extended position. In fluid communication with a central lumen is a plurality of needles (80). The needles are disposed within the access sheath in the retracted position and the needles extend through the side ports outwardly from the access sheath in the extended position.