Tapered Needle and Outer Sleeve for Vascular Access
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Solution Overview
Problem
The existing Seldinger percutaneous entry technique requires a large needle for initial vascular access, which can cause tissue damage and excessive bleeding, and smaller gauge needles are insufficient to accommodate standard wire guides needed for many medical devices.
Innovation Solution
A needle with an intermediate taper and an outer sleeve that receives the needle, allowing for a smaller initial needle entry with a larger wire guide introduction through the sleeve, reducing tissue trauma and enabling access to larger vessels with fewer components and steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a large gauge needle (e.g., 18 gauge) is used for initial vascular access, then the needle can accommodate standard wire guides (0.035-0.038 inch diameter), but the needle causes tissue damage and excessive bleeding
Solution Approach 1:
The needle is divided into two distinct segments: a small gauge outer needle (21-25 gauge) for initial puncture and a larger bore inner needle for wire guide passage. This segmentation allows each segment to fulfill its specific function optimally - the outer needle minimizes tissue trauma while the inner needle provides sufficient bore diameter for standard wire guides.
Solution Approach 2:
The inner needle with larger bore is nested within the outer small gauge needle. This nesting configuration allows the combination to function as a unified initial access device, where the inner needle's larger bore enables wire guide passage through the otherwise restricted outer needle, eliminating the need to choose between small gauge safety and wire guide compatibility.
2Object-affected harmful factors
If a small gauge needle (e.g., 21 gauge or smaller) is used for initial entry, then tissue damage and bleeding are minimized, but the needle bore is too small to accommodate standard wire guides
Solution Approach 1:
The needle system is segmented into an outer small gauge needle for safe initial puncture and an inner larger bore needle for wire guide accommodation. This segmentation resolves the contradiction by allowing the outer needle to minimize tissue damage while the inner needle ensures wire guide compatibility.
Solution Approach 2:
The inner needle acts as an intermediary element that mediates between the outer small gauge needle and the wire guide. It provides the necessary larger bore diameter for wire guide passage while being contained within the protective outer needle during initial insertion.
3Adaptability or versatility
If a multi-component system with inner cannula and outer sleeve is used, then wire guide compatibility is achieved, but the device complexity and number of insertion steps increase
Solution Approach 1:
The inner needle and outer needle are combined into a single integrated assembly that functions as one unit during initial vascular access. This merging eliminates the need for separate insertion steps for each component, reducing procedural complexity while maintaining the ability to accommodate standard wire guides through the inner needle's larger bore.
Data Source
AI summary
The present invention is directed to apparatus and methods for gaining percutaneous access to body anatomy, for example an organ or a body lumen. According to one aspect of the invention, an apparatus is provided comprising a needle and an outer sheath. The needle is receivable within the outer sheath and comprises a plurality of outer diameters. A distal portion of the needle has a lesser diameter than a proximal portion of the needle. Other embodiments are also disclosed.