Nested Needle-Cannula Assembly for Reduced Vessel Trauma

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Solution Overview

Problem

Inserting large needles or catheters into vessels, especially those with thick or tough walls, is challenging due to the need for precise placement to avoid trauma, and existing methods like blunt-tipped cannulas or the Seldinger technique are either difficult to implement or impractical for dialysis settings.

Innovation Solution

A nested assembly of a small sharp needle, a larger cylindrical cannula with expanding diameters and cutting surfaces, and a large access needle, where the small needle is retracted into the cannula after initial entry, allowing the cannula to enlarge the vessel entry hole and minimize trauma, and the access needle is advanced while surrounding the cannula.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a large needle with a sharp tip is used to puncture the vessel wall, then the needle can easily penetrate the vessel, but the needle may contact the vessel wall during advancement causing trauma to the vessel lining

Engineering Contradiction:

Improvepenetration capabilityVSAvoidvessel wall trauma

Core Design Contradiction:

ForceVSObject-affected harmful factors

Solution Approach 1:

The device segments the insertion process into multiple stages: first the sharp needle penetrates the vessel wall, then the blunt cannula is advanced to dilate and guide, and finally the needle is withdrawn leaving only the cannula in place. This segmentation allows each component to perform its specific function without causing unnecessary trauma.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The blunt-tipped cannula acts as an intermediary between the sharp needle and the vessel wall. After the needle creates the initial puncture, the cannula is advanced over the needle to gently dilate the tract and guide the needle into proper position without the sharp tip contacting the vessel wall during advancement.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If a blunt-tipped cannula is used to advance into the vessel, then vessel trauma is minimized, but more force is required and the cannula may not advance to the correct position

Engineering Contradiction:

Improvevessel wall traumaVSAvoidinsertion force

Core Design Contradiction:

Object-affected harmful factorsVSForce

Solution Approach 1:

The sharp needle performs the preliminary action of creating a pilot tract through the vessel wall before the blunt cannula is advanced. This preliminary puncture reduces the resistance the cannula must overcome, allowing it to advance smoothly with minimal force while still minimizing vessel trauma.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The needle is nested within the cannula during insertion. The cannula surrounds the needle, and as the assembly is advanced, the needle leads the way through tissue while the cannula follows, protected by the needle's sharp tip. This nested configuration allows the blunt cannula to benefit from the needle's penetration capability.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Stability of the object's composition

If the needle is advanced deeply into the vessel to ensure proper positioning, then stability is improved, but the sharp tip may impinge on the vessel wall causing damage

Engineering Contradiction:

Improveneedle stabilityVSAvoidvessel lining damage

Core Design Contradiction:

Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The sharp needle is extracted from the vessel after serving its purpose of creating the initial puncture and guiding the cannula. Once the cannula is properly positioned and stabilized in the vessel, the needle is withdrawn, leaving only the blunt cannula in place. This extraction eliminates the source of potential vessel wall trauma while maintaining the stability provided by deep insertion.

Inventive Principle:

Principle #2Taking out (Extraction)

4Object-affected harmful factors

If a catheter with a blunt tip is used for dialysis access, then vessel trauma is reduced, but the catheter is more difficult to insert into thick-walled vessels and costs more

Engineering Contradiction:

Improvevessel wall traumaVSAvoidinsertion difficulty

Core Design Contradiction:

Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The device merges the advantages of both sharp needles and blunt catheters into a single integrated system. The needle-cannula assembly combines the penetration capability of a sharp needle with the trauma-minimizing properties of a blunt catheter, allowing easy insertion into thick-walled vessels while reducing vessel damage.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS20230226320A1Method of making large needle insertion into an artery or vein easier and with less unnecessary trauma to the blood vessel and methods for manufacturing same (NISE)

Publication Date: 2023.07.20 HEMOCLEANSE TECHNOLOGIES LLC

AI summary

A method and devices for making needle insertion safer and easier (NISE). NISE or CISE device includes a small needle, cannula, and large needle in a nested assembly to provide less trauma to a target vessel during large needle insertion. The small needle is movable and within the cannula to a position exterior the cannula. The cannula is movable within the large needle. In a preferred assembly, the cannula is provided with a dulled tip having a beak and successive cutting edges along a tapered shape. The device can be provided in a stand-alone device or alternately integrated into existing off the shelf and currently available vascular devices.