Transseptal Needle Tip Geometry Prevents Sheath Wall Shavings

Solution Overview

Problem

Transseptal crossing procedures, which involve accessing the left atrium from the right atrium of the heart, are challenging due to the reliance on operator skill and the creation of shavings during needle penetration, which can lead to complications and require significant training.

Innovation Solution

The design of a transseptal crossing needle device with an improved needle tip that has a downwardly sloping transverse end surface, reducing contact with the inner sheath walls and incorporating echogenic markers for enhanced ultrasound visualization, along with spacer devices to ensure precise needle placement, minimizes shavings and improves safety and ease of delivery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the needle tip is positioned close to the inner sheath end for accurate delivery, then the needle placement precision is improved, but material shavings are generated during penetration

Engineering Contradiction:

Improveneedle placement precisionVSAvoidmaterial shavings

Core Design Contradiction:

Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The needle tip geometry is inverted from the conventional design. Instead of a transverse cut tip that creates shavings, the patent uses a tip with a downwardly sloping transverse end surface that angles away from the inner sheath walls, causing material to be pushed aside rather than cut away, thereby eliminating shavings while maintaining placement precision

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The needle tip is given a specific local geometric quality with a downwardly sloping transverse end surface. This localized geometric feature at the tip creates a controlled interaction with the tissue, directing force away from the sheath walls to prevent shaving while ensuring precise penetration at the intended target location

Inventive Principle:

Principle #3Local quality

2Ease of operation

If the needle tip contacts the inner sheath walls during delivery, then the needle is guided along the sheath, but material shavings are created

Engineering Contradiction:

Improveneedle delivery guidanceVSAvoidmaterial shavings

Core Design Contradiction:

Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The needle tip geometry is inverted from the conventional design. Instead of a transverse cut tip that creates shavings, the patent uses a tip with a downwardly sloping transverse end surface that angles away from the inner sheath walls, causing material to be pushed aside rather than cut away, thereby eliminating shavings while maintaining placement precision

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The needle tip is given a specific local geometric quality with a downwardly sloping transverse end surface. This localized geometric feature at the tip creates a controlled interaction with the tissue, directing force away from the sheath walls to prevent shaving while ensuring precise penetration at the intended target location

Inventive Principle:

Principle #3Local quality

3Reliability

If multiple visualization checks are used for safe transseptal crossing, then the safety is improved, but the procedure complexity increases

Engineering Contradiction:

Improveprocedure safetyVSAvoidprocedure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent incorporates echogenic markers on the needle shaft that reflect ultrasound waves, creating visible markers on ultrasound imaging. These markers provide continuous visual feedback about needle position and orientation during the procedure, enhancing safety through improved visualization without adding mechanical complexity to the device itself

Inventive Principle:

Principle #32Color changes

Solution Approach 2:

The patent replaces complex mechanical safety mechanisms with a simpler visualization-based approach. By using echogenic markers that provide visual feedback on ultrasound imaging, the system achieves safety through information provision rather than through complex mechanical interlocks or safety devices

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The improved needle tip reduces material shavings and enhances visualization, making the procedure safer and easier by reducing reliance on operator skill, while the echogenic markers and spacer devices facilitate accurate needle placement, reducing the risk of complications.

Implementation Method 1

incorporating echogenic markers for enhanced ultrasound visualization

Methodology Applied

Scientific EffectUltrasound reflection: Reflection

Data Source

PatentUS10327811B2Transseptal crossing needle device

Publication Date: 2019.06.25 CREGANNA UNLTD

AI summary

In a transseptal crossing needle device for inserting an outer sheath through a septum, an inner dilator sheath is received within the outer sheath and a needle having a curved end portion adjacent a tip of a tip portion of the needle is provided, the needle being received in the inner dilator sheath. The needle tip portion comprises an angled transverse end surface terminating at said tip and slanting away from an inner concave curved wall of said inner sheath curved by the needle curved end portion, the needle tip being spaced not only away from said inner concave curved wall of said inner sheath but also away from an inner convex curved wall of said inner sheath opposite said concave wall to reduce or eliminate skiving of material from the concave and convex inner walls of the inner sheath.