Laser-Welded NiTi Stent End Coupling for Stable Expansion

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Solution Overview

Problem

Existing medical devices, such as stents, face challenges in securely joining strand ends made of nickel-titanium materials, particularly in maintaining structural integrity and consistency during insertion and expansion within anatomical structures.

Innovation Solution

The use of coupling structures that are welded to the strand end portions, with the coupling structure being positioned in direct contact before welding, and configured to have a passageway or be axially aligned, ensuring secure alignment and stability without direct connection between welded regions, and utilizing laser welding for securing these structures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If coupling structures are welded to strand end portions to secure connections, then structural integrity and reliability are improved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:

Improveconnection reliabilityVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

A coupling structure serves as an intermediary component between strand end portions, providing a secure connection point. The coupling structure includes a body with a passageway that receives the strand end, and a welded region that is welded to the strand to create a reliable connection without directly joining the strands themselves.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The connection system is segmented into distinct components: the coupling structure body, the passageway for receiving the strand end, and the welded region. This segmentation allows each component to be optimized independently and simplifies the overall assembly process while maintaining connection reliability.

Inventive Principle:

Principle #1Segmentation

2Length of moving object

If coupling structures are made smaller relative to device length, then device compactness is improved, but manufacturing precision requirements increase

Engineering Contradiction:

Improvecoupling structure lengthVSAvoidalignment precision

Core Design Contradiction:

Length of moving objectVSManufacturing precision

Solution Approach 1:

The strand end portion is inserted into the passageway of the coupling structure before welding occurs. This preliminary positioning action ensures proper alignment and reduces the precision requirements for the welding process itself, as the geometry of the passageway guides the strand end into the correct position.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The coupling structure is designed with specific dimensional parameters where its length is less than a specified percentage (e.g., less than 25%, 20%, or 10%) of the overall device length. This parameter optimization allows the coupling structure to be compact while maintaining sufficient space for reliable welding and strand reception.

Inventive Principle:

Principle #35Parameter changes

3Strength

If welding is used to secure coupling structures to strand ends, then connection strength is improved, but heat-affected zone and material property changes increase

Engineering Contradiction:

Improvewelded region strengthVSAvoidheat-affected zone

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The welding process replaces mechanical fastening methods (such as threading or clamping) with a thermal joining process. This substitution creates a stronger, more integrated connection between the coupling structure and the strand end, while the localized nature of welding minimizes the heat-affected zone compared to alternative joining methods.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The welded region is designed to create a self-reinforcing connection where the weld metal fuses the coupling structure body to the strand end portion, forming an integrated structure that strengthens itself through the welding process without requiring additional fastening elements or post-processing.

Inventive Principle:

Principle #25Self-service

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

This method provides a secure and stable connection of strand ends, maintaining device integrity and consistency, allowing for effective deployment and expansion within anatomical structures, while ensuring that the coupling structures are not overly burdensome in size relative to the device.

Implementation Method 1

The securing may be accomplished by welding (e.g., laser welding) the coupling structure to the first strand end portion to create a first welded region and by welding the coupling structure to the second strand end portion to create a second welded region.

Methodology Applied

Scientific EffectLaser welding: Laser Beam Welding

Data Source

PatentUS9149374B2Methods for manufacturing secured strand end devices

Publication Date: 2015.10.06 IDEV TECHNOLOGIES INC

AI summary

A woven, self-expanding stent device has one or more strands and is configured for insertion into an anatomical structure. The device includes a coupling structure secured to two different strand end portions that are substantially aligned with each other. The two different strand end portions include nickel and titanium. The coupling structure is not a strand of the device.