NiTi Strand-End Coupling for Reliable Self-Expanding Stents

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Solution Overview

Problem

Existing medical devices, such as stents and occluders, 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, which are welded to the strand end portions using laser welding, to secure the ends of devices configured for insertion into anatomical structures, ensuring alignment and stability while allowing for axial expansion and compression, and utilizing nickel-titanium materials for compatibility and strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If coupling structures are welded to strand end portions using laser welding, then structural integrity and alignment are improved, but manufacturing complexity increases

Engineering Contradiction:

Improvestructural integrityVSAvoidmanufacturing complexity

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The coupling structures are positioned and aligned with the strand end portions before welding begins. The laser welding process is prepared with predetermined parameters and positioning fixtures in advance, allowing for precise joining without requiring complex real-time adjustments during manufacturing.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Traditional mechanical joining methods (such as mechanical fasteners or interference fits) are replaced with laser welding technology. This substitution provides stronger, more reliable joints while the automation of laser welding systems actually reduces overall manufacturing complexity compared to precision mechanical assembly.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If coupling structures are used to secure strand ends, then reliability of device deployment is improved, but device length increases

Engineering Contradiction:

Improvereliability of device deploymentVSAvoiddevice length

Core Design Contradiction:

ReliabilityVSLength of moving object

Solution Approach 1:

The coupling structures are designed with non-uniform geometry, featuring concentrated mass at the welding interfaces and minimized material in the central region. This local quality variation ensures strong mechanical coupling at critical points while keeping the overall device length as short as possible.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The coupling structures are positioned within or between the strand loops of the device, utilizing the existing spatial arrangement of the strands. This nesting approach allows the coupling structures to be integrated into the device architecture without adding significant external length.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Stability of the object's composition

If multiple coupling structures are used to secure all strand ends, then structural consistency is improved, but manufacturing time increases

Engineering Contradiction:

Improvestructural consistencyVSAvoidmanufacturing time

Core Design Contradiction:

Stability of the object's compositionVSLoss of time

Solution Approach 1:

Multiple laser welding operations are combined into a single automated manufacturing cycle. The coupling structures are positioned simultaneously, and the laser welding system performs multiple welds in sequence without requiring intermediate handling or setup changes, thereby maintaining structural consistency while minimizing total manufacturing time.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

A single coupling structure design is used for all strand ends throughout the device, providing universal applicability. This standardization allows the same manufacturing process and welding parameters to be applied repeatedly across all coupling structures, reducing variability and streamlining production.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 effectively secures strand ends, maintaining structural integrity and consistency, enabling reliable deployment and expansion of medical devices within anatomical structures, enhancing their performance and durability.

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

PatentUS8419788B2Secured strand end devices

Publication Date: 2013.04.16 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.