Helicoidal Stent Strand Tip Rounding via Laser Spheroidality

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Solution Overview

Problem

Stents formed by helicoidally braiding strands with metal wires pose a risk of damaging blood vessels or catheters due to sharp tip ends, as existing technologies have not addressed this issue effectively.

Innovation Solution

The tip ends of the strands are rounded off, either by forming them into an approximate spherical shape, often using a laser beam, to prevent damage and ensure the stent can be stored within a catheter or storage tube.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the stent is formed by helicoidally braiding metal wire strands, then the stent structure is formed, but the sharp tip ends of the strands may damage the blood vessel or catheter

Engineering Contradiction:

Improvestent structure formationVSAvoiddamage to blood vessel or catheter

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The tip ends of the strands are rounded off to form a spherical or curved shape instead of sharp ends. This is achieved by irradiating the tip ends with a laser beam to melt and round them, eliminating the sharp corners that cause damage to blood vessels and catheters during implantation and movement.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The mechanical process of strand tip formation is replaced by laser beam irradiation. Instead of mechanical cutting or forming that leaves sharp edges, the laser beam melts and rounds the tip ends, substituting a thermal process for a mechanical one to achieve a safer tip geometry.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Object-affected harmful factors

If the tip end portion of the strand is rounded off to prevent damage, then safety is improved, but the diameter of the stent before expanding may increase

Engineering Contradiction:

Improvedamage preventionVSAvoidstent diameter before expanding

Core Design Contradiction:

Object-affected harmful factorsVSVolume of moving object

Solution Approach 1:

The laser beam irradiation is applied selectively only to the tip ends of the strands rather than the entire strand. This partial action rounds only the critical tip portions that cause damage, while minimizing the overall volume increase of the stent before expansion. The rounding radius is controlled to be just sufficient for safety without excessive material melting.

Inventive Principle:

Principle #16Partial or excessive action

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 solution prevents damage to blood vessels and catheters by eliminating sharp corners and allows the stent to be safely stored within designated tubes and catheters, ensuring secure implantation and movement without causing harm.

Implementation Method 1

the tip end portion of the strand is irradiated with a laser beam to form the tip end portion of the strand in an approximate spherical shape to round off the tip end portion of the strand

Methodology Applied

Scientific EffectLaser heating: Laser

Data Source

PatentUS10744008B2Stent

Publication Date: 2020.08.18 PENTAS INC

AI summary

A tip end portion of a strand forming a stent is rounded off. In a stent 10 formed by helicoidally braiding a plurality of strands 20, the tip end portion of each of the strands 20 is rounded off.