Guide Wire Spiral Coil Intermediate Portion Curving

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Solution Overview

Problem

Existing guide wires face difficulties in curving to a desired position when reaching occluded lesions, leading to potential blood vessel perforation and compromised passing-through properties, especially in complexly curved blood vessels with calcification.

Innovation Solution

A guide wire design featuring a spiral coil with a smaller intermediate portion diameter, strategically positioned to concentrate stress and facilitate curving at the desired location, combined with a tapered or flat plate portion to enhance flexibility and operability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the guide wire uses a coil with increasing wire-diameter portion to reduce stress and improve flexibility, then flexibility and stress mitigation are improved, but the guide wire becomes difficult to curve to a desired position when reaching occluded lesions

Engineering Contradiction:
ImproveflexibilityVSAvoidcurving capability
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The coil is divided into three distinct segments along the longitudinal direction: a first coil portion with larger wire diameter, a second coil portion with smaller wire diameter, and a third coil portion with intermediate wire diameter. This segmentation allows each portion to serve different functions - the first portion provides structural support, the second portion enables curving at desired positions, and the third portion maintains flexibility while reducing stress concentration.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different portions of the coil are given different wire diameters to create local variations in mechanical properties. The smaller wire diameter in the second coil portion creates a localized flexible region that preferentially curves when force is applied, while other portions maintain their original diameter to preserve overall structural integrity and thrusting-in properties.

Inventive Principle:
Principle #3Local quality

2Force

If the guide wire is thrust in with relatively strong force to navigate complicatedly curved blood vessels and CTO lesions, then thrusting-in properties are improved, but blood vessel perforation may occur

Engineering Contradiction:
Improvethrusting-in forceVSAvoidblood vessel perforation
Core Design Contradiction:
ForceVSObject-affected harmful factors

Solution Approach 1:

The coil structure acts as a cushioning element that distributes the thrusting-in force along the guide wire's length rather than concentrating it at the distal tip. The intermediate wire diameter in the third coil portion specifically addresses stress concentration by providing a transition zone that reduces peak stresses, thereby preventing blood vessel perforation while maintaining adequate thrusting-in capability.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The wire diameter parameter is varied along the longitudinal direction of the coil to optimize mechanical properties. By changing the wire diameter from larger to smaller to intermediate values across different coil portions, the guide wire achieves a balance between thrusting-in force transmission and stress distribution, preventing excessive localized stress that could cause vessel perforation.

Inventive Principle:
Principle #35Parameter changes

3Strength

If the coil and wire main body are fixed with a fixing member to maintain structural integrity, then strength is improved, but the diameter of the section increases which deteriorates passing-through properties

Engineering Contradiction:
Improvestructural integrityVSAvoidprofile diameter
Core Design Contradiction:
StrengthVSLength of moving object

Solution Approach 1:

The invention eliminates the need for separate fixing members by integrating the coil directly onto the wire main body through winding. The coil is fixedly attached in a state where it overlaps the wire main body, creating a compact structure without requiring additional fastening components that would increase the overall diameter and hinder passing-through properties.

Inventive Principle:
Principle #2Taking out (Extraction)

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 guide wire effectively curves at the desired position, reducing the risk of blood vessel perforation and improving passing-through properties, even in complex vascular structures.

Implementation Method 1

a coil intermediate portion disposed between a coil distal portion and a coil proximal portion, and includes a wire having a wire diameter that is smaller than a wire diameter of wires of the coil distal portion and the coil proximal portion

Methodology Applied
Scientific EffectStress concentration:

Data Source

PatentEP3323465B1Guide wire
Publication Date: 2021.07.07 TERUMO KK
  • EP3323465B1 patent drawingFigure 1
  • EP3323465B1 patent drawingFigure 2
  • EP3323465B1 patent drawingFigure 3A~3B

AI summary

[Problem] To provide a guide wire that is curved at a desired position when reaching an occluded lesion and is capable of suppressing occurrence of blood vessel perforation. [Means for Resolution] A guide wire 1 includes a long flexible wire main body 10, and a coil 4 that is formed by winding a plurality of wires 411, 421, and 431 in a spiral shape, and which is disposed at an outer periphery of a distal portion of the wire main body 10 to cover the distal portion. The coil 4 includes a coil distal portion 41 that is disposed on a distal side in the distal portion, a coil proximal portion 42 that is disposed on a further proximal side in comparison to the coil distal portion 41, and a coil intermediate portion 43 that is disposed between the coil distal portion 41 and the coil proximal portion 42, and includes the wire 431 having a wire diameter that is smaller than a wire diameter of the wires 411 and 421 of the coil distal portion 41 and the coil proximal portion 42.