Guide Wire Joining Strength via Asymmetric Interlocking

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Solution Overview

Problem

Conventional guide wires often detach from the coil body at narrowed segments during insertion, leading to difficulties in subsequent medical procedures due to the weak joining strength between the front end joining portion and the coil body.

Innovation Solution

The guide wire features a base end joining portion with an uneven shape in the longitudinal direction, incorporating protruded and depressed portions that enhance the joining strength, and in some embodiments, the front end joining portion is curved or formed with spirally wound twisted wires to prevent detachment and stress concentration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the guide wire is pushed, pulled, or rotated to penetrate a narrowed segment, then the guide wire can advance through the narrowing, but the front end joining portion may detach from the coil body due to applied forces

Engineering Contradiction:
ImproveAbility to push, pull, or rotate guide wireVSAvoidJoining strength between front end joining portion and coil body
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The base end of the front end joining portion is formed with an uneven shape featuring protruded portions and depressed portions, creating an asymmetric structure that interlocks with the coil body. This asymmetric design prevents detachment while allowing the guide wire to be pushed, pulled, or rotated during penetration of narrowed segments.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The protruded portion at the base end is formed in a curved fashion rather than a straight line, creating a curved interlocking structure with the coil body. This curved configuration enhances the joining strength and prevents detachment during manipulation of the guide wire through narrowed segments.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Adaptability or versatility

If the guide wire is bent during insertion, then the guide wire can navigate through the body lumen, but stress concentration occurs at the joining portion

Engineering Contradiction:
ImproveAbility to bend and navigate body lumenVSAvoidStrength of joining portion under bending stress
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The protruded portion is formed in a curved fashion that matches the natural bending behavior of the guide wire during navigation through body lumens. This curved configuration distributes bending stresses along the curve rather than concentrating them at a single point, maintaining joining strength while enabling adaptability to navigate complex anatomical paths.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Data Source

PatentEP3248644B1Guide wire
Publication Date: 2020.08.12 ASAHI INTECC CO LTD
  • EP3248644B1 patent drawingFigure 1
  • EP3248644B1 patent drawingFigure 2
  • EP3248644B1 patent drawingFigure 3

AI summary

[Problem] An object is to provide a guide wire in which the joining strength between a front end joining portion and a coil body of the guide wire is improved to prevent detachment of the front end joining portion from the coil body. [Solution] Provided is a guide wire 1 comprising a core shaft 5, a coil body 3 covering the outer periphery of the core shaft 5, and a joining portion 7 joining the front end of the core shaft 5 to the front end of the coil body 3, in which the base end of the joining portion 7 is formed into an uneven shape in the longitudinal direction along the direction of the outer periphery in a cross-sectional view by means of a rectangular protruded portion 8 protruded to the base end side in the longitudinal direction and a rectangular depressed portion 9 protruded to the front end side in the longitudinal direction.