Segmented Guide Wire Rigidity Control Without Diameter Increase

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Solution Overview

Problem

Existing guide wires and catheters face issues with increased outer diameter when bending rigidity is changed, leading to vessel wall interference and difficulty in insertion, particularly when navigating through body lumens.

Innovation Solution

A guide wire and catheter design featuring a main body portion with segments that can be separated or brought closer together via a linear member, adjusting tension to increase or decrease bending rigidity without significantly increasing the outer diameter.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If coils are twisted or contracted to increase bending rigidity, then rigidity increases, but outer diameter increases causing vessel wall interference

Engineering Contradiction:
Improvebending rigidityVSAvoidvessel wall interference
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The guide wire is divided into multiple segments that can be independently positioned along a linear member. By selectively moving segments closer together or farther apart, bending rigidity is adjusted without requiring coil contraction that increases outer diameter. The segments are distributed along the longitudinal direction and can be positioned at intervals to achieve desired rigidity while maintaining a compact outer profile.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of adjusting rigidity by changing the radial dimension (coil contraction increasing outer diameter), the invention uses the longitudinal dimension by positioning segments at different distances along the linear member. This dimensional shift allows rigidity control through axial spacing rather than radial compression, avoiding vessel wall interference.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Strength

If outer diameter is increased to enhance rigidity, then rigidity improves, but insertion difficulty increases

Engineering Contradiction:
Improvebending rigidityVSAvoidinsertion ease
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The guide wire consists of multiple segments that can be spaced apart along a linear member, allowing the overall structure to remain slender with a small outer diameter for easy insertion. When rigidity is needed, segments are moved closer together rather than increasing the outer diameter, thus maintaining insertion ease while providing rigidity control.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the parameter used to control rigidity from outer diameter to segment spacing. By adjusting the distance between segments along the longitudinal axis rather than changing the radial dimension, the guide wire maintains a consistently small outer diameter for easy insertion while achieving variable rigidity through parameter change.

Inventive Principle:
Principle #35Parameter changes

3Strength

If segment distance is decreased to increase rigidity, then rigidity increases, but device complexity increases

Engineering Contradiction:
Improvebending rigidityVSAvoidstructure complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

Multiple segments are nested along a single linear member, with each segment capable of independent positioning. This nested arrangement allows complex rigidity control functionality to be achieved within a simple, unified structure. The segments can be moved independently along the linear member using simple mechanisms, avoiding the need for complex multi-component systems.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The guide wire incorporates dynamic positioning capability where segments can be moved to different locations along the linear member to adjust rigidity as needed. This dynamic adjustment is achieved through simple mechanisms that allow segments to slide or reposition along the linear member, providing adaptability without excessive structural complexity.

Inventive Principle:
Principle #15Dynamics

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 design effectively increases bending rigidity by decreasing segment distance or enhancing pressure contact force, minimizing outer diameter expansion and improving navigation through body lumens.

Implementation Method 1

increasing tension of the linear member extending between the connection segment and the operation portion

Methodology Applied
Scientific EffectTension: Tension

Implementation Method 2

a pressure contact force applied to the two segments from each other is increased by increasing tension of the linear member

Methodology Applied
Scientific EffectPressure contact force: Pressure Increase

Data Source

PatentEP4691537A1Guide wire and catheter
Publication Date: 2026.02.11 SB KAWASUMI LABORATORIES INC
  • EP4691537A1 patent drawingFigure 1A~1C
  • EP4691537A1 patent drawingFigure 2A~2B
  • EP4691537A1 patent drawingFigure 3A~3D

AI summary

A main body portion 10 includes a plurality of segments 11 and a linear member 20. The plurality of segments 11 are continuously provided in a longitudinal direction of the main body portion 10, and are configured to be separated from or closer to each other in the longitudinal direction. The linear member 20 is inserted into at least a portion of the plurality of segments 11. The linear member 20 is connected to an operation portion 30 in one end. In addition, the linear member 20 is connected to a connection segment 11a which is one of the segments 11 in the other end opposite to the one end. Since the tension of the linear member 20 extending between the connection segment 11a and the operation portion 30 is increased, the distance between the two segments 11 disposed adjacent to each other on the proximal end side with respect to the connection segment 11a is decreased, or the pressure contact force applied to the two segments 11 from each other is increased.