Bendable Catheter Coil Structure for Large Bending Without Plugging

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Solution Overview

Problem

Conventional catheters face difficulties in bending largely, leading to plugged inner cavities and challenges in inserting treatment tools accurately into narrow branches, which complicates medical procedures and increases the risk of tissue damage.

Innovation Solution

A bendable catheter design featuring a flexible tubular main tube with a bendable part and a bending manipulation wire, incorporating a first and second coil structure that allows for significant bending without plugging, ensuring fluid flow and tool insertion, and featuring light permeability for enhanced visibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the catheter is made flexible to allow bending, then the catheter can be inserted into narrow branches, but the inner cavity becomes plugged when bent largely

Engineering Contradiction:
Improvebending capabilityVSAvoidinner cavity patency
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The catheter is divided into multiple segments: a rigid main tube for structural support, a flexible bendable part for navigation, and a transition zone. This segmentation allows the catheter to bend without compromising the integrity and patency of the inner cavity, as each segment performs its specific function independently.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The coils are nested within the bendable part of the catheter, with the flexible tube surrounding the coils. This nested structure allows the coils to provide structural support preventing cavity plugging, while the flexible tube maintains bending capability. The manipulation wire is also nested within the coil structure.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Ease of operation

If the catheter bends largely to reach thin cavities, then insertion into narrow branches is enabled, but the inner cavity gets plugged

Engineering Contradiction:
Improveinsertion into narrow branchesVSAvoidcavity plugging
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

Different parts of the catheter have different mechanical properties: the main tube is rigid for stability, the bendable part is flexible for navigation, and the coils provide localized structural support. This local differentiation allows large bending angles to be achieved without causing cavity plugging, as the coils maintain the inner cavity shape during bending.

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If the catheter structure is simplified, then manufacturing is easier, but the bending capability without plugging is reduced

Engineering Contradiction:
Improvecatheter structureVSAvoidlarge-bend capability
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The catheter employs a flexible tube with integrated coils rather than complex mechanical articulation systems. This flexible shell structure with embedded support elements achieves large-bend capability while maintaining a relatively simple manufacturing process, as it avoids complex joints and moving parts.

Inventive Principle:
Principle #30Flexible shells and thin films

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

Enables large-bend capabilities without plugging, facilitating accurate tool placement and simplifying medical procedures by preventing tissue damage during lesion treatment.

Implementation Method 1

The bendable part has: a tubular bendable tube fixed to the distal end of the main tube and being more flexible than the main tube; the first coil having a distal end arranged within the bendable tube... and the second coil having a central axis extending parallel to a central axis of the first coil... fixed to an inner surface of the bendable tube

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2589405B1Bendable catheter
Publication Date: 2017.01.25 OLYMPUS CORPORATION(JP)
  • EP2589405B1 patent drawingFigure 1
  • EP2589405B1 patent drawingFigure 2
  • EP2589405B1 patent drawingFigure 3

AI summary

The bendable catheter (1) includes a flexible tubular main tube (2); a bendable part (3) having a longitudinal axis and an internal space formed along the longitudinal axis, a bendable part (3) that is arranged at the distal end of the flexible tubular main tube and is capable of being bent; and a bending manipulation wire (8) that allows the bendable part to bend. The main tube (2) has a first lumen (2c) and a second lumen (2d). The bendable part (3) has a tubular bendable tube fixed to the distal end of the main tube (2) and being more flexible than the main tube (2), the first coil (6) having a distal end arranged within the bendable tube (5) and a proximal end provided with an inner cavity communicating with the first lumen (2c), and fixed to at least one of the main tube (2) and the bendable tube (5), and the second coil (7) having a central axis extending parallel to a central axis of the first coil (6), provided adjacent to the first coil (6) in a space formed between the bendable part (3) and the first coil (6), and fixed to an inner surface of the bendable tube (5). The bending manipulation wire (8) is inserted through an inner cavity of the second coil (7) and the second lumen (2d), and a distal end of the bending manipulation wire (8) is fixed to at least one of the bendable tube (5), the first coil (6), and the second coil (7).