Multi-Filar Catheter Tube Structure for Torque and Flexibility

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing intravascular catheters face challenges in providing a combination of desirable pushability, fine torqueability, axial strength stability, maintaining lumen concentricity, and variable flexibility due to difficulties in navigating tortuous vascular pathways.

Innovation Solution

The catheter design incorporates a multi-filar cut pattern with varying cut widths, pitch angles, and material compositions along its length to enhance steerability, torqueability, and flexibility, featuring zones with specific cut patterns and helical segments to improve pushability and resistance to deformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the catheter uses a solid tube construction, then axial strength is improved, but flexibility and steerability deteriorate

Engineering Contradiction:

Improveaxial strengthVSAvoidflexibility

Core Design Contradiction:

StrengthVSAdaptability or versatility

Solution Approach 1:

The catheter tube is segmented into multiple filars (12-40 individual wires) through spiral cuts, transforming a solid tube into a flexible yet strong structure. Each filar maintains axial strength while the collective arrangement provides flexibility and steerability through controlled deformation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The catheter combines multiple materials including nitinol (for superelasticity), inconel (for strength), stainless steel (for rigidity), and polymer liners (for smooth flow). This composite construction resolves the contradiction by distributing mechanical properties across different materials.

Inventive Principle:

Principle #40Composite materials

2Strength

If the catheter uses a solid tube construction, then axial strength is improved, but torqueability deteriorates

Engineering Contradiction:

Improveaxial strength stabilityVSAvoidtorqueability

Core Design Contradiction:

StrengthVSEase of operation

Solution Approach 1:

The tube is cut into 12-40 discrete filars that can rotate and deform independently under torque. This segmentation allows the catheter to transmit torque effectively while maintaining axial strength, as each filar contributes to torque transmission without restricting overall rotational flexibility.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The spiral cut parameters (pitch angle 30-70 degrees, cut width 0.015-0.040 mm, filar spacing 0.015-0.125 mm) are optimized to balance axial strength and torqueability. These parameter changes allow the structure to be stiff axially while remaining responsive to rotational forces.

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If the catheter uses uniform flexibility along its length, then manufacturing is simplified, but ability to navigate tortuous vasculature deteriorates

Engineering Contradiction:

Improvefabrication simplicityVSAvoidvariable flexibility

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

Different zones along the catheter have different cut patterns, pitch angles, and filar configurations to provide variable flexibility. The distal portion has tighter spacing and different pitch for enhanced steerability, while proximal portions have different characteristics for pushability and support, all manufactured through a systematic zoned approach.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The catheter structure is designed to be dynamically adaptable, with cut patterns and filar arrangements that allow different sections to deform at different rates and magnitudes. This dynamic flexibility distribution enables navigation of complex vasculature while maintaining manufacturing feasibility through standardized cutting processes.

Inventive Principle:

Principle #15Dynamics

4Adaptability or versatility

If the catheter uses a cut tube design, then flexibility is improved, but resistance to plastic deformation deteriorates

Engineering Contradiction:

ImproveflexibilityVSAvoidresistance to plastic deformation

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The use of superelastic nitinol and high-strength inconel in the filar construction provides resistance to plastic deformation while maintaining flexibility. These materials can undergo large elastic deformations and return to their original shape, preventing permanent deformation even with repeated use and navigation through tortuous pathways.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The catheter design incorporates a polymer liner and jacket that provide protective cushioning to the metal filars. These protective layers prevent direct contact between filars and external forces, reducing the risk of plastic deformation and extending the catheter's service life.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentUS20260061164A1Multi-filar catheter body construction

Publication Date: 2026.03.05 ORBUSNEICH MEDICAL PTE LTD

AI summary

A catheter, including a catheter tube defining: a proximal end; a distal end; a longitudinal axis; a lumen therethrough; and one or more zones having each having a cut pattern segment therein, wherein cut pattern segment defines a plurality of cuts spaced around a circumference of the tube. The distal end may include a tip segment having a plurality of helical segments extending around the longitudinal axis, wherein each helical segment includes two substantially parallel filars connected at distal ends thereof.