3D Printed Catheter with Variable Stiffness via Dual Filament Extrusion

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Solution Overview

Problem

Existing manufacturing processes for medical catheters and leads face challenges in balancing flexibility and stiffness, material selection, and operational controls due to tortuous paths in the human body, limiting design and manufacturing options.

Innovation Solution

Additive manufacturing systems that allow for the use of a wider range of filament materials to create varying hardness levels and unique combinations of properties, enabling the production of catheters with specific handling properties, including steering capabilities and enhanced material properties like electrical and thermal properties, through high feed forces and rotational motion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional extrusion manufacturing is used, then manufacturing simplicity is maintained, but design flexibility and material selection options are limited

Engineering Contradiction:

Improvedesign flexibilityVSAvoidmanufacturing process complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by varying filament feed forces during additive manufacturing to achieve different hardness levels and material properties in the catheter. By controlling parameters such as feed force, temperature, and material composition during the printing process, the system creates catheters with tailored mechanical properties that conventional extrusion cannot achieve.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent utilizes composite materials by combining multiple filament materials with different properties during additive manufacturing. This allows creation of catheters with varying hardness levels and unique combinations of properties throughout the structure, enabling both flexibility where needed and stiffness for structural support.

Inventive Principle:

Principle #40Composite materials

2Ease of operation

If catheters are made sufficiently flexible to navigate tortuous paths, then navigability is improved, but structural strength and pushability through vasculature are reduced

Engineering Contradiction:

ImprovenavigabilityVSAvoidstructural strength

Core Design Contradiction:

Ease of operationVSStrength

Solution Approach 1:

The patent applies local quality by creating different regions within the catheter with different hardness levels and material properties. The catheter can have softer segments for flexibility and navigation through tortuous vascular paths, and stiffer segments for maintaining structural strength and pushability during deployment.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent segments the catheter structure into different functional zones with varying material properties. By dividing the catheter into segments with different hardness levels, the system achieves both navigability in tortuous paths and sufficient structural strength for vascular deployment.

Inventive Principle:

Principle #1Segmentation

3Manufacturing precision

If high feed forces are applied during additive manufacturing, then manufacturing precision and material property control are improved, but soft filament handling and processing difficulty increase

Engineering Contradiction:

Improvematerial property controlVSAvoidfilament processing ease

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent introduces an intermediary mechanism in the form of a specialized extrusion system that mediates between the high feed forces required for precision and the soft filament materials being processed. The system includes controlled temperature zones and gradual force application mechanisms that enable precise material deposition without damaging soft filaments.

Inventive Principle:

Principle #24Intermediary (Mediator)

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

Facilitates the creation of medical devices with tailored properties, such as varying stiffness and enhanced material characteristics, allowing for more effective navigation and treatment in tortuous body paths, and enabling new treatments and device functionalities.

Implementation Method 1

a heating element thermally coupled to the heating cartridge to heat the interior volume

Methodology Applied

Scientific EffectHeating: Heating

Implementation Method 2

activate the heating element to melt any portion of the first filament or the second filament in the interior volume

Methodology Applied

Scientific EffectMelting: Melting

Data Source

PatentUS11857735B2Systems and methods for manufacturing 3D printed medical devices

Publication Date: 2024.01.02 MEDTRONIC INC

AI summary

Systems and methods of manufacturing 3D printed medical devices. The method includes feeding a first filament and a second filament into an interior cavity of a heating cartridge and melting each of the filaments on a substrate. The heating cartridge is then moved linearly and rotationally relative to the substrate to form a jacket including material from each of the first and second filaments. Further, rotating the substrate provides a uniform mixture and creates support rings between the filament materials within the structure of the jacket.