Vaso-Occlusive Coil Composite Structure for Anchoring and Shape Retention

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Solution Overview

Problem

Existing vaso-occlusive devices face limitations in performance, including breaking performance, shape retention, and anchoring ability, particularly in coupling to delivery assemblies.

Innovation Solution

The development of a vaso-occlusive device formed from braided or woven structures using drawn filled tubes with specific metallic compositions and configurations, including a core and external layer made of different materials, such as platinum and Nitinol, to enhance radiopacity, shape retention, and breaking performance, with intra-device junctions for secure coupling to delivery assemblies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If vaso-occlusive coils use complex three-dimensional secondary shapes and modified stiffness/flexibility, then aneurysm filling performance is improved, but breaking performance and anchoring ability deteriorate

Engineering Contradiction:
Improveaneurysm filling performanceVSAvoidbreaking performance
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent applies composite materials by combining platinum (for radiopacity and strength) with Nitinol (for shape memory and flexibility) in a drawn-filled tube structure. The platinum core provides structural integrity and breaking performance, while the Nitinol outer layer provides shape retention and flexibility, resolving the contradiction between aneurysm filling performance and breaking performance.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes material parameters by controlling the ratio of core to external layer materials, their thicknesses, and mechanical properties. By adjusting these parameters, the device achieves optimal balance between stiffness for anchoring, flexibility for deployment, and shape retention for filling, while maintaining adequate breaking performance.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If vaso-occlusive coils use complex three-dimensional secondary shapes and modified stiffness/flexibility, then aneurysm filling performance is improved, but shape retention deteriorates

Engineering Contradiction:
Improveaneurysm filling performanceVSAvoidshape retention
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The composite structure with platinum core and Nitinol outer layer resolves the contradiction by assigning specific functions to each material. The Nitinol layer with its shape memory effect provides excellent shape retention, while the platinum core provides structural support, enabling both complex three-dimensional shapes for filling and stable shape retention.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies local quality by giving different regions of the coil different material compositions and mechanical properties. The draw-filled tube structure creates local variations in stiffness and flexibility along the coil length, allowing complex shaping in some regions while maintaining shape retention in others.

Inventive Principle:
Principle #3Local quality

3Reliability

If vaso-occlusive coils use complex three-dimensional secondary shapes and modified stiffness/flexibility, then aneurysm filling performance is improved, but anchoring ability deteriorates

Engineering Contradiction:
Improveaneurysm filling performanceVSAvoidanchoring ability
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The composite platinum-Nitinol structure resolves the anchoring contradiction by combining materials with complementary properties. The platinum core provides high strength and rigidity for anchoring, while the Nitinol layer provides flexibility for deployment and shape retention, enabling both excellent anchoring and effective filling.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent optimizes anchoring by carefully controlling material parameters including the thickness ratio of core to outer layer, the mechanical properties of each material, and the overall coil geometry. These parameter adjustments ensure adequate anchoring strength while maintaining filling performance.

Inventive Principle:
Principle #35Parameter changes

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 solution provides improved radiopacity, shape retention, and breaking performance, ensuring effective anchoring and deployment of the vaso-occlusive devices in vascular applications, particularly for treating aneurysms.

Implementation Method 1

Each of the core and external metallic materials has a respective radiopacity

Methodology Applied
Scientific EffectRadiopacity: Absorption (EM radiation)

Implementation Method 2

Each drawn filled tube includes a core made from a core metallic material, and an external layer made from an external metallic material different from the core metallic material

Methodology Applied
Scientific EffectComposite materials: Composite Materials

Data Source

PatentEP4331505B1Vaso-occlusive device and delivery assembly
Publication Date: 2025.07.23 STRYKER CORP
  • EP4331505B1 patent drawingFigure 1~2
  • EP4331505B1 patent drawingFigure 3~4
  • EP4331505B1 patent drawingFigure 5~6

AI summary

A vaso-occlusive treatment system (100), comprising a delivery assembly (104); and a vaso-occlusive device (102) detachably coupled to the delivery assembly (104) by a severable junction (114), the vaso-occlusive device (102) comprising a proximal coil (108) having an inner axial lumen and a proximal end portion (132) coupled to the severable junction (114), and a braid (106) having a proximal end portion coupled to a distal end portion (136) of the proximal coil (108) by a first intra-device junction (300-1), the braid comprising a plurality of elongate braid members, wherein at least one (122) of the braid members extends proximally from the braid through the axial lumen of proximal coil (108) and is secured to the proximal end portion (132) of the proximal coil (108), respectively, to thereby form proximal coil stretch-resisting member (122)..