Hybrid Guidewire Joint with Interlocking Serrations

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Solution Overview

Problem

Guidewire devices face challenges in balancing torquability and flexibility, particularly in navigating tortuous vasculature paths, as existing materials and joints often result in stiffness discontinuities and fragile connections when combining materials with different properties.

Innovation Solution

A hybrid guidewire device with a mechanically interlocking joint between a stainless steel proximal section and a superelastic nitinol distal section, featuring tapered serrations and a surrounding tube structure to stabilize the joint, allowing for effective torque transmission and flexibility, while minimizing stiffness discontinuities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a guidewire uses a single material throughout, then manufacturing is simple, but it cannot simultaneously achieve both high torquability and high flexibility in different sections

Engineering Contradiction:
Improvetorquability and flexibilityVSAvoidmaterial composition
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The guidewire core is divided into multiple sections with different material properties - a proximal section with higher torquability and a distal section with higher flexibility. This segmentation allows each section to be optimized for its specific function while maintaining overall device performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The guidewire employs composite construction by combining different materials in a single device - typically a stiffer material (such as stainless steel or cobalt-chromium alloy) for the proximal section and a more flexible material (such as nitinol) for the distal section, creating a multi-material system that achieves both torquability and flexibility.

Inventive Principle:
Principle #40Composite materials

2Adaptability or versatility

If a guidewire combines materials with different properties to achieve both torquability and flexibility, then navigation capability improves, but joint reliability and structural integrity deteriorate

Engineering Contradiction:
Improvenavigation capabilityVSAvoidjoint integrity
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The distal section is inserted into and combined with the proximal section to form an integrated joint. This merging of sections creates a unified structure that maintains structural integrity while preserving the different material properties needed for navigation capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The distal section is nested within the proximal section at the joint region, with the distal section inserted into the proximal section. This nested configuration provides mechanical interlocking and structural stability while allowing the different material sections to work together effectively.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Stability of the object's composition

If a guidewire uses a tapered joint design, then stiffness discontinuities are reduced, but manufacturing precision requirements increase

Engineering Contradiction:
Improvestiffness continuityVSAvoidjoint taper accuracy
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The joint region features a tapered geometry that creates a gradual transition in stiffness between the proximal and distal sections. This localized tapering at the joint provides a continuous stiffness profile, reducing abrupt transitions while maintaining overall structural integrity.

Inventive Principle:
Principle #3Local quality

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 hybrid guidewire achieves enhanced navigation capabilities by maintaining joint integrity through mechanical interlocks and adhesives, providing a continuous transition of material properties and reducing stiffness discontinuities, thus improving torquability and flexibility.

Implementation Method 1

the amount of frictional surface contact between the guidewire and the vasculature increases

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

The joint includes or is formed by mechanically interlocking the distal end of the proximal section with the proximal end of the distal section

Methodology Applied
Scientific EffectMechanical interlocking: Mechanical Fastener

Implementation Method 3

the distal section is made of or includes a superelastic material such as nitinol

Methodology Applied
Scientific EffectSuperelasticity: Pseudoelasticity

Data Source

PatentEP3630258B1Core-wire joint with micro-fabricated medical devices
Publication Date: 2024.03.20 SCIENTIA VASCULAR INC
  • EP3630258B1 patent drawingFigure 1
  • EP3630258B1 patent drawingFigure 2A
  • EP3630258B1 patent drawingFigure 2B~3

AI summary

The present disclosure relates to core-wire joints for micro-fabricated medical devices, such as guidewires. A hybrid guidewire device includes a core (102) having a joint (105) between a proximal section (110) and a distal section (112) of the core and a tube structure (104) surrounding the joint. The proximal section of the core is made of or includes stainless steel and the distal section is made of or includes a superelastic material such as nitinol. Further, the terminal, distal portion of the proximal section of the core includes serrations (116), and a terminal, proximal portion of the distal section of the core includes complementary serrations (118) sized and shaped to interlock with serrations (116). The distal end of the proximal section mechanically interlocks with a proximal end of the distal section to form the joint.