Electrolytic Detachment Core Wire with Insulated Zones

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Solution Overview

Problem

Current methods for severing intrasaccular implants from delivery wires are inefficient, risking premature detachment and injury due to the rigidity of connections and limited material options for electrolytic severance, which complicates the occlusion of vascular aneurysms and other body cavities.

Innovation Solution

An electrolytically corrodible core wire with a detachment zone treated to have a more amorphous microstructure than the proximal and distal portions, combined with insulating layers to focus corrosion, allowing for faster and more reliable detachment of the implant from the delivery wire.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional mechanical methods are used for severance, then the severance can be performed quickly, but the rigidity of the connection impedes the introduction of the implant and risks premature detachment

Engineering Contradiction:
Improveseverance speedVSAvoidintroduction difficulty
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The delivery wire is segmented into a proximal rigid portion for stable delivery and a distal corrodible portion for controlled detachment. This segmentation allows the wire to provide sufficient strength during introduction while enabling reliable severance through electrolytic corrosion of the distal segment.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The material properties of the delivery wire are changed along its length, with the distal portion having different corrosion characteristics. This parameter change enables the wire to transition from a stable delivery state to a controlled detachment state through electrolytic corrosion, resolving the contradiction between mechanical strength and ease of separation.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If traditional electrolytic severance is used, then the design is simple, but the connection requires extremely limited material options and long detachment time

Engineering Contradiction:
Improveconnection design simplicityVSAvoiddetachment time
Core Design Contradiction:
Device complexityVSLoss of time

Solution Approach 1:

Different portions of the delivery wire have different material properties - the proximal portion uses materials optimized for mechanical strength and delivery, while the distal portion uses materials specifically selected for controlled electrolytic corrosion. This local differentiation enables faster, more reliable detachment while expanding material options beyond what traditional uniform designs allow.

Inventive Principle:
Principle #3Local quality

3Strength

If the corrodible zone diameter is increased to ensure sufficient strength, then the connection strength is improved, but the rigidity increases and detachment time extends

Engineering Contradiction:
Improveconnection strengthVSAvoiddetachment speed
Core Design Contradiction:
StrengthVSProductivity

Solution Approach 1:

The delivery wire system transitions from a static mechanical connection to a dynamic electrochemical separation process. The corrodible zone is designed to progressively dissolve through electrolytic corrosion, allowing the connection to maintain strength during delivery then dynamically separate at a controlled rate, optimizing both connection strength and detachment speed.

Inventive Principle:
Principle #15Dynamics

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 enables faster and more reliable detachment of the implant, reducing procedure time and minimizing the risk of injury by concentrating erosion at a specific area, thus enhancing the safety and efficiency of the implantation process.

Implementation Method 1

Electrolytic severance of the implantable medical devices can involve using an electrolytically corrodible design on the end of a delivery wire

Methodology Applied
Scientific EffectElectrolytic corrosion: Electrolysis

Implementation Method 2

a detachment zone between the proximal portion and the distal portion, wherein the detachment zone has a microstructure that is more amorphous than each of (i) a microstructure of the proximal portion and (ii) a microstructure of the distal portion

Methodology Applied
Scientific EffectMicrostructure treatment: Heat Treatment

Implementation Method 3

a proximal insulating layer annularly contacting the proximal portion; a distal insulating layer annularly contacting the distal portion

Methodology Applied
Scientific EffectElectrical insulation: Dielectric

Data Source

PatentEP2984996B1Electrolytic detachment elements for implant delivery systems
Publication Date: 2018.04.11 COVIDIEN LP
  • EP2984996B1 patent drawingFigure 1
  • EP2984996B1 patent drawingFigure 2~3
  • EP2984996B1 patent drawingFigure 4

AI summary

Detachment of a medical device from a delivery assembly can focus activity of electrolytic detachment to enhance detachment procedures. Electrolytic activity can be focused by insulating nearby areas of a core wire and pre-treating a detachment zone to reduce crystallinity of the detachment zone. Such a delivery system, can include an electrolytically corrodible core wire comprising a proximal portion, a distal portion, and a detachment zone between the proximal portion and the distal portion; a proximal insulating layer annularly contacting the proximal portion; a coil helically winding about and contacting at least a portion of the proximal insulating layer; a tube annularly contacting at least a portion of the helical coil; a distal insulating layer annularly contacting the distal portion; and a hub of an implant annularly contacting at least a portion of the distal insulating layer; wherein a distal end of the proximal insulating layer and a proximal end of the distal insulating layer are axially spaced apart to expose the detachment zone.