Mechanical Detachment Wire for Embolic Coil Delivery

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current embolic coil detachment systems in vascular occlusion devices face challenges with reliability, speed, convenience, and the length/stiffness of distal sections, particularly due to time-consuming electrolytic processes and the need for high-pressure or battery-operated mechanisms.

Innovation Solution

A mechanical detachment system for embolic coils featuring a delivery tube with a lumen and a detachable wire having a terminating feature, where at least one stretch-resistant member is secured within the coil lumen, allowing for quick and reliable release by pulling the wire with a predetermined force to sever at a mechanically weakened section or through a friction fit, without the need for electrolysis or high pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electrolytic detachment is used to release the embolic coil from the delivery system, then the coil can be detached, but the process is time-consuming and reduces productivity

Engineering Contradiction:
Improvedetachment reliabilityVSAvoiddetachment speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent replaces the electrolytic detachment mechanism with a purely mechanical detachment system. A detachable wire with a mechanically weakened section (such as a reduced cross-section or pre-formed fracture point) allows the wire to be pulled and severed mechanically, eliminating the need for electrolytic processes. This mechanical approach enables faster detachment while maintaining reliability through the controlled weakness point in the wire structure.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Stability of the object's composition

If a stretch-resistant member is added to prevent coil stretching, then coil integrity is improved, but the device complexity increases

Engineering Contradiction:
Improvecoil shape stabilityVSAvoiddelivery system structure
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The stretch-resistant member is nested within the lumen of the embolic coil, with its ends secured to the coil structure. This nested configuration provides stretch resistance without adding external complexity to the delivery system. The member is contained within the coil's own space, utilizing the existing structural envelope rather than requiring additional external components.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Device complexity

If the delivery tube distal end is retained by physical friction fit rather than attachment, then the detachment mechanism is simplified, but the retention reliability during delivery may be reduced

Engineering Contradiction:
Improvedetachment mechanism simplicityVSAvoiddelivery tube retention
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The delivery tube distal end is retained by the detachable wire through physical friction fit at a specific location, rather than through a comprehensive attachment mechanism. This localized friction fit provides sufficient retention during delivery while allowing for simple mechanical detachment when needed. The friction fit is concentrated at the interaction point between the wire and tube end, rather than distributed throughout the structure.

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 system provides a simpler, more reliable, and quicker detachment method with shorter stiff sections, reducing the risk of coil entanglement and improving the precision and efficiency of embolic coil placement within blood vessels.

Implementation Method 1

sever at a mechanically weakened section

Methodology Applied
Scientific EffectStress concentration: Fracture Mechanics

Implementation Method 2

retained by the wire physically against without being attached in any way to the proximal junction

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3181064B1Occlusive device delivery system with mechanical detachment
Publication Date: 2021.07.14 DEPUY SYNTHES PROD INC
  • EP3181064B1 patent drawingFigure 1A~1C
  • EP3181064B1 patent drawingFigure 2A~2C
  • EP3181064B1 patent drawingFigure 2D~2E

AI summary

A delivery system for an embolic coil including a delivery tube having a lumen. A proximal coil junction is disposed between the delivery tube and the embolic coil. Insertable through the lumen and extending proximally beyond the proximal end of the delivery tube is a detachable wire with a terminating feature disposed on its distal end. At least one stretch resistant member is disposed within a lumen formed by the embolic coil. A distal end of each of the at least one stretch resistant members is secured to a distal end of the embolic coil, while each of the at least one stretch resistant members is also secured proximate the proximal end of the embolic coil. The distal end of the delivery tube is retained by the wire physically against without being attached in any way to the proximal junction.