Implantable Device Header Adhesion via Surface Roughening

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Solution Overview

Problem

Current implantable medical devices (IMDs) face challenges in achieving strong and reliable connections between the device container and the header, particularly in terms of adhesion and durability, which can lead to premature failure under side load conditions.

Innovation Solution

The use of a thermoset polymer header, such as epoxy, molded onto a textured surface of the metallic device container, which enhances adhesion through surface roughening techniques like laser treatment and dry blasting, and controlled curing processes to achieve high fracture toughness and failure strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a thermoset polymer header is molded onto a smooth metallic device container surface, then the manufacturing process is simpler, but the bond strength and adhesion between header and container are insufficient under side load conditions

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidbond strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The metallic device container surface is pre-treated with surface roughening techniques (laser treatment, dry blasting) before molding the thermoset polymer header onto it. This preliminary action creates a textured surface that enhances mechanical interlocking and adhesion, resolving the contradiction by preparing the surface in advance to achieve both strong bonding and manufacturing feasibility.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The solution combines the thermoset polymer header material with the metallic device container, creating a composite structure. The thermoset polymer provides fracture toughness and chemical adhesion, while the metal provides structural strength. This composite approach enables the bond to withstand side load conditions while maintaining manufacturing practicality.

Inventive Principle:
Principle #40Composite materials

2Reliability

If the header material is made more brittle to increase fracture toughness, then resistance to crack propagation improves, but the overall strength and durability under side load decreases

Engineering Contradiction:
Improvecrack resistanceVSAvoidoverall strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent optimizes the chemical composition and curing parameters of the thermoset polymer to achieve the desired balance between fracture toughness and overall strength. By controlling crosslink density, molecular weight, and curing conditions, the material exhibits enhanced crack resistance while maintaining sufficient ductility and strength to withstand side load conditions without premature failure.

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 significantly increases the side load failure strength of the IMD by improving the bond between the header and the device container, ensuring the integrity and longevity of the device under mechanical stress.

Implementation Method 1

The use of a thermoset polymer header, such as epoxy, molded onto a textured surface of the metallic device container, which enhances adhesion through surface roughening techniques

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

surface roughening techniques like laser treatment

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Implementation Method 3

surface roughening techniques like laser treatment and dry blasting

Methodology Applied
Scientific EffectAbrasion: Abrasion

Implementation Method 4

controlled curing processes to achieve high fracture toughness and failure strength

Methodology Applied
Scientific EffectCuring: Photopolymerisation

Data Source

PatentEP2790781B1Implantable device header and method
Publication Date: 2022.01.05 CARDIAC PACEMAKERS INC
  • EP2790781B1 patent drawingFigure 1
  • EP2790781B1 patent drawingFigure 2
  • EP2790781B1 patent drawingFigure 3A~3B

AI summary

Systems and methods for implantable medical devices and headers are described. In an example, an implantable medical device includes a device container including an electronic module within the device container. A header core includes a bore hole portion and at least two electronic connection features disposed within the bore hole portion. The bore hole portion includes at least one cavity configured to allow placement of at least one of the electronic connection features within the bore hole portion. The at least two electronic connection features are electrically coupled to the electronic module within the device container. The header core is configured to allow location of the at least two electronic connection features in a selected configuration within the bore hole portion. A header shell is disposed around the header core and attached to the device container.