Patterned Conductive Coating for Cochlear Implants

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Solution Overview

Problem

Cochlear implants face challenges with electrical shielding from silver-based antibiotic coatings affecting inductive link power and data transfer, and removable magnets require additional surgeries for MRI compatibility, which can lead to biofilm formation and infection risks due to dead space.

Innovation Solution

A non-conductive surface with a patterned conductive coating on the coil housing and magnet housing, using a silver-based or antibiotic coating to minimize shielding effects and prevent biofilm formation, while maintaining effective data and energy transfer and MRI compatibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a silver-based conductive coating is applied to the implant housing, then antibiotic protection and fungal decay prevention are improved, but electrical shielding of the inductive link occurs, negatively affecting power transfer and data communication

Engineering Contradiction:
Improveinfection preventionVSAvoidpower transfer efficiency
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The conductive coating is segmented into a non-shielding pattern consisting of discontinuous segments, gaps, or openings rather than a continuous coating. This segmentation reduces the overall conductivity and shielding effect while maintaining localized antibiotic protection at the implant site.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The coating is applied with varying properties in different regions - the non-shielding pattern allows certain areas to have reduced conductivity. This local variation in coating density or conductivity enables simultaneous achievement of antibiotic protection in critical areas while minimizing shielding effects in areas affecting the inductive link.

Inventive Principle:
Principle #3Local quality

2Object-affected harmful factors

If a removable internal magnet is included for MRI compatibility, then interaction with external MRI magnetic fields is reduced, but additional surgeries are required to remove or replace the magnet, creating dead space that may lead to biofilm formation

Engineering Contradiction:
ImproveMRI field interactionVSAvoidinfection risk
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The magnet is made removable and can be extracted from the implant housing. During MRI procedures, the magnet is removed to eliminate harmful interactions with external magnetic fields. The removable design allows the magnet to be taken out during surgery and prevents dead space formation when properly reinstalled.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The magnet is removed in advance before MRI scanning to prevent harmful interactions during the procedure. This preliminary removal action eliminates the risk of torque, imaging artifacts, and magnet weakening that would occur if the magnet remained in place during MRI.

Inventive Principle:
Principle #10Preliminary action

3Loss of energy

If the conductive coating is kept at a low level to minimize shielding, then power transfer and data communication are maintained, but antibiotic protection effectiveness is reduced

Engineering Contradiction:
Improveinductive link efficiencyVSAvoidantibiotic protection
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The coating is designed as a non-shielding pattern with segmented structures that provide sufficient antibiotic coverage while maintaining gaps that prevent continuous electrical shielding. The segmentation allows optimization of both protection effectiveness and inductive link performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The coating combines conductive materials (such as silver) with non-conductive materials or structures to create a composite pattern. This composite approach provides antibiotic protection through the conductive components while the non-conductive elements prevent continuous shielding effects that would interfere with the inductive link.

Inventive Principle:
Principle #40Composite materials

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 ensures unimpeded data and energy transfer, reduces RF-heating risks, and prevents biofilm formation, enhancing the safety and functionality of cochlear implants by minimizing electrical interference and infection risks.

Implementation Method 1

an implanted coil for receiving a transcutaneous coil signal from an external transmitting coil

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

silver coating over the inductive coil may cause some electrical shielding of the inductive link, thereby negatively affecting both power transfer to the implant device and also data communication in both directions

Methodology Applied
Scientific EffectElectrical shielding: Faraday Cage

Implementation Method 3

silver ions are antibiotic (even against drug-resistant bacteria) and also prevent fungal decay around the implanted device

Methodology Applied
Scientific EffectAntibiotic effect of silver ions:

Implementation Method 4

an internal magnet in the center of the implanted coil for providing an attractive magnetic force to a corresponding external magnet in the external coil

Methodology Applied
Scientific EffectMagnetic attraction: Magnetism

Data Source

PatentEP2282810B1Conductive coating of implants with inductive link
Publication Date: 2017.08.09 MED EL ELEKTROMEDIZINISCHE GERAETE GMBH
  • EP2282810B1 patent drawingFigure 1
  • EP2282810B1 patent drawingFigure 2
  • EP2282810B1 patent drawingFigure 3

AI summary

An implantable device includes an implanted coil for receiving a transcutaneous coil signal from an external transmitting coil. A coil housing contains the coil and has a non- conductive surface. A conductive coating covers at least a portion of the housing surface and forms a non-shielding pattern that minimizes interaction with the coil signal.