Galvanic Implant Using Cobalt-Titanium Couple for Antimicrobial Ion Elution

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Solution Overview

Problem

Current implant devices struggle to achieve antimicrobial properties in vivo without requiring external operations or treatments, leading to increased patient burden due to potential microbial growth and infection.

Innovation Solution

An implant device composed of a cobalt-based alloy and a titanium-based alloy, where the two materials form an electric circuit in vivo, allowing for the elution of antimicrobial ions to impart antimicrobial properties to the surface and surrounding area, eliminating the need for external treatments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an implant device is used without antimicrobial properties, then the device structure remains simple, but microbial growth and infection occur requiring additional surgery

Engineering Contradiction:
Improveantimicrobial propertyVSAvoiddevice structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The implant device combines two biocompatible metals with different electrode potentials (anode and cathode materials) to create a galvanic couple. This composite structure generates electric current through galvanic corrosion, which eliminates bacteria on contact without requiring external power sources or complex control systems, thus achieving antimicrobial functionality while maintaining relatively simple device structure.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The implant device utilizes the body's own electrolyte environment to generate electric current through the galvanic couple formed by the two metals. The system is self-powered, requiring no external power sources, batteries, or complex control mechanisms. The antimicrobial action is automatic and continuous as long as the implant is in place, significantly reducing device complexity compared to externally powered antimicrobial systems.

Inventive Principle:
Principle #25Self-service

2Reliability

If externally powered antimicrobial systems are used, then antimicrobial effectiveness is achieved, but patient burden increases due to external operations and treatments

Engineering Contradiction:
Improveantimicrobial propertyVSAvoidpatient burden
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The implant device is completely self-contained and self-powered, utilizing the galvanic potential difference between two biocompatible metals to generate continuous electric current for bacterial elimination. No external power sources, batteries, wiring, or control systems are needed. The device automatically activates upon implantation using the body's natural electrolyte environment, eliminating all external operations and treatments required by conventional antimicrobial systems.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention extracts and eliminates the need for external power sources and control systems from the antimicrobial system. By incorporating the power generation function directly into the implant structure through the galvanic couple, all external equipment, terminals, and operational interventions are removed, significantly reducing patient burden while maintaining effective antimicrobial action.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If antimicrobial metals are used alone without galvanic coupling, then biocompatibility is maintained, but antimicrobial effectiveness is insufficient

Engineering Contradiction:
Improveantimicrobial effectivenessVSAvoidgalvanic corrosion
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The invention changes the electrochemical parameters of the implant by combining two metals with different standard electrode potentials. This creates a galvanic couple where the anode undergoes controlled corrosion to generate electric current. The galvanic corrosion, which would normally be harmful, is harnessed as the mechanism for producing the antimicrobial electric current, transforming a potential harm into a beneficial function.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention converts the harmful effect of galvanic corrosion into a beneficial antimicrobial mechanism. The electric current generated by the galvanic couple, which would normally indicate material degradation, is used to eliminate bacteria on contact. The corrosion process itself becomes the power source for the antimicrobial function, turning what was previously a harmful byproduct into the core mechanism for infection prevention.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 implant device effectively achieves antimicrobial properties upon implantation, significantly reducing patient burden by preventing microbial growth and infection without additional surgical interventions.

Implementation Method 1

An implant device made of a cobalt-based alloy and a titanium-based alloy, wherein two kinds of materials forming an electric circuit in vivo are used, and ions of an antimicrobial metal are eluted under a presence of an electrolyte

Methodology Applied
Scientific EffectGalvanic corrosion: Electrolysis

Data Source

PatentEP3424466B1Antibacterial apparatus for in-vivo implantation
Publication Date: 2022.06.15 MEDTRONIC SOFAMOR DANEK
  • EP3424466B1 patent drawingFigure 1
  • EP3424466B1 patent drawingFigure 2(a)~3(c)
  • EP3424466B1 patent drawingFigure 4(a)~5(c)

AI summary

An antimicrobial implant device consisting of a rod (2) comprising a second material and a ring (3) comprising a first material that is fit on at least a part of a circumference of the rod (2), wherein at least a surface of the first material comprises an antimicrobial metal; at least a surface of the second material is nobler than the first material; an electric circuit is formed between the first material and the second material when the device is implanted in vivo for use; and ions of the antimicrobial metal are eluted from the first material under a presence of an electrolyte to impart an antimicrobial property to a surface and/or a surrounding area of the first material.