Textured Titanium Nitride Electrode Surface for Implantable Devices

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Solution Overview

Problem

High-voltage electrical pulses delivered by implantable medical devices, such as cardioverter defibrillators, interfere with the ability to sense the effectiveness of therapy due to prolonged post-shock recovery times, which can delay additional therapy and reduce overall effectiveness.

Innovation Solution

A method of preparing electrodes with a textured titanium nitride layer by modifying the titanium surface using a laser in a nitrogen gas environment, increasing the surface area and reducing impedance, thereby accelerating the dissipation of electrical charge.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high-voltage electrical pulses are delivered to provide effective therapy, then therapy effectiveness is improved, but post-shock recovery time increases delaying subsequent therapy

Engineering Contradiction:

Improvetherapy effectivenessVSAvoidpost-shock recovery time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent changes the electrical parameters of the electrode by forming a textured titanium nitride surface layer, which alters the impedance characteristics. This parameter change allows for reduced impedance that accelerates charge dissipation, thereby reducing post-shock recovery time while maintaining therapy effectiveness

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite surface structure by reacting titanium with nitrogen to form titanium nitride on the electrode surface. This composite material structure (titanium substrate with titanium nitride surface layer) provides optimized electrical properties that reduce impedance and accelerate charge dissipation

Inventive Principle:

Principle #40Composite materials

2Measurement precision

If electrical charge dissipates slowly in tissue, then sensing capability is maintained, but post-shock recovery time increases reducing therapy effectiveness

Engineering Contradiction:

Improvesensing capabilityVSAvoidpost-shock recovery time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent modifies the electrode's electrical parameters through surface treatment, creating a textured titanium nitride layer that reduces impedance. This parameter change enables faster charge dissipation while preserving the electrode's ability to sense physiological signals, as the impedance reduction is optimized to affect transient charge dissipation without compromising steady-state sensing

Inventive Principle:

Principle #35Parameter changes

3Loss of time

If impedance of electrodes is decreased to dissipate charge quickly, then post-shock recovery time is reduced, but electrode design complexity increases

Engineering Contradiction:

Improvepost-shock recovery timeVSAvoidelectrode design complexity

Core Design Contradiction:

Loss of timeVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical or structural electrode design modifications with a surface chemistry approach. Instead of changing the electrode's physical structure or geometry, the invention uses chemical reaction (nitridation) and surface texturing to achieve the desired impedance reduction, simplifying the overall device design

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent achieves impedance reduction through controlled changes in surface properties (composition, texture, area) rather than modifying bulk electrode design. This approach to parameter change at the surface level avoids complicating the overall electrode design while achieving the desired electrical characteristics

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 textured titanium nitride layer reduces post-shock recovery time, enhancing the ability to sense therapy effectiveness and improve the delivery of subsequent electrical pulses.

Implementation Method 1

delivering energy to a portion of the titanium surface, modifying the portion of the titanium surface with the energy delivered to the titanium surface

Methodology Applied

Scientific EffectLaser ablation: Laser Ablation

Implementation Method 2

removing titanium from the portion of the titanium surface. The titanium nitride is formed at the portion of the titanium surface where titanium has been removed

Methodology Applied

Scientific EffectEvaporation: Evaporation

Implementation Method 3

forming titanium nitride by reacting titanium at the portion of the titanium surface with nitrogen from the nitrogen gas environment

Methodology Applied

Scientific EffectChemical reaction (nitridation): Chemical Bonding

Data Source

PatentUS10112043B2Laser generated surface finishes for implantable medical devices and electrodes

Publication Date: 2018.10.30 CARDIAC PACEMAKERS INC

AI summary

A method of preparing an electrode for use with an implantable medical device, the electrode including a titanium surface, the method including: maintaining a nitrogen gas environment proximate to the titanium surface, delivering energy to a portion of the titanium surface, modifying the portion of the titanium surface with the energy delivered to the titanium surface, and forming titanium nitride by reacting titanium at the portion of the titanium surface with nitrogen from the nitrogen gas environment. Modifying includes increasing a surface area of the portion of the titanium surface, and removing titanium from the portion of the titanium surface. The titanium nitride is formed at the portion of the titanium surface where titanium has been removed.