Slurry Electrodes for Safe Direct Current Nerve Conduction Block

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Solution Overview

Problem

Direct current (DC) nerve conduction block has not been clinically adopted due to the risk of nerve damage from non-reversible Faradaic reaction products during stimulation with traditional electrodes.

Innovation Solution

The use of slurry electrodes with an ionically conductive membrane and electrically conducting high surface area particles to deliver DC nerve conduction block, preventing damaging Faradaic reactions by converting DC to ionic current within the slurry, which is then applied to neural tissue.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional electrodes are used to deliver DC nerve conduction block, then nerve conduction block is achieved, but nerve damage occurs due to non-reversible Faradaic reaction products

Engineering Contradiction:

Improvenerve conduction block effectivenessVSAvoidnerve damage from Faradaic reaction products

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an ionically conductive membrane as an intermediary between the DC electrode and neural tissue. This membrane converts electrical current to ionic current, preventing direct Faradaic reactions at the tissue interface while maintaining effective nerve conduction block. The membrane acts as a mediator that transforms the mode of current delivery to eliminate harmful reaction products.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the physical-chemical parameters of the electrode-tissue interface by using an ionically conductive membrane with high ionic conductivity. This parameter change enables ionic current transmission while blocking electron transfer, thereby preventing Faradaic reactions. The membrane's specific ionic conductivity parameter allows safe DC delivery without the harmful effects of traditional electrodes.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If KHFAC is used to produce nerve conduction block, then steady state depolarization is achieved, but onset response is produced in the nerve

Engineering Contradiction:

Improvenerve conduction blockVSAvoidonset response in the nerve

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the alternating current mechanism (KHFAC) with a direct current mechanism delivered through an ionically conductive membrane. This substitution changes the fundamental physics of nerve interaction from AC-induced steady state depolarization to DC-induced ionic current block, eliminating the onset response while maintaining effective conduction block.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Object-generated harmful factors

If DC waveform is applied through flanking electrode to neutralize onset response, then onset response is eliminated, but nerve conduction is lost after several applications

Engineering Contradiction:

Improveonset response eliminationVSAvoidduration of nerve conduction block

Core Design Contradiction:

Object-generated harmful factorsVSDuration of action of stationary object

Solution Approach 1:

The ionically conductive membrane serves as a mediator that enables sustained DC delivery without the need for flanking electrodes. By converting electrical current to ionic current at the membrane interface, the system achieves both onset response elimination and sustained duration of action, resolving the contradiction between neutralizing onset response and maintaining long-term conduction block effectiveness.

Inventive Principle:

Principle #24Intermediary (Mediator)

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

Enables safe and effective DC nerve conduction block without generating irreversible reaction products, enhancing patient safety and potential clinical adoption by maintaining neural tissue integrity.

Implementation Method 1

an ionically conductive membrane... The DC is converted to an ionic current within the slurry electrode, and the ionic current establishes a nerve conduction block

Methodology Applied

Scientific EffectIonic conduction: Conduction (electrical)

Implementation Method 2

a plurality of electrically conducting high surface area particles

Methodology Applied

Scientific EffectSurface area effect:

Data Source

PatentEP3731924B1Slurry electrodes for direct current nerve conduction block

Publication Date: 2024.10.23 CASE WESTERN RESERVE UNIV

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AI summary

The present disclose relates to slurry electrodes that can deliver direct current (DC) nerve conduction block to neural tissue. Such slurry electrodes can include an ionically conductive membrane having a first side and a second side. Slurry electrodes can also include a mechanism that is configured to encapsulate a slurry against the first side of the ionically conductive membrane. The slurry can include an ionically conductive material and a plurality of electrically conducting high surface area particles. The mechanism and the first side of the ionically conductive membrane make up a housing for the slurry. Slurry electrodes can also include a connector configured to establish an electrical connection between the slurry and the DC generator.