Head Electrode Support Structure for Self-Applied Biopotential Sensing

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Solution Overview

Problem

Existing electrode systems for measuring electrophysiological signals, such as EEG, EOG, and EMG, are difficult for untrained individuals to apply correctly and comfortably, especially when self-applying, due to high contact impedance and discomfort with dry electrodes, and require trained personnel for wet electrodes.

Innovation Solution

A support structure with predefined electrode positions and varying flexibility allows for easy, precise, and comfortable self-application by users, using wet electrodes with minimal skin contact force, and adapts to facial structures for high signal quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If wet electrodes are used to reduce contact impedance and improve signal quality, then measurement precision is improved, but device complexity and ease of operation worsen due to requiring trained personnel for application

Engineering Contradiction:
Improvesignal qualityVSAvoidease of application
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The electrode system is segmented into modular components: a flexible substrate with multiple electrode elements arranged in specific patterns, each electrode pre-loaded with conductive gel, allowing the complex measurement function to be divided into manageable, pre-configured units that simplify application while maintaining signal quality

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The electrodes are pre-prepared with conductive gel loaded into reservoirs or applied to the electrode surface before use. The flexible substrate is pre-configured with electrode positions corresponding to standard measurement systems (e.g., 10-20 system), eliminating the need for trained personnel to perform complex application procedures during actual use

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If dry electrodes are used to simplify application for self-use, then ease of operation is improved, but measurement precision worsens due to high contact impedance

Engineering Contradiction:
Improveease of self-applicationVSAvoidcontact impedance
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

A flexible substrate acts as an intermediary carrier that holds multiple electrodes in predetermined positions. This substrate can be easily handled and self-applied by users, while the electrodes themselves maintain wet electrode properties with conductive gel for low contact impedance, combining the ease of dry electrode application with the measurement quality of wet electrodes

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If pressure is applied to improve contact between dry electrodes and scalp, then contact impedance is reduced, but object-generated harmful factors worsen due to discomfort and headaches

Engineering Contradiction:
Improvecontact impedanceVSAvoiddiscomfort and headaches
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The electrode system changes the physical state of the contact medium from dry to wet (conductive gel), which fundamentally alters the contact impedance characteristics. The gel provides continuous ionic conduction without requiring mechanical pressure, changing the contact parameter from pressure-dependent to material-dependent, thereby eliminating discomfort while maintaining low impedance

Inventive Principle:
Principle #35Parameter changes

4Manufacturing precision

If individual electrodes are applied manually to achieve precise positioning, then manufacturing precision is improved, but ease of operation worsens due to time-consuming application requiring trained personnel

Engineering Contradiction:
Improveelectrode position accuracyVSAvoidapplication time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

Multiple individual electrodes are merged onto a single flexible substrate with predetermined positioning. The substrate integrates multiple electrode elements at precise locations corresponding to standard measurement systems, combining what would require multiple separate manual placement operations into a single self-applied unit, dramatically reducing application time while maintaining position accuracy

Inventive Principle:
Principle #5Merging (Combining)

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 efficient, precise, and comfortable self-application of electrodes with high signal quality and reduced discomfort, suitable for long-term use by ensuring accurate electrode positioning and reduced impedance.

Implementation Method 1

The moderately viscous gel lens, in addition to its electrolyte effect, has adhesive properties, allowing the electrode to adhere better to the skin than wet electrodes with gel coating or dry electrodes.

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

The moderately viscous gel lens, in addition to its electrolyte effect, has adhesive properties

Methodology Applied
Scientific EffectElectrolyte conduction: Electrolyte

Data Source

PatentEP4398801B1Electrode arrangement for measuring biopotentials on a person's head
Publication Date: 2026.03.18 FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV
  • EP4398801B1 patent drawingFigure 1a~1b
  • EP4398801B1 patent drawingFigure 2
  • EP4398801B1 patent drawingFigure 3a~3b

AI summary

The invention relates to a device having: an electrode arrangement with a plurality of electrodes for measuring electrical signals on the facial surface of a user's head and behind the user's ear; and a support structure. The support structure defines, at least in part, a relative position of the electrodes with respect to one another. The support structure, without external force being applied by the user is, within a tolerance range, dimensionally stable, and, with external force being applied by the user, can be deformed in order to change the distance between two adjacent electrodes and/or to adjust to face and head structures for comprehensive coverage. The support structure is designed to position at least a part of the electrode arrangement on the facial surface and behind the ear.