Flexible Dry EEG Electrodes for Reliable Scalp Contact

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Solution Overview

Problem

Existing EEG devices face challenges in ensuring reliable signal capture due to poor scalp contact, discomfort, and lack of discretion, particularly for consumer applications.

Innovation Solution

A portable EEG device with flexible supports and integrated electronic circuits, using active dry electrodes with conductive strips and a housing that forms a means of attachment to clothing or accessories, ensuring even pressure distribution and ease of use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If gel electrodes are used to ensure good conductivity, then signal reliability is improved, but device complexity and time consumption increase

Engineering Contradiction:
Improvesignal reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the gel substance from the electrode structure, transitioning from gel-based electrodes to dry electrodes. This eliminates the need for gel application and drying time, reducing device complexity and preparation time while maintaining signal reliability through the active electronic components that compensate for the absence of gel.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the chemical/conductive mechanism of gel electrodes with an active electronic system. The dry electrodes are equipped with electronic components (amplifiers, filters, analog-to-digital converters) that actively compensate for the increased impedance caused by the absence of gel, thereby maintaining signal reliability without requiring gel application.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If raised bump sensors are used to reach the scalp, then contact quality is improved, but user comfort deteriorates

Engineering Contradiction:
Improvecontact qualityVSAvoiduser comfort
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent changes the physical parameters of the electrode structure by eliminating raised bumps and instead using flat or gently contoured dry electrodes. The contact quality is maintained not through mechanical pressure from bumps but through the active electronic components that amplify and filter signals, allowing for comfortable prolonged wear while ensuring reliable scalp contact.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If multiple separate components are used to ensure adjustability, then adaptability is improved, but ease of use deteriorates

Engineering Contradiction:
ImproveadaptabilityVSAvoidease of use
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent merges multiple separate adjustable components (electrode holders, positioning mechanisms, electronic circuits) into an integrated headband structure. The headband incorporates all necessary components in a unified design that automatically adapts to different head sizes and shapes, eliminating the need for manual assembly and adjustment by the user while maintaining high adaptability.

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

The device provides high-quality EEG signals with improved user comfort and discretion, suitable for consumer applications, while maintaining ease of use and ergonomic design.

Implementation Method 1

Surface electroencephalography allows the measurement of variations in diffuse electrical potentials across the surface of the skull. These variations in electrical potentials are commonly called electroencephalographic signals or EEG signals.

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

for each sensor, an electronic circuit for filtering and amplifying the electrical signals detected by said sensor

Methodology Applied
Scientific EffectSignal amplification:

Implementation Method 3

for each sensor, an electronic circuit for filtering and amplifying the electrical signals detected by said sensor

Methodology Applied
Scientific EffectSignal filtering: Filter (electronic)

Data Source

PatentEP4385411B1Portable electroencephalographs
Publication Date: 2026.04.15 SNAP INC
  • EP4385411B1 patent drawingFigure 1A~1B
  • EP4385411B1 patent drawingFigure 1C~1D
  • EP4385411B1 patent drawingFigure 1E~2A

AI summary

In one aspect, this description relates to a portable device (10) for acquiring electroencephalographic (EEG) signals emitted by a user. The portable device comprises a flexible support (11) designed to conform to a localized region of the user's skull and an array of sensors (13) for electrical signals generated by the user's neural activity, arranged on said support (11) so as to make contact with the scalp when the device is worn by the user. For each sensor, an electronic circuit for filtering and amplifying the electrical signals detected by said sensor is integrated into the flexible support (11) and forms, together with said sensor, an active electrode.The portable device further includes a housing (12) comprising an electronic chain for processing signals from said electronic filtering and amplification circuits, said housing being mechanically connected to the flexible support to form, with said support, a means of attachment to a garment or accessory (101) intended to be worn by the user.