Ear-EEG Real-Time Calibration via Impedance and ML

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Solution Overview

Problem

Existing methods for assessing EEG signal quality from wearable Ear-EEG devices are inadequate for real-time calibration, particularly in consumer devices, due to the lack of effective techniques for detecting noise and ensuring optimal signal quality for applications like BCI and neurodegenerative disease detection.

Innovation Solution

A processor-implemented method and system for real-time calibration of EEG signals from wearable Ear-EEG devices, which involves receiving bioelectric signals, determining electrode contact through impedance values, verifying signal quality using flat channel detection, selecting appropriate electrodes based on signal characteristics, evaluating a quality index using machine learning, and recalibrating the device as needed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If visual inspection of EEG time series is used to assess signal quality, then expert judgment can identify noise and signal capture issues, but this approach is infeasible for consumer devices and lacks consistency as inspection may differ from one expert to another

Engineering Contradiction:
Improvesignal quality assessment accuracyVSAvoidcomplexity of quality assessment system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces manual visual inspection (mechanical/expert system) with an automated computational system that uses signal processing algorithms and machine learning models to assess EEG signal quality, making the process feasible for consumer devices while maintaining consistency

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

Solution Approach 2:

The system enables self-assessment of signal quality through automated algorithms that continuously monitor and evaluate EEG signals without requiring external expert intervention, allowing the device to independently determine signal quality and trigger appropriate actions

Inventive Principle:
Principle #25Self-service

2Reliability

If scalp EEG recording is used to obtain brain activity signals, then good signal quality can be achieved, but the method lacks mobility and causes discomfort to the user

Engineering Contradiction:
Improvesignal qualityVSAvoiduser comfort and mobility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent extracts the EEG recording function from the traditional scalp electrode system and relocates it to ear wearable devices, separating the signal acquisition capability from the uncomfortable scalp contact while maintaining the essential brain activity monitoring function

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the physical location parameter of electrode placement from scalp to ear, and modifies the electrode-skin interface parameters to achieve both comfort and adequate signal quality in the new location

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If ear wearable EEG devices are used to provide user-friendly monitoring with freedom of movement, then user comfort and mobility are improved, but the recorded signals contain significant noise and may fail to capture EEG from some channels due to poor skin-electrode connectivity

Engineering Contradiction:
Improveuser comfort and mobilityVSAvoidsignal quality and channel capture
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent implements real-time feedback mechanisms that continuously monitor signal quality metrics and provide feedback to adjust electrode contact pressure, trigger user alerts for recalibration, or activate noise reduction algorithms to maintain adequate signal quality

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent performs preliminary calibration and impedance checking before actual EEG recording to ensure adequate skin-electrode connectivity, and uses preliminary signal quality assessment to identify and correct potential issues before they affect data collection

Inventive Principle:
Principle #10Preliminary action

4Quantity of substance

If multiple electrodes are used to record EEG signals from ear wearables, then more brain activity channels can be monitored, but it becomes difficult to determine which electrodes have good contact and are receiving valid signals

Engineering Contradiction:
Improvenumber of monitoring channelsVSAvoiddifficulty of identifying functional electrodes
Core Design Contradiction:
Quantity of substanceVSDifficulty of detecting and measuring

Solution Approach 1:

The patent uses visual indicators (analogous to color changes) to display the status of each electrode, providing immediate visual feedback about which electrodes have good contact and are functioning properly, making it easy for users to identify problematic channels

Inventive Principle:
Principle #32Color changes

Solution Approach 2:

The patent replaces manual assessment of electrode contact quality with automated impedance measurement and signal quality analysis systems that objectively determine which electrodes are functioning properly

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

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 solution enables real-time assessment and optimization of EEG signal quality, ensuring that only high-quality signals are used for applications like BCI, thereby improving the reliability and accuracy of brain activity monitoring.

Implementation Method 1

determining a contact of each of the plurality of electrodes with the user in order to receive the multitude of bioelectric signals based on a set of impedance values, wherein the set of impedance values is an impedance between each of the plurality of electrodes and a skin-body interface of the user

Methodology Applied
Scientific EffectElectrical Impedance: Electrical Resistance

Data Source

PatentEP4529842A1Method and system for real-time calibration of ear-EEG device
Publication Date: 2025.04.02 TATA CONSULTANCY SERVICES LTD
  • EP4529842A1 patent drawingFigure 1
  • EP4529842A1 patent drawingFigure 2
  • EP4529842A1 patent drawingFigure 3A

AI summary

The embodiments of the present disclosure herein address unresolved problems of quality of signals in real time for wearables to provide optimal signals which can be used for brain signal based applications. Further, conventional techniques fail to provide real-time calibration of wearable devices, to understand the quality of the signals from the wearable device. Embodiments herein provide a method and system for a real-time calibration of one or more Electroencephalography (EEG) signals received from a wearable Ear-EEG device. The system is leveraging quality of signals in real time for wearables to provide optimal signals which can be used for early detection of neurodegenerative disease and brain-computer interface (BCI) applications. Further, the system is able to detect electrodes in the wearable device where the EEG signals have not been collected because the contact was not established.