EEG Signal Processing for Reliable BIS/BAS Measurement
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Solution Overview
Problem
Existing methods for measuring BIS/BAS responses using EEG are susceptible to ocular artefacts and provide unreliable results, especially in non-laboratory settings, making it difficult to determine individual responses accurately for consumer applications.
Innovation Solution
A computer-implemented method and system for processing EEG signals using a narrow frequency range of 26-29 Hz, specifically filtering and converting signals to the frequency domain, and calculating the asymmetry index using high-pass and low-pass filters, along with normalization techniques to minimize artefacts and enhance signal quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the alpha frequency range (8-12 Hz) is used for BIS/BAS measurement, then the measurement can be performed based on well-established neuroscience theory, but the results are highly susceptible to ocular artefacts and provide unreliable measurements
Solution Approach 1:
The patent changes the frequency parameter from the traditional alpha range (8-12 Hz) to a higher frequency range (26-29 Hz or 27-28.5 Hz). This parameter change allows the measurement to remain based on prefrontal cortex asymmetry theory while avoiding the ocular artefact contamination that plagues the lower alpha frequencies, thereby resolving the contradiction between theoretical foundation and measurement reliability
Solution Approach 2:
The patent converts the potential harm of using frequency ranges that are susceptible to artefacts into a benefit by deliberately selecting a frequency range (26-29 Hz) that is less affected by ocular artefacts. This transforms the challenge of artefact contamination into an opportunity to use a more robust frequency range that provides cleaner, more reliable measurements
2Measurement precision
If traditional frequency ranges are used for EEG analysis, then comprehensive brain activity information is captured, but the BIS/BAS measurement becomes unreliable due to artefact contamination
Solution Approach 1:
The patent extracts only the specific frequency information needed for reliable BIS/BAS measurement (26-29 Hz range) from the full EEG spectrum, rather than using the complete frequency range. This extraction approach discards the contaminated lower frequencies while retaining the useful higher frequencies, achieving precise measurement without excessive information loss
Solution Approach 2:
The patent applies local quality by focusing analysis on a specific frequency band (26-29 Hz) rather than uniformly analyzing all frequencies. This localized approach concentrates computational resources and analytical attention on the frequency range that provides the best signal-to-noise ratio for BIS/BAS measurement, improving precision without needing to process the entire spectrum
3Ease of operation
If signal processing is simplified for consumer applications, then ease of operation increases, but measurement accuracy and reliability deteriorate
Solution Approach 1:
The patent performs preliminary action by pre-defining the optimal frequency range (26-29 Hz) and asymmetry calculation methodology based on scientific research. This preliminary optimization is built into the device, so that during actual consumer use, the complex signal processing has already been configured to deliver accurate individual measurements without requiring user intervention or complex setup
Solution Approach 2:
The patent implements self-service through automated artefact rejection and quality assessment algorithms that automatically evaluate and filter signals. The system independently performs the complex tasks of signal validation, artefact identification, and quality control, providing accurate measurements without requiring user expertise in signal processing, thus maintaining both ease of operation and measurement precision
Data Source
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AI summary
A method for processing EEG signals, the method comprising: reading the EEG signals from two frontal electrodes of an electroencephalograph; converting the EEG signals to a frequency domain; determining values of a BIS/BAS response on the basis of an asymmetry between the EEG signals. The method comprises calculating the asymmetry between the EEG signals in the frequency domain in a frequency range from 26 to 29 Hz.