Evoked Potential Detection via Dynamic Frequency Adjustment
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Solution Overview
Problem
Current methods for detecting evoked potentials using Steady-State Evoked Visual Potentials (SSVEPs) are slow to respond due to variability in EEG signals among individuals and over time, requiring users to concentrate for extended periods, which can be tedious and inefficient, especially in applications like controlling devices with flashing images or sounds.
Innovation Solution
A method that adjusts the frequency of sensory stimulation signals based on user reaction latency, selecting frequencies that result in evoked potentials within a threshold time frame, allowing for dynamic frequency adjustment and storage of optimal frequencies for individual users and specific conditions, such as different times of day or emotional states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed frequency stimulation signal is used for SSVEP detection, then the system structure is simple, but the response time is slow and the detection efficiency is low
Solution Approach 1:
The patent applies dynamics by making the stimulation frequency adjustable and adaptable rather than fixed. The system dynamically selects optimal frequencies based on real-time detection of evoked potentials and user reaction latencies, allowing the frequency to change during operation to maintain fast response times while managing complexity through software-based adaptation.
Solution Approach 2:
The patent changes the frequency parameter of the stimulation signal based on detected evoked potentials and reaction latencies. By adjusting this key parameter dynamically, the system optimizes detection speed and accuracy without requiring complex hardware modifications, resolving the contradiction between simplicity and responsiveness.
2Productivity
If the stimulation frequency is adjusted dynamically based on user reaction, then the detection speed and efficiency improve, but the system complexity increases
Solution Approach 1:
The patent implements feedback by continuously monitoring user reactions (evoked potentials and reaction latencies) and using this information to adjust the stimulation frequency. This closed-loop feedback mechanism enables the system to adapt to individual user characteristics and optimize detection efficiency while managing complexity through iterative learning and adaptation.
Solution Approach 2:
The system performs self-adjustment of stimulation frequencies based on detected user responses without requiring external intervention. The automated frequency selection and adaptation process enables the system to optimize its own performance, improving detection efficiency while minimizing the need for complex external control mechanisms.
3Adaptability or versatility
If multiple frequencies are tested to find optimal values, then the adaptability to individual users improves, but the calibration time and process complexity increase
Solution Approach 1:
The patent applies preliminary action by pre-testing multiple candidate frequencies during calibration to identify the optimal frequency for each user before actual use. This advance preparation allows the system to store and recall individualized frequency preferences, enabling fast adaptive responses during operation while keeping calibration time manageable through efficient pre-characterization.
Solution Approach 2:
The system tests a set of candidate frequencies (excessive action) during calibration to ensure comprehensive coverage of potential optimal values. By testing more frequencies than strictly necessary but storing only the best results for future use, the system achieves high adaptability to individual users while limiting the impact on calibration time through selective retention of optimal parameters.
Data Source
AI summary
Method and apparatus for detecting an evoked potential in a physiological signal of a user, in response to the generation of a sensory stimulation signal played by a human machine interface intended for the user. The sensory stimulation signal is periodic and adjustable in frequency. For a given sensory stimulation signal, the frequency of the given signal is adjusted to a first frequency, and then a latency in the user's reaction between the moment the given signal is generated and the moment the evoked potential is detected when such detection occurs is measured. If the latency is lower than a threshold, information is stored according to which the first frequency is attributable to a sensory stimulation signal. Otherwise, the method is repeated with a second frequency in place of the first frequency, the second frequency being different from the first frequency.