Non-sensitive stimulation method and system for brain-computer interface

Abstract

The invention relates to the technical field of brain-computer interface systems, in particular to a non-sensitive stimulation method and system for a brain-computer interface, and the method comprises the steps: arranging an LED lamp strip in an edge region of a user view in an interaction region; setting the stimulation frequency and the flicker initial phase of the LED lamp strip according to the control signal; a stimulation signal corresponding to the control signal is generated through the LED lamp strip; and collecting an electroencephalogram signal generated when the user watches the stimulation signal in the interaction area. The LED lamp strip is arranged in the edge area of the visual field of the user, the direct visual burden of the user is reduced, and the comfort degree of long-time use is improved. And the stimulation frequency and the flicker initial phase of the LED lamp strip are set according to the control signal, so that the accuracy and the controllability of the stimulation signal are ensured. The stimulation signal corresponding to the control signal is generated through the LED lamp strip, and the electroencephalogram signal generated when the user watches the stimulation signal in the interaction area is collected, so that effective collection and analysis of the electroencephalogram signal are ensured.

Description

Technical Field

[0001] The present application relates to the technical field of brain-computer interface systems, and in particular to a non-sensitive stimulation method and system for brain-computer interfaces. Background Art

[0002] The brain-computer interface system is a system that uses the bioelectric signals of the human brain to achieve communication and control between the human brain and computers or other electronic devices. It is a brand-new communication and control method. The human brain is in an active state for a long time, which makes the "intention" signal easily drowned in the massive background noise of the brain. This characteristic of the human brain makes the modulation of "intention" particularly important. The visual evoked potential (VEP) BCI system designs the control instructions as corresponding visual stimuli. The user can effectively modulate the control "intention" by looking at the visual stimuli. After collecting the corresponding EEG signals, the output of the control instructions can be realized after being recognized by the signal enhancement and decoding algorithms.

[0003] The VEP paradigm can effectively induce the brain to produce electrical signals that can be effectively distinguished. The characteristics of this type of electrical signal are relatively stable and have good interpretability, which makes VEP-BCI the most studied paradigm. In the prior art, the display is flickered so that the user receives the corresponding visual stimulation. However, since the flickering instruction can easily induce visual fatigue, especially long-term staring at dynamic stimuli, this type of paradigm is not suitable for long-term use by users.

[0004] Therefore, there is an urgent need for a non-sensitive stimulation scheme for brain-computer interfaces that can reduce the user's visual fatigue caused by flickering stimulation and improve the user experience. Summary of the invention

[0005] In view of this, it is necessary to provide a non-sensory stimulation method and system for brain-computer interface to solve the problem in the prior art that flashing instructions easily induce visual fatigue and are not suitable for long-term use by users.

[0006] A non-sensory stimulation method for a brain-computer interface, comprising: The LED light strip is set at the edge of the user's field of view in the interactive area; Set the stimulation frequency and flashing start phase of the LED light strip according to the control signal; Generate a stimulation signal corresponding to the control signal through the LED light strip; The electroencephalogram (EEG) signal generated by the user gazing at the stimulation signal in the interaction area is collected.

[0007] Preferably, the number of LED light strips is four; The stimulation frequencies of the LED light strips are 7 Hz, 8 Hz, 9 Hz, and 10 Hz, respectively; and the corresponding flashing start phases of the LED light strips are 0, π / 2, π, and 3π / 2, respectively.

[0008] Preferably, the color of the LED light strip is set to white, and the brightness is greater than 300 nits.

[0009] Preferably, collecting the EEG signal generated by the user looking at the stimulation signal in the interactive area, and then further comprising: Decoding the EEG signal to obtain a decoding result; Mapping and obtaining control instructions according to the decoding result; The terminal to be controlled is controlled by the control instruction.

[0010] Preferably, collecting the electroencephalogram signal generated by the user gazing at the stimulation signal in the interactive area includes: the sampling frequency of the collection is 250 Hz.

[0011] Preferably, the method further includes: arranging a display in the interactive area; and generating a stimulation signal through the LED light strip and the display.

[0012] Compared with the prior art, the beneficial effects of the present application are as follows: the present application sets the LED light strip at the edge area of ​​the user's field of vision, which reduces the user's direct visual burden and improves the comfort of long-term use. The stimulation frequency and flashing start phase of the LED light strip are set according to the control signal, ensuring the accuracy and controllability of the stimulation signal. The LED light strip generates a stimulation signal corresponding to the control signal, and collects the EEG signal generated by the user looking at the stimulation signal in the interactive area, ensuring the effective collection and analysis of the EEG signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of the system layout for non-sensitive stimulation of brain-computer interface provided in an embodiment of the present application.

[0014] Figure 2 It is a flow chart of the non-sensitive stimulation method for brain-computer interface provided in the embodiment of the present application.

[0015] Figure 3 It is a flow chart of a non-sensitive stimulation method for brain-computer interface provided in another embodiment of the present application.

[0016] Figure 4 4 is a schematic diagram of the structure of a non-sensitive stimulation system 400 for a brain-computer interface provided in an embodiment of the present application. DETAILED DESCRIPTION

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] See also Figure 1-Figure 3 , Figure 1 It is a schematic diagram of the system layout of non-sensory stimulation for brain-computer interface provided in an embodiment of the present application; Figure 2 : is a flow chart of a non-sensitive stimulation method for a brain-computer interface provided in an embodiment of the present application; the non-sensitive stimulation method for a brain-computer interface comprises the following steps: S101: Setting an LED light strip in an edge area of ​​a user's field of view in an interactive area.

[0019] The LED light strips in this application can be any kind of micro LED light strips that meet the requirements, such as LED light strips that support PWM (pulse width modulation) control. The microcontroller can receive instructions from the host computer and control the LED light strips. Each light strip should be controlled independently to avoid confusion caused by multiple light strips flashing at the same time. The LED light strips are used as visual stimulation sources to induce EEG signals by flashing at different frequencies and phases.

[0020] The LED light strips are set at the edge of the user's field of vision in the interactive area. Light strips of different frequencies are evenly distributed at the edge of the user's field of vision. Edge vision is also sensitive to flickering stimulation, but the user's direct attention is less. At the same time, the light strips are naturally integrated with the ambient atmosphere light strips and do not attract the user's direct attention. This ensures that the user can receive stimulation in different directions and reduce local visual fatigue.

[0021] In addition, when setting up light strips, avoid concentrating all light strips in one area, which will cause excessive visual burden on users in a certain direction. You can also try to arrange the light strips symmetrically. A symmetrical layout can reduce the discomfort caused by visual asymmetry and improve user comfort. Make sure that light strips of different frequencies are distributed on the left and right sides and the upper and lower sides to maintain visual balance. Make sure that there is enough distance between light strips of different frequencies to reduce mutual interference. In particular, a certain interval should be maintained between high-frequency and low-frequency light strips.

[0022] In actual applications, users can also adjust the position of the light strip according to their needs to improve the adaptability of the system and user experience.

[0023] S102: Setting the stimulation frequency and flashing start phase of the LED light strip according to the control signal.

[0024] Stimulation frequency is a key factor in inducing steady-state visual evoked potentials (SSVEP). Flickering stimulation of different frequencies will generate EEG signals of different frequencies in the brain, which can be collected and decoded by EEG (Electroencephalography). Studies have shown that the human brain is very sensitive to flickering stimulation of specific frequencies, especially frequencies in the range of 10-15 Hz. These frequencies can effectively induce stable SSVEP signals with a high signal-to-noise ratio.

[0025] Furthermore, the number of LED light strips may be 4. In practical applications, commonly used frequency ranges include 7 Hz, 8 Hz, 9 Hz, 10 Hz, etc. By selecting different frequencies, multi-channel control commands can be implemented to improve the control accuracy and flexibility of the system.

[0026] Setting the flashing start phase of light strips with different frequencies can reduce the mutual interference between different frequency stimuli. For example, if the flashing start phases of multiple light strips are the same, their signals may overlap, making decoding difficult. By setting different start phases, it can be ensured that the signals of each frequency are distinguished in time, thereby improving the distinguishability of the signals. By setting different start phases, the time domain and frequency domain characteristics of the signal can also be optimized, making it more suitable for processing by the decoding algorithm.

[0027] Therefore, by setting different starting phases, the ability to resist interference between different LED strips and external interference can be improved. For example, changes in ambient light and user blinking may introduce noise. Different starting phases can help the system better identify the real stimulus signal and improve the robustness of the entire system.

[0028] In addition, different users may have different reactions to stimulation of the same frequency. By setting different starting phases, the system's adaptability to different users can be improved, which can reduce users' visual fatigue caused by single-frequency flickering and improve comfort for long-term use.

[0029] Furthermore, the color of the LED light strip is set to white, and the brightness is greater than 300 nits. The color of the light strip will affect the intensity of visual stimulation and the visual comfort of the user. Different colors may cause different physiological responses, but the impact of color is smaller than that of frequency. White light is usually the most effective color because it contains all components of the visible spectrum and can stimulate retinal cells more evenly. Other colors (such as red, green, and blue) can also induce SSVEP, but the effect may not be as significant as white light. In practical applications, white light is the most commonly used color because it can provide strong visual stimulation while reducing the user's visual fatigue.

[0030] S103: Generate a stimulation signal corresponding to the control signal through the LED light strip.

[0031] The LED light strips generate stimulation signals corresponding to the control signals. For example, for four LED light strips, the stimulation frequencies of each light strip are 7 Hz, 8 Hz, 9 Hz, and 10 Hz, and the starting phases are 0, π / 2, π, and 3π / 2, respectively: Place a light strip at the upper left edge of the user's field of view, set to 7 Hz, phase 0.

[0032] Place another light strip at the upper right edge of the user's field of view, set to 8 Hz with a phase of 90°.

[0033] Place the third light strip at the lower left edge of the user's field of view and set it to 9 Hz with a phase of 180°.

[0034] Place the fourth light strip at the lower right edge of the user's field of view and set it to 10 Hz with a phase of 270°.

[0035] The above-mentioned light strip setting ensures that users can receive stimulation in different directions and reduce local visual fatigue. The relatively symmetrical arrangement can maintain visual balance and reduce the discomfort caused by visual asymmetry. At the same time, the light strip blends naturally with the ambient light strip and does not attract the user's direct attention.

[0036] S104: Collecting an electroencephalogram signal generated by the user gazing at the stimulation signal in the interaction area.

[0037] The EEG signals generated by the user looking at the stimulation signal in the interactive area are collected to ensure effective collection and analysis of the EEG signals. Preferably, the sampling frequency of the collection is 250 Hz.

[0038] Furthermore, the electroencephalogram (EEG) signal generated by the user looking at the stimulation signal in the interactive area is collected, and then the following steps are further included: The EEG signal is decoded to obtain a decoding result. Before decoding, the collected EEG signal can also be preprocessed, including filtering, noise reduction, and removal of power frequency interference, to improve signal quality. Features are then extracted from the preprocessed signal. Common features include frequency domain features (such as power spectrum density), time domain features (such as waveform peaks), etc. A decoding algorithm (such as canonical correlation analysis (CCA), support vector machine (SVM), deep learning model, etc.) is then used to convert the features into a representation of the user's intent.

[0039] For example, the decoding algorithm usually outputs a classification result, indicating the user's current control intention. If the user is looking at a 7 Hz light strip, the decoding result may be "Command 1". Based on the decoding result, the control instruction is mapped. The decoding result is mapped to a specific control command. For example, the decoding result "Command 1" can be mapped to "move forward", "Command 2" can be mapped to "turn left", etc.

[0040] The control command is used to control the terminal to be controlled. The control command is sent to the terminal to be controlled through an appropriate communication protocol (such as serial communication, network communication, etc.). After receiving the control command, the terminal to be controlled performs the corresponding action.

[0041] Further, such as Figure 3 As shown, Figure 3 : is a schematic diagram of the system layout of the non-sensory stimulation for brain-computer interface provided by this embodiment. It also includes: setting a display in the interactive area; generating stimulation signals through the LED light strip and the display. The micro LED light strip can be used as the main source of visual stimulation, inducing EEG signals by flashing at different frequencies and phases, while the display can display more complex visual stimulation, such as images, videos, etc., and the micro LED light strip and the display are used in combination. Therefore, this embodiment combines the advantages of both, which can reduce visual fatigue and provide a rich interactive experience.

[0042] Based on the same inventive concept, the present application also provides a non-sensitive stimulation system 400 for a brain-computer interface, such as Figure 4 The schematic diagram of the structure of the non-sensitive stimulation system 400 for brain-computer interface shown in FIG. 1 includes: LED light strip 401, arranged at the edge area of ​​the user's field of view in the interactive area; The stimulation generation module 402 is used to set the stimulation frequency and the flashing start phase of the LED light strip; The stimulation generating module 402 is further used to generate a stimulation signal corresponding to the control signal through the LED light strip; The signal collection module 403 is used to collect the EEG signal generated when the user looks at the stimulation signal in the interaction area.

[0043] Furthermore, the non-sensitive stimulation system 400 for brain-computer interface also includes: A decoding module 404 is used to decode the EEG signal to obtain a decoding result; A mapping module 405, configured to map and obtain a control instruction according to the decoding result; The control module 406 is used to control the terminal to be controlled through the control instruction.

[0044] Furthermore, it also includes: The display 407 is arranged in the interactive area and is used to display the stimulation signal.

[0045] Furthermore, the stimulation generating module 402 is also used to control the LED light strip and the display, and generate stimulation signals through the LED light strip and the display.

[0046] In the above embodiment, the specific implementation method of each functional module of the non-sensitive stimulation system 400 for brain-computer interface can refer to the introduction in the above embodiment of the non-sensitive stimulation method for brain-computer interface, and will not be repeated in this embodiment.

Claims

1. A non-sensitive stimulation method for brain-computer interface, characterized in that: include: The LED light strip is set at the edge of the user's field of view in the interactive area; Set the stimulation frequency and flashing start phase of the LED light strip according to the control signal; Generate a stimulation signal corresponding to the control signal through the LED light strip; The electroencephalogram (EEG) signal generated by the user gazing at the stimulation signal in the interaction area is collected.

2. The method according to claim 1, characterized in that include: The number of LED light strips is four; The stimulation frequencies of the LED light strips are 7 Hz, 8 Hz, 9 Hz, and 10 Hz, respectively; and the corresponding flashing start phases of the LED light strips are 0, π / 2, π, and 3π / 2, respectively.

3. The method according to claim 1, characterized in that Set the color of the LED light strip to white and the brightness to greater than 300 nits.

4. The method according to claim 1, characterized in that Collecting the electroencephalogram signal generated by the user looking at the stimulation signal in the interactive area, and then further comprising: Decoding the EEG signal to obtain a decoding result; Mapping and obtaining control instructions according to the decoding result; The terminal to be controlled is controlled by the control instruction.

5. The method according to claim 1, characterized in that Collecting the electroencephalogram signal generated by the user looking at the stimulation signal in the interactive area, including: the sampling frequency of the collection is 250 Hz.

6. The method according to any one of claims 1 to 5, characterized in that: Also includes: Disposing a display in the interactive area; A stimulation signal is generated by the LED light strip and the display.

7. A non-sensitive stimulation for brain-computer interface, characterized in that: include: LED light strips are arranged at the edge of the user's field of view in the interactive area; A stimulus generation module is used to set the stimulus frequency and flashing start phase of the LED light strip; The stimulation generating module is further used to generate a stimulation signal corresponding to the control signal through the LED light strip; The signal acquisition module is used to collect the electroencephalogram signal generated by the user looking at the stimulation signal in the interactive area.

8. The method according to claim 7, characterized in that: Also includes: A decoding module, used for decoding the EEG signal to obtain a decoding result; A mapping module, used for mapping and obtaining control instructions according to the decoding result; The control module is used to control the terminal to be controlled through the control instruction.

9. The method according to claim 7, characterized in that: Also includes: A display is arranged in the interaction area and is used to display the stimulation signal.

10. The method according to claim 9, characterized in that: Also includes: The stimulation generating module is further used to control the LED light strip and the display, and to generate stimulation signals through the LED light strip and the display.

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