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CN-121996067-A - Local SSMVEP stimulation and lateral MI linkage triggering method based on gazing region driving, brain-computer interface system and application

CN121996067ACN 121996067 ACN121996067 ACN 121996067ACN-121996067-A

Abstract

The invention provides a local SSMVEP stimulation and side MI linkage triggering method based on gazing area driving, a brain-computer interface system and application, wherein the method determines the current effective gazing area of a user in at least three different gazing areas in real time, the local SSMVEP stimulus activation and the lateral MI task prompt which are uniquely corresponding to the region are synchronously triggered to form a cooperative trigger link of 'gazing region-local stimulus-lateral task'. The system realizes the linkage through the cooperative work of the eye tracking and region judging unit, the linkage triggering control unit, the stimulus presenting unit and the task prompting unit. The invention is used as a basic front-end technology of the multi-mode BCI, realizes the accurate alignment and synchronization of the stimulus, the task and the user intention, and provides a key bottom layer support for improving the system performance and the user experience.

Inventors

  • HE YONGZHENG
  • WANG PENGGANG
  • Nan Jiahui
  • CAO JIAYI

Assignees

  • 河南翔宇医疗设备股份有限公司

Dates

Publication Date
20260508
Application Date
20260119

Claims (10)

  1. 1. The local SSMVEP stimulation and lateral MI linkage triggering method based on the fixation area driving is characterized by comprising the following steps of: acquiring the gaze point coordinates of a user in real time, and mapping the gaze point coordinates to at least three preset different gaze areas to determine a current effective gaze area; based on the current effective gazing area, linkage trigger control is executed: A. stimulus control, namely activating only one local SSMVEP visual stimulus target corresponding to the current effective gazing area, and enabling SSMVEP visual stimulus targets of other non-corresponding areas to be in a non-activated state; B. A task prompt control step of synchronously generating lateral motor imagery prompt information associated with the current effective gazing area so as to guide a user to execute a specific motor imagery task bound with the current effective gazing area; And B, triggering in the same processing period based on the same current effective gazing area information to form a cooperative triggering link of gazing area-local stimulation-side task.
  2. 2. The local SSMVEP stimulation and side-by-side MI coordinated triggering method based on gaze area driving according to claim 1, wherein the at least three different gaze areas include a left area, a central area and a right area, and the cooperative triggering link of "gaze area-local stimulation-side-by-side task" is specifically that when the current effective gaze area is the left area, the left local SSMVEP stimulation is triggered and the left limb motor imagery is prompted, when the current effective gaze area is the central area, the central local SSMVEP stimulation is triggered and the bilateral limb or trunk motor imagery is prompted, and when the current effective gaze area is the left area, the right local SSMVEP stimulation is triggered and the right limb motor imagery is prompted.
  3. 3. The method for triggering local SSMVEP stimulation and side-looking MI linkage based on gaze area driving according to claim 1, wherein the local SSMVEP visual stimulation target and the side-looking motor imagery prompt message are presented through the composite state change of the same visual element, when a certain area is gazed, the visual element representing task content in the area is activated to be SSMVEP stimulation target, and the visual significance of the visual element is synchronously enhanced to be used as task prompt, and the visual element of a non-gazing area is weakened to be displayed.
  4. 4. The local SSMVEP stimulation and lateral MI linkage triggering method based on gaze area driving according to claim 1, wherein the local SSMVEP visual stimulation targets and the lateral motor imagery prompt information are presented separately on a display space, the stimulation targets are arranged in a core visual area in a concentrated manner, and the prompt information is arranged in a peripheral annotation area.
  5. 5. The gaze area driven based localized SSMVEP stimulation and lateral MI coordinated triggering method of any one of claims 1-4, wherein the lateral motor imagery cue information comprises at least one of a visual cue, an auditory cue, or a tactile cue.
  6. 6. A brain-computer interface system for implementing the local SSMVEP stimulation and side-by-side MI coordinated triggering method based on gaze area driving according to any one of claims 1-5, comprising: The eye tracking and region judging unit is used for acquiring the gaze point coordinates of the user in real time and mapping the gaze point coordinates to at least three preset different gazing regions so as to determine the current effective gazing region; The linkage trigger control unit is connected with the eye movement tracking and region judging unit and is used for generating a linkage control signal based on the current effective gazing region; The stimulation presentation unit is connected with the linkage trigger control unit and is used for responding to a stimulation control instruction in the linkage control signal and only activating one local SSMVEP visual stimulation target corresponding to the current effective gazing area; The task prompt unit is connected with the linkage trigger control unit and is used for responding to the task prompt instruction in the linkage control signal and synchronously generating side-type motor imagery prompt information associated with the current effective gazing area.
  7. 7. The brain-computer interface system according to claim 6, wherein the coordinated trigger control unit pre-stores a region-stimulus-task mapping relationship, and the at least three different gazing regions include a left region, a center region, and a right region, and map to different local SSMVEP stimulus parameters and different motor imagery task prompt contents, respectively.
  8. 8. The brain-computer interface system according to claim 6, wherein the functions of the stimulus presentation unit and the task prompt unit are implemented by the same graphics rendering unit, and the stimulus activation and task prompt are accomplished simultaneously by changing the states of the same set of visual elements.
  9. 9. The brain-computer interface system according to claim 6, wherein the visual stimulus target display area controlled by the stimulus presentation unit and the prompt information display area controlled by the task prompt unit do not overlap each other on the physical screen.
  10. 10. Use of a local SSMVEP stimulus based on gaze area actuation and side note MI coordinated triggering method as claimed in any one of claims 1-5, comprising the steps of: acquiring the gaze point coordinates of a user in real time, mapping the gaze point coordinates to at least three preset gaze areas, and determining a current effective gaze area; In response to the current effective gazing area, executing local stimulation control, namely activating only one local SSMVEP visual stimulation target corresponding to the current effective gazing area and generating specific motor imagery prompt information associated with the area at the same time, wherein the SSMVEP visual stimulation target of the non-current effective gazing area is in an inactive state; Synchronously acquiring brain electrical signals of a user; Extracting SSMVEP features related to the local SSMVEP visual stimulus target and MI features related to the motor imagery prompt information from the electroencephalogram signals respectively; judging whether the number of collected MI effective samples with the motor imagery prompt information as a label reaches a preset threshold value or not; Performing adaptive decoding according to the judgment result: If the number of MI valid samples does not reach a preset threshold, decoding based on SSMVEP features to generate a first control instruction; if the number of the MI effective samples reaches a preset threshold, decoding based on a fusion result of the SSMVEP features and the MI features to generate a second control instruction; and outputting a control signal to drive the associated external equipment or update the interactive interface according to the first control instruction or the second control instruction.

Description

Local SSMVEP stimulation and lateral MI linkage triggering method based on gazing region driving, brain-computer interface system and application Technical Field The invention relates to the technical field of brain-computer interfaces, in particular to a local SSMVEP stimulation and lateral MI linkage triggering method based on gaze area driving, a brain-computer interface system and application Background In a fused brain-computer interface study based on steady state visual evoked potential (SSVEP/SSMVEP) and Motor Imagery (MI), how to effectively present visual stimuli and guide MI tasks is a fundamental and critical issue. Conventional approaches typically simply superimpose both, for example, by continuously presenting multiple SSVEP blinking targets in a fixed location on the screen (e.g., left and right), while indicating to the user, via a central text or icon, that a particular side motor imagery (e.g., "imagine left hand movement") is being performed. This approach suffers from the significant drawback that, first, the stimulus and task are spatially and cognitively disjointed. The user may look at a flickering target on the right side (for SSVEP recognition), but needs to imagine left-hand motion, and this inconsistency causes that the brain vision attention network is hard to cooperate with the activities of the sensory motor cortex, and the specificity of MI brain electrical signals is weakened. Second, visual disturbances are severe. The multi-target continuous flicker itself forms visual noise, and the superposition of static or dynamic task prompts further increases the cognitive load of the user, which is easy to cause visual fatigue and distraction. Essentially, the prior art lacks a bottom trigger mechanism capable of precisely binding specific visual stimuli to specific cognitive tasks one-to-one and in millisecond level according to the user's real-time intention. Therefore, developing a collaborative stimulus-task triggering method capable of realizing "fixation, selection and triggering" becomes an urgent need for improving the performance of multi-mode BCI and improving the user experience. Disclosure of Invention The invention aims to overcome the defects in the prior art and provides a local SSMVEP stimulation and side MI linkage triggering method based on fixation area driving, a brain-computer interface system and application. The method is characterized in that a real-time gazing area of a user is used as a unified control information source, two operations of selectively activating local SSMVEP stimulation of a corresponding area and generating side MI task prompts bound with the semantics of the area are synchronously triggered, so that an efficient and accurate collaborative triggering link of gazing area-local stimulation-side tasks is constructed. The technical problems solved by the invention at least comprise: 1. how to improve the accuracy of initial Motor Imagery (MI) recognition: in the traditional MI brain-computer interface, the characteristics of the brain-electrical signals of the initial user are not obvious, and the classification accuracy is usually only about five to six, so that the operation is unreliable, and the rehabilitation training effect is influenced. Therefore, the invention aims to solve the problem of improving the separability and the recognition accuracy of MI signals at the initial stage of training by utilizing the visual attention guiding and local stimulation strategies so as to realize the plug-and-play brain-computer interface. 2. How to reduce interference and fatigue caused by visual stimulus: Traditional SSVEP full screen or multi-sided target blinking is prone to cross-target interference and visual fatigue, and may even create epileptic risk for some patients. The invention aims to solve the problem of how to adaptively activate local SSMVEP stimulation according to the user fixation side, thereby reducing the stimulation quantity and interference and improving the comfort level and the signal stability. 3. How to shorten MI training sample acquisition time and efficiently acquire tagged data: Conventional MI data acquisition phases typically last fifteen to twenty minutes or longer, requiring the user to remain stationary and repeat imaginative actions, a process that is time consuming and tedious. The invention aims to solve the problem of how to combine SSMVEP classification results with a gazing side to realize synchronous motor imagery prompt and data acquisition, so that a labeled MI sample is generated efficiently, and the training burden is reduced. The technical scheme of the invention is as follows: According to one aspect of the invention, a local SSMVEP stimulation and side-grade MI linkage triggering method based on fixation area driving is disclosed, which comprises the following steps: acquiring the gaze point coordinates of a user in real time, and mapping the gaze point coordinates to at least three preset different g