JP5688154B2 - Electrical device control system and method based on SSVEP - Google Patents

Description

  The present disclosure relates to Brain Computer Interface (BCI) technology based on steady state visual evoked potentials (SSVEP). In particular, the features of the present disclosure include a simple electrode configuration for the acquisition of electroencephalogram (EEG) signals, a computationally efficient and accurate processing for analyzing the electroencephalogram signals, and a visual stimulus generator associated with specific equipment, simple and reliable A multi-device power interface unit, and an SSVEP-based electrical device or appliance control system and method that provides a simple, robust and assistance-free system activation process that avoids or eliminates visual fatigue and / or user frustration.

  With the development of Brain Computer Interface (BCI) systems and devices, various aspects of brain waves measured from the human scalp have been intensively studied. BCI is a direct communication path between the brain and external devices. BCI is often intended to support, reinforce, or repair human recognition or sensorimotor function.

  BCI technology plays a major role in the development of systems that help users freely control neural function alternative devices using electromyogram (EMG), electrocorticogram (ECoG), or electroencephalogram (EEG) signals. Fulfill. EEG is a common non-invasive modality that can be applied to people with severe disabilities. EEG signals result from electrical activity that can be detected outside the human scalp. EEG signals are generated by neural firing in the brain and reflect related synaptic activity caused by post-synaptic potentials generated by thousands of cortical neurons of similar spatial orientation.

  EEG signal acquisition involves scalp electrodes or leads, typically using locations specified by the International 10-20 method. In EEG, the micropotentials evoked by sensory stimuli are particularly important. This is because these temporally synchronized transient waves show how the cell group behaves in response to afferent firing carried by the primary sensory fibers. When a slight stimulus is presented to the subject, a transient brain response to this stimulus occurs.

  In general, an EEG-based neural function replacement system consists of a signal acquisition system, a signal processing algorithm, and an application device. In EEG-based neural function replacement systems, two modalities are widely used: natural EEG and event-related potential (ERP) such as visual evoked potential (VEP). Evoked potentials show the effects of stimuli in the brain and are sensitive to changes in sensory and sensory processing. The main advantage of VEP technology is its time resolution that is limited only by the sampling rate of the measurement device.

  VEP can be classified into transient visual evoked potential (TVEP) and steady state visual evoked potential (SSVEP). SSVEP is a periodic response modulated at a frequency higher than 6 Hz to visual stimuli and can be recorded at the scalp position corresponding to the visual cortex. The visual stimulus can be generated by a checkerboard or other pattern displayed on a light emitting diode (LED) or liquid crystal display (LCD). SSVEP has the same fundamental frequency as that of visual stimuli and their harmonics. In a system based on SSVEP, multiple stimuli encoded at multiple frequencies can be presented in the field of view, and various SSVEP responses can be generated by shifting the user's interest or attention to one of the multiple stimuli. .

  In the prior art that targets stimulus selection, it is not possible to generate a reliable SSVEP signal for accurately operating an EEG-based neural function replacement system without burdening a thinking subject with visual fatigue. Further, conventional stimulation systems require unnecessarily complicated electrical circuitry, increasing system overhead and / or cost.

  Also, the conventional electrode configuration is unnecessarily complicated. For example, the electrodes are placed at as many as 64 different scalp positions to obtain a reliable SSVEP signal, which increases costs and undesirably increases signal processing time. Several attempts have been made to acquire SSVEP signals by placing few electrodes on the human scalp, but such attempts have resulted in poor and inaccurate SSVEP signals, and thus poor control of neural function replacement devices. Become accurate and uncertain.

  Another problem arises from the existing algorithms used to process SSVEP signals. Current algorithms are complex, yield inaccurate or inconsistent results, and lack the ability to effectively distinguish between similar stimuli that are close or adjacent. Since current implementations of EEG-based neural function replacement systems are not easy to use as a way to control multiple devices in response to EEG signals, they are not flexible, reliable, and cost effective, Another problem arises.

  Since the EEG-based neural function replacement system has a great positive impact on the lives of persons with disabilities, it is necessary to improve the existing EEG-based neural function replacement system. Therefore, it would be desirable to provide a solution that addresses at least one of the above problems associated with EEG-based neural function replacement systems.

  In accordance with certain aspects of the present disclosure, an automated process for controlling a set of devices based on EEG data generated by an individual's brain is provided. The set of devices comprises a set of visual stimulus generators and a set of electrical devices, each electrical device being associated with a predetermined visual stimulus generator. The process may cause each visual stimulus generator to be in a first state (e.g., a dormant or inactive state, or the output of visual stimuli from each visual stimulus generator such that the visual stimulus generators are distinguished from each other) A state in which generation of SSVEP at a frequency related to the device control operation is avoided) to obtain first EEG data generated by the individual's brain, and the first EEG data is the visual stimulus generator. In response to the activation instruction of the visual stimulus generator, each visual stimulus generator in the set of visual stimulus generators is determined according to the activation command of the individual. Transition to a second state that outputs visual stimuli such that the visual stimulus generators in the set of visual stimulus generators are distinguished from each other. In the absence of a visual stimulus generator activation command, the visual stimulus generator can be maintained in a first state. When in the second state, each visual stimulus generator may output visual stimuli at a presentation frequency at which the visual stimuli are distinguished. In determining that the first EEG data is related to self-behavioral behavior representing the activation command of the visual stimulus generator, the first EEG data is analyzed and over a specific period, such as between activation commands. Alternatively, an individual who has awakened may identify closed eyes and / or a closed eye-open eye sequence.

  The process according to the present disclosure further obtains second EEG data related to SSVEP generated by the individual's brain while the user was gazing at a particular visual stimulus generator, and the second EEG data is Determine if the user is pointing to the specific visual stimulus generator that they were looking at. If the second EEG data does not point to a particular visual stimulus generator in the set of visual stimulus generators that the user has focused on, each visual stimulus generator can be transitioned to a first state.

  In addition, the process identifies the particular visual stimulus generator that the user was gazing at, and determines the operating state of a particular electrical device associated with or corresponding to the particular visual stimulus generator (eg, determining, changing power state, etc. Or by switching). Upon adjustment of the operating state of a particular electrical device (eg, before adjustment, after adjustment, and during adjustment), each visual stimulus generator can be transitioned back to the first state.

  In accordance with one aspect of the present disclosure, a set of electrical device control systems based on the generation of SSVEP by the system user's brain is connected to each set of visual stimulus generators, each outputting a visual stimulus. A visual stimulus generator controller for selectively outputting visual stimuli such that each visual stimulus generator distinguishes between visual stimulus generators, and an EEG system or unit for providing EEG data generated by a user's brain And a device identification system. The device identification system includes a processing device connected to a memory in which a part of the user state detection module exists. When executed, the user state detection module is a visual stimulus such that the EEG data generated according to the behavior of the user's own power is awakened over a specific period of time and the eyes are closed and / or the eye-open eye sequence is continuous. It includes a set of program instructions for determining if it is related to a generator activation command. The visual stimulus generator controller outputs the visual stimulus output from each visual stimulus generator such that the visual stimulus generators are distinguished from each other until the activation command of the visual stimulus generator is detected. The first state that can be kept in the first state to be avoided, after which the visual stimulus generator controller outputs a second visual stimulus such that each visual stimulus generator distinguishes between the visual stimulus generators. The visual stimulus generator can be transitioned to.

  The memory may further comprise a device identification module having a program instruction set that identifies a particular visual stimulus generator that the user was looking at based on the captured EEG data, thereby relating to the particular visual stimulus generator Identification and selective control of electrical devices to be performed is facilitated.

  According to certain aspects of the present disclosure, a first EEG signal difference between O1-Fz and a second EEG signal difference between O2-Fz, with a set of electrodes spatially organized according to the EEG 10-20 montage standard. An EEG acquisition system for detecting at least one of the above is provided. The set of electrodes may have fewer than five electrodes that detect EEG signals at a given time.

In addition or as an alternative, in accordance with certain aspects of the present disclosure, the control process for a set of devices based on the SSVEP generated by the individual's brain can be performed while the individual is gazing at the baseline landscape. Obtaining first EEG data associated with the EEG data generated by the brain, associated with the first EEG data and associated with a set of fundamental frequencies f _k and a set of harmonic multiples nf _k of each fundamental frequency f _k to generate a plurality of reference power spectral density amplitude value, generating a device identification threshold T _I using a plurality of reference power spectral density amplitude.

The process further, personal to a particular visual stimulus generator in each visual stimulus generator set to provide a visual stimulus in substantially equal specific presentation frequency associated fundamental frequency f _k is at the fundamental frequency f _k of a set Generating second EEG data associated with the SSVEP generated by the individual's brain while gazing, and associated with the second EEG data and a set of fundamental frequencies f _k and a set of each fundamental frequency f _k generating a plurality of reference power spectral density amplitude values associated with the harmonic multiples nf _k, each of the plurality of active power spectral density amplitude values based on a comparison of at least one reference power spectral density amplitude value and the device identification threshold T _I Multiple scaling of active power spectral density amplitudes by selectively scaling active power spectral density amplitude values Generate a value, it may determine whether the primary active power spectral density amplitude value exists in relation to the plurality of threshold active power spectral density amplitude.

Such treatment, visual stimulus at asking frequencies identified dominant frequency f _D is equal to a specific fundamental frequency f _k at the fundamental frequency f _k of a set together with associated principal active power spectral density amplitude value, related to the dominant frequency f _D Identifying a particular visual stimulus generator that identifies the electrical device associated with the particular visual stimulus generator, and setting or adjusting the operating state of the electrical device associated with the particular visual stimulus generator .

  According to certain aspects of the present disclosure, a control system of a set of devices based on SSVEP generated by an individual's brain is connected to each set of visual stimulus generators, each outputting a visual stimulus, Visual stimulus generator controller that selectively outputs visual stimuli such that each visual stimulus generator distinguishes between visual stimulus generators, and EEG data supply or acquisition that provides EEG data generated by the user's brain A system and a device identification system. The device identification system includes a processing apparatus connected to a memory in which a part of the device identification module exists.

The device identification module includes a set of program instructions that, when executed, identify a specific visual stimulus generator by a device identification operation, which is acquired while the individual is gazing at the specific visual stimulus generator. Generating a plurality of active power spectral density amplitude values related to the set EEG data and related to the set of fundamental frequencies f _k and the set of harmonic multiples nf _k , wherein at least one reference power spectral density amplitude value and a device identification threshold T Generating a plurality of threshold active power spectral density amplitude values by selectively scaling each active power spectral density amplitude value in the plurality of active power spectral density amplitude values based on the comparison of _I Exist in relation to multiple threshold active power spectral density amplitude values Determines whether or not.

The device identification operation, further, determines dominant frequency f _D is equal to a specific fundamental frequency f _k at the fundamental frequency f _k of a set together with associated principal active power spectral density amplitude value, related to the dominant frequency f _D Frequency Identifying a specific visual stimulus generator in a set of visual stimulus generators that provide visual stimuli at, identifying an electrical device associated with the specific visual stimulus generator, and identifying a specific visual stimulus generator and associated electrical device A set of identifiers associated with at least one of the groups may be output.

  According to certain aspects of the present disclosure, the system further includes a system control unit that changes an operating state of an electrical device associated with a particular visual stimulus generator in response to receiving one or more identifiers, instructions, or instructions. May be provided. The system control unit can output an electrical device control command based on the identifier. The system may further comprise a device control interface that communicates with the system control unit and sets or adjusts the operating state of the electrical device associated with the particular visual stimulus generator.

The memory may include a calibration unit that includes a set of program instructions for performing a calibration operation. The calibration operation analyzes the reference EEG data associated with the EEG signal generated by the individual's brain while the individual is gazing at the reference scene, and is associated with the reference EEG data and a set of fundamental frequencies f _k and generating a plurality of reference power spectral density amplitude values associated with the harmonic multiples nf _k of a set of each basic frequency f _k, generating a device identification threshold T _I using a plurality of reference power spectral density amplitude.

  In accordance with certain aspects of the present disclosure, one or more computers that store program instruction sequences that, when executed, facilitate or enable device control operations based on SSVEP according to embodiments of the present disclosure, such as the following embodiments: Further provided is a readable recording medium.

  Hereinafter, embodiments of the present disclosure will be described with reference to the following drawings.

1 is a schematic diagram of an appliance control system based on SSVEP according to an embodiment of the present disclosure. FIG. 1 is a schematic diagram of an electrode configuration related to an international EEG 10-20 montage according to an embodiment of the present disclosure. FIG. 2 is a block diagram of a system control and communication unit according to an embodiment of the present disclosure. FIG. FIG. 3 is a block diagram of a device identification unit according to an embodiment of the present disclosure. FIG. 3 is a schematic diagram of a representative device configuration GUI 500 according to an embodiment of the present disclosure. 6 is a flowchart of an exemplary SSVEP based electrical device or appliance control process according to an embodiment of the present disclosure. 5 is a flowchart of a typical reference parameter generation process according to an embodiment of the present disclosure. 5 is a flowchart of a representative device identification process according to an embodiment of the present disclosure.

  Embodiments of the present disclosure relate to systems, apparatus, devices, and processes that selectively control the operation of one or more electrical devices such as appliances based on the acquisition and analysis of EEG signals associated with SSVEP. SSVEP occurs when the user is selectively gazing at the visual stimulus generator. Many embodiments include multiple visual stimulus generators, each visual stimulus generator being associated with a given electrical device or appliance. Each visual stimulus generator outputs, displays or presents a visual or optical stimulus or signal to the user such that the visual stimulus generators are or can be distinguished. For example, according to a detailed embodiment, each visual stimulus generator can output visual stimuli at a unique or discriminative presentation frequency and / or a discriminative spatial presentation pattern. A visual stimulus may cause, cause, or generate a partial SSVEP in the user's brain at an SSVEP frequency that is related to the presentation frequency. The visual stimulus generator may be an LED string or other type of optical signal presentation device.

  An EEG acquisition system, subsystem, or unit can easily capture or acquire EEG signals generated by the user's brain. The user wearable headgear can place a set of electrodes that can capture the EEG signal associated with the SSVEP at a specific location relative to the user's scalp.

  In many embodiments, the set of electrodes has a small or minimal number of electrodes. The system control and communication unit can capture the EEG signal as sampled EEG data. The device identification unit can analyze the captured EEG signal in a computationally efficient manner and determine which visual stimulus generator has produced the captured EEG signal. This identifies the electrical device or appliance associated with the visual stimulus generator that the user was gazing at.

  The device identification unit may transmit a device identifier (ID) and / or a power interface ID to the system control and communication unit, and the system control and communication unit may send the related device control command and / or the related power interface control command to the multi-device interface. Issue to the unit. In response, the multi-device interface unit can transmit, adjust, or set the operating state of the electrical device or appliance associated with the visual stimulus generator. For example, the multi-device interface unit can transition a power interface associated with an electrical device or appliance from an off state to an on state, or from an on state to an off state. This allows the electrical device or appliance associated with the visual stimulus generator to transition from the off state to the on state, or from the on state to the off state. Thus, the EEG acquisition unit, system control and communication unit, device identification unit, and multi-device interface unit can automatically change the operating state of the electrical device associated with the visual stimulus generator that the user was gazing at. .

  In many embodiments, the system control and communication unit does not determine or detect the visual stimulus generator unless the device identification unit has detected a self-supporting or self-supporting user activity or behavior associated with or representative of the visual stimulus activation command. The transition is made to a state in which the generation of the visual stimulus of each visual stimulus generator is avoided such that the visual stimulus generators are distinguished from each other. In many embodiments, self-user behavior includes a state or situation in which an awake user has closed both eyes for a predetermined period of time. When a user generated visual stimulus generator activation command is detected or identified, the device identification unit identifies the visual stimulus generators to the system control and communication unit (eg, temporal and / or spatial distinctions). An activation notification can be sent that allows the generation of visual stimuli by each visual stimulus generator.

  In some embodiments, the device identification unit indicates whether the captured EEG signal represents or is related to a situation where both eyes are closed, and in some cases the situation where both eyes are closed is the user awake or the user is sleeping It can be determined whether the condition is relevant. Depending on or following the state of the user who is awake with both eyes closed for a predetermined period of time, the system control and communication unit transitions the set of visual stimulus generators to the active state. This allows a user with open eyes to focus on the active visual stimulus generator associated with the electrical device of interest. Thus, the system is enabled, activated, or reset for electrical device identification and control actions for the user closing both eyes for a predetermined period of time. In some embodiments, in response to detecting an awake user state with both eyes closed over a predetermined period of time, followed by detection of a state in which both eyes are open (eg, immediately following both eyes closed) (Re) activation of a set of visual stimulus generators can occur.

  Many embodiments of the present disclosure provide continuous, ongoing, or unnecessarily persistent or long-term vision during normal device or appliance operation or when the user is sleeping or about to sleep. Avoid activation of the stimulus generator (e.g., the visual stimulus generator remains inactive unless a visual stimulus generator activation command related to the behavior of a particular awake user's eyes closing is detected) ). As a result, embodiments of the present disclosure can minimize or eliminate user distraction and / or visual fatigue.

  After (re) activation or resetting of the system in response to the detection of a situation where both eyes are closed for a specific period of time, the device identification unit analyzes the captured EEG signal in one or more of the ways described herein. The electrical device that the user is interested in can be identified. The system control and communication unit can issue appropriate control commands to the multi-device unit, thereby switching the operating state of the electrical device of interest. The system control and communication unit can then cause the set of visual stimulus generators to transition to a sleep or off state, thereby reducing, minimizing, or eliminating user visual fatigue. In some embodiments, the system further transitions the set of visual stimulus generators to an inactive state or leaves the set of visual stimulus generators in an inactive state in response to detecting a sleep state of a user with both eyes closed. can do.

  Embodiments of the present disclosure activate or deactivate electrical devices by determining, based on EEG, which visual stimulus generator has generated an SSVEP signal associated with a presentation frequency at which the visual stimulus generator is driven. It comes to be activated. Also, many embodiments of the present disclosure provide a system activation process that allows a user to selectively activate or deactivate an electrical device on their own. Thus, embodiments of the present disclosure may be particularly useful or useful for users who are physically disabled or disabled. Embodiments of the present disclosure may also be useful or convenient for healthy individuals.

  In the following, with reference to FIGS. 1-8, embodiments of the present disclosure will be described that address one or more of the above problems associated with existing SSVEP-based BCI systems and technologies. For convenience, the description herein is primarily directed to electrical device or appliance control systems, devices, and techniques. However, this does not exclude many embodiments of the present disclosure from other applications that require or require basic principles such as the operations, functions, or performance characteristics described herein.

  In the following description, similar or similar reference signs represent similar or similar elements. Further, the description of particular reference signs shown in particular drawings may suggest simultaneous examination of other drawings in which such reference signs are shown. In addition, the terms unit, module, and element may include one or both of hardware and software in the various embodiments described herein. In this disclosure, the term set is used according to known mathematical definitions (eg, Peter J. Eccles, “An Introduction to Mathematical Reasoning: Numbers, Sets, and Functions,” “Chapter 11: Properties of Finite Sets "(eg, as described in p. 140), defined as a non-empty finite elemental structure that mathematically represents at least one cardinality (ie The set defined may correspond to a singlet or a single element set, or a multiple element set). In general, the elements of a set may or may include values that depend on the device, structure, signal, function or function processing, or type of set under consideration.

Exemplary System Features FIG. 1 is a schematic diagram of an appliance control system 10 based on SSVEP according to an embodiment of the present disclosure. In an embodiment, the system 10 operates on a plurality of visual stimulus generators 20a-d, an EEG signal acquisition unit 100, a system control and communication unit 200, a device identification unit 300, and at least an electrical device or appliance 50a-d. And a multi-device interface unit such as a multi-device power supply interface unit 400 that selectively supplies power.

  In many embodiments, the EEG signal acquisition unit 100, the system control and communication unit 200, the device identification unit 300, and the multi-device power interface unit 400 are, for example, one or more connected to a trunk, home, or line power source. Can be connected to the main or primary power supply 80 via an electrical outlet. The visual stimulus generators 20a-d, the EEG signal acquisition unit 100, and the device identification unit 300 may be connected to the system control and communication unit 200 as described below. Further, the multi-device power supply interface unit 400 can perform wireless or wired communication with the system control and communication unit 200.

  The multi-device power interface unit 400 includes a control module 410, a plurality of power interfaces 420a-d, such as electrical outlets that can be connected to each electrical device or appliance 50a-d, and commands or devices from the system control and communication unit 200. A communication module 450 that receives a control command and a relay module 460 that selectively supplies power to specific power supply interfaces 420a-d in response to such a command, as will be described later, are provided.

  Each visual stimulus generator 20a-d provides, outputs, displays or presents visual stimuli or optical signals. In many embodiments, at least one of the visual stimulus generators 20a-d has an LED string, and in the example, the LED string is a 3x4 or other size LED that outputs light of at least one central wavelength. It is a column. Additionally or alternatively, the visual stimulus generators 20a-d may be another type of device, such as a portion of a flat panel display screen.

  Visual stimulus generators 20a-d may be selectively enabled, controlled, or driven by system control and communication unit 200. In many embodiments, the system control and communication unit 200 outputs visual stimuli such that each active visual stimulus generator 20a-d distinguishes or can distinguish between visual stimulus generators 20a-d. A set of visual stimulus generators 20a-d are selectively driven or signaled. For example, the system control and communication unit 200 can drive each visual stimulus generator 20a-d according to a unique or discriminative presentation pattern. In many embodiments, the presentation pattern may be a temporal pattern such that a particular visual stimulus generator 20a-d outputs a visual stimulus at a unique or distinct presentation frequency. In certain embodiments, the presentation pattern may additionally or alternatively include a spatial pattern and / or an optical wavelength alternation or modulation scheme.

  Visual stimulus generators 20a-d may be associated with each electrical device 50a-d connected to multi-device power interface unit 400. In many embodiments, the system control and communication unit 200 and / or the device identification unit 300 may be a specific visual stimulus generator 20a-d and / or an electrical device 50a-d and a specific device provided by the multi-device power interface unit 400. Associations, relationships, or mappings with the power supply interfaces 420a-d can be set. As a result, a particular electrical device or appliance 50a-d connected to a particular power interface 420a-d is associated with a particular visual stimulus generator 20a-d.

  For example, by associating an appropriate visual stimulus generator ID with an appropriate electrical device ID or an appropriate power interface ID, a specific visual stimulus generator 20a-d and a specific electrical device 50a-d or a specific power interface 420a- A relationship with d can be set. Such an ID can be stored at an associated memory address (eg, in a data structure). In embodiments where the first through fourth electrical devices 50a-d are the television 50a, the electric fan 50b, the stereo system 50c, and the lighting 50d, the first visual stimulus generator 20a is associated with the television 50a, and the second The visual stimulus generator 20b is associated with the electric fan 50b, the third visual stimulus generator 20c is associated with the stereo system 50c, and the fourth visual stimulus generator 20d is associated with the illumination 50d.

  The visual or conceptual association between a particular visual stimulus generator 20a-d and a particular electrical device 50a-d is naturally communicated to the user depending on the location or position of the visual stimulus generator relative to the electrical device 50a-d. More specifically, the visual stimulus generators 20a-d may install or place the visual stimulus generators 20a-d on, next to, or close to the particular electrical device 50a-d. d can be related conceptually or visually. As a result, when the user gazes at the visual stimulus generator 20a-d, both the specific visual stimulus generator 20a-d and its associated electrical device 50a-d enter the user's field of view. In another embodiment, it is not necessary to associate a particular visual stimulus generator 20a-d with a particular electrical device 50a-d by the position of the visual stimulus generator relative to the electrical device 50a-d; rather, such conceptual The association can be learned or memorized by the user.

  In many embodiments, each visual stimulus generator 20a-d is distinct or distinct that causes or causes an associated unique or distinct SSVEP generation frequency and / or SSVEP generation pattern in a portion of the user's brain. Output visual or optical stimuli or signals according to the presentation frequency or period that can be done. In an embodiment, the first visual stimulus generator 20a is driven to output an optical signal at a presentation frequency of approximately 6 Hz, and the second visual stimulus generator 20b is configured to output an optical signal at a presentation frequency of approximately 7 Hz. The third visual stimulus generator 20c is driven to output an optical signal at a presentation frequency of approximately 8 Hz, and the fourth visual stimulus generator 20d is configured to output an optical signal at a presentation frequency of approximately 13 Hz. Driven by.

  When the user gazes at a particular active visual stimulus generator 20a-d, the optical signal output by that visual stimulus generator is the fundamental frequency associated with the presentation frequency at which the visual stimulus generator 20a-d is driven and An SSVEP signal having a power spectrum including a set of harmonic multiples may be generated. Thus, a particular visual stimulus generator 20a-d may trigger SSVEP to correlate with the presentation frequency at which the visual stimulus generator 20a-d is driven.

  The EEG signal acquisition unit 100 detects an EEG signal related to the SSVEP signal. In one embodiment, the EEG signal acquisition unit 100 includes a signal amplification unit 110 that receives EEG signals from the plurality of electrodes 120a-d. Electrodes 120a-d can be carried by user wearable headgear 130, or electrodes 120a-d can be placed directly by the user's scalp. Specifically, the electrodes 120a-d can be wet electrodes or dry electrodes. For example, the electrodes 120a-d can be wet electrodes or dry electrodes. Electrodes 120a-d may be carried, supported or mounted by headgear 130 in place that would be associated with a particular scalp position defined by the International EEG 10-20 montage.

  FIG. 2 is a schematic diagram of an electrode configuration related to the EEG 10-20 montage standard according to an embodiment of the present disclosure. In one embodiment, the first and second electrodes 120a, b are carried by the headgear 130 to a position associated with or likely to be associated with the occipital scalp positions O1 and O2 associated with portions of the visual cortex. The third electrode 120c is carried by the headgear 130 to a position that would be related to Fz, and the fourth electrode 120d is carried by the headgear 130 to a position that would be related to Cz. As described below, in one embodiment, the particular electrical device 50a-d that the user wishes to control by supplementing the EEG information with an electrode structure having electrodes 120a-c disposed at O1, O2, and Fz. Can be made reliable, accurate and computationally efficient.

  In some embodiments, the maximum number of electrodes 120a-d detects an EEG signal at any time. For example, this maximum number of electrodes 120a-d can be three (eg, associated with capturing EEG signals associated with at least one of O1 and O2 and Fz and Cz) or four (eg, O1, O2, Fz, And Ez signal acquisition associated with each of Cz). In another embodiment, EEG signals can be captured by three or more than four electrodes 120a-d.

  Returning to FIG. 1, a signal amplification unit 110 is connected to each electrode 120a-d and then receives an associated EEG signal. The signal amplifying unit 110 provides the amplified and optionally filtered (eg, 50 Hz notch filter, and optionally 5-30 Hz bandpass filter) or otherwise processed EEG signal to the system control and communication unit 200. To do. In some embodiments, the signal amplification unit 110 provides a first EEG signal and a second EEG signal to the system control and communication unit 200. The first EEG signal is defined by the signal difference between the first and third electrodes 120a, c, and the second EEG signal is defined by the signal difference between the second and third electrodes 120b, c. That is, the signal amplification unit 110 outputs EEG signals to the two channels. The first channel transmits an EEG signal defined by O1-Fz, and the second channel transmits an EEG signal defined by O2-Fz. The signal amplification unit 110 can use the signal supplied by the fourth electrode 120d related to Cz as a reference signal.

  When the visual stimulus generators 20a-d are activated, the system control and communication unit 200 captures or samples digital EEG data associated with the EEG signal received from the signal amplification unit 110. The system control and communication unit 200 may use a) a first EEG signal as first EEG data related to the signal difference O1-Fz, and b) a second EEG signal related to the signal difference O2-Fz. It can be saved as EEG data. The system control and communication unit 200 sends such EEG data to the device identification unit 300 for analysis.

  The device identification unit 300 receives, acquires, or acquires EEG data captured by the system control and communication unit 200, and analyzes the characteristics of such data in response to a visual stimulus generator and / or device identification operation. Or characterize. In many embodiments, device identification unit 300 analyzes data associated with the EEG power spectrum. For example, the device identification unit 300 generates power spectral density data and performs specific operations on such data to cause the visual stimulus generators 20a-d that caused the power spectral density data to be real-time or near real-time, as described below. Can be determined or identified.

  Prior to a real-time or near real-time device identification operation, the system 10 performs a calibration operation that includes capturing and analyzing one or more types of reference EEG data from the user. The calibration operation is a binocular open eye calibration operation that captures the reference EEG data when both eyes are open when the user is looking at a part of the surrounding environment without or associated with the visual stimulus generator presentation frequency. including. More specifically, reference EEG data with both eyes open can be captured when the user is gazing at the reference environment, landscape, or image. The reference environment or scene may be part of an ambient environment that lacks or has no optical signal source providing visual stimuli at or near the presentation frequencies of the visual stimulus generators or their higher harmonic frequencies. For example, both eyes are open when the user is viewing a standard environment under ambient lighting and any visual stimulus generator 20a-d and associated electrical device 50a-d in or near the user's field of view is in an off state. Reference EEG data can be captured. In some embodiments, such as a wall that is illuminated uniformly or substantially uniformly with a broad spectrum optical signal source in the same or substantially the same color scheme (eg, a white wall illuminated with normal room lighting). Reference EEG data with both eyes open can be captured when the user is looking at a neutral neutral landscape.

  Further, the calibration operation may include a both-eye closed eye calibration operation that captures reference EEG data in which both eyes are closed when the user holds the eyes closed for a predetermined time. In many embodiments, as part of the calibration operation, the device identification unit 300 generates reference power spectral density data, a set of reference parameters or values, and threshold parameters or values, a) being watched by the user The visual stimulus generators 20a-d can be identified in real time or near real time, and b) automatically activate or deactivate the visual stimulus presentation by the visual stimulus generators 20a-d by itself as described below. be able to.

Exemplary System Control and Communication Unit Features FIG. 3 is a block diagram of a system control and communication unit 200 according to an embodiment of the present disclosure. In an embodiment, the system control and communication unit 200 includes a controller 210, a data acquisition or sampling unit 220, a memory 225, a first communication module 230, a set of visual stimulus drivers 240, and a second communication module. 250. Certain embodiments further include a repeater 255. Certain elements of system control and communication unit 200 are connected by a set of shared or common signal paths, such as data bus 290 and / or control bus 292, to transmit data and / or signals.

  The controller 210 may include an instruction processor such as a microcontroller or part of a microprocessor. The controller 210 may operate according to a program instruction sequence that defines and / or implements part of an SSVEP-based electrical device control process according to an embodiment of the present disclosure. Such program instructions reside in memory 225.

  The data acquisition unit 220 samples the EEG signal received from the signal amplification unit 110 and stores the sampling data in the memory 225. In some embodiments, the data acquisition unit 220 can be an on-chip element provided by a microcontroller. The memory 225 may include one or more volatile and / or nonvolatile data storage elements such as buffers, random access memory (RAM), and read only memory (ROM). In a microcontroller based embodiment, the memory 225 may include on-chip memory and / or off-chip memory.

  The first communication module 230 transfers data with the device identification unit 300. More specifically, the first communication module 230 sends the sampled EEGEEEG data to the device identification unit 300. The first communication module 230 may further receive data from the device identification unit 300, such as a power interface ID, a visual stimulus generator ID, and / or an electrical device or appliance ID. In general, the first communication module 230 may include a standard data transfer interface, such as a serial interface (eg, an RS-232 or universal serial bus (USB) interface).

  The second communication module 250 selectively communicates with the multi-device power interface unit 400. For example, the second communication module 250 can transmit a power interface ID or an electrical device ID to the multi-device power interface unit 400. In many embodiments, the second communication module 250 performs wireless signal communication. The second communication module 250 can be connected to the repeater 255. When signal transmission to the multi-device power supply interface unit 400 is necessary, the controller 210 can selectively activate the repeater 255 to supply power to the second communication module 250.

  Finally, the set of visual stimulus drivers 240 selectively provides a set of drive signals to the visual stimulus generators 20a-d. In an embodiment, the set of drive signals may include a square wave signal. The predetermined square wave signal can drive an associated visual stimulus generator 20a-d, such as an LED string.

Exemplary Device Identification Unit Features FIG. 4 is a block diagram of a device identification unit 300 according to an embodiment of the present disclosure. In an embodiment, the device identification unit 300 includes a processing unit 302, at least one data storage unit 304, a graphics unit 306 connected to a display device 308, and an I / O unit 310 connected to a set of input devices 312. And a memory 320. In some embodiments, the device identification unit 300 further comprises a network interface unit 314 that may be connected to a network such as a local area network (LAN), a wide area network (WAN), or the Internet 316. The elements of device identification unit 300 may be connected by a common set of buses 390.

  The processing unit 302 may include an instruction processor that executes a stored program instruction sequence. The I / O unit 310 may include one or more types of I / O interfaces, such as a serial interface (eg, RS-232 and / or USB interface) that enables data transfer including system control and communication unit 200. . For example, the I / O unit 310 can receive sampled EEG data from the system control and communication unit 200 and store the data in the memory 320. The I / O unit 310 further receives input from a set of input devices 312 that may include one or more computer mice, keyboards, touch screens, and / or other types of user input interfaces. Display device 308 may include a computer monitor. Data storage unit 304 may include hard disk drives and / or other types of devices that read and write program instruction sequences or data by way of fixed or removable computer-readable media.

  The memory 320 may include one or more types of computer readable media such as volatile (eg, RAM) and / or non-volatile (eg, ROM) memory. Such media include an operating system 322 (eg, Microsoft Windows®-based operating system), device configuration module 330, calibration module 332, user status detection module 334, device identification module 336, EEG signal analysis library 338. , A device configuration memory 340, a sampling data memory 342, and an identification memory 344 exist. In many embodiments, the instrument configuration module 330, the calibration module 332, the user condition detection module 334, the device identification module 336, and the EEG signal analysis library 338 are part of an SSVEP-based device control process according to embodiments of the present disclosure. Includes a sequence of program instructions that enable, define and / or implement a section. The instrument configuration memory 340 may include instrument configuration data that may define or indicate an association or relationship between a particular visual stimulus generator 20a-d and a particular electrical device 50a-d and / or power interface 420a-d. Can hold. The instrument configuration memory 340 may further include EEG data analysis parameters such as sampling rate and number of samples to consider in device identification operations. The sampling data memory 342 can store sampled EEG data received from the data acquisition unit 220, and the identification memory 344 is a process for identification and control of the electrical devices 50a-d according to embodiments of the present disclosure. Data can be stored. Such processing data may correspond to, for example, power spectrum data described later. One or more of the device configuration module 330, the calibration module 332, the user status detection module 334, and the device identification module 336 may be part of the device configuration memory 340, the sampling data memory 342, the identification memory 344, and / or the EEG signal analysis library 338. One or more can be accessed to facilitate electrical device control operations based on SSVEP in accordance with features of the present disclosure.

  In an embodiment, device identification unit 300 includes a personal computer such as a desktop or laptop computer system. One or more portions of the instrument configuration module 330, the calibration module 332, the user state detection module 334, the device identification module 336, and the EEG signal analysis library 338 are LabVIEW (www.ni.com/labview/, National Instruments Corporation, Austin) , TX USA), etc., or can be performed by or in conjunction with a visual programming, measurement, data analysis, testing, and / or control environment. Additionally or alternatively, one or more portions of such modules 330-338 can be implemented by a sequence of program instructions written according to a programming language such as C, C ++, C #, or Java.

Characteristics of Exemplary SSVEP-Based Device Control Process In general, the SSVEP-based device control process according to the present disclosure includes a system configuration process, a calibration process, a user status detection process, and a device identification process. Some of such processing occurs in connection with execution of program instructions associated with the instrument configuration module 330, calibration module 332, user state detection module 334, and device identification module 336, respectively. In many embodiments, the EEG signal analysis library 338 is accessed, invoked, or activated by the calibration module 332, the user state detection module 334, and / or the device identification module 336 in part of the SSVEP-based device control process. A program instruction sequence for standard and / or customized EEG signal analysis routines or functions (eg, based on standard signal analysis routines, functions, or operations). Hereinafter, features of device control processing based on SSVEP according to the embodiment will be described in detail.

Exemplary System Configuration and Device Association Processing Features In many embodiments, the system configuration or set-up operation includes a power source to which visual stimulus generators 20a-d and electrical devices 50a-d and / or electrical devices 50a-d are connected. Setting up one or more associations or relationships with the interfaces 420a-d may be included. The system configuration or set-up operation further includes defining or identifying EEG data acquisition parameters, eg, sampling rate and / or number of samples to be considered for device identification (or time period to be considered accordingly). As described above, the system configuration operation can be performed by the GUI.

  FIG. 5 is a schematic diagram of a typical device configuration GUI 500 according to an embodiment of the present disclosure. In an embodiment, the device configuration GUI 500 includes a graphical window 502 that assists in generating device configuration data or parameters in response to user input. The graphical window 502 can include a number of graphical controls. For example, the graphical window 502 is a text box that receives a user input specifying a EEG sampling rate and some as a set of buttons 510a-d associated with the user input to define a number of electrical devices 50a-d under consideration. Or a list box 520, a text box or list box 522 that receives user input specifying the number of EEG samples to be analyzed in the device identification operation, a text box or list box 524 that receives user input specifying the identification timeout period, May include a text box or list box 526 that receives user input specifying the active period that closed and a calibration start button 528. In certain embodiments, graphical window 502 may also include an EEG signal display window 530 and a power spectrum display window 532.

  In many embodiments, the graphical window 502 includes a visual stimulus generator icon or symbol 22a-d associated with each visual stimulus generator 20a-d and an electrical device or appliance icon associated with each electrical device or appliance 50a-d. 52a-d and, optionally, power interface icons 422a-d associated with each power interface 420a-d controlled by the multi-device power interface unit 400. Visual stimulus generator icons 22a-d, electrical device icons 52a-d, and power interface icons 422a-d are spatially displayed or oriented relative to each other to provide each visual stimulus generator 20a-d, each electrical device. 50a-d and each power supply interface 420a-d is shown to be physically and conceptually related to each other. In certain embodiments, the icons can be graphically (re) positioned or rearranged in positions relative to each other to reflect the latest physical and conceptual relationships.

  In many embodiments, the device configuration module 330 generates or manages the generation of the device configuration GUI 500. The device configuration module 330 further stores device configuration data or parameters in the device configuration memory 340 in response to user input received by the device configuration GUI 500. For physically handicapped users, system equipment configuration operations can be activated by an assistant such as a caregiver or relative.

Exemplary Calibration Process Features The calibration operation includes the calibration module generating calibration data or parameters that can be stored in the instrument configuration memory 340 (eg, in response to a user selecting the calibration button 528). In many embodiments, the calibration operation includes a binocular open eye calibration operation that identifies the visual stimulus generators 20a-d, devices 50a-d, and / or power interface 420a-d. In some embodiments, the calibration operation further includes a binocular closed eye calibration operation that selectively and automatically transitions the visual stimulus generators 20a-d from the inactive state to the active state in response to user behavior. In general, the calibration operation can be performed only once (eg, for a user whose neurological state or brain function is stable or generally stable over time) or as needed from a system performance perspective. .

A) Characteristics of typical eye-closed eye calibration process The eye-closed eye calibration operation acquires reference EEG data in which both eyes are closed during one or more eye-closed eye calibration periods when an awake user is closing or closing both eyes. Including capturing the unit. The closed eye configuration period is a predetermined or program specified period, for example, approximately 1-10 seconds (eg, approximately 2-8 seconds, or approximately 2-6 seconds, or approximately 1-4 or 2-4). Seconds), or another period depending on the details of the embodiment. In some embodiments, the calibration module 332 may instruct the user to close his eyes, such as by a text display on the calibration GUI 500 and / or a set of audible sounds or voice messages. Following the acquisition of EEG data during the bi-eyes closed period, the calibration module 332 may further instruct the user to reopen the eyes with one or more audible sounds or voice messages.

  During or after acquisition of EEG data with the eyes of the awake user closed, the data acquisition unit 220 or calibration module 332 may filter the reference EEG data with the eyes closed with a predetermined EEG frequency band. For example, the calibration module 332 may perform bandpass filtering on the reference EEG data with both eyes closed to eliminate and / or significantly attenuate EEG data having a frequency range of approximately 8-12 Hz or out-of-band frequencies. it can. In such an embodiment, the bandpass filtered EEG data includes alpha band data and excludes or substantially excludes lower frequency (theta and delta) and higher frequency (beta and gamma) bands.

  In general, when a person closes both eyes, the amplitude of the EEG signal in the alpha band is greatly increased and the EEG signal in the beta band is greatly decreased. Similarly, when the human eyes are open, the amplitude of the EEG signal in the alpha band is greatly reduced relative to the amplitude of the signal in the beta band. Thus, using the amplitudes of alpha and / or beta band signals, which are or can be distinguished, alone or in conjunction with each other, a) whether the awake user has closed or opened both eyes and / or b) It can be determined whether or not the user has transitioned to a state in which both eyes are likely to remain closed for a long time.

  The calibration module 332 may be associated with a state in which one or more awake user's eyes are closed, eg, an awake user's eyes that are present or exist for a predetermined or program-specified period of time. One or more reference quantities of signal energy can be determined or generated. In some embodiments, the calibration module 332 may close the EEG with the eyes of the awake user closed associated with a minimum activation command period of approximately 1-4 seconds (eg, and 1, 2, or 3 seconds) as follows: Generate a reference amount of signal energy.

Where X _i ² is the i-th sample of the average value of the filtered reference EEG signal with both eyes closed, and N _A is the total number of samples considered over the minimum activation command period (eg, EEG sampling rate is _{N a} when minimum active command period is 2 seconds 125Hz is 250). Calibration module 332 to T _A, the user can be defined as the threshold energy of activation instructions to determine issued the activation command of the visual stimulus generator. As described later, in the post-calibration system operation, user state detection module 334, the EEG data acquisition with respect to T _A real-time, near real time or periodically analyzed, enlightened user visual stimulus generator It can be determined whether an activation command has been issued. For example, the user state detection module 334 analyzes the EEG data acquisition with respect to T _A, transitions from both eyes opened state to a state where both eyes are closed to persist over the minimum active command period, followed by It can be detected that both eyes have transitioned to the open state before the expiration of the maximum activation command period (eg, approximately 3-5 seconds, or approximately 4 seconds).

  In certain embodiments, the calibration module 332 may additionally or alternatively indicate whether the user has transitioned to a state that is likely or likely to keep both eyes closed for a substantial or long-term period, such as a sleep state. A reference amount of EEG signal energy can be determined or generated. For example, the calibration module 332 may be associated with a sleep indication period of approximately 5-30 seconds (eg, approximately 6-20 seconds, or approximately 6, 8, or 10 bars) specified or programmed as follows: A reference amount of EEG signal energy that is closed by both eyes of an awake user can be determined or generated.

Where, i th sample of the average value of X _i ² is the reference EEG signal is both eyes, which is filtered closed, N _S is the total number of samples taken into consideration over the sleep indications period (e.g., EEG sampling rate at 125Hz _{N s} when the sleep indication period is 6 seconds is 750). Calibration module 332 to T _S, the user can be defined as a threshold for arousal / sleep state for determining the eyes whether long-term close fall into state or fall likely as sleep state.

In some embodiments, T _S is defined as having a mathematical correlation T _A, depending on the length of sleep symptoms period for such, minimum and / or maximum activation command period multiples with T _A Can be done. As described below,
In post-calibration system operation, user state detection module 334, real time EEG data acquisition with respect to T _S, and near real-time or periodically analyzed, the user is sleeping, sleeping likely, or hold the both eyes The likelihood of remaining closed for a period of time can be determined.

B) Typical Binocular Open Eye Calibration Processing Features The binocular open eye calibration operation involves the data acquisition unit capturing the reference EEG data with both eyes open from the user during the binocular open eye calibration period. During the binocular open eye calibration period, the user watches the part of the environment where the visual stimulus or optical signal remains constant or essentially constant with respect to the rate at which the visual stimulus generators 20a-d periodically present the visual stimulus. Keep your eyes open while you are. In many embodiments, during the binocular open eye calibration operation, the system control and communication unit 200 disables or deactivates the visual stimulus generators 20a-d, and the user can provide the visual stimulus generator presentation frequency and at least some of its harmonics. There is no need to look at a part of the environment where the optical signal is presented or displayed cyclically or periodically at the same frequency as the wave multiple (for example, near the 2-5 th harmonic).

  The binocular open eye calibration period can be approximately 1-8 seconds (eg, approximately 2-6 seconds, or approximately 2, 3, and 4 seconds) or another period depending on the details of the embodiment. In some embodiments, the system 10 keeps both eyes open for a predetermined period of time (eg, at least about 2-4 seconds) by gazing at the user or a wall or surface that is empty or substantially optically uniform. You can give instructions. Such user commands can be issued with a text display on the calibration GUI 500 and / or a set of audible sounds or voice messages. Following acquisition of EEG data during the binocular open eye calibration period, the system 10 can inform the user that the binocular open eye calibration operation is complete with one or more audible sounds or voice messages. This allows the user that system 10 is ready to identify and / or control visual stimulus generators 20a-d, electrical devices 50a-d, and / or power interface 420a-d in accordance with certain embodiments of the present disclosure. I can tell you.

  The first communication module 230 of the system control and communication unit 200 can transfer the reference EEG data with both eyes open to the sampling data memory 342, and the calibration module 332 can provide such EEG data, as will be described in detail below. A set of reference identification values or parameters and device identification thresholds or parameters associated with can be generated or determined.

In many embodiments, calibration module 332 includes a plurality of reference power spectral density amplitude values (hereinafter referred to as reference power spectral density amplitude basis b) associated with each presentation frequency f _k associated with the operation of visual stimulus generators 20a-d. Are generated to determine a reference power spectral density parameter associated with such a presentation frequency.

For the sake of clarity, four presentation frequencies f ₁ , f ₂ , f ₃ , and f ₄ are assumed below. As described above, when a user gazes at certain visual stimulus generators 20a-d that output visual stimuli at the presentation frequency _fk , such visual stimuli produce or cause SSVEPs that exhibit substantially the same frequency. It is expected. Therefore, when the visual stimulus generators 20a-d are activated, the power spectral density data generated from the captured EEG is expected to include or include components having harmonics of the fundamental frequencies _fk and _fk .

For each fundamental frequency _fk , a reference power spectral density amplitude basis b can be generated for a particular harmonic of _fk and _fk . Harmonics, for example, a second harmonic of the first harmonic and _{f k} of _{f k,} Referred to herein respectively 2f _k and 3f _k. More particularly, in the example, the reference power spectral density amplitude basis b associated with each of f ₁ , f ₂ , f ₃ , and f ₄ and their first and second harmonics is as follows: .

In the above equation, δ is a frequency offset of approximately 0.1-1.0 Hz (eg, 0.25 Hz or 0.5 Hz). The frequency offset δ is a predetermined value and in some embodiments may be related to the ratio of the sampling rate to the sampling period. For example, if the EEG data sampling rate is approximately 125 Hz, the device identification operation takes into account the EEG samples captured in the current or latest device identification period or time of approximately 2 seconds, and δ is 125/250 or δ = 0. May be 5.

Calibration module 332 may further generate a plurality of representative or average reference power spectral density amplitude basis b _nk associated with each fundamental frequency f _k . With regard to the notation b _nk , n = 1 is related to the fundamental frequency f _k , n = 2 is related to the first harmonic 2f _k of the fundamental frequency, and n = 3 is related to the second harmonic 3f _k of the fundamental frequency. To do. In some embodiments, each representative reference power spectral density amplitude basis function b _nk may be related to the normal form of a particular reference power spectral density amplitude basis function b. For example, a plurality of average reference power spectral density amplitude basis functions b _nk can be generated as follows.

The calibration module 332 may further generate a composite reference power spectral density amplitude value BL _k associated with each fundamental frequency f _k . The combined reference power spectral density amplitude value BL _k can be generated using the average reference power spectral density amplitude base function b _nk according to the following equation, for example.

Therefore, the following equation holds for the fundamental frequencies f ₁ to f ₄ .

Finally, the device identification threshold T _I may be produced as follows.

However, M = ₁ , ₂ , ₃ , ₄ is associated with each fundamental frequency f ₁ , f ₂ , f ₃ , and f ₄ .

Calibration module 332 may store the synthesized reference power spectral density amplitude value BL _k and device identification threshold T _I in the device configuration memory 340. As described later, the device identification operation may include specific synthetic reference power spectral density amplitude value BL _k and device identification threshold T _I.

Exemplary User State Detection Processing Features Following the calibration operation, the system 10 performs a device identification operation to perform visual stimulus generators 20a-d, electrical devices 50a-d, and / or in accordance with many embodiments of the present disclosure. Alternatively, the power supply interfaces 420a-d can be identified. In many embodiments, upon completion of the calibration operation, the system control and communication unit 200 transitions the visual stimulus generators 20a-d to the inactive or hibernate state. Further, when the calibration operation is completed, the data acquisition unit 220 captures EEG data continuously, basically continuously, periodically, or periodically, and the first communication module 230 captures such EEG. Data is transferred to the sampling data memory 342 of the device identification unit. User condition detection module 334 analyzes the captured real-time or near real-time EEG data to indicate that the user has issued a command to system 10, such as a visual stimulus generator command or an electrical device control command. A set of self-powered or autonomous user behavior can be identified. In many embodiments, the user state detection module 334 analyzes the EEG data to determine whether the user is a) awake or asleep, and b) the visual stimulus generator activation or electrical device if awake. It can be determined whether the control signal is issued.

Detection of Eyes Closed for a Long Time In one embodiment, a determination is made whether a user has entered a state where he / she is likely to keep his eyes closed for a long time (eg, the user is likely to sleep or have fallen asleep). In order to do this, the user condition detection module 334 may periodically perform a bandpass filtered real-time or near real-time, eg, approximately every 1-10 seconds (eg, approximately every 4-8 seconds, or approximately every 6 seconds). The normalized energy of sampled EEG data (eg, EEG data that has been bandpass filtered in relation to or substantially related to the frequency in the alpha band) can be determined. Greater than threshold T _{S in} the normalized energy of such EEG data arousal / sleep state if the user state detection module 334, while the user's eyes are closed at least sleep signs period, closed long term It is determined that it is likely to become. If the user status detection module 334 determines that the user will or will keep both eyes closed for a long time, the user status detection module 334 can notify the system control and communication unit 200 of sleep; In response, the system control and communication unit 200 leaves the visual stimulus generators 20a-d in an inactive state. If the current or latest EEG samples normalized energy of sequence is less than T _S, the user condition detection module 334 determines that the user did not close a long period of time eyes, it indicates that the user is awake.

User Command Detection The user status detection module 334 allows the user to selectively activate the visual stimulus generators 20a-d in the system 10 and / or as a result of one or more self-powered or autonomous user behaviors. It can be determined whether the user has issued a visual stimulus generator activation command or an electrical device control command that can cause the control action to be performed.

  In some embodiments, the visual stimulus generator activation command or the electrical device control command is related to a predetermined or program-specified period, time interval, or situation where a user who has awakened over a window has closed both eyes. To do. For example, the activation instruction of the visual stimulus generator may be related to a situation in which a user who has been awake for the first period closes both eyes and is generated within the second period. In some embodiments, the visual stimulus generator activation command may relate to a transition to a situation where both eyes are closed for a predetermined period, such as a minimum activation command period (eg, approximately 1-3 seconds). And ends within a period of time, such as a maximum activation command period (eg, approximately 3-4 seconds) that is at least equal to the minimum activation command period and typically at least slightly longer. Therefore, the minimum activation command period can be included in the maximum activation command period. Furthermore, the maximum activation command period is typically shorter or much shorter than the sleep sign period. The end of the situation where both eyes are closed within the maximum activation command period is a state where the user is likely to remain awake or remain awake, and the user is likely to remain closed for a long time ( For example, it represents that the state related to sleep).

In view of the above, the user state detection module 334 that analyzes the EEG data continuously or repeatedly captures with respect to T _A, transitions from both eyes opened state to a state where both eyes are closed, and It can be confirmed that the closed state of both eyes lasts for the minimum activation command period. The user state detection module 334 can further analyze the continuously captured EEG data to confirm a transition from a state where both eyes are closed to a state where both eyes are opened prior to the maximum activation command period. If so, the user status detection module 334 determines that the user has issued a visual stimulus generator activation command.

  When the user state detection module 334 determines that the user has issued a visual stimulus generator activation command, the user state detection module 334 notifies the system control and communication unit 200 and the device identification unit 300 of the activation. Until the activation command of the visual stimulus generator is detected, that is, until the system control and communication unit 200 receives the activation notification, the system control and communication unit 200 keeps the visual stimulus generators 20a-d in the inactive state. Leave.

Exemplary Device Identification Processing Features In response to notification of system activation, the system control and communication unit 200 causes each visual stimulus generator 20a-d to present or output an optical signal at a specific fundamental frequency _fk. Activate or drive the visual stimulus generators 20a-d. In addition, the device identification module 336 analyzes real-time, near real-time, or current captured EEG data to identify the specific visual stimulus generator 20a-d that the user has watched.

  More particularly, in many embodiments, the device identification module 336 may be such as approximately 1-8 seconds (eg, approximately 2, 3, or 4 seconds) when the visual stimulus generators 20a-d are activated. A plurality of first, origin, or primitive power spectral density amplitude values associated with EEG data captured at the current or latest device identification period or time are generated. Such power spectral density amplitude values are referred to below as the active power spectral density amplitude basis g.

For each fundamental frequency f _k , an active power spectral density amplitude basis g can be generated for specific harmonics of f _k and f _k , eg 2f _k and 3f _k . More specifically, in an embodiment that includes fundamental frequencies f ₁ , f ₂ , f ₃ , and f ₄ , an active power spectral density amplitude group associated with each fundamental frequency f _k and each of its first and second harmonics. The function g is as follows.

In the above equation, δ is a frequency offset of approximately 0.1-1.0 Hz (eg, 0.25 Hz or 0.5 Hz).

Device identification module 336 may also generate a plurality of reference reference representatives or average active power spectral density amplitude basis functions g _nk associated with each fundamental frequency f _k . In some embodiments, each reference reference representative active power spectral density amplitude basis g _nk can be associated with a particular active power spectral density amplitude basis g, and selectively scaled according to its value for BL _k , Filtered or weighted. In an embodiment, a plurality of reference reference average active power spectral density amplitude basis functions g _nk may be generated as follows. However, n = 1 is related to the fundamental frequency f _k (ie, 1f _k ), n = 2 is related to the first harmonic 2f _k of the fundamental frequency, and n = 3 is related to the second harmonic 3f _k of the fundamental frequency. Related.

A) related to the fundamental frequency _{f 1}

B) Related to fundamental frequency f ₂

C) related to the fundamental frequency _{f 3}

D) related to the fundamental frequency _{f 4}

Device identification module 336 may further generate a combined active power spectral density amplitude value g _k associated with each fundamental frequency f _k . In some embodiments, g _k is generated using a particular baseline reference average active power spectral density amplitude basis function g _nk , eg, according to:

Therefore, the following equation holds for the fundamental frequencies f ₁ to f ₄ .

Device identification module 336 may further generate a threshold active power spectral density amplitude value g _Tk associated with each fundamental frequency f _k . The threshold active power spectral density amplitude value g _Tk is determined against the associated composite reference power spectral density amplitude value BL _k and the device identification threshold T _I , for example according to:

Therefore, the following equation holds for the fundamental frequencies f ₁ to f ₄ .

The device identification module 336 can then generate or determine a primary, primary, or maximum active power spectral density amplitude value G based on the threshold active power spectral density amplitude value g _Tk . For example, the maximum active power spectral density amplitude value G can be defined according to the following equation:

Maximum activity power spectral density amplitude values G are related or may represent the primary frequency f _D of the power spectral density data under consideration. For each visual stimulus generator 20a-d is driven by f _1, f 2, _f 3 or one equal to or essentially equal presentation frequency f _4,, major or maximum activity power spectral density amplitude values G It relates to or represents which of the fundamental frequencies f ₁ , f ₂ , f ₃ or f ₄ is in particular the main frequency f _D. This indicates which of the visual stimulus generators 20a-d specifically caused, induced or affected the generation of an EEG sample from which the active power spectral density amplitude basis was generated.

After generation of the maximum activity power spectral density amplitude value G, the device identification module 336 determines the main presentation frequency f _D, at least the major presentation frequency f _D to associated visual stimulus generator ID, the electrical device ID, and power supply interface ID Judge one. Subsequently, the device identification module 336 transmits one or more of the visual stimulus generator ID, the electric device ID, and the power supply interface ID to the system control and communication unit 200 so that the visual stimulus generator 20a- Control (eg, activation or deactivation) of devices 50a-d associated with d is performed.

To better understand the calibration and device identification process described above, the first to fourth visual stimulus presentation frequencies f ₁ , f ₂ , f ₃ , and f ₄ are approximately equal to 6 Hz, 7 Hz, 8 Hz, and 13 Hz, respectively. In the example, device identification unit 300 considers the fundamental frequencies and associated first and second harmonic frequencies as shown in Table 1.

Considering the above equation, if each composite active power spectral density amplitude value g _k is smaller than the device identification threshold value T _I , each associated threshold active power spectral density amplitude value g _Tk will be zero and the maximum active The power spectral density amplitude value G is accordingly equal to zero. In such a situation, it can not be correctly determined key presentation frequency f _D and the specific visual stimulus generator 20a-d the user has watched.

If the device identification module 336 is unable to determine the main presentation frequency f _D, device identification module 336 for the next (e.g., overlapping the EEG data sample sequence analyzed most recently, immediately following, or otherwise followed) EEG sample sequence and analysis, trying to successfully identify key presentation frequency f _D can be (again) try. In many embodiments, when the device identification module 336 is unable to determine the main presentation frequency f _D after attempting identification of a predetermined period of time or within a predetermined number of times, the device identification module 336 notifies the identified failure to the system control and communication unit 200 can do. The system control and communication unit 200 can then deactivate the visual stimulus generators 20a-d. After the user state detection module detects another visual stimulus generator activation command (eg, in response to the awake user closing both eyes for approximately 2 seconds), the system control and communication unit 200 may receive the visual stimulus generator. can reactivate 20a-d, the device identification module 336 attempts to determine the main presentation frequency f _D with the same or similar method as in (again) can try.

Exemplary Device Control Processing Features Upon receiving at least one of a visual stimulus generator ID, device ID, and power interface ID, the system control and communication unit 200 activates the second communication module 250 and associated device control. Commands can be sent to the multi-device power interface unit 400. For example, the system control and communication unit 200 can send a device control command including an ID such as a device ID and / or a power interface ID to the multi-device power interface unit 400. In response to this, the multi-device power interface unit 400 issues an appropriate power interface control command to the relay module 460, thereby determining the operation status of the specific power interface 420a-d related to the received power interface ID or device ID. Can be set or adjusted (eg, activated or deactivated, or switched power state). As a result, the electrical devices 50a-d connected to the identified power supply interfaces 420a-d can be controlled. If the electrical device 50a-d under consideration is turned off, it can be transitioned to the on state. Otherwise, the electrical devices 50a-d under consideration can be transitioned from the on state to the off state.

  In some embodiments, the system control and communication unit 200 can deactivate the visual stimulus generators 20a-d after sending the power interface ID to the multi-device power interface 400. In response to detecting a specific user behavior, such as detecting a closed state of the awake user's eyes associated with a visual stimulus generator activation command that can be detected by the user state detection module 334, the visual stimulus generators 20a-d Can be reactivated.

  FIG. 6 is a flowchart of an exemplary SSVEP-based electrical device or appliance control process 600 according to an embodiment of the present disclosure. In the processing 600 according to the embodiment, in the first processing portion 602, system device configuration parameters are set. The system equipment configuration parameters include the number of electrical devices 50a-d to consider, EEG sampling parameters (eg, sampling rate and / or number of samples to consider during device identification trial), identification timeout period or number of identification trials, visual Active period in which both eyes are closed, which may represent a stimulus generator activation command, and / or one of visual stimulus generator icon 22a-d or ID and electrical device icon 52a-d or ID and power interface icon 422a-d or ID Or a set of associations between both. In many embodiments, device configuration parameters may be set by the device configuration GUI 500. Device configuration parameters may be stored in device configuration memory 340 of the device identification unit.

  In a second processing portion 604, calibration data or parameters associated with the user are acquired, generated, or captured. The calibration data may include both-eye closed eye calibration data and both-eye open eye calibration data that can be stored in the device configuration memory 340. In the third processing portion 606, the visual stimulus generators 20a-d are transitioned to the active state, and in the fourth processing portion 608, whether an activation command of the visual stimulus generator related to the user's own behavior is detected. Determined. The activation command may be related to, for example, detection of a situation where an awake user who has existed or continued for a predetermined period of time, eg, approximately 2 seconds, closed both eyes. If a user who has been awake for a reasonable period of time does not detect a situation where his eyes are closed, for example, the awake user will not intentionally generate a visual stimulus generator activation command or the user will sleep As such, process 600 may remain in fourth process portion 608.

  Following detection of a user command to activate the visual stimulus generator, in the fifth processing portion 610, the visual stimulus generator 20a-d is activated and in the sixth processing portion 612, the visual stimulus generator 20a- EEG data related to the generation of SSVEP is captured when d is activated. In a seventh processing portion 620, a device identification attempt is initiated, during which device identification operations are performed to identify a particular visual stimulus generator 20a-d, a particular electrical device 50a-d, and / or a particular power interface. 420a-d can be identified. In an eighth processing portion 630, it is determined whether identification of a particular visual stimulus generator 20a-d, a particular electrical device 50a-d, and / or a particular power interface 420a-d is successful within an identification timeout. . If so, in the ninth processing portion 632, appropriate control commands are issued to control the operation of the electrical devices 50a-d associated with the identified visual stimulus generators 20a-d. In a ninth processing portion 632, the operating state of the particular electrical device 50a-d associated with the visual stimulus generator 20a-d that was automatically identified as the visual stimulus generator 20a-d that the user was gazing at is set. Or it can be transitioned (e.g., switch power state).

  In a tenth processing portion 634, it is determined whether a situation has occurred in which one or more visual stimulus generators have been deactivated. Such a situation may be related to the latest successful device identification attempt, or the device identification attempt failed after a timeout period. In the eleventh processing portion 640, the visual stimulus generators 20a-d are disabled and then processed 600 if an inactive state occurs or if the identification timeout period has passed without successful device identification. Returns to the third processing portion 606 to determine if a situation has occurred in which the visual stimulus generator is (re) activated.

FIG. 7 is a flowchart of an exemplary reference parameter generation process 700 according to an embodiment of the present disclosure. In a process 700 according to an embodiment, in a first process portion 702, reference EEG data with both eyes open is captured, and the fundamental frequencies of a plurality of visual stimulus generators, a predetermined dash harmonic relative to these fundamental frequencies, and considerations A plurality of reference power spectral density amplitude primitives b are generated that are associated with a predetermined frequency offset relative to the fundamental and harmonic frequencies being generated. In the second processing portion 704, representative or average reference power spectral density amplitude primitives b _nk associated with the fundamental frequency under consideration and the harmonics of the fundamental frequency are generated, and in the third processing portion 706 A combined reference power spectral density amplitude value BL _k associated with each fundamental frequency is generated. In a fourth processing portion 708, the device identification threshold T _I is generated using the synthetic reference power spectral density amplitude value BL _k.

FIG. 8 is a flowchart of an exemplary device identification process 800 according to an embodiment of the present disclosure. In process 800 according to an embodiment, during a first process portion 802, while a user is gazing at a particular active visual stimulus generator 20a-d in a set of active visual stimulus generators 20a-d. EEG data is captured. In the second processing portion 804, the fundamental frequencies associated with the active visual stimulus generators 20a-d, a predetermined number of harmonics (eg, first and second harmonics) of those fundamental frequencies, and considerations. A plurality of active power spectral density amplitude primitives g are generated that are associated with a predetermined frequency offset (eg, corresponding to a frequency offset δ) with respect to the fundamental frequency and the high frequency. In a third processing portion 806, a reference reference representative or average active power spectral density amplitude basis function g _nk associated with the considered fundamental frequency and harmonics of the fundamental frequency is generated, and in a fourth processing portion 808, a representative _{Alternatively} , a composite active power spectral density amplitude value g _k associated with each fundamental frequency f _k is generated using an average active power spectral density amplitude basis function.

In a fifth processing portion 810, a threshold active power spectral density amplitude value g _Tk associated with each fundamental frequency is generated. In an embodiment, in the fifth processing portion, each combined active power spectral density amplitude value g _k and the device identification threshold T _I can be compared. If synthesis activity power spectral density amplitude g _k is the device identification threshold T _I above, in the processing portion of the fifth, related synthetic reference power spectral density amplitude value BL _k on the combined activity power spectral density amplitude g _k And the threshold active power spectral density amplitude value g _Tk is set to the difference between the synthetic active power spectral density amplitude value g _k and the synthetic reference power spectral density amplitude value BL _k . If the combined active power spectral density amplitude value g _k is smaller than the device identification threshold value T _I , the threshold active power spectral density amplitude value g _Tk can be set to zero.

In a sixth processing portion 812, it is determined whether the main or maximum active power spectral density amplitude value G can be determined from the threshold active power spectral density amplitude value _gTk . If so, the processing portion 814 of the seventh, major fundamental frequency f _D associated with maximum activity power spectral density amplitude values G have been identified, the processing portion 816 of the eighth or the primary fundamental frequency f _D Basic major basic frequency f particular visual stimulus generator 20a-d, which are driven by _D is identified manner. Further, in a ninth processing portion 818, at least one of the visual stimulus generator ID, electrical device ID, and power interface ID is transmitted to the system control and communication unit 200 and associated with the identified visual stimulus generator 20a-d. The operating state (for example, power state) of the specific electrical device 50a-d to be set is set, adjusted, or switched.

  If there is no primary active power spectral density amplitude value, then in a tenth processing portion 820 it is determined whether the identification timeout period or the maximum number of device identification attempts has been exceeded. If not, process 800 returns to first process portion 802. Otherwise, in the eleventh processing portion 822, the system control and communication unit 200 is notified of the identification failure and the visual stimulus generators 20a-d can be deactivated accordingly.

  As described above, various embodiments of the present disclosure are for solving at least one of the above-described problems. These embodiments are naturally included in the scope of the following claims, and are not limited to the specific forms and arrangement of elements as described, and those skilled in the art will naturally fall within the scope of the following claims from the present disclosure. Various variations and / or modifications will be conceived which may be included.

Claims (27)

A set of device control methods based on SSVEP generated by an individual brain,
The individual, the first relating to EEG signals generated by the individual brain while it was gazing views of the reference there is no visual stimulation frequency approximately equal to the fundamental frequency f _k at the fundamental frequency f _k of a set Providing EEG data,
Generating a plurality of reference power spectral density amplitude values associated with the harmonic multiples nf _k of a set of fundamental frequency f _k and the fundamental frequency f _k of the set as well as associated with the first EEG data,
Generates device identification threshold T _I using the plurality of reference power spectral density amplitude value,
The personal to a particular visual stimulus generator in each visual stimulus generator set of visual stimulus generator to provide a visual stimulus in substantially equal specific presentation frequency associated fundamental frequency f _k at the fundamental frequency f _k of the set is Generating second EEG data related to SSVEP generated by the individual's brain while gazing,
Generating a plurality of active power spectral density amplitude values related to the second EEG data and related to the set of fundamental frequencies f _k and the set of harmonic multiples nf _k ;
Selectively at least one reference power spectral density amplitude value and each active power spectral density amplitude values in the plurality of active power spectral density amplitude values based on a comparison between the active power spectral density amplitude value and the device identification threshold T _I Generate multiple threshold active power spectral density amplitude values by scaling to
A method of determining whether a primary active power spectral density amplitude value exists in association with the plurality of threshold active power spectral density amplitude values. Identified dominant frequency f _D is equal to a specific fundamental frequency f _k at the fundamental frequency f _k of the set with associated principal active power spectral density amplitude value,
The method of claim 1 , wherein a visual stimulus generator in the set of visual stimulus generators providing a visual stimulus at a presentation frequency associated with the dominant frequency f _D is identified. The identified electrical device associated with the visual stimulus generator to provide a visual stimulus at asking frequency associated with the dominant frequency f _D,
The dominant frequency f _D the set or adjust the operating state of the electrical device associated with the visual stimulus generator to provide a visual stimulus at asking frequency associated with the method of claim 2. 4. The method according to claim 3 , wherein, in setting or adjusting an operation state of the electrical device, a device control command is issued to a device interface unit that automatically controls the operation state of the device in response to a device control command. The method according to claim 4 , wherein the device interface unit switches a power state of the device in response to the device control command. 4. The method of claim 3 , wherein each visual stimulus generator in the set of visual stimulus generators is associated with a separate electrical device. Part of the standard environment under ambient lighting, or the same or substantially the same, when the reference scene is in the off state of any visual stimulus generator and associated electrical device in or near the user's field of view in color scheme comprises a portion of uniformly or substantially uniformly illuminated wall optical signal source of a broad spectrum, the method of claim 1. Output of visual stimuli by each visual stimulus generator such that each visual stimulus generator in the set of visual stimulus generators is distinguished from each other in the set of visual stimulus generators is avoided. Automatically transition to the state of
(A) each visual stimulus generator in the set of visual stimulus generators is in a first state; and (b) both eyes are closed for a predetermined period when the individual is awake. Providing third EEG data related to the EEG signal generated by the individual,
The method of claim 1, further comprising: determining whether the third EEG data is related to self-behavioral behavior by the individual representing the activation of a visual stimulus generator activation command. In response to the activation command of the visual stimulus generator, each visual stimulus generator in the set of visual stimulus generators, and each visual stimulus generator in the set of visual stimulus generators is connected to each other. 9. The method of claim 8, further comprising automatically transitioning to a second state that outputs a visual stimulus as distinguished. A set of device control systems based on SSVEP generated by an individual's brain,
A set of visual stimulus generators, where each visual stimulus generator outputs a visual stimulus;
A visual stimulus generator controller connected to each visual stimulus generator and selectively outputting to each visual stimulus generator a visual stimulus such that the visual stimulus generators in the set of visual stimulus generators are distinguished from each other;
An EEG data acquisition system that captures EEG data generated by the user's brain;
A device identification system,
The device identification system includes:
A processing device;
A memory connected to the processing device,
The memory includes a set of program instructions that, when executed, identify a particular visual stimulus generator in the set of visual stimulus generators by a device identification operation;
The device identification operation is:
Related to EEG data acquired while the individual was gazing at the specific visual stimulus generator in the set of visual stimulus generators and to a set of fundamental frequencies f _k and a set of harmonic multiples nf _k Generate multiple active power spectral density amplitude values,
At least one reference power spectral density amplitude value and the device identification threshold T _I and selectively each active power spectral density amplitude values in the plurality of active power spectral density amplitude values based on a comparison between the active power spectral density amplitude value Generate multiple threshold active power spectral density amplitude values by scaling,
A system for determining whether a primary active power spectral density amplitude value exists in association with the plurality of threshold active power spectral density amplitude values. The device identification operation determines dominant frequency f _D is equal to a specific fundamental frequency f _k at the fundamental frequency f _k of the set with associated principal active power spectral density amplitude value,
Wherein identifying a visual stimulus generator at the dominant frequency f said set of visual stimuli generator for outputting a visual stimulus in the relevant frequency _D, system of claim 10. The device identification operation identifies an electrical device associated with the visual stimulus generator for outputting a visual stimulus at a frequency related to the dominant frequency f _D, system of claim 11. The device identification operation, outputs at least one related to the identifier from a group of the visual stimulus generator and electrical devices associated therewith for outputting a visual stimulus at a frequency related to the dominant frequency f _D, claim 11 System. Wherein in response to receipt of the identifier includes the dominant frequency f _D the system control unit for changing the operating state of the electrical device associated with the visual stimulus generator for outputting a visual stimulus in the relevant frequency, claim 13 systems. The system of claim 14 , wherein the system control unit outputs an electrical device control command based on the identifier. In communication with the system control unit, in response to the electrical device control command, the dominant frequency f _D sets the operating state of the electrical device associated with the visual stimulus generator for outputting a visual stimulus in the relevant frequency or adjust The system of claim 15 comprising a device control interface. The device control interface in response to said electrical device control command, which switches the power state of the electrical device associated with the visual stimulus generator for outputting a visual stimulus the at frequencies related to the dominant frequency f _D, The system of claim 16 . The memory includes a calibration unit that includes a set of program instructions that, when executed, perform a calibration operation;
The calibration operation is
The individual, the reference EEG data relating to EEG signals generated by the individual brain while it was gazing views of the reference there is no visual stimulation frequency approximately equal to the fundamental frequency f _k at the fundamental frequency f _k of a set Analyze
Generating a plurality of reference power spectral density amplitude values associated with the harmonic multiples nf _k of the set of fundamental frequency f _k and the fundamental frequency f _k of the set as well as associated with the reference EEG data,
Generating the device identification threshold T _I using the plurality of reference power spectral density amplitude value, according to claim 10 systems. Part of the standard environment under ambient lighting, or the same or substantially the same, when the reference scene is in the off state of any visual stimulus generator and associated electrical device in or near the user's field of view 19. The system of claim 18 , comprising a portion of a wall that is uniformly or substantially uniformly illuminated by a broad spectrum optical signal source with a color scheme of: Further comprising a control and communication unit connected to the processing device;
The control and communication unit is configured to distinguish each visual stimulus generator in the set of visual stimulus generators from visual stimulus by each visual stimulus generator such that the visual stimulus generators in the set of visual stimulus generators are distinguished from each other. Configured to automatically transition to a first state where output is avoided,
The memory further includes a user state detection module having a program instruction sequence that, when executed, performs a user state detection operation;
The user state detection operation includes: (a) each visual stimulus generator in the set of visual stimulus generators is in a first state; and (b) a predetermined period when the individual is awake. Analyzing EEG data generated by the individual when both eyes are closed; and (a) each visual stimulus generator in the set of visual stimulus generators is in a first state; and b) When the individual is awake, when the eyes are closed for a predetermined period of time, the EEG data generated by the individual represents an instruction to activate the visual stimulus generator. 11. The system of claim 10, comprising determining if it relates to self-behavior. The control and communication unit is configured to output each visual stimulus generator in the set of visual stimulus generators according to an instruction of an activation command of the visual stimulus generator, and each visual stimulus generator includes the set of visual stimulus generators. 21. The system of claim 20, wherein the system is configured to automatically transition to a second state that outputs a visual stimulus such that the visual stimulus generators in the are distinguished. An EEG acquisition unit, a set of visual stimulus generators that output visual stimuli such that each visual stimulus generator distinguishes between the visual stimulus generators, and a set of electrical devices associated with the set of visual stimulus generators A sequence of program instructions for operating a set of electrical device control systems based on SSVEP generated by an individual's brain, comprising a device identification unit and a system control unit; A computer-readable recording medium storing a program instruction sequence to be executed,
The control operation is
The individual, the first relating to EEG signals generated by the individual brain while it was gazing views of the reference there is no visual stimulation frequency approximately equal to the fundamental frequency f _k at the fundamental frequency f _k of a set Get EEG data,
Generating a plurality of reference power spectral density amplitude values associated with the first EEG data and associated with a set of fundamental frequencies f _k and a set of harmonic multiples nf _k of each fundamental frequency f _k ;
Generates device identification threshold T _I using the plurality of reference power spectral density amplitude value,
The personal to a particular visual stimulus generator in each visual stimulus generator set of visual stimulus generator to provide a visual stimulus in substantially equal specific presentation frequency associated fundamental frequency f _k at the fundamental frequency f _k of the set is Obtaining second EEG data related to SSVEP generated by the individual's brain while gazing,
Generating a plurality of active power spectral density amplitude values related to the second EEG data and related to the set of fundamental frequencies f _k and the set of harmonic multiples nf _k ;
Selectively at least one reference power spectral density amplitude value and each active power spectral density amplitude values in the plurality of active power spectral density amplitude values based on a comparison between the active power spectral density amplitude value and the device identification threshold T _I Generate multiple threshold active power spectral density amplitude values by scaling to
A computer readable recording medium for determining whether a primary active power spectral density amplitude value exists in relation to the plurality of threshold active power spectral density amplitude values. A program instruction sequence that, when executed, causes the system to perform a control action;
The control operation is
At least one reference power spectral density amplitude value and the device identification threshold T _I multiple thresholds activity of each active power spectral density amplitude values in the plurality of active power spectral density amplitude value based on the comparison selectively to scaling Generate power spectral density amplitude value,
23. The computer readable recording medium of claim 22, wherein a determination is made as to whether a primary active power spectral density amplitude value exists in association with the plurality of threshold active power spectral density amplitude values. A program instruction sequence that, when executed, causes the system to perform a control action;
The control operation is
Identified dominant frequency f _D is equal to a specific fundamental frequency f _k at the fundamental frequency f _k of the set with associated principal active power spectral density amplitude value,
Wherein identifying a visual stimulus generator in the set of visual stimuli generator for providing a visual stimulation presentation frequency associated with the dominant frequency f _D, computer-readable medium of claim 23. A program instruction sequence that, when executed, causes the system to perform a control action;
The control operation is
The identified electrical device associated with the visual stimulus generator to provide a visual stimulus at asking frequency associated with the dominant frequency f _D,
The dominant frequency f _D wherein the visual stimulus generator set or adjust the operating conditions of the electrical devices associated with providing a visual stimulation presentation frequency associated with, a computer readable recording medium of claim 24. A program instruction sequence that, when executed, causes the system to perform a control action;
The control operation is
Output of visual stimuli by each visual stimulus generator such that each visual stimulus generator in the set of visual stimulus generators is distinguished from each other in the set of visual stimulus generators is avoided. Automatically transition to the state of
(A) each visual stimulus generator in the set of visual stimulus generators is in a first state; and (b) both eyes are closed for a predetermined period when the individual is awake. Analyzing the EEG data generated by the individual,
(A) each visual stimulus generator in the set of visual stimulus generators is in a first state; and (b) both eyes are closed for a predetermined period when the individual is awake. And determining whether the EEG data generated by the individual is related to self-behavioral behavior by the individual representing the activation of a visual stimulus generator activation command. Medium. When executed, each visual stimulus generator in the set of visual stimulus generators and each visual stimulus generator in the set of visual stimulus generators are activated in response to the activation command of the visual stimulus generator. 27. The computer readable record of claim 26, further comprising a program instruction sequence for performing a control action further comprising automatically transitioning to a second state that outputs a visual stimulus such that the stimulus generators are distinguished from each other. Medium.