JPH078297B2 - EEG induction device - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electroencephalogram guiding apparatus for efficiently inducing a target electroencephalogram.

[Conventional technology]

It is known that there is a close relationship between human brain waves and their physiological and psychological states. For example, a lot of α waves (about 8 to 13 Hz) are generated in the relaxed state, a lot of β waves (about 14 to 30 Hz) are generated in the active state, and a θ wave ( About 4 to 7 Hz) often occurs. On the contrary, if the guidance is made so that a large number of predetermined electroencephalograms are generated, the corresponding physiological / psychological state is likely to occur.

Conventionally, by utilizing the interaction between such an electroencephalogram and its physiological and psychological states, an α wave is induced by externally stimulating the body, leading to a relaxed state of the body and spirit, and stress Various devices for reducing or unifying the spirit have been proposed.

For example, the biofeedback device described in JP-A-55-63656 picks up an electroencephalogram with electrodes attached to the head, extracts an α wave from the electroencephalogram signal, and hears it from an earphone depending on the intensity of the α wave. By changing the sound and notifying whether or not an α wave is generated by the difference in the sound,
It is designed to guide the user to a relaxed state.

Further, the relaxing device described in JP-A-62-87165 artificially creates an α-wave signal having a fluctuation of a 1 / f characteristic by using random noise generated by a random noise generation circuit, and uses this α-wave signal. The light source is flashed to give a light stimulus to guide the user to a relaxed state.

[Problems to be Solved by the Invention]

However, in the case of the biofeedback device,
In order to achieve a relaxed state, the user himself / herself recognizes the difference in the sounds generated by the earphones, while inducing his / her own mental state so that the sounds corresponding to the α waves are the strongest. We have to go. For this reason, when using it, repeatedly practice in advance how to concentrate the mind and make the α wave strong, and learn to change the mental state to some extent by one's will. Need to be kept. Therefore, not everyone can obtain the desired effect immediately, and there is a problem in that the effect greatly varies depending on the user.

Further, also in the case of the relaxation device, since the brain wave is guided by using an artificial α-wave signal that is completely unrelated to the brain wave of the user, the guidance effect is not constant and the difference is large depending on the person. There was a problem.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electroencephalogram guiding apparatus capable of efficiently inducing an electroencephalogram of interest without the need for any preliminary learning with a simple circuit configuration. .

[Means for Solving the Problems]

In order to achieve the above object, an electroencephalogram guiding apparatus of the present invention includes a means for detecting physiological changes in the body, and a first bandpass filter for passing only a frequency band component corresponding to an electroencephalogram induced in the detection signal. A pulse width modulation means for generating a signal having a constant signal level which is pulse width modulated by the output signal of the first bandpass filter, and a frequency band component corresponding to an electroencephalogram induced from the signal output by the pulse width modulation means A second bandpass filter for passing the signal and a body stimulating means for converting the output signal of the second bandpass filter into a predetermined body stimulating signal and giving it to the user.

As the physiological change of the body to be detected, the electroencephalogram is generally the most suitable, but in addition to this, physiological changes having the same properties as the electroencephalogram, for example, brain magnetic field, skin potential, skin vibration, Skin resistance and the like can be used. Also,
Various stimulus signals such as optical stimulus, sound stimulus, electrical stimulus, and vibration stimulus can be used as the physical stimulus signal.

[Work]

In human brain waves, a so-called pull-in phenomenon that is synchronized with an external stimulus signal is seen. The effect of this entrainment becomes greater as the induced brain wave and the phase of the stimulation signal given from the outside become more synchronized. The present invention utilizes such characteristics of the living body.

The means for detecting the physiological change of the body is a predetermined part of the user, for example, the head in the case of an electroencephalogram or a brain magnetic field, and the arm in the case of a skin potential, skin vibration, or skin resistance. Mounted in position.

Similarly, the body stimulating means also has a predetermined position, for example, in front of the user's eye in the case of light stimulation, in the vicinity of the ear in the case of sound stimulation,
In the case of electrical stimulation or vibration stimulation, it is attached to a predetermined body position such as an arm.

When the predetermined physiological change signal is detected from the body of the user by the means for detecting the physiological change, the detected signal is the first signal.
In the band-pass filter, only the frequency band component corresponding to the electroencephalogram intended for induction is selected and sent to the pulse width modulation means.

The pulse width modulation means performs pulse width modulation based on the signal sent from the first band-pass filter, and generates a signal whose signal level is constant and whose pulse width changes according to the input signal. Therefore, the phase of the signal output from the pulse width modulation means is the signal sent from the first band-pass filter, that is, the signal component corresponding to the electroencephalogram intended for induction in the detected physiological change signal. Are signals that almost match.

The second bandpass filter selectively passes only a predetermined frequency band component corresponding to the electroencephalogram for the purpose of induction from the signal and sends it to the body stimulating means. Then, the physical stimulation means converts the output signal sent from the second band-pass filter into a predetermined physical stimulation signal and feeds it back to the user.

The user is induced with the target electroencephalogram by the body stimulation signal, and the physiological change signal of the body corresponding to the induced electroencephalogram is detected again by the means for detecting the physiological change, and the same operation is repeated thereafter.

Therefore, when the induction of the electroencephalogram by the device of the present invention is started, a kind of oscillation circuit incorporating the user himself into a closed loop is formed, and the inside of this closed loop is regarded as a signal component corresponding to the electroencephalogram for the purpose of induction. For example, only signals whose phases are synchronized will circulate. As a result, only the target electroencephalogram is strongly induced by the pulling action of the phase-synchronized circulation signal, and the user is quickly pulled into the desired electroencephalogram state.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of an electroencephalogram guiding device of the present invention. This embodiment is an example in which an electroencephalogram is used as a physiological change detected from the body and an optical stimulus is used as a body stimulation signal. In the figure, 1a and 1b are a pair of electrodes for picking up an electroencephalogram from the user's head, 3 is a biological amplifier that amplifies the electroencephalogram signal picked up by the electrodes 1a and 1b to a signal level suitable for subsequent processing, 4 Is a first bandpass filter, 5 is a pulse width modulation circuit, 6 is a second bandpass filter, and 7 is a photostimulator.

The first and second bandpass filters 4 and 6 are filters that selectively pass only the frequency band component corresponding to the electroencephalogram intended for induction from the electroencephalogram signals picked up by the electrodes 1a and 1b. 8 to 13Hz when inducing
The pass band characteristic is set to 4 to 7 Hz when inducing a θ wave, and 14 to 30 Hz when inducing a β wave.

The pulse width modulation circuit 5 is a circuit for generating a square wave signal having a constant signal level which is pulse width modulated by the brain wave signal sent from the bandpass filter 4. The simplest is, for example, the well-known comparator shown in FIG. Should be adopted.

The optical stimulator 7 is a circuit that generates stimulating light that blinks in synchronization with the amplitude change of the output signal of the second band-pass filter 6, and includes a light-emitting element such as an LED and its drive circuit. There is.

The optical stimulator 7 and the electrodes 1a, 1b are incorporated in, for example, a headband, and when the headband is worn on the head, the electrodes 1a, 1b come into contact with a predetermined position of the head 2 and the optical stimulation is performed. The light emitting element of the device 7 is devised so as to be in a predetermined position in front of the eye.

Next, referring to FIG. 3, the operation will be described by taking the case of inducing an α wave as an example. Each waveform (a) in FIG.
1 to (c) correspond to the waveforms at the positions (a) to (c) in FIG.

The user wears the headband on his head and switches on the device.
When turned on, the electrodes 1a and 1b pick up brain waves and send them to the biological amplifier 3. This electroencephalogram signal (FIG. 3 (a)) is amplified by the biological amplifier 3, and then only the frequency band component of the α wave is selected by the first bandpass filter 4 and sent to the pulse width modulation circuit 5.

The pulse width modulation circuit 5 performs pulse width modulation using the α-wave signal sent from the first band-pass filter 4, and as shown in FIG. 3 (b), the pulse width W _P has an α-wave signal. A square wave signal having a constant signal level that varies according to is generated. Therefore, this square wave signal becomes a signal whose phase is substantially the same as that of the input α wave signal.

The second band-pass filter 6 extracts only the frequency component of 8 to 13 Hz corresponding to the target α wave from the square wave signal sent from the pulse width modulation circuit 5, and is shown in FIG. 3 (c). It is sent to the optical stimulator 7 as a waveform signal as shown.

The photostimulation device 7 uses the output signal of the second band-pass filter 6 to control the blinking of a light emitting element such as an LED, and the blinking light stimulates the user to induce a desired α-wave.

Then, the α-wave induced by the above-mentioned optical stimulus is again generated by the
It is picked up by 1a and 1b, and thereafter the same operation as above is repeated.

Therefore, when the induction of the electroencephalogram by the device of the present invention is started, a kind of oscillation circuit in which the user himself / herself is incorporated into the closed loop is formed. Therefore, only the α-wave signal component circulates in the closed loop, and the circulating signal becomes a waveform signal whose phase is substantially synchronized with the α-wave of the user himself picked up by the electrodes 1a and 1b. As a result, the blinking phase of the stimulating light fed back from the photostimulation device to the user is also substantially synchronized with the user's own α-wave, and the pulling-in action strongly and promptly induces the target α-wave.

FIG. 4 shows the actually measured waveform of the electroencephalogram induction in the above embodiment. The waveforms (a) to (c) are shown in (a) to (c) of FIG.
(C) Corresponds to the position waveform.

As is apparent from the waveforms shown in FIGS. 4A to 4C, the brain waves picked up by the electrodes 1a and 1b, the square wave signal output from the pulse width modulation circuit 5, and the second bandpass filter. It can be seen that the phases of the three output signals of 6 are almost the same. Therefore, it is understood that the action of drawing the electroencephalogram is also strong.

Although the embodiment described above is an example of the case of inducing the α wave, the θ wave and the β wave can be similarly induced by changing the pass band frequencies of the bandpass filters 4 and 6. Further, although the electroencephalogram was used as the physiological change signal of the body, a brain magnetic field, skin potential, skin vibration, skin resistance, etc., which have the same properties as the electroencephalogram, can also be used. Further, although the optical stimulus is used as the physical stimulus signal, sound stimulus, electrical stimulus, vibration stimulus or the like may be used.

〔The invention's effect〕

As is clear from the above description, according to the present invention, pulse width modulation is used to generate a stimulation signal whose phase is substantially in phase with the target brain wave to induce the target brain wave. Even though the circuit configuration is simple, the target electroencephalogram can be strongly and promptly induced without the need for conventional learning.

Furthermore, since the signal component corresponding to the electroencephalogram for the purpose of induction in the detected physiological change signal is once converted into a signal with a constant signal level, the strength of the detected physiological change signal of the body fluctuates. Can also perform stable EEG induction.

Moreover, since the intensity of the induced electroencephalogram is high, the afterglow effect is also increased, and various excellent effects are exhibited such that the induced electroencephalogram continues to be output for a long time even after the device of the present invention is removed.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a concrete circuit example diagram of a pulse width modulation circuit in the above embodiment, FIG. 3 is an operation explanatory diagram of the above embodiment, and FIG. It is a measured waveform diagram of the electroencephalogram guidance in an Example. 1a, 1b ... Electrode, 2 ... Head, 3 ... Bio-amplifier, 4 ...
... First band filter, 5 ... Pulse width modulation circuit, 6 ...
… Second bandpass filter, 7 …… Photostimulator.

Claims (1)

[Claims] 1. A means for detecting a physiological change in a body, a first bandpass filter for passing only a frequency band component corresponding to an electroencephalogram induced in the detection signal, and an output signal of the first bandpass filter. A pulse width modulating means for generating a signal having a constant signal level pulse width modulated by the pulse width modulating means, and a second bandpass filter for passing only a frequency band component corresponding to an electroencephalogram induced from a signal output from the pulse width modulating means, A brain wave guiding apparatus comprising: a body stimulating means for converting an output signal of the second band-pass filter into a predetermined body stimulating signal and giving the same to a user.