JPH0226484Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention divides the frequency band occupied by the brain wave signal into a plurality of bands, and calculates the total value of the power or amplifier spectrum of the brain wave signal included in each band,
That is, the present invention relates to an electroencephalogram band spectrum recording device that sequentially records band spectrum data.

[Conventional technology]

Conventional devices of this kind supply brain wave signals to a group of analog filters having sequentially different passbands and follow an integrating circuit, scan and detect the outputs of each, and supply them to a recorder. As shown in FIG. 6, each band spectrum was drawn continuously in the width direction of the recording paper.

[Problems that conventional technology and ideas try to solve]

This makes it possible to measure changes in each band spectrum of the brain wave signal over a long period of time, but since steep band characteristics cannot be obtained due to the use of analog filters, highly accurate measurement cannot be expected. Since it was only written together, the distribution state of the band spectrum and its changes could only be roughly observed.

In view of this point, it is an object of the present invention to provide an electroencephalogram band spectrum recording device that can record the ratio of each band spectrum to the total power or amplifier spectrum of an electroencephalogram signal.

[Means for solving the problem] In order to achieve this objective, the present invention includes a Fourier transformer 1 that generates a spectrum with a predetermined frequency resolution for an electroencephalogram signal, as shown in FIG.
A plurality of pieces n that divide the frequency band occupied by the brain wave signal.
spectrum summation means 2 for summing the spectra included in each of the frequency bands B ₁ to B _o for each unit time ΔT, and each total value SB ₁ to B o of each frequency band;
A band spectral ratio calculation means 3 that totals SB _o and calculates the ratio of each of the above-mentioned total values to the total value, for example, %, and shifts the dot printing position from the reference position in order according to these ratio values, that is, the band spectral ratio. A print signal generating means 4 generates a print signal every ΔT in each unit time, prints dots of the print signal in the width direction of the recording paper, and prints each dot of the percentage value on a curve every unit time ΔT. The printer 5 is configured to shift the printing line in the length direction of the recording paper so as to draw the image.

[Effect]

The Fourier transformer 1 performs frequency analysis on the brain wave signal with a predetermined frequency resolution and generates a power or amplifier spectrum. The spectrum summation means 2 calculates the total value of the spectra included in each of the frequency bands B ₁ to B _o , that is, the band spectra SB ₁ to _{SB o} for each unit time ΔT. The band spectral ratio calculating means 3 calculates the ratio, for example, %, of each total value SB ₁ to SB o _-1 or SB _o to the total value of each total value SB ₁ to SB _o . The print signal generating means 4 generates a percentage value, for example, a %band spectrum, into respective values %SB ₁ and %SB ₂
...Convert to a print signal for a band graph that shifts the print position by %SB _o-1 or %SB _o . printer 5
uses this print signal as input to print dots in the width direction of the recording paper 5a, and also shifts the print line in the length direction of the recording paper 5a every ΔT. As a result, the % band spectra of each band B ₁ to B _o (shown enlarged in the length direction) are drawn as shown on the recording paper 5a. Actually, the printing element and the recording paper 5a
By slowing down the relative movement speed in the longitudinal direction, a line drawn band graph shape is obtained as shown in FIG. The reference position 5b is printed in advance on the recording paper 5a or is printed sequentially by the printer 5. 100
The % line 5c is drawn in the same manner or by calculating %SB _o as well and sequentially printing the corresponding print signals.

[Embodiment of the invention] In Fig. 3, 11 is an electrode switcher that selects any two channels of electrodes from a plurality of electrodes attached to the subject's head, 12 is a two-channel amplifier, and 13 is a two-channel amplifier. , is a multiplexer that alternately switches and selects the amplified output of two channels 128 times per second. 14 is an FFT transformer that performs Fourier analysis according to a well-known FFT (fast Fourier transform) calculation format using a microcomputer. This FFT converter has a frequency resolution of 0.5Hz for two channels of digitized brain wave signals.
The power spectrum is detected and integrated at 62 points (excluding 0 and 0.5 Hz), that is, up to 32 Hz. Reference numeral 15 denotes a microcomputer that constitutes each of the aforementioned sections 2 to 5. Reference numeral 16 denotes a printer that is provided with one printing element in the width direction of the recording paper 16a being fed and prints two channels of print signals in dots every time the recording paper 16a moves by a unit amount. 17 is
This is a monitor cathode ray tube that displays the power spectrum integral value that is the output of the FFT converter 14 in waveform.

The microcomputer 15 uses a timer to control the FFT converter 14 every 10 seconds specified by this timer.
RAM that stores spectral data of two channels integrated over 10 seconds, ROM that stores the program, and operates according to this program.
Consists of CUP, etc. First, each spectrum data of two channels is averaged every 10 seconds to 120 seconds, which is set as an analysis time, according to the program stored in the ROM and stored in the RAM so as to constitute the spectrum summation means 2. . At that time, the CPU analyzes each spectrum data in the δ band (1 to 3.5 Hz) and the θ band (4 to 7.5 Hz).
Hz), α1 band (8~10.0Hz), α2 band (10.5~12.5
Hz) and the β band (13 to 32.0 Hz), and adds the result for each channel and each band, and temporarily stores the result in the RAM as band spectra Sδ, Sθ, Sα1, Sα2, and Sβ. Next, according to the program constituting the band spectral rate calculation means 3, the CPU calculates the total value Sδ+Sθ+Sα1 of each total value.
+Sα2+Sβ is calculated, and the percentage of each total value with respect to this total value is calculated, and the % band spectrum %Sδ,
Once the above as %Sθ, %Sα1, %Sα2, %Sβ
Store in RAM. Furthermore, according to the program constituting the print signal generating means 4, the CPU
Add the band spectra in order, each addition result %Sδ,
%Sδ + %Sθ, %Sδ + %Sθ + %Sα1, %Sδ + %Sθ
A two-channel print signal indicating the print position corresponding to +%Sα1+%Sα2 is output.

The operation is as follows.

The FFT converter 14 frequency-analyzes the two channels of electroencephalogram signals selected by the electrode switch 11 with a resolution of 0.5 Hz, and generates a sequentially integrated spectrum. The microcomputer 15 takes in the spectrum integrated every 10 seconds to 120 seconds, and performs analysis and processing according to FIG. 4. printer 16
performs a printing operation within 10 to 120 seconds each time a printing signal is supplied. First, in channel 1, the 0% position is printed using a print signal generated by the printer 16 itself. Then each % is set in response to the input print signal.
Printing is performed while sequentially shifting by amounts corresponding to the band spectra %Sδ, %Sθ, %Sα1, and %Sα2. Finally, 100% is the print signal generated by the printer 16 itself.
Print the position.

Furthermore, if a microcomputer is similarly used as the print signal generating means 4 to generate interpolated print signals continuously and intermittently between every other print signal, as shown in Fig. 5 (enlarged in the length direction). ), making it easier to read the band graph. Furthermore, as a method to make the bar graph easier to read, it is also possible to use a multicolor printer and color code each print signal. In the above embodiment, the spectral data is δ
Although it was divided into five bands from band to β band, the number of divisions can be changed arbitrarily.

[Effect of idea]

As described above, according to the present invention, the ratio of each band spectrum to all spectra of brain waves is recorded in the form of a band graph as a ratio to a predetermined recording width. Therefore, compared to simply displaying the level of each band spectrum, diagnosis based on band spectra can be performed more precisely. Further, since each change is also drawn as a curve in the length direction of the recording paper, it is extremely advantageous as a trend monitor.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an electroencephalogram band spectrum recording device according to the present invention, FIG. 2 is a recording waveform thereof, FIG. 3 is a block diagram of an embodiment of the present invention, and FIG. 4 is a diagram showing the operation of the microcomputer. FIG. 5 is a recording waveform diagram according to another embodiment, and FIG. 6 is a recording waveform diagram of a conventional electroencephalogram band spectrum recording apparatus.

Claims (1)

[Scope of utility model registration request] A Fourier transformer that performs frequency analysis on a continuously input brain wave signal and sequentially generates a power or amplifier spectrum with a predetermined frequency resolution, and a Fourier transformer that divides the frequency band occupied by the brain wave signal into a plurality of frequency bands. spectrum totaling means for summing the included spectra for each unit time; band spectral ratio calculation means for summing each spectrum total value of the plurality of frequency bands and calculating a ratio of the spectrum total value to this total value; a print signal generating means for generating a print signal for sequentially shifting the dot print position from the reference position in accordance with these ratio values for each unit time; and print signal generation means for printing dots in the width direction of the recording paper in response to the print signal. and a printer that shifts the print line in the longitudinal direction of the recording paper so that each dot print of the ratio value draws a curve for each unit time.