JPS5819292B2 - Biosignal measurement device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses semiconductor switching to determine circuit conditions related to distribution of multiple electrodes attached to a living body to arbitrary recording channels, biological signal amplification, etc. according to settings at an input section. The present invention relates to a biological signal measuring device using an element.

In general, in medical electronic devices that monitor patients or diagnose diseases based on electrical signals induced from living bodies, a large number of electrodes attached to living bodies are arbitrarily combined according to various diagnostic logics selected or developed by doctors. At the same time, the biological signals induced during this time are amplified and recorded under arbitrary circuit conditions, that is, with arbitrary amplification degrees or filter characteristics.

Therefore, setting circuit conditions including electrode combinations in a medical electronic device is not only complicated but also a difficult task that requires accuracy.

In the case of electroencephalographs in particular, it is common practice to attach as many as 27 electrodes, mainly on the head, and to combine and amplify the electrical signals obtained from these as appropriate before recording them with a 17-channel pen recording section. Therefore, handling it is more difficult than you might imagine.

Therefore, in order to improve this operability to some extent, the display device and the circuit condition output circuit are connected to the registers belonging to each channel in which the circuit conditions are arbitrarily written, and the circuit conditions of multiple channels can be set using a common input section. There is also known a measurement condition setting device that displays the measurement conditions.

In addition, for electroencephalogram measurement, combinations of multiple electrodes attached to the head and each recording channel are arbitrarily written into a random access memory (RAM) from the input section, and the contents of the RAM are sequentially read out in synchronization with channel switching to set the circuit. In addition, an electroencephalogram pattern selector is also well known that allows the contents of the program to be displayed and confirmed by pressing a read key if necessary.

In all of these, due to the circuit system for setting and displaying circuit conditions, only simple circuit conditions can be set.

In view of this point, it is an object of the present invention to provide a biological signal measuring device that can easily and diversely change, set, and select measurement patterns that define the circuit conditions of each recording channel.

According to the present invention, this problem is solved by processing various commands related to circuit conditions from the input section by computer, and making it possible to view the circuit conditions in an appropriate display format on the cathode ray tube in response to the commands.

Next, the present invention will be explained according to illustrated embodiments.

FIG. 1 is a main circuit diagram of the biological signal measuring device according to the present invention, and 1 is a main circuit diagram of a biological signal measuring device according to the present invention. The electrode switching circuit 13 is composed of a latch circuit, a semiconductor switch, etc., and is composed of a preamplifier 2 and a main amplifier 3, which can adjust the high- and low-frequency cutting frequencies and gain of the filter using digital signals. 4 is a multi-channel pen recording section; 5 is a read-only memory (ROM) 6 consisting of a microprocessor;
I is a signal processing circuit that controls the operation of the entire device according to a program stored in advance.I stores and reads circuit condition data of the electrode switching circuit 1 and preamplifier 2, and is rewritable and erased even when the device is powered off. Random access memory (RAM) consisting of a non-volatile area that is powered by a battery to prevent data from being lost and a work area that is powered by the device power supply to read or write data to this non-volatile area.
, 8 is a keyboard for selecting, setting, and changing measurement patterns that define the circuit conditions of each channel, and for commanding display of circuit conditions necessary for selection and programming.

The keyboard 8 has an encoder inside, and each pushbutton switch of the keyboard converts a control signal or data into a digital signal.

Furthermore, 9 is a cathode ray tube control circuit that generates control signals for displaying circuit condition data in various formats on a cathode ray tube for measurement and programming; 10 is a monitor camera that mainly monitors the condition of the subject; 14 The video amplification/switching circuit 11 amplifies the video signal from the cathode ray tube control circuit 9 and switches the input with the signal from the monitor camera 10 if necessary, and the horizontal and vertical synchronizing signals and the video signal are introduced through this circuit 11. This is a cathode ray tube display section consisting of a cathode ray tube 12.

Electrode switching circuit 1, preamplifier circuit 2, signal processing circuit 5, R
The OM 6, RAM 7, keyboard 8, and cathode ray tube control circuit 9 are connected to an address bus for informing the storage location of programs, circuit conditions, and display data necessary for the operation of each circuit, and for transferring program contents and data between each circuit. are connected to each other through a data bus and a control bus for issuing commands from the signal processing circuit 5 to each circuit and requesting interrupt processing from each circuit to the signal processing circuit 5.

FIG. 2 shows the circuit configuration of the electrode switching circuit 1, where 21 is an electrode data decoder, 22 is a channel address decoder, and 23 is a cross point with a flip-flop (FF) provided at the intersection of the input line and the output line. It's a switch.

There are 23 input lines for brain wave signals corresponding to the number of head electrodes on the keyboard (FPl, EP2s F3.F4...
・), 4 wires for other biological signals such as electrocardiogram signals (
It consists of a total of 27 pieces (Xt to X4).

There are two output lines for each of the 17 channels (Gt, G
2).

The FF of either line is set for each of the output line and the input line in synchronization with the memory write signal MW from the signal processing circuit 5, and therefore the connection between the output line and the input line is established at the intersection point where both FFs are set. It will be done.

FIG. 3 shows the selection and setting of numerous measurement patterns on the keyboard 8, which functions as an input section for commanding the operation of the device.
An arrangement of pushbutton switches for changing and setting circuit conditions to the circuit is shown.

31 is a group of various biological signal switches, 32 is a head electrode switch group, 33 is a channel switch group, 34 is a pattern switch group, 35 is a group of circuit condition setting switches for the preamplifier 2, and SET is a setting of circuit conditions to the circuit. and a setting switch for writing circuit conditions into the non-volatile area of the RAM 7.

Each switch of the head electrode switch group 32 is arranged on a rigid body imitating the head, corresponding to its actual position.

The amplifier circuit switch group 35 is composed of GAIN switches for adjusting the gain of the preamplifier 2, Lo Cut switches for adjusting the low cutoff frequency of the filter, and HiCut switches for adjusting the high cutoff frequency. There are pairs of pushbutton switches for step-up and step-down, respectively.

FIG. 4 shows the circuit configuration of the cathode ray tube control circuit 9.

Data DBO to DB such as display format and circuit conditions read out from the non-volatile area and work area of RAM 7
7 is the address ABO-A where this data should be stored first.
After the BIO is sent to the refresh memory 42 via the address bus and multiplexer 41 and its address is specified, it is sent to the refresh memory 42 via the data bus.
Sent to 2.

This refresh memory 42 has a memory capacity equivalent to one screen of a cathode ray tube.

All the data to be displayed now is refreshed in the memory 42.
When stored, multiplexer 41 supplies address signals MAO-MA9 from control section 43 to refresh memory 42 in response to a control signal sent from signal processing circuit 5 through the control bus, and reads out the stored data.

The read data is temporarily held in the latch circuit 44 and converted into a character signal by the character generator 45.

The signal is then converted into a serial signal by a parallel-to-serial converter 46, and further converted into a video signal for display on a cathode ray tube by a video control circuit 47.

The parallel-serial conversion circuit 46 and the control unit 43 each have a capacity of 8M.
It is synchronized with an H2 clock generator 48 and a synchronous counter 49 that counts down the clock.

The data DBO to DB7 are also applied to the control section 43, and display control is also performed as a command signal from the signal processing circuit 5.

In the biological signal measuring device having the above-mentioned circuit configuration, operations are performed as follows, centering on keyboard operations.

When the power switch (not shown) is turned on, the signal processing circuit 5 reads display format data from the non-volatile area of the RAM 7 and sends the address and data to the cathode ray tube control circuit 9 according to a startup processing routine preprogrammed in the ROM 6. Inform.

In the cathode ray tube controller 9, this data is temporarily stored in the refresh memory 42 according to the address specification, and then
After the processing described above, the display format shown in FIG. 5 is shown on the cathode ray tube 12.

However, the electrode G1 of each channel. G2 is displayed as CAL (calibration).

In addition, in the display format of Fig. 5, CAL50μ
■ indicates the reference voltage, that is, the calibration voltage, to be left in the recorded waveform of the brain wave, and R-L-E indicates the grounding state of the electrode, and in this example, the right ear (R) and the left ear. It shows that the electrode attached to (L) is grounded.

Next, when it is desired to measure using measurement pattern 5, for example, when the pattern switch P of the keyboard 8 is pressed, a key interrupt signal is applied from the encoder of the keyboard 8 to the signal processing circuit 5 through the control bus.

When the signal processing circuit 5 receives this interrupt signal, the program jumps to a key processing routine, and the keyboard is specified via the address bus.

Next, from keyboard 8 is pattern switch P.

Data corresponding to is sent from the encoder to the signal processing circuit 5 via the data bus.

Through this series of operations, the signal processing circuit 5 learns that the keyboard 8 requests the measurement pattern 5, reads out the circuit condition data of the measurement pattern 5 from the non-volatile area of the RAM 7 according to the program stored in the ROM 6 in advance, and
This data is transferred to the working area of the RAM 7 and also to the refresh memory 42, and the circuit conditions of the measurement pattern 5 are displayed on the cathode ray tube 12 in the display format shown in FIG.

That is, the correspondence between the electrodes G1 and G2 of each channel in the measurement pattern 5, the gain of the preamplifier 2, the low-frequency cutoff wave number LC, and the high-frequency cutoff wavenumber HC of the filter.

CAL voltage etc. can be listed.

Next, press the setting switch SET on the keyboard 8, and the circuit condition data of measurement pattern 5 will be displayed according to the predetermined program.
The data is transferred from the working area of the RAM 7 to the electrode switching circuit 1 and the preamplifier 2 through the address bus and data bus, and is set (loaded) to each circuit through the above-mentioned operation process by the MW pulse sent through the control bus.

As a result, the electrodes are connected and the amplification degree and filter characteristics are set as indicated.

Furthermore, when you turn on the record switch (not shown),
Based on the selected measurement pattern, biological signals such as brain waves, electrocardiograms, and respiratory waves are recorded in parallel on the multi-channel pen recording section.

Similarly, other measurement patterns 1 to 4 and 6 to 8 correspond to the corresponding pattern switches P1 to P4 and P6 to P on the keyboard 8.
8 can be selected.

The electrode connections of measurement patterns 1 to 8 are set in advance to standard conditions, and once the circuit conditions of the preamplifier 2 are set during use, a wide variety of measurements can be performed by selecting pattern switches P1 to P8. .

In addition, according to the present invention, as described in detail below, standard measurement patterns can be changed and free measurement patterns can be set, that is, various programs for circuit conditions can be programmed using the keyboard 8 based on the display on the cathode ray tube. This is easily possible.

First, if the measurer wishes to change the circuit conditions of the preamplifier 2 of channel 11 of pattern 5, for example, he presses the pattern switch P, and measurement pattern 5 is displayed on the cathode ray tube (FIG. 5).

Next, when the channel switch Chll is pressed, a key interrupt signal is given to the signal processing circuit 5 through the control bus, and the execution program moves to the key processing routine.

As a result, the keyboard 8 is specified through the address bus, and then data corresponding to the channel switch Chll is taken into the signal processing circuit 5 from the encoder through the data bus.

The signal processing circuit 5 puts new data and address based on this data on a data bus and an address bus, respectively, and applies them to the cathode ray tube control circuit 9.

The cathode ray tube control circuit 9 changes the characters "Chll" on the cathode ray tube 12 to "white" characters based on these data.

Next, when the gain setting switch GAIN [Il or ■ is pressed, the cathode ray tube display changes to the display format shown in FIG.

In other words, the GAIN characters to be set and the current circuit conditions are displayed in white.

Further, by pressing the setting switch GAIN↑ or GAIN as many times as necessary, the gain increases or decreases in steps.

At this time, the "Gain 1 white" character can be moved up or down to confirm the setting value.

Similarly, if you want to change the filter's low-frequency and high-frequency cutoff wavenumber characteristics, use Lo Cut and HiCut.
By pressing the button a predetermined number of times, the desired circuit conditions are set.

When all the circuit conditions are set to the desired values as described above, the setting switch SET is pressed.

Then, the cathode ray tube display returns to the display format shown in FIG. Set.

In this case, it is possible to make all the circuit conditions other than channel 11 the same, and the ACC (A #
Channel? When the Control) switch (not shown) is set to the desired value, the displays other than Chll change to this value, and all the circuit conditions are stored and set to the circuit along with the previously set 11 channel gain.

Further, if necessary, the standard electrode connections of measurement patterns 1 to 8 can be changed by the following operations.

First, when you turn on the lock key (not shown), the CRT display changes to the display format shown in Figure 7 (PAT-
2 to PAT-8, the description of the electrode numbers is omitted).

This display format shows the current state of electrode connection for each measurement pattern.

For example, if you want to change the electrode connection for channel 1 of measurement pattern 1, press pattern switch P1 and channel switch Chi, then press the two desired electrode switches.
The electrodes are displayed in order in the columns G1 and G2.

In this case, it is possible to press the setting switch again, but once the setting switch
When ET is pressed, the displayed contents are transferred from the working area of the RAM 7 to the non-volatile area and stored.

For other channels, press the channel switch and electrode switch in the same way, and then press the setting switch SET each time.
It can be changed by pressing .

For other measurement patterns, first press the desired pattern switch and perform the same operation.

When the measurement pattern change is completed and the lock key is turned off, the display format returns to FIG. 5.

To temporarily change the electrode connection, press the desired pattern switch with the lock key turned off, and set the desired channel switch and electrode switch in the display format shown in FIG.

In this case, since the changed contents are only stored in the working area of the RAM 7, if another measurement pattern is selected after the measurement is completed, the contents before the change are returned.

Furthermore, the device according to the invention has standard measurement patterns 1 to 8.
Free patterns can be set outside of the .

To do this, first press the pattern switch Free to change to the display format shown in FIG. 5 (however, the title is different).

Then, the channel is set by the channel switch, and the electrode G1 to be connected is set by the electrode switch. Set G2.

Then press the setting switch SET and save the settings to RAM7.
It is stored in the nonvolatile area of , and set in the electrode switching circuit 1.

In this way, electrode connections are set for each channel.

The circuit conditions for the preamplifier 2 are set in the same way as for the standard measurement pattern.

In addition, although the above-mentioned example was a case of an electroencephalogram in which electrical signals induced from 27 biological electrodes are appropriately combined and recorded by a 17-channel pen recording section, the present invention is limited to this example. The present invention can also be implemented in a biological signal measuring device with a small number of electrodes or channels.

As is clear from the above description, the present invention not only allows a wide variety of measurement patterns to be selected, checked, set, and changed based on the display format appropriate for each occasion on the cathode ray tube, but also allows for the selection, checking, and setting of measurement patterns by a doctor conducting monitoring or diagnosis. (1) Store circuit conditions frequently used in diagnostic logic in advance.

Since readout and setting can be performed with two key operations, precise measurement of biological signals can be easily performed.

In a further preferred embodiment, the video input of the cathode ray tube can be switched, and when the video signal of a television camera that can monitor the subject's condition is input, it can be used with something like an electroencephalogram that measures the subject in the normal room. However, it is possible to accurately grasp the subject's eye blinks, body movements, etc. that cause artifacts (noise), making it easier to analyze the recorded data, and enabling even more efficient and precise measurements.

[Brief explanation of the drawing]

FIG. 1 is a main circuit diagram of a biological signal measuring device according to the present invention,
Fig. 2 is a circuit diagram of the switching circuit, Fig. 3 is a switch arrangement diagram of the keyboard according to the present invention, Fig. 4 is a circuit diagram of the cathode ray tube control circuit in Fig. 1, and Figs. 5 to 7 are circuits using cathode ray tubes. Indicates the display format of conditions. 1... Electrode switching circuit, 2... Preamplifier, 3... Main amplifier, 4... Recording section,
5... Signal processing circuit, 6... ROM,
7...RAM, 8...Keyboard, 9...CRT control circuit, 10...-
-Monitor camera, 11...video switching amplifier circuit, 12...braun tube, 13...amplifying circuit.

Claims (1)

[Scope of Claims] 1. An electrode switching circuit that distributes signals induced from a plurality of electrodes mounted on a living body to arbitrary recording channels, an amplification circuit that amplifies the output of the electrode switching circuit, and the amplification circuit. a recording section for recording signals for each channel; a random access memory including a non-volatile area for storing circuit condition data for both circuits or the former circuit; and a non-volatile area for reading circuit condition data from the non-volatile area. an input section for commanding writing of circuit conditions into the circuit, setting of circuit conditions to the circuit, and displaying the circuit conditions in a fixed display format, and displaying the circuit condition data to be displayed on the cathode ray tube in a fixed display format. A biological signal comprising a cathode ray tube control circuit that generates a signal, a signal processing circuit that performs an operation based on commands of the input section according to a predetermined program, and a cathode ray tube display section that is connected to the cathode ray tube control circuit. measuring device. 2. The biological signal measuring device according to claim 1, characterized in that the cathode ray tube display section is provided with a changeover switch so that a video signal other than the output of the cathode ray tube control circuit can be input.