JP7238497B2 - DATA RECORDING SYSTEM, DATA RECORDING METHOD AND DATA RECORDING PROGRAM - Google Patents

Description

The present invention relates to a data recording system, data recording method and data recording program.

As a method for inspecting the functions of the spinal cord, peripheral nerves, muscles, etc., there is known a method of measuring an electric potential or a magnetic field generated from a living body based on their activities. Representative methods include biopotential measurement, in which neural activity is stimulated externally and the evoked potential of neural activity is measured using electrodes attached to the body surface, and neural activity is stimulated externally, and a magnetic sensor is used. There is a biomagnetic field measurement that measures the induced magnetic field caused by nerve activity current.

Biopotential measurement has the advantage that the obtained potential signal strength is relatively large and it is possible to evaluate minute nerve activity. are doing. On the other hand, in biomagnetic field measurement, it is possible to specify a lesion site with high resolution by estimating a signal source, but the obtained magnetic field signal strength is relatively small.

Therefore, comparing the data obtained by simultaneously measuring both the electric potential and the magnetic field on the same subject in the same posture is very important for improving the accuracy of function tests of the spinal cord, peripheral nerves, and muscles. important to

In order to suppress stimulation artifacts and improve the measurement accuracy of the evoked potential in the biopotential measuring device, a switch is used to electrically connect the lead-out electrode and the amplifier circuit of the biopotential measuring device while the stimulus is being applied. A method for canceling is proposed (Patent Document 1). Here, a stimulus artifact is noise generated in response to a stimulus.

As described above, in order to improve the accuracy of functional tests of the spinal cord, peripheral nerves, muscles, etc., the biopotential measurement device and the biomagnetic field measurement device are used to measure the potential of the same subject. It is conceivable to do both at the same time. In this case, it is necessary to prevent the noise generated by the biopotential measuring device from being included in the magnetic field signal measured by the biomagnetic field measuring device.

However, a biopotential measuring device that measures an evoked potential of nerve activity using electrodes attached to the body surface may itself become a source of noise. When magnetic field noise is generated based on the operation of the biopotential measurement device, the magnetic field noise not derived from the living body is superimposed on the biomagnetic signal measured by the bioelectrical potential measurement device, degrading the signal quality.

An object of the present invention is to reduce the influence of noise generated from a biopotential measurement device on a biomagnetic field measurement device.

In order to solve the above technical problems, a data recording system according to one aspect of the present invention includes a biopotential measuring device for measuring a potential difference between electrodes attached to a living body, and an electric potential between the electrodes and the biopotential measuring device. It comprises a switch for connection, and a processing unit that acquires the electrical connection timing of the switch and processes measurement data from the biomagnetic field measuring device that operates together with the biopotential measuring device.

ADVANTAGE OF THE INVENTION According to this invention, the influence of the noise which generate|occur|produces from a biopotential measuring device on a biomagnetic field measuring device can be reduced.

1 is a schematic diagram of a biological signal measurement system including a data recording system according to a first embodiment; FIG. 2 is a block diagram showing an example of a functional configuration of a data recording system included in the biomedical signal measurement system of FIG. 1; FIG. 3 is a diagram showing an example of the hardware configuration of the data recording device of FIG. 2; FIG. FIG. 3 is a diagram showing an example of processing biomagnetic field measurement data measured by the biomagnetic field measurement device of FIG. 2 by a data recording device; 3 is a flowchart showing an example of processing for extracting effective biomagnetic field measurement data by the data recording system of FIG. 2; FIG. 3 is a diagram showing another example of processing the biomagnetic field measurement data measured by the biomagnetic field measuring device of FIG. 2 in a data recording device; FIG. 3 is a flowchart showing another example of processing for extracting effective biomagnetic field measurement data by the data recording system of FIG. 2; FIG. It is a figure explaining the influence of the magnetic field noise which operation|movement of a biopotential measuring device has on a biomagnetic field measuring device. FIG. 11 is a block diagram showing the functional configuration of a data recording system according to a second embodiment; FIG.

Embodiments will be described below with reference to the drawings. In addition, in each drawing, the same code|symbol may be attached|subjected to the same component part, and the overlapping description may be abbreviate|omitted. In the following, a code indicating a signal is also used as a code indicating a signal value or a code indicating a signal line. The code indicating the voltage is also used as the code indicating the voltage value or the code indicating the voltage line to which the voltage is supplied.
(First embodiment)
FIG. 1 is a schematic diagram of a biological signal measurement system 1 including a data recording system according to the first embodiment. The biological signal measurement system 1 measures a plurality of types of biological signals, such as magneto-encephalography (MEG) signals and electro-encephalography (EEG) signals. A biological signal measurement system 1 includes a measurement device 3 , a stimulation device 5 , a data recording server 42 , and an information display system 22 . The information display system 22 has a monitor display 26 that displays signal information obtained by measurement, analysis results, and the like. Although the data recording server 42 and the information display system 22 are depicted separately here, at least a portion of the data recording server 42 may be incorporated into the information display system 22 .

A subject (hereinafter also referred to as living body P) lies face up on the measurement table 4 with electroencephalogram measurement electrodes (or sensors) attached to the head, and puts the head in the depression 31 of the dewar 30 of the measurement device 3. . The dewar 30 is a holding container for a cryogenic environment using liquid helium, and a large number of magnetic sensors for magnetoencephalography are arranged inside a recess 31 of the dewar 30 . The measuring device 3 collects electroencephalogram signals from the electrodes and magnetoencephalography signals from the magnetic sensor, and outputs the collected biological signals to the data recording server 42 . For example, the electroencephalogram signal and the magnetoencephalogram signal are collected by the measuring device 3 while the stimulation device 5 is stimulating the subject.

The data recorded in the data recording server 42 is read out by the information display system 22, displayed, and analyzed. Generally, the dewar 30 containing the magnetic sensor and the measurement table 4 are arranged in a magnetically shielded room, but the magnetically shielded room is omitted for convenience of illustration.

The information display system 22 may synchronize and display waveforms of magnetoencephalogram signals from a plurality of magnetic sensors and waveforms of electroencephalogram signals from a plurality of electrodes on the same time axis. An electroencephalogram signal represents the electrical activity of nerve cells (the flow of ionic charges occurring in the dendrites of neurons during synaptic transmission) as a voltage value between electrodes. Magnetoencephalography signals represent minute magnetic field fluctuations caused by electrical activity in the brain. Brain magnetic fields are detected with a highly sensitive Superconducting Quantum Interference Device (SQUID) sensor.

FIG. 2 is a block diagram showing an example of the functional configuration of the data recording system 2 included in the biological signal measurement system 1 of FIG. The data recording system 2 includes a stimulation unit 10 for stimulating a living body P, a biomagnetic field measuring device 20, a pair of lead-out electrodes 34 attached to the living body P, a switch 40, a biopotential measuring device 50, and data recording. a device 60;

For example, the stimulation unit 10 is included in the stimulation device 5 in FIG. 1, and the biomagnetic field measurement device 20, lead-out electrodes 34, switch 40, and biopotential measurement device 50 are included in the measurement device 3 in FIG. Data recording device 60 is included in data recording server 42 of FIG. Note that the data recording system 2 may include only the switch 40 , the biopotential measuring device 50 and the data recording device 60 .

The stimulation unit 10 applies electrical stimulation, magnetic stimulation, or mechanical stimulation to the living body P. Thereby, the evoked potential generated from the living body P in response to stimulation can be measured by the biopotential measuring device 50, and the induced magnetic field generated from the living body P in response to stimulation can be measured by the biomagnetic field measuring device 20. . For example, the stimulation section 10 may apply stimulation to the living body P in response to a synchronization signal generated by the measuring device 3 .

By applying stimulation to the living body P from the stimulation unit 10 in response to the synchronization signal generated by the measuring device 3, the application timing of the stimulation and the turn-on timing of the switch 40 can be synchronized. As a result, when measuring the induced magnetic field with the biomagnetic field measuring device 20, as will be described later, it is possible to extract the biomagnetic field data with little magnetic field noise measured while the switch 40 is off. Data processing can be made more efficient.

The biosignal measurement system 1 may measure the biopotential and biomagnetic field spontaneously generated by the living body P by using the measurement device 3 instead of having the stimulation device 5 shown in FIG. 1 .

The biomagnetic field measurement device 20 uses a sensor to measure a weak biomagnetic field that is generated in association with muscle or nerve activity that is induced in response to a stimulus. For example, the biomagnetic field measuring device 20 shown in FIG. 2 is a magnetoencephalograph that measures a magnetic field generated by electrical activity of nerve cells in the brain.

The body magnetic field measurement device 20 measures or calculates the time (latency) from the application of a stimulus to the appearance of a response waveform, the amplitude of the response waveform, their distribution, and the like. The biomagnetic field measurement device 20 stores magnetic field data and the like obtained by measurement or calculation in the data recording device 60 . A SQUID, for example, is used as a sensor used for measuring a magnetic field by the biomagnetic field measuring device 20 .

The biopotential measuring device 50 measures the biopotential generated with the activity of muscles and nerves induced in response to a stimulus as a potential difference between a pair of lead-out electrodes 34 attached to the living body P, and the potential obtained by the measurement. Data and the like are stored in the data recording device 60 . In this embodiment, the biopotential measuring device 50 is connected to the pair of lead-out electrodes 34 via the switch 40, and when measuring the potential difference between the pair of lead-out electrodes 34, the switch 40 is in the ON state (electrical connection state).

A switch 40 is provided corresponding to each of the pair of lead-out electrodes 34 . The switch 40 is turned on (conduction, electrically connected state) or off (interrupted, electrically disconnected state) by a switching signal output from the switch control unit 70 . The switch 40 may output to the data recording device 60 switch information indicating that it is on or off. For example, the switch information may be a level signal whose ON state is high level and whose OFF state is low level. The switch information is an example of information indicating electrical connection timing by the switch 40 .

The biopotential measuring device 50 measures the potential difference of the lead-out electrode 34 for a predetermined period from the application of the stimulus to the living body P by the stimulation unit 10 . The switch 40 is turned on during a predetermined period during which the biopotential measuring device 50 measures the potential difference of the lead-out electrode 34 in response to a switching signal from the switch control section 70, and turned off during other periods. That is, the switch 40 is turned on only when the biopotential measuring device 50 measures the evoked potential. In this manner, the data recording system 2 controls the biomagnetic field measuring device 20, the biopotential measuring device 50, the stimulation section 10, and the switch 40 in synchronization with each other.

The data recording device 60 has a switch control section 70 and an averaging processing section 80 . The data recording device 60 stores biomagnetic field data measured by the biomagnetic field measurement device 20, established potential data measured by the biopotential measurement device 50, and switch information indicating the on/off state of the switch 40 based on the switch information. are stored in association with the time. As will be described later, the data recording device 60 does not store the biomagnetic field measurement data during the ON period of the switch 40, so the memory capacity for storing the biomagnetic field measurement data can be reduced. The data recording device 60 is an example of a processing unit that acquires electrical connection timing from the switch 40 and processes magnetic field measurement data from the biomagnetic field measurement device 20 operating together with the biopotential measurement device 50 .

The switch control unit 70 operates under the control of the data recording device 60, for example. The switch control unit 70 generates a switching signal for turning on the switch 40 when the biopotential measuring device 50 measures the biopotential, and generates a switching signal for turning off the switch 40 while the biopotential measuring device 50 does not measure the biopotential. do.

The data recording device 60 may cause the switch control section 70 to generate the switching signal based on the timing of application of stimulation to the living body P by the stimulation section 10 . In this case, for example, the data recording device 60 receives the synchronizing signal output by the measuring device 3 to the stimulation unit or information indicating the output timing of the synchronizing signal. Thereby, the application timing of stimulation to the living body P by the stimulation unit 10 and the ON timing of the switch can be synchronized with each other.

By providing the switch 40 and the switch control unit 70 in the data recording system 2, for example, the length of the signal line for transmitting the switching signal to the switch 40 can be shortened, and the operability and controllability of the switch 40 can be improved. can be done. For example, the shorter the signal line length of the switching signal, the shorter the time lag from the output of the switching signal by the switch control unit 70 to the switching of the switch 40, and the higher the switching accuracy of the switch 40.

Since the switch control unit 70 is provided in the data recording device 60 , the data recording device 60 can recognize the switching timing of the switch 40 . Therefore, the data recording device 60 may recognize the state of the switch 40 without receiving switch information from the switch 40. In this case, a signal line for transmitting switch information from the switch 40 to the data recording device 60 is unnecessary. can be

The averaging processing unit 80 performs a process of averaging the biomagnetic data measured by the biomagnetic field measurement device 20 to reduce the influence of noise. As will be described later, the biomagnetic field data averaged by the averaging processor 80 is data in which the magnetic field noise caused by the current flowing between the lead-out electrode 34 and the biopotential measuring device 50 is reduced. Therefore, the averaging process can further reduce noise contained in the biomagnetic field data. Note that the averaging processing unit 80 may be provided outside the data recording device 60 or outside the data recording system 2 .

The biopotential measuring device 50 measures the time (latency) from the application of the stimulus to the appearance of the response waveform and the amplitude of the response waveform. The amplitude of the measured response waveform is used as an index for testing. For example, test methods using the biopotential measuring device 50 include a motor-evoked potential test (MEP; Motor-Evoked Potentials), a somatosensory-evoked potential test (SEP; Somatosensory-Evoked Potentials; SEP), a nerve conduction test (NCS; Nerve Conduction Studies) are known.

In general, the biomagnetic field is very weak compared to the environmental magnetic field such as geomagnetism, so the biomagnetic field measurement is usually performed in a magnetic shield room that shields the environmental magnetic field. It is also known that the strength of a magnetic field is generally inversely proportional to the square of the distance from the magnetic field source. In order to improve the detection strength and detection accuracy of the magnetic field, the sensor of the biomagnetic field measurement device 20 is arranged near the living body P, which is the subject (it is desirable that the sensor and the living body P are in close contact).

As a result, the sensor of the biomagnetic field measuring device 20 is arranged at a position close to the lead-out electrode 34, and various noises generated along with the operation of the biopotential measuring device 50 are not given to the biomagnetic field measuring device 20. become. For example, distant radiation noise may be drawn into the vicinity of the biomagnetic field measurement device 20 . This is because the lead-out electrode 34 functions as an antenna, receives electromagnetic waves propagating in space, and generates current.

In addition, noise may be drawn into the vicinity of the biomagnetic field measurement device 20 due to the power supply and amplifier of the biopotential measurement device 50 . Furthermore, when the signal of the potential difference received by the lead-out electrode 34 is transmitted to the biopotential measurement device 50, the magnetic field generated by the current along the lead wire from the lead-out electrode 34 may become noise.

Noise unfavorable to the biomagnetic field measuring device 20 is likely to occur when the biopotential measuring device 50 measures the potential difference with the switch 40 set to the ON state. In this embodiment, by electrically disconnecting the lead-out electrode 34 and the biopotential measuring device 50 by the switch 40, noise caused by the operation of the biopotential measuring device 50 can be reduced. In addition, the data recording device 60 detects whether the switch 40 is on or off to determine whether noise is likely to occur when the switch 40 is on and when the switch 40 is off so that noise is less likely to occur. period can be determined.

For example, the biomagnetic field measurement device 20 may recognize the application timing of stimulation to the living body P by the stimulation unit 10 . Thereby, the stimulation application timing, the ON/OFF timing of the switch 40, and the operation of the biomagnetic field measuring device 20 can be synchronized with each other. Furthermore, the biopotential measuring device 50 may recognize the timing of applying stimulation to the living body P by the stimulation section 10 . Thereby, the stimulation application timing, the ON/OFF timing of the switch 40, the operation of the biomagnetic field measurement device 20, and the operation of the biopotential measurement device 50 can be synchronized with each other.

FIG. 3 is a diagram showing an example of the hardware configuration of the data recording device 60 of FIG. The data recording device 60 is, for example, an information processing device, and includes a CPU (Central Processing Unit: processor) 61, a RAM (Random Access Memory) 62, a ROM (Read Only Memory) 63, an auxiliary storage device 64, an input/output interface 65, and a display device 66 , which are interconnected by a bus 67 .

The CPU 61 controls the overall operation of the data recording device 60 and performs various types of information processing. The CPU 61 executes a data recording program stored in the ROM 63 or the auxiliary storage device 64 to process measurement data measured by the biomagnetic field measurement device 20 and the biopotential measurement device 50 . The RAM 62 is used as a work area for the CPU 61 and may include a non-volatile RAM that stores main control parameters and information. The ROM 63 stores various programs and parameters used by the various programs. The data recording program of the present invention may also be stored in ROM 63 . The auxiliary storage device 64 is a storage device such as an SSD (Solid State Drive) or HDD (Hard Disk Drive). Various data, files, etc. required for the operation of the device 60 are stored.

The input/output interface 65 includes both a user interface such as a touch panel, a keyboard, a display screen, and operation buttons, and a communication interface that takes in information from various sensors or the data recording server 42 and outputs analysis information to other electronic devices. . Display device 66 corresponds to monitor display 26 of information display system 22 of FIG. The waveform of the data measured by the biomagnetic field measuring device 20 and the biopotential measuring device 50 is displayed on the display device 66 .

FIG. 4 is a diagram showing an example of processing the biomagnetic field measurement data measured by the biomagnetic field measuring device 20 of FIG. In FIG. 4 , processing of the biomagnetic field measurement data by the data recording device 60 is performed while the biomagnetic field is being measured by the biomagnetic field measurement device 20 . In FIG. 4, description of biopotential measurement data is omitted.

When the biomagnetic field measurement data is processed while the biomagnetic field is being measured by the biomagnetic field measuring device 20, the data recording device 60 stores the biomagnetic field measurement data from the biomagnetic field measuring device 20 as well as the switch information and the biopotential measuring device 50. of biopotential measurement data are received sequentially. The data recording device 60 may acquire the timing information of the synchronization signal for controlling the stimulation section 10 together with the switch information, the biomagnetic field measurement data, and the biopotential measurement data.

Based on the switch information, the data recording device 60 extracts (thin-outs) the biomagnetic field measurement data during the period when the switch 40 is off, and stores the extracted biomagnetic field measurement data in the RAM 62 (FIG. 3) of the data recording device 60 or the auxiliary storage. Stored in a storage device such as device 64 (FIG. 3). The data recording device 60 may store the time information indicating the measurement time of the biomagnetic field measurement data in the storage device together with the biomagnetic field measurement data after thinning.

As a result, the data recording device 60 can acquire biomagnetic field measurement data with little magnetic field noise, excluding the biomagnetic field measurement data containing magnetic field noise while the switch 40 is on. Note that the data recording device 60 may detect the ON/OFF state of the switch 40 by using a switching signal for switching ON/OFF of the switch 40 instead of the switch information.

The data recording device 60 averages the extracted biomagnetic field measurement data. As a result, the influence of noise contained in biomagnetic field measurement data in which magnetic field noise has been reduced can be further reduced. When the biomagnetic field data measured by the biomagnetic field measurement device 20 is averaged, it is preferable that the stimulus application timing to the living body P by the stimulation device 10 is matched with the off timing of the switch 40 . Further, when averaging biopotential data measured by the bioelectricity measuring device 50 , it is preferable that the stimulus application timing to the living body P by the stimulation device 10 is matched with the ON timing of the switch 40 .

By the way, the period in which the switch 40 is on is the period during which the biopotential is measured by the biopotential measuring device 50 . That is, the period during which the switch 40 is on is the period during which the potential difference of the lead-out electrode 34 is transmitted to the biopotential measuring device 50, and the current flowing between the lead-out electrode 34 and the biopotential measuring device 50 during the transmission of the potential difference causes Magnetic field noise may occur. If the biomagnetic field measurement device 20 measures the biomagnetic field together with the magnetic field noise, correct biomagnetic field measurement data cannot be obtained.

FIG. 5 is a flowchart showing an example of processing for extracting effective biomagnetic field measurement data by the data recording system 2 of FIG. That is, FIG. 5 shows an example of a data recording method by the data recording system 2 and a data recording program for causing the data recording system 2 to perform recording processing. Similar to FIG. 4, FIG. 5 shows an example in which biomagnetic field measurement data is processed while the biomagnetic field measurement device 20 is measuring the biomagnetic field. For example, the flow shown in FIG. 5 is realized by the CPU 61 (FIG. 3) of the data recording device 60 included in the data recording system 2 executing the data recording program.

First, in step S10, the data recording device 60 receives biomagnetic field measurement data and switch information indicating the state of the switch 40 each time the biomagnetic field measurement device 20 measures biomagnetic field measurement data.

Next, in step S12, the data recording device 60 determines whether or not the switch 40 is in the OFF state based on the received switch information. When the switch 40 is off, the data recording device 60 shifts the process to step S14. When the switch 40 is on, the data recording device 60 returns the process to step S10 to receive the next biomagnetic field measurement data and switch information.

In step S14, the data recording device 60 stores the biomagnetic field measurement data received in step S10 in a storage device such as the RAM 62 or the like. That is, the data recording device 60 extracts the biomagnetic field measurement data received when the switch 40 is off as valid data.

Next, in step S16, the data recording device 60 ends the processing when the biomagnetic field measurement device 20 finishes the measurement. On the other hand, if the biomagnetic field measuring device 20 continues measurement, the data recording device 60 returns the process to step S10 to receive the next biomagnetic field measurement data and the information indicating the state of the switch 40 .

FIG. 6 is a diagram showing another example of processing the biomagnetic field measurement data measured by the biomagnetic field measuring device 20 of FIG. In FIG. 6 , processing of the biomagnetic field measurement data by the data recording device 60 is performed after the biomagnetic field is measured by the biomagnetic field measurement device 20 . Also in FIG. 6, description of biopotential measurement data is omitted.

In FIG. 6, the data recording device 60 pre-stores the biomagnetic field measurement data from the biomagnetic field measurement device 20, the switch information, and the biopotential measurement data from the biopotential measurement device 50 together with time information in the storage device. Keep The storage device is the RAM 62 (FIG. 3) of the data recording device 60, the auxiliary storage device 64 (FIG. 3), or the like. In addition to the switch information, the biomagnetic field measurement data, and the biopotential measurement data, the data recording device 60 may store the synchronization signal information for controlling the stimulation section 10 together with the time information in the storage device.

Based on the switch information stored in the storage unit, the data recording device 60 extracts the biomagnetic field measurement data during the period when the switch 40 is on from the storage unit. Then, the data recording device 60 stores the extracted biomagnetic field measurement data (after decimation) in the RAM 62 (FIG. 3) or the auxiliary storage device 64 (FIG. 3) of the data recording device 60 together with time information indicating the measurement time of the biomagnetic field measurement data. 3) Store in a storage device such as . 4, the data recording device 60 can acquire the biomagnetic field measurement data excluding the biomagnetic field measurement data containing the magnetic field noise while the switch 40 is on. After that, the data recording device 60 may average the extracted biomagnetic field measurement data in the same manner as in FIG.

Note that the thinned-out biomagnetic field measurement data may be overwritten on the un-thinned biomagnetic field measurement data. Alternatively, the biomagnetic field measurement data after thinning may be set by setting a valid flag corresponding to the biomagnetic field measurement data before thinning stored in the storage device.

FIG. 7 is a flowchart showing another example of processing for extracting effective biomagnetic field measurement data by the data recording system 2 of FIG. That is, FIG. 7 shows an example of a data recording method by the data recording system 2 and a data recording program for causing the data recording system 2 to perform recording processing. Similar to FIG. 6, FIG. 7 shows an example in which the biomagnetic field measurement data is processed after the biomagnetic field is measured by the biomagnetic field measuring device 20. In FIG.

For example, the flow shown in FIG. 7 is realized by the CPU 61 (FIG. 3) of the data recording device 60 included in the data recording system 2 executing the data recording program. Before the flow of FIG. 7 is started, the biomagnetic field data is measured by the biomagnetic field measurement device 20, and the biomagnetic field measurement data acquired by the measurement is stored in the storage device together with the state of the switch 40. Suppose there is

First, in step S20, the data recording device 60 reads biomagnetic field measurement data and switch information indicating the state of the switch 40 when the biomagnetic field measurement data is acquired from the storage device. For example, the data recording device 60 reads the biomagnetic field measurement data to be processed in order of earliest measurement time.

Next, in step S22, the data recording device 60 determines whether or not the switch 40 is in the OFF state based on the read switch information. If the switch 40 is off, the data recording device 60 shifts the process to step S24. If the switch 40 is in the ON state, the data recording device 60 returns the process to step S20 to read the next biomagnetic field measurement data and the information indicating the state of the switch 40 .

In step S24, the data recording device 60 validates the biomagnetic field measurement data read out in step S20. That is, the data recording device 60 extracts the biomagnetic field measurement data read out corresponding to the switch information indicating that the switch 40 is turned off as valid data. The data recording device 60 may set a valid flag corresponding to valid biomagnetic measurement data stored in the storage device, or transfer the valid biomagnetic measurement data to another storage area such as the RAM 62. good.

Next, in step S26, the data recording device 60 terminates the process when all the biomagnetic field measurement data necessary for the process have been obtained. On the other hand, if the data recording device 60 cannot acquire the biomagnetic field measurement data necessary for processing, the data recording device 60 returns the process to step S20 to read the next biomagnetic field measurement data and the information indicating the state of the switch 40.

FIG. 8 is a diagram for explaining the influence of magnetic field noise on the biomagnetic field measuring device 20 caused by the operation of the biopotential measuring device 50. As shown in FIG. FIG. 8 shows a state in which the living body P is brought into close contact with the sensor portion of the biomagnetic field measuring device 20, and the living body P is not stimulated by the stimulation unit 10, and the magnetic field is measured by the biomagnetic field measuring device 20 in the magnetic shield room. shows an example of the power spectrum distribution when

FIG. 8A shows magnetic field data measured in a state in which the lead-out electrode 34 is not attached to the living body P and the biopotential measuring device 50 is installed outside the magnetically shielded room. FIG. 8B shows magnetic field data measured in a state in which the lead-out electrode 34 is attached to the living body P, the switch 40 is turned on, and the lead-out electrode 34 is connected to the biopotential measuring device 50 installed in the shield room. In FIG. 8B, the amplitude on the high frequency side is higher than in FIG. 8A, and it can be seen that the magnetic field noise is superimposed on the biomagnetic field.

FIG. 8C shows magnetic field data measured with the switch 40 turned off and the connection between the biopotential measuring device 50 installed in the shield room and the lead-out electrode 34 disconnected. It can be seen that magnetic field noise on the high frequency side is reduced in FIG. 8(C) compared to FIG. 8(B) in which the switch 40 is on. That is, by extracting the biomagnetic field data measured by the biomagnetic field measuring device 20 while the switch 40 is off by the data recording device 60, the biomagnetic field measurement data less affected by magnetic field noise can be obtained.

As described above, in the first embodiment, the biomagnetic field data measured by the biomagnetic field measuring device 20 during the period when the switch 40 connecting the lead-out electrode 34 and the biopotential measuring device 50 is on is excluded from the processing target. , the noise contained in the biomagnetic field measurement data can be reduced. That is, it is possible to reduce the influence of noise generated from the measurement environment of the biopotential measurement device such as the lead-out electrodes 34 on the biomagnetic field measurement device 20 . As a result, the biomagnetic field measurement by the biomagnetic field measurement device 20 and the biopotential measurement by the biopotential measurement device 50 can be performed simultaneously with high accuracy while the living body P is kept in the same posture.

Further, by averaging the extracted biomagnetic field measurement data, the effect of noise contained in the biomagnetic field measurement data with reduced magnetic field noise can be further reduced.

By applying stimulation to the living body P by the stimulation unit 10, the evoked potential generated from the living body P in response to the stimulation can be measured by the biopotential measuring device 50, and the induced magnetic field generated from the living body P in response to the stimulation can be measured. It can be measured by the biomagnetic field measuring device 20 .

Further, by applying stimulation to the living body P from the stimulation unit 10 in response to the synchronization signal generated by the measuring device 3, the application timing of the stimulation and the turn-on timing of the switch 40 can be synchronized. As a result, when the induced magnetic field is measured by the biomagnetic field measuring device 20, the biomagnetic field data with little magnetic field noise measured while the switch 40 is off can be extracted, and the data processing of the biomagnetic field data is made efficient. can do.

FIG. 9 is a block diagram showing an example of the functional configuration of the data recording system 2 according to the second embodiment. The data recording system 2 is included in the biological signal measurement system 1 shown in FIG. In the data recording system 2 shown in FIG. 9 , the switch control section 70 is arranged in the biopotential measuring device 50 , and the data recording device 60 does not have the switch control section 70 . Other configurations of the data recording system 2 are the same as those of the data recording system 2 shown in FIG.

Since the switch control unit 70 is inside the measuring device 3, the length of the signal line for transmitting the switching signal to the switch 40 can be made shorter than in FIG. can. For example, the time lag from when the switch control unit 70 outputs the switching signal to when the switch 40 switches can be further shortened, and the switching accuracy of the switch 40 can be improved.

As described above, the same effect as in the first embodiment can be obtained in the second embodiment.

In the above-described embodiment, an example was described in which noise was removed from biomagnetic field data measured by a magnetoencephalograph such as MEG. Noise may be removed from the data. Here, the magnetocardiograph measures the magnetic field generated by the electrical activity of the myocardium. A magnetometer measures the magnetic fields generated in the spinal cord and spinal nerves (cervical and lumbar). A magnetomyograph measures the magnetic field generated by the electrical activity of muscles.

Although the present invention has been described above based on each embodiment, the present invention is not limited to the requirements shown in the above embodiments. These points can be changed within the scope of the present invention, and can be determined appropriately according to the application form.

1 biosignal measurement system 3 measurement device 4 measurement table 5 stimulator 10 stimulator 20 biomagnetic field measurement device 22 information display system 26 monitor display 30 dewar 31 recess 34 derivation electrode 42 data recording server 40 switch 50 biopotential measurement device 60 data recording Device 61 CPU
62 RAMs
63 ROMs
64 auxiliary storage device 65 input/output interface 66 display device 67 bus 70 switch control section 80 averaging processing section P living body

JP 2017-221515 A

Claims (10)

a biopotential measuring device for measuring a potential difference between electrodes attached to a living body;
a switch for electrically connecting the electrode and the biopotential measuring device;
a processing unit that acquires the electrical connection timing of the switch and processes measurement data from a biomagnetic field measuring device that operates together with the biopotential measuring device;
A data acquisition system comprising: The processing unit is
Acquiring the measurement data measured by the biomagnetic field measurement device and switch information indicating the electrical connection timing during measurement of the measurement data by the biomagnetic field measurement device;
2. The data recording system according to claim 1, wherein the measurement data measured when the switch information indicates an OFF state of the switch is extracted as valid measurement data. The processing unit is
After measuring the measurement data by the biomagnetic field measurement device, reading the measurement data and the switch information indicating the electrical connection timing from a storage device;
2. The data recording system according to claim 1, wherein the measurement data read corresponding to the switch information indicating the OFF state of the switch is extracted as valid measurement data. 4. The apparatus according to any one of claims 1 to 3, further comprising an averaging processing unit that performs averaging of measurement data measured by the biomagnetic field measurement device while the switch is disconnected from the electrical connection. or the data recording system according to item 1. 5. The data recording system according to any one of claims 1 to 4, further comprising a switch control section for controlling electrical connection of said switch. A stimulation device that applies stimulation to the living body,
6. The data recording system according to any one of claims 1 to 5, wherein the electrical connection of the switch and the application of stimulation to the living body by the stimulator are performed in synchronization. 7. The data recording according to claim 6, wherein the electrical connection of the switch, the application of stimulation to the living body by the stimulator, and the measurement of the biomagnetic field by the biomagnetic field measurement device are performed synchronously. system. The electrical connection of the switch, the application of stimulation to the living body by the stimulation device, the measurement of the biomagnetic field by the biomagnetic field measurement device, and the measurement of the biopotential by the biopotential measurement device are performed in synchronization. 7. The data acquisition system of claim 6, characterized by: A data recording method using a data recording system comprising a biopotential measuring device for measuring a potential difference between electrodes attached to a living body and a switch for electrically connecting the electrodes and the biopotential measuring device,
Acquiring the electrical connection timing by the switch,
A data recording method, comprising: processing data measured by a biomagnetic field measurement device that operates together with the biopotential measurement device, based on the acquired electrical connection timing. A data recording program that causes a data recording system comprising a biopotential measuring device for measuring a potential difference between electrodes attached to a living body and a switch for electrically connecting the electrodes and the biopotential measuring device to process data. There is
In the data acquisition system,
Acquiring the electrical connection timing by the switch,
A data recording program characterized by processing data measured by a biomagnetic field measuring device operating together with the biopotential measuring device based on the acquired electrical connection timing.

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