JP2021069930A - Dipole group digitizing method and dipole group display system - Google Patents

Abstract

To present a spatial extent of a dipole group and variation in dipole direction.SOLUTION: A dipole group digitizing method includes a step of quantifying a dipole group on the basis of each position of dipoles that are signal sources.SELECTED DRAWING: Figure 5

Description

The present invention relates to a dipole group quantification method and a dipole group display system.

Conventionally, when the magnetoencephalogram is used for the purpose of clinical examination, the equivalent current dipole method is used. In the equivalent current dipole method, the current source (dipole) that produces the magnetic field measured on the scalp is estimated. Physicians determine the localization of epileptic lesions by clinically analyzing multiple current sources (dipoles).

Patent Document 1 discloses a technique for calculating a region in which an estimated solution of a current source (dipole) is statistically reliable for the purpose of evaluating the reliability of an estimated current source (dipole).

According to the technique disclosed in Patent Document 1, it is possible to estimate and display the position and orientation of a current source (dipole) from a plurality of characteristic waveform information (IED: Interictal Epileptiform Discharge). However, according to the technique disclosed in Patent Document 1, there is a problem that the relationship between a plurality of current sources (dipoles) and an epileptic lesion cannot be quantitatively quantified and displayed.

In addition, doctors need to manually measure the spatial spread of multiple displayed current sources (dipoles) and the variation in the orientation of the dipoles, which is a problem that they are forced to perform extremely complicated work. ..

The present invention has been made in view of the above, and an object of the present invention is to present a spatial spread of a dipole group and variations in the orientation of dipoles.

In order to solve the above-mentioned problems and achieve the object, the dipole group quantification method of the present invention is characterized by including a step of quantifying a dipole group based on each position of a dipole as a signal source. And.

According to the present invention, it is possible to exhibit the spatial spread of the dipole group and the variation in the orientation of the dipoles.

FIG. 1 is a schematic view showing the configuration of the biological signal measurement system according to the first embodiment. FIG. 2 is a block diagram schematically showing the functional configuration of the server. FIG. 3 is a diagram showing an example of the hardware configuration of the information processing device. FIG. 4 is a diagram showing an example of a functional block configuration of the information processing device. FIG. 5 is a flowchart showing the flow of the dipole group digitization process. FIG. 6 is a diagram showing a display example of a quantitative evaluation index of the dipole group. FIG. 7 is a diagram showing a display example of a quantitative evaluation index of the dipole group. FIG. 8 is a diagram showing a display example of a polygon including a dipole group. FIG. 9 is a diagram showing a display example of a polygon including a dipole group. FIG. 10 is a diagram showing a display example of quantifying and quantifying the orientation of the dipole. FIG. 11 is a diagram showing a display example of quantifying and quantifying the orientation of the dipole. FIG. 12 is a flowchart showing the flow of the dipole group digitization process when the spatial filter method is used. FIG. 13 is a diagram showing an example of a plurality of dipoles calculated by using the spatial filter method. FIG. 14 is a diagram showing a quantitative quantification method using the probability density distribution of the dipole group according to the second embodiment and a display example (single display) thereof. FIG. 15 is a diagram showing a quantitative quantification method using the probability density distribution of the dipole group according to the second embodiment and a display example (shading display) thereof.

A method for quantifying a dipole group and an embodiment of a dipole group display system will be described in detail with reference to the accompanying drawings.

(First Embodiment)
This embodiment has the following features in evaluating the relationship between a plurality of current sources (dipoles) in the diagnosis of epilepsy localization and an epilepsy lesion. In short, the present embodiment is characterized in that a plurality of embodiments are quantified, and the obtained numerical values are visualized (for example, graphically) and presented to provide a material for determining whether or not epilepsy is surgically possible.

(Outline of biological signal measurement system)
FIG. 1 is a schematic view showing the configuration of the biological signal measurement system 1 according to the first embodiment. The outline of the biological signal measurement system 1 according to the present embodiment will be described with reference to FIG.

The biological signal measurement system 1 that functions as a dipole group display system includes a plurality of types of biological signals (for example, MEG: Magnetoencephalography) signals and electroencephalograms (for example) of a subject from a specific source (biological site). EEG: Electro-encephalography) A system that measures and displays signals. In the present invention, the biological signals to be measured are not limited to magnetoencephalography signals and electroencephalogram signals, for example, for cardiac activity. It may be an electric signal (an electric signal that can be expressed as an electrocardiogram) or the like that is generated accordingly.

As shown in FIG. 1, the biological signal measurement system 1 includes a measuring device 3 that measures one or more biological signals of a subject, and a server 40 that records one or more types of biological signals measured by the measuring device 3. The information processing device 50, which is a biological signal display device for analyzing one or more types of biological signals recorded on the server 40, is included. The measuring device 3 is a magnetoencephalograph that collects measured values such as a cerebral magnetic field and a timing at which a stimulus is applied. Although the server 40 and the information processing device 50 are shown separately in FIG. 1, for example, at least a part of the functions of the server 40 may be incorporated in the information processing device 50.

In the example of FIG. 1, the subject (measurement subject) lies on his / her back on the measurement table 4 with an electrode (or sensor) for measuring brain waves attached to his / her head, and lie in the recess 32 of the duwa 31 of the measurement device 3. Insert the head. The Duwa 31 is a container for holding an extremely low temperature environment using liquid helium, and a large number of magnetic sensors for measuring magnetoencephalography are arranged inside the recess 32 of the Duwa 31. The measuring device 3 collects the electroencephalogram signal from the electrode and the electroencephalogram signal from the magnetic sensor, and collects the collected electroencephalogram signal and the data including the electroencephalogram signal (hereinafter, may be referred to as "measurement data") as a server. Output to 40. The measurement data output to the server 40 is read out by the information processing device 50, displayed, and analyzed.

Generally, the dewar 31 and the measurement table 4 incorporating the magnetic sensor are arranged in the magnetic shield room, but the magnetic shield room is not shown in FIG. 1 for convenience.

The information processing device 50 is a device that displays waveform data of electroencephalogram signals from a plurality of magnetic sensors and waveform data of electroencephalogram signals from a plurality of electrodes in synchronization on the same time axis. The electroencephalogram signal is a signal that represents the electrical activity of nerve cells (the flow of ionic charges that occur in the dendrites of neurons during synaptic transmission) as a voltage value between electrodes. The magnetoencephalographic signal is a signal representing a minute electric field fluctuation generated by the electrical activity of the brain. The brain magnetic field is detected by a highly sensitive Superconducting Quantum Interference Device (SQUID) sensor. These electroencephalogram signals and magnetoencephalogram signals are examples of "biological signals".

Here, FIG. 2 is a block diagram schematically showing the functional configuration of the server 40. As shown in FIG. 2, the server 40 has a data acquisition unit 41 and a data storage unit 42.

The data acquisition unit 41 periodically acquires measurement data from the measuring device 3. Here, the measurement data is individual waveform data measured by a plurality of magnetic sensors of the Duwa 31 of the measuring device 3.

In addition, the data acquisition unit 41 includes quantitative evaluation indexes such as the spatial spread (cohesion) of the dipole group processed by the dipole group digitization process in the information processing device 50 described later, the presence or absence of surgery, the postoperative course, and the like. Obtain in relation to surgical information.

The data storage unit 42 stores the measurement data acquired from the measuring device 3. In addition, the data storage unit 42 includes quantitative evaluation indexes such as the spatial spread (aggregation degree) of the dipole group processed by the dipole group digitization process in the information processing device 50, and surgery such as the presence or absence of surgery and the postoperative course. A database (episode DB) 43 that describes the relationship with information is stored.

(Hardware configuration of information processing device)
FIG. 3 is a diagram showing an example of the hardware configuration of the information processing device 50. The hardware configuration of the information processing apparatus 50 will be described with reference to FIG.

As shown in FIG. 3, the information processing device 50 includes a CPU (Central Processing Unit) 101, a RAM (Random Access Memory) 102, a ROM (Read Only Memory) 103, an auxiliary storage device 104, and a network I / F 105. And an input device 106 and a display device 107, which are connected to each other by a bus 108.

The CPU 101 is an arithmetic unit that controls the overall operation of the information processing device 50 and performs various types of information processing. The CPU 101 executes an information display program stored in the ROM 103 or the auxiliary storage device 104 to control the display operation of the measurement collection screen and the analysis screen.

The RAM 102 is a volatile storage device used as a work area of the CPU 101 and stores main control parameters and information. The ROM 103 is a non-volatile storage device that stores basic input / output programs and the like. For example, the above-mentioned information display program may be stored in the ROM 103.

The auxiliary storage device 104 is a storage device such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive). The auxiliary storage device 104 stores, for example, a control program that controls the operation of the information processing device 50, various data and files necessary for the operation of the information processing device 50, and the like.

The network I / F 105 is a communication interface for communicating with devices on the network such as the server 40. The network I / F 105 is realized by, for example, a NIC (Network Interface Card) compliant with TCP (Transmission Control Protocol) / IP (Internet Protocol).

The input device 106 is an input function of a touch panel, a user interface such as a keyboard, a mouse, and operation buttons. The display device 107 is a display device that displays various types of information. The display device 107 is, for example, a display unit realized by a touch panel display function, a liquid crystal display (LCD), an organic EL (Electro-Luminescence), or the like. The display device 107 displays the measurement collection screen and the analysis screen, and the screen is updated according to the input / output operation via the input device 106.

The hardware configuration of the information processing device 50 shown in FIG. 3 is an example, and other devices may be provided. Further, the information processing device 50 shown in FIG. 3 has, for example, a hardware configuration assuming a PC (Personal Computer), but is not limited to this, and may be a mobile terminal such as a tablet. In this case, the network I / F 105 may be a communication interface having a wireless communication function.

(Functional block configuration of information processing device)
FIG. 4 is a diagram showing an example of a functional block configuration of the information processing device 50. The functional block configuration of the information processing apparatus 50 will be described with reference to FIG.

As shown in FIG. 4, the information processing apparatus 50 includes a search means 501, an estimation means 502, a generation means 503, an analysis means 504, a calculation means 505, and a display means 506.

The search means 501 acquires individual waveform data measured by a plurality of magnetic sensors of the duwa 31 of the measuring device 3 from the data storage unit 42 of the server 40. The search means 501 searches for waveform information (IED: Interictal Epileptiform Discharge) characteristic of epilepsy from individual waveform data measured by a plurality of magnetic sensors.

The estimation means 502 estimates a dipole (signal source), which is a current source that generates a magnetic field, at the time of the searched characteristic waveform information (see Non-Patent Document 1).

The generation means 503 evaluates the dipole estimation result in the estimation means 502 to generate a dipole group. The evaluation at this time is that the dipole is estimated outside the brain, the calculated dipole reliability (GOF: Goodness Of Fit value or CV: Confidence Volume value) is low, or the dipole's evaluation. This is performed to exclude dipole outliers that are not subject to evaluation in conventional clinical diagnosis when estimating a dipole such as too high / too low intensity (see Non-Patent Document 8).

The analysis means 504 cluster-analyzes the dipole group generated by the generation means 503.

Further, the analysis means 504 can also apply post-processing that excludes outliers after performing cluster analysis. For example, when an algorithm called k-means ++ (see Non-Patent Document 6) is used, the confidence interval is calculated using the calculated standard deviation of the dipole group, and the dipoles that do not fit within a certain confidence interval are set as outliers. By doing so, it is possible to exclude dipoles that are outliers. Outliers refer to those that do not form a group among the obtained dipoles.

Analytical means 504 may also use algorithms that include outlier removal. By using a method that can consider outliers such as DBSCAN (see Non-Patent Document 7), the dipoles that form the group and the dipoles that are the outliers can be separated in the clustering.

The calculation means 505 calculates a quantitative evaluation index of the dipole group according to the cluster analysis by the analysis means 504.

Here, the calculation of the quantitative evaluation index of the dipole group in the calculation means 505 will be described in detail. Generally, the calculation means 505 converts a group of dipoles into quantitative values such as volume and angle dispersion based on the respective positions of the dipoles as signal sources and the respective orientations of the dipoles. Represent and quantify.

The calculation means 505 calculates one or more of the following parameters in order to quantitatively evaluate the spatial spread of the dipole.
・ Volume of polyhedron containing multiple dipoles ・ Volume of ellipsoid containing multiple dipoles ・ Average distance from the center of gravity of multiple dipoles to each dipole ・ Standard deviation of the distance from the center of gravity of multiple dipoles to each dipole

Further, the calculation means 505 uses the following parameters in order to quantitatively evaluate the anisotropy of the dipole.
・ Standard deviation of orientation of multiple dipoles

The display means 506 displays the quantitative evaluation index of the dipole group on the display device 107 together with the spatial information represented by the index.

Next, the flow of the dipole group digitization process will be described.

Here, FIG. 5 is a flowchart showing the flow of the dipole group digitization process. Prior to the process, the measuring device 3 performs magnetoencephalography measurement and outputs individual waveform data measured by the plurality of magnetic sensors of the Duwa 31 to the server 40. The server 40 stores individual waveform data measured by a plurality of magnetic sensors of the duwa 31 of the measuring device 3 in the data storage unit 42.

Then, as shown in FIG. 5, first, the search means 501 acquires individual waveform data measured by the plurality of magnetic sensors of the Duwa 31 of the measuring device 3 from the data storage unit 42 of the server 40 (step S1).

Next, the search means 501 searches for waveform information characteristic of epilepsy called IED from individual waveform data measured by a plurality of magnetic sensors (step S2).

Next, the estimation means 502 estimates the dipole, which is a current source that generates a magnetic field, at the time of the searched characteristic waveform information (step S3), and calculates the location in the brain where the IED is generated.

Next, the generation means 503 evaluates the dipole estimation result in the estimation means 502 to generate a dipole group. Specifically, the generation means 503 selects dipoles such as those whose dipoles are estimated to be outside the brain and those whose calculated dipole reliability (GOF: Goodness Of Fit) is low. (Step S4), it is determined whether the number of dipoles has reached the specified number (for example, X), or whether the search has been completed for the entire measurement section, and if not reached, or the entire measurement section. If the search has not been completed, the process returns to step S2 and the process is performed again (No in step S5).

On the other hand, when the number of dipoles reaches a specified number, or when the search for the entire measurement section is completed (Yes in step S5), the analysis means 504 clusters the dipole group generated by the generation means 503. (Clustering) (step S6). Such cluster analysis is performed to separate epileptic lesions of the type with multiple lesions.

Then, the calculation means 505 calculates a quantitative evaluation index such as the spatial spread (cohesion degree) of the dipole group obtained in response to the cluster analysis by the analysis means 504 (step S7).

By executing the processes of steps S1 to S7 in the CPU 101 of the information processing apparatus 50, it is possible to perform the processes that the doctors have manually performed individually at one time in a fully automatic manner. Become.

It should be noted that each process up to this point can be processed in the same manner by using machine learning or the like or by manually inputting by a doctor.

Next, the display means 506 displays the quantitative evaluation index calculated in step S7 on the display device 107 together with the surgical information obtained by referring to the information of the epilepsy DB 43 stored in the data storage unit 42 of the server 40 (step S8). ).

As a result, it is possible to support the doctor's diagnosis by providing the doctor with a judgment material for surgery. In addition, by quantitatively comparing with past data, it is possible to provide similar cases that can be used as a reference for treatment policy.

Here, FIGS. 6 and 7 are diagrams showing a display example of the quantitative evaluation index of the dipole group. FIG. 6 shows a display example displayed three-dimensionally, and FIG. 7 shows a display example displayed two-dimensionally. If the quantitative value of the dipole group is the standard deviation of the orientation, the display means 506 displays the orientation in three dimensions or two dimensions. As shown in FIGS. 6 and 7, it is possible to quantify the spatial extent (aggregation degree) of the dipole group as the volume of the ellipsoid and display the ellipsoid in the three-dimensional space or the two-dimensional space. is there.

In addition, these displays shall be superimposed on an anatomical image such as MRI. By superimposing the spatial arrangement of the dipole group on the anatomical image, it becomes possible to more intuitively consider the relationship between the multiple dipoles and the epileptic lesion.

By displaying in this way, the doctor can more intuitively recognize the localization of the dipole group. In addition, when explaining to the patient, it is more persuasive to explain using the visualization function.

Although the above has been described with the example of a magnetoencephalograph, the present invention is not limited to this, and the present invention can also be applied to an electroencephalograph.

As described above, according to the present embodiment, the doctor can quantify and display the spatial spread of the plurality of dipoles and the variation in the direction that has been sensuously judged by the doctor by the computer. Since it is possible to more accurately consider the relationship between the epileptic lesion and multiple dipoles, the doctor can more accurately diagnose the localization of the epileptic lesion, which is one of the criteria for determining the feasibility of surgery.

The calculation example of the quantitative evaluation index of the dipole group in the calculation means 505 is not limited to the above. Hereinafter, other calculation examples will be described.

8 to 11 are diagrams showing other calculation methods of the quantitative evaluation index of the dipole group in the calculation means 505. In FIGS. 8 to 11, the calculation is performed in two dimensions for the sake of simplicity, but it is actually three-dimensional.

8 and 9 are diagrams showing a display example of a polygon including a dipole group. 8 and 9 show the polygons included in the estimated coordinates of the dipole. The left side of FIGS. 8 and 9 is a plot of the coordinates of the dipole group with respect to the entire brain image, and the right side of FIGS. 8 and 9 is an enlarged display showing a polygon. The area of this polygon is one index showing the spatial extent of the dipole group. FIG. 8 shows a case where the degree of cohesion of the dipole is high, and FIG. 9 shows a case where the degree of cohesion of the dipole is low.

The smallest polygon containing a point cloud is called a convex hull, and can be obtained by using a gift wrapping method (Non-Patent Document 1), a QuickHull method (Non-Patent Document 2), or the like. Once the convex hull is determined, the area of the convex hull is determined by obtaining the number of pixels inside and the size of the pixels of the MRI image.

In FIG. 9, since the cohesiveness of the dipole group is lower than that in FIG. 8, the range to be excised at the time of surgery may be large.

Next, FIGS. 10 and 11 are diagrams showing a display example of quantifying and quantifying the orientation of the dipole. FIG. 10 shows a case where the dipole orientations are the same, and FIG. 11 shows a case where the dipole orientations are different. Since the dipole shown in FIG. 10 has a high variation in orientation as compared with FIG. 11, a complicated epileptic lesion is recalled. If the orientation variation is small, it can be assumed that the epilepsy has a single lesion.

In the present embodiment, the estimation means 502 estimates a single dipole (signal source), but the present invention is not limited to this. In addition to the method of estimating a single dipole, the estimation means 502 can be used as a current source analysis method by a spatial filter method such as the minimum norm method (see Non-Patent Document 4) and the LCMV Beamformer method (see Non-Patent Document 5). Can also be applied.

The spatial filter method is a method in which tens of thousands of dipoles are arranged in the brain in advance, and the change over time of the current in each dipole can be obtained. For example, the brain as 15cm cube of cubes, 3375 pieces of dipoles in which the 15 ³ sets the current source for each axis 1cm is calculated. Here, it is set as a cube, but it can also be arranged in a spherical shape. Alternatively, a method of arranging the signal source according to the actual shape of the brain may be used.

Here, FIG. 12 is a flowchart showing the flow of the dipole group digitization process when the spatial filter method is used. Since steps S1 to S2 and steps S6 to S8 shown in FIG. 12 are the same as those in FIG. 5, the description thereof will be omitted.

The estimation means 502 estimates the dipole (signal source) by the spatial filter method at the time of the characteristic waveform information searched in step S2 (step S11). The estimation means 502 can obtain the current intensity of each dipole arranged in the brain in advance by using a signal source estimation method using a spatial filter such as the minimum norm method or the sLORETA method.

Next, the estimation means 502 registers the dipole (signal source) obtained in step S11 (step S12).

Next, the estimation means 502 determines whether or not the specified number of IEDs has been calculated (step S13). When the estimation means 502 completes the registration of dipoles for the number of predetermined IEDs (for example, 20) or the search for the entire measurement section (Yes in step S13), the following The process proceeds to step S14. On the other hand, when the estimation means 502 has not completed the registration of dipoles for a predetermined number of IEDs (for example, 20), or has not completed the search for the entire measurement section (step S13). No), the process returns to step S2.

Next, the estimation means 502 aggregates the registered dipoles (signal sources) (step S14), and proceeds to the next step S6. Specifically, the estimation means 502 is likely to be involved in the generation of IED by averaging the current intensities of the dipoles at the same position and extracting only the dipoles having a value equal to or higher than a certain current intensity. Select dipoles. As a dipole aggregation method, in addition to the simple averaging, the same processing can be performed by a weighted averaging with different weights depending on the location of the brain, a method using the median current intensity, or the like.

Here, FIG. 13 is a diagram showing an example of a plurality of dipoles calculated by using the spatial filter method. FIG. 13 shows an example using the minimum norm method. In the example of estimating a single dipole, one dipole can be calculated at a certain time. On the other hand, when the spatial filter method is used, the number of dipoles at a certain time can be calculated by the number of dipoles preset in the brain as shown in FIG.

(Second Embodiment)
Next, the second embodiment will be described.

The second embodiment is different from the first embodiment in that the quantitative evaluation index of the dipole group is calculated using only the position of the dipole which is the signal source. Hereinafter, in the description of the second embodiment, the description of the same part as that of the first embodiment will be omitted, and the parts different from the first embodiment will be described.

Here, the calculation of the quantitative evaluation index of the dipole group in the calculation means 505 according to the second embodiment will be described in detail. Generally, the calculation means 505 expresses the cohesiveness of the dipole group as a quantitative numerical value such as a volume or a distance from the center of gravity based on each position of the dipole which is a signal source.

The calculation means 505 calculates one or more of the following parameters in order to quantitatively evaluate the spatial spread of the dipole.
・ Volume of polyhedron containing multiple dipoles ・ Volume of ellipsoid containing multiple dipoles ・ Average distance from the center of gravity of multiple dipoles to each dipole ・ Standard deviation of the distance from the center of gravity of multiple dipoles to each dipole ・ From multiple dipoles In the calculated probability density distribution, the volume in the range with a density above a certain value

For example, the calculation means 505 calculates the probability density distribution from the coordinates of the dipole group by a statistical method. Then, the calculation means 505 calculates the volume in the range having a density equal to or higher than a certain value in the probability density distribution, and uses it as a quantitative evaluation index of the dipole group.

Here, FIG. 14 is a diagram showing a quantitative quantification method using the probability density distribution of the dipole group according to the second embodiment and a display example (single display) thereof, and FIG. 15 is a diagram showing the second embodiment. It is a figure which shows the quantitative quantification method using the probability density distribution of such a dipole group, and the display example (shading display).

As shown in FIG. 14, the display means 506 colors a range exceeding a certain value and plots it on a brain image. FIG. 14A is a plot of the coordinates of the dipole group. FIG. 14B is a plot of the coordinates of the dipole group and the range obtained from the probability density distribution. In the case of the display shown in FIG. 14, it is possible to quantify the volume in the range where the probability density exceeds a certain value as an index showing the spread.

Further, as shown in FIG. 15, the display means 506 may change the shade of the display color in a range exceeding a certain value according to the calculated probability density distribution. FIG. 15A is a plot of the coordinates of the dipole group. FIG. 15B is a plot of the coordinates of the dipole group and the range obtained from the probability density distribution. As shown in FIG. 15, it is possible not only to quantify but also to visualize the spatial spread of the dipole group in detail by displaying the probability density distribution in shades of color.

As described above, according to the present embodiment, the doctor can quantify and display the spatial spread of the plurality of dipoles and the variation in the direction that has been sensuously judged by the doctor by the computer. Since it is possible to more accurately consider the relationship between the epileptic lesion and multiple dipoles, the doctor can more accurately diagnose the localization of the epileptic lesion, which is one of the criteria for determining the feasibility of surgery.

(Third Embodiment)
Next, a third embodiment will be described.

In the third embodiment, in the second embodiment, the group evaluation is performed using the parameters of the position and orientation of the dipole which is the signal source. Hereinafter, in the description of the third embodiment, the description of the same part as that of the first embodiment or the second embodiment is omitted, and the description is different from the first embodiment or the second embodiment. The part will be described.

The basic device configuration is the same as that of the second embodiment described above. In the second embodiment, the analysis means 504, the calculation means 505, and the display means 506 use only the dipole position information, but in the third embodiment, in addition to the dipole position information. Also use orientation information.

Analytical means 504 performs cluster analysis using parameters of the position and orientation of the dipole that is the signal source. For example, the analysis means 504 uses a six-dimensional parameter in which the three-dimensional inclination of each axis is added to the three-dimensional coordinates of the position of the dipole that is the signal source. The analysis means 504 uses five-dimensional parameters when spherical coordinates are used. The method of cluster analysis is the same as that of the first embodiment, but as an outlier exclusion method, an outlier exclusion method such as excluding a dipole having a deviation of a certain numerical value or more from the main direction of the orientation of a cluster is excluded. Can also be applied.

The calculation means 505 quantitatively evaluates the variation in the orientation of the dipole in addition to quantifying the spatial spread. Specifically, the calculation means 505 calculates the following parameters individually or in plurality.
・ Standard deviation of orientation of multiple dipoles ・ Average vector length of multiple dipoles ・ Average pairwise cosine distance of multiple dipoles

The average vector length of multiple dipoles is obtained by averaging the unit vectors representing the orientation of each dipole. When the directions of the multiple dipoles are aligned, the average vector length approaches 1, and conversely, when the directions are not aligned, it approaches 0.

For the average of the pairwise cosine distances of multiple dipoles, two dipoles are selected from the dipole group and their cosine distances are calculated. Such processing is calculated between all pairs and an average value is obtained. This value approaches 0 when the directions of the multiple dipoles are the same, and approaches 1 when the directions vary.

The display means 506 displays the quantitative evaluation index of the dipole group on the display device 107 together with the spatial information represented by the index.

As described above, according to the present embodiment, the doctor can quantify and display the spatial spread of the plurality of dipoles and the variation in the direction that has been sensuously judged by the doctor by the computer. Since it is possible to more accurately consider the relationship between the epileptic lesion and multiple dipoles, the doctor can more accurately diagnose the localization of the epileptic lesion, which is one of the criteria for determining the feasibility of surgery.

Further, in each of the above-described embodiments, when at least one of the functional units of the biological signal measurement system 1 is realized by executing a program, the program is provided by being incorporated in a ROM or the like in advance. Further, the program executed by the biometric signal measurement system 1 according to each of the above-described embodiments is a file in an installable format or an executable format, and is a CD-ROM, a flexible disc (FD), or a CD-R (Compact Disc Recordable). ), DVD (Digital Versatile Disc), or the like, which may be recorded and provided on a computer-readable recording medium.

Further, the program executed by the biological signal measurement system 1 of each of the above-described embodiments may be stored on a computer connected to a network such as the Internet and provided by downloading via the network. ..

Further, the program executed by the biological signal measurement system 1 of each of the above-described embodiments may be configured to be provided or distributed via a network such as the Internet. Further, the program executed by the biometric signal measurement system 1 of each of the above-described embodiments has a module configuration including at least one of the above-mentioned functional units, and the actual hardware is such that the CPU starts from a ROM or the like. By reading and executing the program, each of the above-mentioned functional units is loaded on the main memory and generated.

1 Display system 43 Database 107 Display unit 501 Search means 502 Estimate means 503 Generation means 504 Analysis means 505 Calculation means 506 Display means

Japanese Patent No. 3111933

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Claims (10)

Including the step of quantifying a group of dipoles based on the respective positions of the dipoles that are the signal source.
A dipole group quantification method characterized by this. The quantifying step further quantifies the dipole group based on the orientation of the dipole.
The dipole group quantification method according to claim 1, wherein the dipole group is quantified. An analysis step for cluster analysis of the dipole group and
A calculation step for calculating a quantitative evaluation index of the dipole group according to the cluster analysis, and
The dipole group quantification method according to claim 1 or 2, wherein the method comprises. Including steps to exclude outliers,
The dipole group quantification method according to any one of claims 1 to 3, wherein the dipole group is quantified. Including the step of quantifying the dipole group based on the density distribution of the dipole group.
The dipole group quantification method according to any one of claims 1 to 4, wherein the dipole group is quantified. A dipole group display system that realizes the dipole group quantification method according to any one of claims 1 to 5.
With multiple sensors
A search means for searching for characteristic waveform information from individual waveform data measured by the plurality of sensors, and
An estimation means for estimating the dipole that is the signal source at the time of the searched characteristic waveform information,
A generation means that evaluates the dipole estimation result and generates a dipole group,
A dipole group display system characterized by being equipped with. Display and
A display means for displaying the quantitative evaluation index of the dipole group on the display unit together with the spatial information represented by the quantitative evaluation index.
The dipole group display system according to claim 6, wherein the dipole group display system is provided. The estimation means estimates the dipole by the spatial filter method.
The dipole group display system according to claim 6 or 7. The generation means selects the dipole estimated by the estimation means.
The dipole group display system according to any one of claims 6 to 8, wherein the dipole group display system is characterized. It also has a database that associates pre-recorded quantitative evaluation indexes of dipole groups with surgical information.
The display means refers to the database and displays the surgical information related to the calculated quantitative evaluation index surgical information of the dipole group on the display unit.
The dipole group display system according to claim 7.

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