JP2009160281A - Brain function site estimation system and method, scalp-shape measuring support apparatus and method, and computer program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately estimate a brain function site corresponding to a signal observation point attached on a subject' scalp when executing a brain measurement experiment using a near-infrared optical imaging apparatus. <P>SOLUTION: This brain function site estimation system includes a three-dimensional position measuring instrument for measuring the shape of the subject's head surface and the signal observation point, and a computer computing three-dimensional position information output from the three-dimensional position measuring instrument. The computer takes a spatial map of the position of the signal point on the subject's head surface on a position of standard brain/head surfaces, estimates the position on the brain surface from the position of the standard brain/head surfaces, and estimates the brain function site from the estimated position of the brain surface. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a brain function site estimation system and a brain function site estimation method, a scalp shape measurement support device and a scalp shape measurement support method, and a computer program that estimate a brain function from a subject's head surface position. Brain function site estimation system, brain function site estimation method, scalp shape measurement support device, scalp shape measurement support method, and computer program for estimating the correspondence between scalp signal observation points and brain functions without using MRI data About.

  More particularly, the present invention relates to a brain function site estimation system, a brain function site estimation method, a scalp shape measurement support device, a scalp shape measurement support method, and a computer program, and in particular, a brain function site estimation system and a brain function site. The present invention relates to an estimation method, a scalp shape measurement support device, a scalp shape measurement support method, and a computer program.

  The state of the human heart is given by brain activity (hereinafter also referred to as “brain function”). In recent years, research to elucidate the mechanism of the brain by biological approaches has been conducted. In order to quantitatively evaluate brain phenomena (emotion, cognition, memory, etc.) caused by stimulation, it is necessary to present the stimulation to a person and directly measure the brain function related to the stimulation with high spatio-temporal resolution. is there.

  For example, a functional magnetic resonance imaging apparatus (fMRI: functional Magnetic Resonance Imaging) is used to give a visual stimulus to a subject and measure the brain activation site, that is, the brain function at that time. In order to give a visual stimulus, a display device for visual stimulus can be placed in a shielded room in which an fMRI is provided, and the subject can measure while viewing the display device. At present, fMRI is used in various medical situations, and its measurement accuracy is also improved. For example, wearing a mask on the subject's head, attaching an eyecap that opens a space in front of the eyes, transmitting visual stimuli from the stimulus generator to the mask through an optical fiber, and using a mirror to stimulate the subject's eyes A proposal has been made for a brain function measuring apparatus configured to fall under the above (for example, see Patent Document 1).

  Several proposals have also been made for brain function measurement methods using near infrared spectrophotometry (NIRS) and brain waves. In brain function measurement using near-infrared light or brain waves, a signal observation point is provided at a specific position on the head surface, and the function of the brain can be understood by observing and analyzing signal changes at that observation point.

  When light in the near-infrared region is projected from outside the brain and scattered light and reflected light are dispersed, each concentration in the brain tissue is determined based on the difference in the near-infrared absorption spectra of oxygen-bound and oxygen-desorbed hemoglobin. It can be estimated non-invasively. It can monitor oxygen metabolism accompanying brain activity, has sub-second sub-second resolution, and has high resistance to electromagnetic noise compared to fMRI, MEG, EEG, etc. due to optical measurement, measurement analyzer and head An advantage is that the mounting equipment is small and light. For example, a biological light measurement method that removes baseline fluctuations in a biological light measurement method using near infrared light and obtains an accurate measurement value has been proposed (see, for example, Patent Document 2).

  In addition, proposals have also been made for methods for measuring brain function using electroencephalograms. The brain function can be observed from the outside as a scalp potential including an electroencephalogram signal. For example, a sensor that detects a biological signal from a living body or a body fluid, and receives time-series data from the sensor, and converts the time-series data into m-point time-series data in a high-dimensional m-space using a time delay constant value τ. Reconstructing, transferring the time series data at the m points to a computer comprising a bus interface, an adder / subtractor and a storage means to calculate a correlation integral, receiving a correlation integral of the calculation result, and receiving a correlation index of the correlation integral There has been proposed a biological signal processing apparatus that includes a host computer that obtains a correlation dimension using, and that can perform high-speed analysis with a small configuration (see, for example, Patent Document 3).

  For brain function measurement on the scalp such as near infrared spectrophotometry and brain waves, a certain position on the subject's head surface becomes the signal observation point, and in order to know the function of the brain, the source of the obtained signal is where in the brain It is necessary to estimate whether it corresponds to the position. This kind of problem is universal in brain function measurement using the head surface as an observation point.

  For example, in the field of electroencephalogram measurement, an international 10-20 system that sets a plurality of reference points on the head surface is known (also an international 10-20 system such as an international 10-10 system that is an extension of the international 10-20 system). There are also standards based on this). In the international 10-20 system, the nasal root, pinna and occipital nodule (protrusion behind the head) are used as reference points, and the distance between them is divided into 10%, 20%, 20%, etc. Set the reference point. Since the standard coordinate value of each point on the brain table corresponding to each reference point has a small inter-individual standard deviation, the international 10-20 system can be used as a guide when considering brain functional localization. In addition, an instrument “Electro-Cap” for checking each reference point set at the head surface position has already been sold (for example, see Non-Patent Document 1). It is common to set a signal observation point at a head surface position along the system, and an instrument such as an Electric-Cap can be used.

  On the other hand, in brain function measurement on the scalp by near infrared spectrophotometry, it is possible to measure at an observation point at an arbitrary position with a fine interval of 20 mm or less. However, since it is required to estimate the position of the brain function, an instrument such as Electric-Cap cannot be used.

  Several brain function measurement methods for measuring the brain function corresponding to the signal observation point of the scalp have been proposed so far, but in general, the process of measuring the subject's head surface position and the subject's head surface position Is converted into the brain surface position of the standard brain, and the process of specifying the brain function based on the brain surface position of the standard brain. The “standard brain” mentioned here is a model that normalizes the data of multiple subjects and models each subject's brain image so that the anatomical position can be identified by coordinates. The standard brain atlas of Talairach is known. By aligning the head surface position of the subject with the brain surface position of the standard brain, the brain function table assigned to each coordinate of the standard brain is referred to and the brain function indicated by the specific standard brain position is obtained. be able to.

FIG. 66 schematically shows an example of a brain function measurement method (for example, see Non-Patent Document 2). In the illustrated method, the brain function is estimated from the head surface position of the subject by the following steps (1) to (3).
(1) Using the MRI data of the subject including the head surface and the standard brain, the brain surface position closest to the specific head surface position is obtained by a search algorithm.
(2) A three-dimensional coordinate conversion map is generated from the MRI data of the subject brain and the MRI data of the standard brain, and the brain surface position of the standard brain is obtained from the specific brain surface position of the subject using the obtained conversion map.
(3) By referring to the brain function table assigned to each coordinate of the standard brain, it is obtained which brain function the specific standard brain position indicates.

  According to the method shown in FIG. 66, it is possible to obtain positioning accuracy that can be used in fMRI studies (about 10 mm). However, in order to estimate the position of the brain, MRI data of the head for each subject is necessary. MRI is a very expensive and large-scale apparatus, and is installed only in a university hospital or other large-scale medical institution. Also, the position accuracy depends on the standard brain conversion algorithm.

FIG. 67 schematically shows another example of the brain function measuring method (for example, see Non-Patent Document 3). In the illustrated method, the brain function is estimated from the head surface position of the subject by the following steps (1) to (4).
(1) The positional relationship between the subject's head surface and one head surface extracted from the MRI database is simply obtained, and one of the subject's specific head surface positions is extracted from the MRI database based on the positional relationship. Find the head surface position. This operation is repeated for the number of MRI data included in the MRI database.
(2) Using the MRI data including one head surface and the standard brain extracted from the MRI database, the brain surface position closest to the specific head surface position determined in (1) is obtained by a search algorithm. This operation is repeated for the number of MRI data included in the MRI database.
(3) A three-dimensional coordinate conversion map is generated from one MRI data taken out of the MRI database and the MRI data of the standard brain, and the brain surface position of the standard brain is obtained using the obtained conversion map. This operation is repeated for the number of MRI data included in the MRI database. Finally, an average value is obtained from the obtained brain surface positions of a plurality of standard brains to obtain a final solution.
(4) With reference to the brain function table assigned to each coordinate of the standard brain, which brain function the specific standard brain position indicates is obtained.

  According to the method shown in FIG. 67, MRI data for each subject is not necessary, but MRI data for other subjects is necessary. In addition, the position accuracy depends on the quality of the database composed of MRI data of other subjects.

JP-A-8-173398 JP 2007-111101 A JP-A-9-56833 http: // www / electro-cap. com / Okamoto, M .; Dan, H .; , Sakamoto, K .; Takeo, K .; Oda, I .; , Isobe, S .; , Suzuki, T .; , Kohyama, K .; , And Dan, I .; “Three-dimensional probabilistic anatomic cranio-cerebral correlation via the international 10-20 system oriented fortran amplification 99 (N) Singh, A .; Okamoto, M .; Dan, H .; , Jurkak, V .; and Dan, I .; “Spatial registration of multi-channel multi-subject fNIRS data to MNI space without MRI” (NeuroImage, 7, 842-51 (2005))

  In brain function measurement using near-infrared light or EEG, a signal observation point is provided at a specific position on the head surface, and the function of the brain can be understood by observing and analyzing signal changes at that observation point (see above) . In this case, a certain position on the subject's head surface becomes the observation point, and in order to know the working of the brain, where the source of the obtained signal corresponds to the position of the brain, that is, between the signal observation point and the brain function It is necessary to estimate the correspondence.

  However, the conventional brain function measuring method has problems that the accuracy when measuring the head surface is low and that MRI data of the subject's head is required to estimate the position of the brain.

  In brain function measurement with near-infrared light, it is possible to perform measurement with a fine interval of 20 mm or less and an arbitrary position as an observation point. For this reason, there is a demand for estimating the position of the brain function at any position on the head surface with high position accuracy.

  In addition, in order to obtain MRI data of the subject's head, it is necessary to use an MRI measuring apparatus that is installed only in some hospitals, research institutions, and universities. For brain function measurement using near-infrared light or brain waves It is generally difficult to prepare such an expensive device.

  The present invention takes into account the technical problems described above, and its main purpose is to provide an excellent brain function site estimation system and brain function site capable of estimating brain function from the head surface position of the subject with high accuracy. An estimation method, a scalp shape measurement support device, a scalp shape measurement support method, and a computer program are provided.

  A further object of the present invention is to provide an excellent brain function site estimation system, brain function site estimation method, scalp shape measurement support device, and scalp capable of accurately estimating the correspondence between scalp signal observation points and brain functions. To provide a shape measurement support method and a computer program.

  A further object of the present invention is to provide an excellent brain function site estimation system and brain function site estimation capable of accurately estimating the correspondence between scalp signal observation points and brain functions without using MRI data of a subject. A method, a scalp shape measurement support device, a scalp shape measurement support method, and a computer program are provided.

The present invention has been made in view of the above problems, and the first aspect thereof is a brain function site estimation system that estimates brain function from the head surface position of a subject,
From the relationship between the measured head surface coordinates of the subject and the head surface coordinates of the standard brain, a head surface position converting means for converting a specific head surface position of the subject into a specific head surface position of the standard brain by geometric deformation,
A brain surface position searching means for determining a brain surface position closest to the head surface position of the standard brain by a search algorithm using MRI data including the standard brain head surface and the standard brain;
A brain function estimation means for referring to a brain function table assigned to each coordinate of the standard brain and estimating which brain function a specific standard brain position indicates;
It is a brain functional part estimation system characterized by comprising.

The second aspect of the present invention is a brain function site estimation system that estimates brain function from the head surface position of a subject,
A subject head surface shape acquisition means for acquiring information on the head surface shape of the subject consisting of three-dimensional position information at a plurality of reference points set on the head surface of the subject;
A head surface position converting means for converting the three-dimensional position information of the signal observation point attached to the subject's head surface into a corresponding position on the standard brain head surface based on the subject head surface shape;
A brain surface position estimating means for estimating a brain surface position of a standard brain from a standard brain head surface position associated with a signal observation point on a subject brain head surface by the head surface position converting means;
A brain function estimating means for estimating a brain function corresponding to the brain surface position of the standard brain estimated by the brain surface position estimating means;
It is a brain functional part estimation system characterized by comprising.

  However, “system” here refers to a logical collection of a plurality of devices (or functional modules that realize specific functions), and each device or functional module is in a single housing. It does not matter whether or not.

  In order to quantitatively evaluate brain phenomena (emotion, cognition, memory, etc.) caused by stimulation, it is necessary to present the stimulation to a person and directly measure the brain function related to the stimulation with high spatio-temporal resolution. is there.

  MRI and fMRI used in various medical scenes have improved measurement accuracy, and by using fMRI, it is possible to give a visual stimulus to a subject and measure the brain activation site, that is, the brain function at that time. . However, in order to obtain MRI data of the subject's head, it is necessary to use an MRI measuring device that is installed only in some hospitals, research institutions, and universities. It is generally difficult to prepare such an expensive device.

  On the other hand, according to the brain functional region estimation system according to the first aspect of the present invention, the specific head of the subject is determined by geometric deformation based on the relationship between the measured head surface coordinates of the subject and the head surface coordinates of the standard brain. The table position is converted into a specific head surface position of the standard brain, and then the brain surface position nearest to the head surface position of the standard brain is searched using the MRI data including the standard brain head table and the standard brain Then, the brain function table assigned to each coordinate of the standard brain is referred to, and the brain function indicated by the specific standard brain position is obtained. Therefore, MRI data for each subject is unnecessary, and the brain function can be estimated with high accuracy from the head surface position of the subject.

  In addition, according to the brain functional part estimation system according to the second aspect of the present invention, information on the shape of the head surface of the subject, which includes three-dimensional position information at a plurality of reference points set on the head surface of the subject, is acquired. The three-dimensional position information of the signal observation point attached to the subject's head surface is converted into a corresponding position on the standard brain head surface based on the subject head surface shape. That is, by mapping the head surface position of the signal observation point on the examiner's head to the head surface position of the standard brain, the correspondence between the signal observation point on the scalp and the brain functional part without using the MRI data of the subject. Can be estimated. Then, using the existing standard brain / standard brain head surface data, the head surface position of the standard brain can be converted to the brain surface position of the standard brain, and the brain function corresponding to the brain surface position of the standard brain is specified. be able to.

  Here, in the brain functional part estimation system according to the second aspect of the present invention, the head surface position conversion means first repeats the process of selecting any three reference points to form a partial space, Each of the heads of the standard brain is divided into a plurality of subspaces, an oblique coordinate system is assigned to each subspace, and the first subspace including the coordinate position of the signal observation point is identified from the subject's head surface Then, a partial space corresponding to the second partial space on the standard brain brain surface including the coordinate position of the signal observation point is selected, and affine transformation is performed between the oblique coordinates of the first and second partial spaces. Thus, the signal observation point on the standard brain surface can be obtained.

  In addition, the subject head surface shape obtaining means specifies information on the head surface shape of the subject by specifying a plurality of reference positions defined by the international 10-20 system or a standard based on the international 10-20 system on the head surface of the subject. Can be obtained.

In addition, the third aspect of the present invention supports the scalp shape measurement work by specifying a plurality of reference positions defined by the international 10-20 system or a standard based thereon on the subject's head surface. A scalp shape measurement support device,
3D position measurement means for measuring 3D position information in space;
Arithmetic processing means for arithmetically processing the three-dimensional position information output from the three-dimensional position measuring device;
A display that presents a screen related to the three-dimensional position information that is measured by the three-dimensional position measuring means or that has been arithmetically processed by the arithmetic processing means;
Four reference positions Nz (nasal root), Iz (protrusion tip of the posterior skull), LPA (left auricle point), RPA (right ear) measured by the operator on the head surface of the subject using the three-dimensional position measuring means. Means for maintaining the position of the intermediary point);
When a temporary measurement is performed using Cz (center portion) as a point where a straight line connecting the midpoint of two line segments of Nz-Iz and LPA-RPA intersects the head surface, 2 of Nz-Iz and LPA-RPA is displayed on the display. A Cz temporary measurement support means for displaying a relationship between a temporary Cz measurement target position and a current position measured using the three-dimensional position measurement means;
Means for holding a temporary Cz position measured by an operator through support by the Cz temporary measurement support means;
When measuring the distance between Nz-provisional Cz-Iz, the three reference lines Nz, Iz, LPA, RPA, and the straight line connecting Nz-provisional Cz-Iz are displayed on the display in three dimensions. , Nz, Iz, and Cz, the operator can measure a plurality of points at a head surface position on a straight line passing through a total of three points, and the operator can use the three-dimensional position measuring means to measure the head surface position on the straight line. Nz-provisional Cz-Iz distance measurement support means for generating a parametric curve connecting Nz and Iz via a plurality of points measured in step 3D and displaying them three-dimensionally;
The intermediate point of the parametric curve connecting Nz and Iz is determined as a formal Cz position, and four reference points Fpz, Fz, Pz, and Oz distributed on the parametric curve are determined. Cz-Iz distance measuring means;
Means for holding the position of the determined (formal) Cz and the four reference points Fpz, Fz, Pz and Oz;
For each of the three straight lines LPA-Cz-RPA, Fpz-T3-Oz, and Fpz-T4-Oz using the already determined reference points Nz, Iz, LPA, RPA, Cz, Fpz, Fz, Pz, Oz. In addition to supporting the operator's measurement by displaying a three-dimensional line on the display, a parametric curve is generated by connecting a plurality of points measured by the operator at the head surface position on the line, and the distance is measured. LPA-Cz-RPA, Fpz-T3-Oz, Fpz-T4-Oz distance measuring means,
Based on the measurement results of the LPA-Cz-RPA, Fpz-T3-Oz, Fpz-T4-Oz distance measuring means, the LPA-Cz-RPA, Fpz-T3-Oz, Fpz-T4- Means for determining the position of each reference point C3, C4, T3, T4, Fp1, Fp2, F7, F8, T5, T6, O1, O2 on each parametric curve connecting Oz;
Means for holding the position of each of the determined reference points C3, C4, T3, T4, Fp1, Fp2, F7, F8, T5, T6, O1, O2;
A point measured by the operator using the three-dimensional position measuring means at a point where the operator crosses the scalp on a straight line connecting the intermediate points of the line segments F7-Fz in a plane including the three reference points F7, Fz, F8 is a reference point F3. The point measured by the operator using the three-dimensional position measuring means at a point where the operator crosses the scalp on a straight line connecting the midpoints of the line segments F8-Fz in a plane including the three reference points F7, Fz, F8. Is determined as a reference point F4, and the operator uses the three-dimensional position measurement means at a point where the operator crosses the scalp on a straight line connecting the midpoints of the line segments T5-Pz in a plane including the three reference points T5, Pz, T6. The measured point is determined as a reference point P3, and the operator moves the three-dimensional position at a point where the operator intersects the scalp on a straight line connecting the midpoints of the line segments T6-Pz in a plane including the three reference points T5, Pz, T6. Measuring hand It means for determining the point of measurement as a reference point P4 with,
Means for holding each determined reference point F3, F4, P3, and P4;
A scalp shape measurement support device.

  In the brain functional part estimation system according to the second aspect of the present invention, when the subject head surface shape acquisition means estimates the brain function from the head surface position of the signal observation point provided in the subject, the head surface shape measurement of the subject is performed. In addition, the operator needs to operate the three-dimensional position measuring device for measuring the three-dimensional position of the signal observation point. According to the scalp shape measurement support device according to the third aspect of the present invention, the operator's work burden can be reduced through the user interface during such an operator operation.

According to a fourth aspect of the present invention, there is provided a computer program written in a computer-readable format so that a process for estimating a brain function from a head surface position of a subject is executed on the computer. ,
From the relationship between the measured head surface coordinates of the subject and the head surface coordinates of the standard brain, a head surface position converting means for converting a specific head surface position of the subject into a specific head surface position of the standard brain by geometric deformation,
A brain surface position searching means for determining a brain surface position closest to the head surface position of the standard brain by a search algorithm using MRI data including the standard brain head surface and the standard brain;
A brain function estimation means for referring to a brain function table assigned to each coordinate of the standard brain and estimating which brain function a specific standard brain position indicates;
It is a computer program for making it function as.

According to a fifth aspect of the present invention, there is provided a computer program written in a computer-readable format so that a process for estimating a brain function from a head surface position of a subject is executed on the computer. Subject head surface shape acquisition means for acquiring information on the subject's head surface shape consisting of three-dimensional position information at a plurality of reference points set on the subject's head surface;
A head surface position converting means for converting the three-dimensional position information of the signal observation point attached to the subject's head surface into a corresponding position on the standard brain head surface based on the subject head surface shape;
A brain surface position estimating means for estimating a brain surface position of a standard brain from a standard brain head surface position associated with a signal observation point on a subject brain head surface by the head surface position converting means;
A brain function estimating means for estimating a brain function corresponding to the brain surface position of the standard brain estimated by the brain surface position estimating means;
It is a computer program for making it function as.

Further, the sixth aspect of the present invention is defined by an international 10-20 system or a standard based on this on the subject's head surface using a three-dimensional position measuring means by which an operator measures three-dimensional position information of a space. A computer program written in a computer-readable format to execute a process for supporting a scalp shape measurement operation on a computer by specifying a plurality of reference positions,
Four reference positions Nz (nasal root), Iz (protrusion tip of the posterior skull), LPA (left auricle point), RPA (right ear) measured by the operator on the head surface of the subject using the three-dimensional position measuring means. Means for maintaining the position of the intermediary point);
When a temporary measurement is performed using Cz (center portion) as a point where a straight line connecting the midpoint of two line segments of Nz-Iz and LPA-RPA intersects the head surface, 2 of Nz-Iz and LPA-RPA is displayed on the display. A Cz temporary measurement support means for displaying a relationship between a temporary Cz measurement target position and a current position measured using the three-dimensional position measurement means;
Means for holding a temporary Cz position measured by an operator through support by the Cz temporary measurement support means;
When measuring the distance between Nz-provisional Cz-Iz, the three reference lines Nz, Iz, LPA, RPA, and the straight line connecting Nz-provisional Cz-Iz are displayed on the display in three dimensions. , Nz, Iz, and Cz, the operator can measure a plurality of points at a head surface position on a straight line passing through a total of three points, and the operator can use the three-dimensional position measuring means to measure the head surface position on the straight line. Nz-provisional Cz-Iz distance measurement support means for generating a parametric curve connecting Nz and Iz via a plurality of points measured in step 3D and displaying them three-dimensionally;
The intermediate point of the parametric curve connecting Nz and Iz is determined as a formal Cz position, and four reference points Fpz, Fz, Pz, and Oz distributed on the parametric curve are determined. Cz-Iz distance measuring means;
Means for holding the position of the determined (formal) Cz and the four reference points Fpz, Fz, Pz and Oz;
For each of the three straight lines LPA-Cz-RPA, Fpz-T3-Oz, and Fpz-T4-Oz using the already determined reference points Nz, Iz, LPA, RPA, Cz, Fpz, Fz, Pz, Oz. In addition to supporting the operator's measurement by displaying a three-dimensional line on the display, a parametric curve is generated by connecting a plurality of points measured by the operator at the head surface position on the line, and the distance is measured. LPA-Cz-RPA, Fpz-T3-Oz, Fpz-T4-Oz distance measuring means,
Based on the measurement results of the LPA-Cz-RPA, Fpz-T3-Oz, Fpz-T4-Oz distance measuring means, the LPA-Cz-RPA, Fpz-T3-Oz, Fpz-T4- Means for determining the position of each reference point C3, C4, T3, T4, Fp1, Fp2, F7, F8, T5, T6, O1, O2 on each parametric curve connecting Oz, and each determined reference point Means for holding the positions of C3, C4, T3, T4, Fp1, Fp2, F7, F8, T5, T6, O1, O2,
A point measured by the operator using the three-dimensional position measuring means at a point where the operator crosses the scalp on a straight line connecting the intermediate points of the line segments F7-Fz in a plane including the three reference points F7, Fz, F8 is a reference point F3. The point measured by the operator using the three-dimensional position measuring means at a point where the operator crosses the scalp on a straight line connecting the midpoints of the line segments F8-Fz in a plane including the three reference points F7, Fz, F8. Is determined as a reference point F4, and the operator uses the three-dimensional position measurement means at a point where the operator crosses the scalp on a straight line connecting the midpoints of the line segments T5-Pz in a plane including the three reference points T5, Pz, T6. The measured point is determined as a reference point P3, and the operator moves the three-dimensional position at a point where the operator intersects the scalp on a straight line connecting the midpoints of the line segments T6-Pz in a plane including the three reference points T5, Pz, T6. Measuring hand It means for determining the point of measurement as a reference point P4 using, and means for holding the respective reference points determined F3, F4, P3, and P4,
It is a computer program for making it function as.

  The computer program according to each of the fourth to sixth aspects of the present invention defines a computer program described in a computer-readable format so as to realize predetermined processing on the computer. In other words, by installing the computer program according to the fourth to sixth aspects of the present invention in the computer, a cooperative action is exhibited on the computer, and the first to third aspects of the present invention are achieved. The same function and effect as those of the brain function site estimation system or scalp shape measurement support device can be obtained.

  According to the present invention, an excellent brain function site estimation system and brain function site estimation method, a scalp shape measurement support device, and a scalp shape measurement support method, which can estimate a brain function from a head surface position of a subject with high accuracy, In addition, a computer program can be provided.

  In addition, according to the present invention, an excellent brain function site estimation system, brain function site estimation method, scalp shape measurement support device, and scalp shape measurement support device capable of estimating the correspondence between the scalp signal observation point and the brain function with high accuracy, A scalp shape measurement support method and a computer program can be provided.

  In addition, according to the present invention, an excellent brain function site estimation system and brain function that can estimate the correspondence between scalp signal observation points and brain functions with high accuracy using only a three-dimensional position measurement device. A site estimation method, a scalp shape measurement support device, a scalp shape measurement support method, and a computer program can be provided.

  According to the brain functional region estimation system according to the present invention, MRI data for each subject is not necessary. Moreover, although the position accuracy for estimating the brain function site depends on the geometric deformation algorithm, the accuracy can be ensured by dividing the head surface into regions and performing geometric deformation for each region.

  The present invention can be applied to, for example, a brain measurement experiment using a near-infrared light imaging apparatus to accurately determine which functional part of the brain corresponds to the signal observation point attached to the subject's head surface. Can be estimated.

  The present invention can be applied to the field of brain function measurement in which a signal observation point is provided at a specific position on the head surface, and it is possible to estimate brain function from the head surface position easily and with high accuracy. We can expect great development in the interpretation of the data obtained by

  According to the brain function site estimation apparatus according to the present invention, the signal observation point can be determined while confirming the correspondence between the position on the head surface and the brain function. After searching and selecting, brain function signal measurement can be started.

  In addition, if the scalp shape of the subject measured using the scalp shape measurement support device according to the present invention is stored, it can be reused by the same subject, and signal observation is possible even when measurement is performed multiple times. The position reproducibility of the point can be ensured.

  The present invention has the potential to be widely applied in the field of non-invasive brain function measurement in the future. For example, it can be sufficiently applied to a non-invasive brain-machine interface.

  Other objects, features, and advantages of the present invention will become apparent from more detailed description based on embodiments of the present invention described later and the accompanying drawings.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 schematically shows a procedure of a brain function site estimation method according to the present invention. In the illustrated method, the brain function is estimated from the head surface position of the subject by the following steps (1) to (3).
(1) The specific head surface position of the subject is converted into the specific head surface position of the standard brain by geometric deformation from the relationship between the measured head surface coordinates of the subject and the head surface coordinates of the standard brain.
(2) A brain surface position closest to the head surface position of the standard brain is obtained by a search algorithm using the MRI data including the standard brain head surface and the standard brain.
(3) By referring to the brain function table assigned to each coordinate of the standard brain, it is obtained which brain function the specific standard brain position indicates.

  In the brain functional site estimation method shown in FIG. 1, MRI data for each subject is not necessary. Moreover, although the position accuracy for estimating the brain function site depends on the geometric deformation algorithm, the accuracy can be ensured by dividing the head surface into regions and performing geometric deformation for each region.

  In brain function measurement on the scalp, such as near-infrared spectrophotometry and electroencephalogram, a position on the subject's head is the observation point, and the source of the obtained signal is located anywhere in the brain in order to know how the brain works. It is necessary to estimate whether it corresponds (that is, a brain functional part). As described above, in the brain function measurement using the head surface as the observation point, estimating the correspondence between the signal observation point and the brain function is a universal technical problem.

  In brain function measurement using electroencephalograms, the reference point defined in the international 10-20 system is used as a signal observation point, and the brain can measure using a commercially available instrument that examines each reference point set at the head surface position. Yes, there are also standards based on the international 10-20 system, such as the international 10-10 system, which is an extension of the international 10-20 system. On the other hand, in brain function measurement with near-infrared light, it is possible to measure with a fine interval of 20 mm or less and an arbitrary position as an observation point. There is a demand for estimating the position of brain function.

  By applying the brain functional part estimation method shown in FIG. 1, it is possible to accurately estimate which functional part of the brain the signal observation point attached to the subject's head surface corresponds to. According to this brain function site estimation method, it is possible to estimate the correspondence between the signal observation point at any position on the head surface and the brain function using only a relatively inexpensive three-dimensional position measurement device. No MRI data is required.

  The process for estimating the correspondence between the signal observation point on the scalp and the brain function is constituted by the following procedures 1 to 3.

Procedure 1: A subject's head surface shape is measured using a three-dimensional position measuring device.
Procedure 2: A signal observation point is measured using a three-dimensional position measurement device, and the position of the standard brain head surface is obtained by spatial mapping from the position of the signal observation point on the subject's head surface.
Procedure 3: The position of the standard brain on the brain surface is estimated from the position of the standard brain head surface, and the brain function is examined from the estimated brain surface position of the standard brain.

  FIG. 2 shows an overview configuration of a brain function site estimation system according to an embodiment of the present invention. The illustrated brain functional region estimation system includes a three-dimensional position measurement device that measures the head surface shape and signal observation points of a subject, and a computer that performs arithmetic processing on the three-dimensional position information output from the three-dimensional position measurement device. . The three-dimensional position measurement device may be any device that can measure the three-dimensional position information of the space. For example, FASTRAK manufactured by POLHEUS may be applied. In addition, when the computer is connected to a three-dimensional position measurement device and inputs three-dimensional position information, the position of the signal point on the subject's head surface is spatially mapped to the position on the standard brain head surface, and further the standard brain head A process of estimating a position on the brain surface from the position of the table and estimating a brain functional part from the estimated position of the brain table is performed. According to this brain functional region estimation system, in a subject, the position of the signal observation point attached to the person's head surface corresponds to which position in the brain, and what kind of brain function it has Can do.

  In addition to processing the information notified from the three-dimensional position measuring device, the computer further includes a three-dimensional graphics or a user interface function for the operator to easily perform measurement using characters and sounds. Also good.

  FIG. 3 schematically shows a hardware configuration example of a computer. The illustrated computer is configured so that the control device executes various processes using environment variables and system variables developed on the storage device. Further, the user interface function is realized by using the output device and the input device.

  FIG. 4 shows a functional configuration for performing three-dimensional position information processing (more specifically, processing for estimating the correspondence between the head surface position of the subject and the brain function site) on the computer shown in FIG. Is schematically shown.

  The input module group includes a three-dimensional position measurement value input unit and a mouse / keyboard input unit.

  The three-dimensional position measurement value input unit has a role of acquiring three-dimensional position information transmitted from the three-dimensional position measurement device to the computer as needed. In order to display the sent data on the screen, in addition to sending the 3D position information to the screen output module (described later), the 3D information is also sent to the measurement progress management module for data holding and calculation. Send.

  Input to the management module via the mouse / keyboard input unit, input related to screen display (change of viewpoint to 3D display screen, etc.), input processing related to measurement progress (cancellation of previous measurement data, saving to file, etc.) Used for.

  The output module group includes a screen output unit and a sound output unit.

  The screen output unit outputs a screen that displays the three-dimensional position information of each reference point when measuring the reference point defined by the international 10-20 system or a standard based on the international 10-20 system on the head surface of the subject. By further displaying auxiliary lines and numerical values on this screen, it has an important role of supporting the operator to easily find the position to be measured next in the predetermined measurement order.

  The sound output unit cooperates with the operation of the screen output unit to output an appropriate sound in a necessary scene to assist the measurer in measurement. The operator mainly needs to perform the measurement while observing the head of the subject, and it may be difficult to check the measurement information at any time with the screen output. In that case, information based on sound that can be used without moving the line of sight is very useful. In particular, in a case where a plurality of points are continuously measured, such as distance measurement between Nz and provisional Cz-Iz (described later), the measurement time can be greatly reduced as compared with the case of only screen output.

  The holding module group holds the head surface measurement / calculation data related to the three-dimensional position of the head surface measured from the scalp of the subject, the head surface coordinate data of the standard brain obtained in advance, and the like.

  Head surface measurement / calculation data is used from an output module or a computation module. Data calculated by the calculation module based on the measurement data is also held here.

  The standard brain head surface coordinate data is used for obtaining the standard brain head surface position from the brain measurement observation position set on the subject's head surface and when outputting to the three-dimensional screen.

  The management module group is related to all module groups for input, output, hold, and calculation, and outputs the screen of the 3D position measurement location, cancels the previous measurement value according to the user's instruction via the mouse / keyboard ( (Undo), file storage, screen and sound output adapted to the progress state of the measurement procedure, and management of the measurement progress state such as calculation / retention data update in the operation module according to the progress position of the measurement procedure.

  The calculation module group includes a straight line calculation unit connecting the midpoints of the two segments, a parametric curve interpolation unit, a straight line calculation unit connecting the midpoints between the two points in the plane, a calculation unit for the distance between the points and the straight line, A division unit into a plurality of three-dimensional subspaces and a calculation unit for a position on the standard brain surface from a position on the subject's head surface are included.

  A straight line calculation unit that connects two line segment intermediate points is an arithmetic module that is used when measuring an intermediate point from two measurement points on the head surface.

  The parametric curve interpolation unit is an arithmetic module used when obtaining the distance of a specific section from discrete three-dimensional position information.

  A straight line calculation unit connecting intermediate points between two points in the plane is an arithmetic module used when measuring two intermediate points from three measurement points on the scalp.

  The calculation unit for the distance between a point and a straight line is a module that calculates the shortest distance connecting the point and the straight line, and is used as needed to support the operator's three-dimensional measurement. The calculation module calculates the distance between the straight line calculated by each of the above-mentioned calculation modules and the three-dimensional position currently indicated by the head surface measurement operator, and notifies the operator through real-time screens and sounds to reduce the load on the operator. It can play a big role (described later).

  The division unit of the head surface into a plurality of three-dimensional subspaces reorganizes the plurality of three-dimensional position information into a set of triangles, and regards each triangle as another three-dimensional space, thereby making the head table a plurality of three-dimensional spaces. It is an arithmetic module that divides into a dimensional subspace.

  The position calculation unit from the position on the subject's head surface to the position on the standard brain head surface is a module for obtaining the three-dimensional position on the standard brain head surface from a certain three-dimensional position on the subject's scalp.

  Below, each procedure performed on the brain functional region estimation system shown in FIG. 2 will be introduced. However, since the method of converting the head surface position of the standard brain to the brain surface position in the procedure 3 and the method of specifying the brain function corresponding to the brain surface position of the standard brain are already known in the art, the procedure is described below. Only 1 and procedure 2 are handled.

Step 1:
In procedure 1, the head surface shape of the subject is measured using a three-dimensional position measuring device. Since the accuracy of the data obtained by this processing has a strong influence on the procedure 2 and subsequent steps, high position accuracy is required. In order to quickly measure the head surface shape while reducing the burden on the operator who performs head surface measurement and to ensure high positional accuracy of the obtained data, the present inventors use the following four elements in combination. I devised the technique.

(1) A straight line connecting the midpoints of two line segments (2) A straight line connecting the midpoints between two points in the plane (3) Interpolation of discrete position information using a parametric curve (4) Operator's interface by user interface Load reduction

  The scalp shape of the subject is measured by specifying a plurality of reference positions on the head surface defined by the International 10-20 System (described above) or a standard based on the system. FIG. 5 shows the reference position defined by the international 10-20 system, but it has been confirmed that there is no individual difference in the positional relationship between the head surface and the brain region. The main purpose of the present invention is to examine the positional relationship between the head surface and the brain, and the international 10-20 system can be suitably used.

  FIG. 6 shows a scalp shape measurement procedure by measuring the reference position of the subject's head surface in the form of a flowchart.

  First, the operator uses a three-dimensional position measuring device to directly identify the subject's head shape while confirming four reference positions [Nz (nasal root), Iz (protrusion tip at the rear of the skull), LPA ( Left auricle point, RPA (right auricle point)] are measured (step S1).

  Next, provisional measurement of Cz (center portion) is performed using a straight line connecting the midpoints of two line segments connecting two sets of two opposing points among the four points subjected to the three-dimensional position measurement in step S1 ( Step S2). Details of the “straight line connecting the midpoints of two lines” will be described later.

  When it is Cz that performs temporary measurement, the two line segments referred to here are Nz-Iz and LPA-RPA. And the point which intersects the straight line which connects the intermediate point of these two line segments, and the head surface is temporary Cz. Here, if there is a uniform curve without distortion between Nz-Iz and between LPA-RPA, this is the center. Actually, since the human head has a distortion in the head shape of each individual, the point measured in step S2 is a temporary position. The official Cz position is determined in the next step S3.

  The point where the straight line connecting the midpoint between the two line segments Nz-Iz and LPA-RPA and the surface of the head intersects with the head surface is Cz. Cz (center part) is a straight line drawn from Nz to Iz along the head. And is based on the definition of the international 10-20 system, which is the midpoint of the straight line drawn along the head from LPA to RPA. Cz is not determined until the distance between Nz-Iz and the distance between LPA and RPA is measured, and the midpoint of the distance between Nz and Iz obtained by one measurement is not the midpoint of the distance between LPA and RPA. Repeated re-measurement is required.

  In the present embodiment, Cz is measured under the assumption of an ideal state (a uniform curve without distortion), and the distance between Nz and Iz is measured using this point. Thereafter, the intermediate point between Nz and Iz is defined as formal Cz. As a result, it is possible to save the trouble of repeated remeasurement while maintaining the positional accuracy.

  Moreover, in the brain function site | part estimation system which concerns on this embodiment, the operation | work of such repeated remeasurement by an operator is supported.

  FIG. 7 shows a configuration example of an input support screen presented on the computer display when the operator makes a temporary measurement of Cz. When the two line segments are Nz-Iz and LPA-RPA, these line segments are ideally orthogonal on the horizontal plane. FIG. 7A shows a three-dimensional display of the four reference points measured by the operator as viewed from above. FIG. 7B shows a three-dimensional view of the four reference points measured by the operator viewed from an oblique direction. The center of the cross drawn by the thick line at the approximate center of the screen shown in the figure is the temporary Cz measurement target position. Also, the numbers displayed on each screen indicate the distance between the current measurement position and the measurement target position. As the distance from the measurement target position approaches, feedback is given such as changing the color of the character displaying the distance, for example, from yellow to orange to red, or to sound a sound according to the distance. In this way, a straight line connecting the midpoints of the two line segments Nz-Iz and LPA-RPA is displayed with three-dimensional graphics, and the position to be a temporary Cz measurement target and the three-dimensional position measurement device by characters and colors. It is possible to clarify the relationship with the current position being measured, and to enable quick and accurate measurement using sound, thereby reducing the load on the operator through the user interface.

  Next, based on the interpolation of discrete position information using a parametric curve, a distance measurement between Nz and provisional Cz-Iz is performed (step S3). Details of “interpolation of discrete position information using parametric curves” will be described later.

  At the time of this distance measurement, a plurality of head surface positions on a straight line passing through a total of three points of Nz and Iz measured in step S1 and provisional Cz obtained in step S2 are measured. Then, a parametric curve connecting Nz and Iz is generated via a plurality of measured points, and the distance is measured. As a result, the coordinates of the intermediate point of the parametric curve connecting Nz and Iz are determined, and this is the official Cz position. Further, the four points Fpz, Fz, Pz, and Oz distributed on the parametric curve obtained by measurement are also determined.

  When measuring the distance of a certain section on the head surface, the measurement by the three-dimensional position measurement device is different from the measurement using the measure. This is because when a three-dimensional position measuring device is used, the distance is calculated from discretely obtained three-dimensional positions. Since the human head is a complicated curved surface, in this embodiment, a highly accurate distance measurement is performed using a parametric curve.

  Moreover, in the brain function site | part estimation system which concerns on this embodiment, when measuring the distance between Nz-temporary Cz-Iz, an operator's operation | work is supported through a user interface.

  FIG. 8 shows a configuration example of an input support screen presented on the computer display when the operator measures the distance between Nz and provisional Cz-Iz. FIG. 8A shows these four reference points measured by the operator [Nz (nasal root), Iz (protrusion tip of posterior skull), LPA (left pinna), RPA (right pinna)]], and temporary A three-dimensional display of Cz viewed from above. Further, FIG. 8B shows that the operator measures at the head surface position on a straight line passing through the total of three points of Nz, Iz, Cz in addition to the four reference points Nz, Iz, LPA, RPA and temporary Cz that have already been measured. 3D shows a state in which a parametric curve connecting Nz and Iz via a plurality of points is viewed obliquely. At this time, when the operator uses a three-dimensional position measuring device to measure at the head surface position on a straight line passing through a total of three points of Nz, Iz, and Cz, the number representing the distance between the current measurement position and the measurement target position is Displayed on the screen. Further, as the distance from the measurement target position approaches the measurement position, feedback is given such as changing the color of the character displaying the distance, for example, from yellow to orange to red, or sounding a sound according to the distance.

  In this way, straight lines, measurement points, and parametric curves that pass through the three points Nz, provisional Cz, and Iz are displayed in three-dimensional graphics, and the relationship between the measurement target position and the current position is clearly indicated by characters and colors. In addition, quick and accurate measurement is possible using sound.

  Next, distances between LPA-Cz-RPA, Fpz-T3-Oz, and Fpz-T4-Oz are measured (step S4). Through the steps S1 to S3 so far, the positions of the reference points Nz, Iz, LPA, RPA, Cz, Fpz, Fz, Pz, Oz have already been determined. Therefore, using these points, a parametric curve that connects LPA-Cz-RPA, Fpz-T3-Oz, and Fpz-T4-Oz, respectively, is generated by the same procedure as step S3. Perform distance measurements sequentially. And using these distance measurement results, each reference point C3, C4, T3, T4, on each parametric curve connecting LPA-Cz-RPA, Fpz-T3-Oz, and Fpz-T4-Oz. The positions of Fp1, Fp2, F7, F8, T5, T6, O1, and O2 are determined.

  Finally, the three-dimensional positions of the reference points F3, F4, P3, and P4 are measured (step S5). In order to specify the positions of F3, F4, P3, and P4, a “straight line connecting intermediate points between two points in the plane” is used. Details of the “straight line connecting intermediate points between two points in the plane” will be described later.

  For example, when measuring the three-dimensional position of the reference point F3, it is a straight line connecting the midpoints of the line segments F7-Fz in the plane including the three reference points F7, Fz, F8 whose positions have already been determined. And the point which the operator measured using the three-dimensional position measuring device in the point which cross | intersects the head surface on this straight line is determined as the reference point F3. Of course, the position of F3 can also be specified by measuring the distance by the same processing as in steps S1 to S4 described above. However, the distance measurement requires several to several tens of position measurements, and the work burden on the operator is excessive. Therefore, the position is directly specified by one position measurement here.

  In addition, a point measured by the operator using a three-dimensional position measuring device at a point where the scalp intersects on a straight line connecting the midpoint of the line segment F8-Fz in a plane including the three reference points F7, Fz, F8. Determine as F4.

  In addition, the point measured by the operator using the three-dimensional position measuring device at the point where the scalp intersects the straight line connecting the midpoint of the line segment T5-Pz in the plane including the three reference points T5, Pz, T6 is the reference point. Determine as P3.

  Further, a point measured by the operator using a three-dimensional position measuring device at a point where it intersects the scalp on a straight line connecting the midpoints of the line segments T6-Pz in a plane including the three reference points T5, Pz, T6. Determine as P4.

  The measurement of the head surface shape of the subject in the procedure 1 is efficiently performed using the geometric characteristics of each reference point defined by the international 10-20 system. Also need. In this embodiment, as described with reference to FIGS. 7 and 8, for example, it should be well understood that the operator's work load is reduced through the user interface.

A straight line connecting the midpoints of two lines:
In the international 10-20 system, as shown in FIG. 5, the midpoint on the head surface connecting the points LPA and RPA and the midpoint on the head surface connecting the points Nz and Iz intersect at one point. Is defined as Cz. However, it is difficult to specify the position where the midpoint on the head surface of the points LPA and RPA and the midpoint on the head surface of the points Nz and Iz intersect with one point by a measuring instrument such as a measure. Usually, it is an operation of searching for the point Cz by trial and error.

  On the other hand, in the present embodiment, a highly accurate measurement method is used while reducing the load on the measurer using the geometric properties of the space. In this measurement method, temporary Cz is temporarily measured using a straight line connecting the midpoint between the two line segments Nz-Iz and LPA-RPA. This method will be described in detail.

  When the four reference points Nz, Iz, LPA, and RPA are determined in step S1, two line segments Nz-Iz and LPA-RPA can be defined as shown in FIG.

Next, the midpoint of each line segment is obtained, and the midpoints are defined as m ₁ and m ₂ . Then, the defined as ₁ plane Π the line LPA-RPA through to point m ₁ and normal vector as shown in FIG. 10, points to a normal vector to the line segment Nz-Iz, as shown in FIG. 11 m _The plane passing through ₂ is defined as Π2.

At this time, all the arbitrary points on the plane Π ₁ are equidistant from the reference points LPA and RPA, and all the arbitrary points on the plane Π ₂ are equidistant from the reference points Nz and Iz.

Then, as shown in FIG. 12, when an intersection line between planes Π ₁ and Π ₂ is defined as L ₁ , all arbitrary points on this straight line L ₁ are equidistant from the reference points LPA and RPA, and the reference It is equidistant from the points Nz and Iz.

Operator input support screen is a shown in FIG. 7, by visually presenting the straight line L _1, and is easy to identify the point at which the operator intersection between the straight line L ₁ and the head surface with a three-dimensional position measuring device ing. The intersection of the straight line L ₁ and the head surface is a temporary Cz. The distances of the straight lines connecting the temporary Cz measured here and each of the four reference points Nz, Iz, LPA, and RPA are equidistant as shown in FIG. Is not taken into account.

  According to the definition of the international 10-20 system, the coordinate of the intermediate point of the parametric curve connecting Nz and Iz is the position of Cz (see FIG. 14). In order to obtain correct Cz, it is necessary to measure the head surface shape of the subject. In order to measure the curve on the head surface passing through the reference point Nz, the provisional Cz, and the reference point Iz, these three points are displayed three-dimensionally on the input support screen of the operator shown in FIG. A curve on the head surface (parametric curve) is obtained from the three-dimensional position measurement.

  Then, the coordinates of the intermediate point of the parametric curve connecting Nz and Iz are determined, and this is the official Cz position.

Interpolation of discrete location information using parametric curves:
In the international 10-20 system, information on the head surface shape and distance is used in a plurality of sections such as between the reference points Nz, Iz, and Cz and between the reference points LPA, Cz, and RPA. When trying to measure the subject's head with a measuring device such as a measure, the work may be difficult depending on the subject's hairstyle.

  In this embodiment, the three-dimensional position measurement device is used to discretely measure the three-dimensional position of each point on the subject's head surface and interpolate between them with a parametric curve, so that the head surface shape and the section distance are accurately measured. The measurement method that identifies is adopted.

  Here, a case where information on the head surface shape and distance between the reference points LPA, Cz, and RPA is acquired will be described.

  When the processing up to step S3 in the flowchart shown in FIG. 6 is completed, three reference points LPA, Cz, and RPA are determined as shown in FIG.

  Next, as shown in FIG. 16 (similar to FIG. 8), line segments in the three-dimensional space passing through these reference points LPA, Cz, and RPA are visually presented to the operator. The operator uses a three-dimensional position measuring device to discretely plot a plurality of positions on the head surface in this line segment. As a result, as shown in FIG. 17, a plurality of points connecting the three reference points LPA, Cz, and RPA are obtained.

  A parametric curve is used to connect a plurality of points plotted by the operator using a three-dimensional position measuring device in a line segment passing through these three reference points LPA, Cz, and RPA.

  In the present embodiment, the natural cubic spline is employed so as to guarantee the passage of each point plotted by the operator and to draw a smooth curve like the head surface. The parametric curve is defined by the following equation. Of course, the gist of the present invention is not limited to a specific method of interpolating a specific discrete point into a curve, and an interpolation formula that can obtain an equivalent effect can also be used.

  FIG. 18 shows the result of interpolating a plurality of discretely plotted points shown in FIG. 17 with a parametric curve. From the parametric curve, the head surface shape and distance can be measured.

  Using the above results, other reference points defined in the international 10-20 system can be automatically determined. FIG. 19 shows how other reference points T3, C3, T4, and C4 are obtained on a parametric curve passing through LPA, Cz, and RPA. These reference points T3, C3, T4, and C4 are positions set every 10% or 20% of the overall length as shown in the drawing, and both the head surface shape and distance information are required.

A straight line connecting the midpoints between two points in the plane:
In the international 10-20 system, as shown in FIG. 5, in the curve on the head surface connecting the reference points F7, Fz, F8, the intermediate point between F7 and Fz is defined as F3.

  Usually, it is necessary to measure the distance with a measuring device such as a measure. On the other hand, in the present embodiment, a measurement method for specifying F3 by one three-dimensional one measurement using the geometric property of space is used.

  When step S4 of the flowchart shown in FIG. 6 is completed, three reference points F7, Fz, F8 are determined, and two line segments F7-Fz and F8-Fz can be defined as shown in FIG.

Next, as shown in FIG. 21, a plane passing through the three reference points F7, Fz, and F8 is defined as Π ₃ , and a midpoint between the two points F7 and Fz is defined as m ₃ . Then, as shown in FIG. 22, a straight line passing through the point m ₃ and intersecting with the line segment F7-Fz perpendicularly and belonging to the plane Π ₃ is defined as L ₂ . All points on the straight line L ₂ are equidistant from the points F7 and Fz (see FIG. 23).

FIG. 24 shows a configuration example of an input support screen presented on the computer display when the operator measures the three-dimensional position of the point F3. As shown in FIG. 24A and FIG. 24B, the four reference points Nz, Iz, LPA, RPA and other reference points determined so far based on these are displayed in three dimensions. Point F3 is a point where the straight line L ₂ and the head surface intersect, on the screen shown in FIG. 24, the measurement target position is displayed at the center of the cross. Then, when the operator measures the point F3 on the head surface of the subject using the three-dimensional position measurement device, a number representing the distance between the current measurement position and the measurement target position is displayed in the above screen. Further, as the distance from the measurement target position approaches the measurement position, feedback is given such as changing the color of the character displaying the distance, for example, from yellow to orange to red, or sounding a sound according to the distance.

Through operation via the input support screen shown in FIG. 24, the operator, linear L ₂ can measure the point of intersection with the head surface of the subject, as a reference point F3 (see FIG. 23).

  The measurement method described above can be similarly applied when measuring the intermediate point F4 between F8 and Fz, the intermediate point P3 between T5 and Pz, and the intermediate point P4 between T6 and Pz.

Step 2:
In the procedure 2, using the scalp shape of the subject obtained in the procedure 1, that is, the coordinates of a plurality of reference positions on the measured head surface, signal points attached to the subject's head surface become standard brains ( The position on the head surface (standard brain head surface) of the standard brain is examined.

  The reason for associating with the position on the standard brain surface in this procedure 2 is that there is no data indicating the correspondence between the head surface position of the subject and the brain surface position. If there is no correspondence between the head surface position of the subject and the brain surface position, it is not possible to examine to which position on the brain surface a certain position on the head surface corresponds. Therefore, in the present embodiment, a method is employed in which the head surface position of the standard brain corresponding to the head surface position of the subject is examined, and subsequently the brain surface position of the standard brain is obtained from the head surface position of the standard brain. A typical example of the standard brain / standard brain surface data is “MN1152” provided by the Montreal Neurological Institute.

  Data indicating the correspondence between the head surface position and the brain surface position of the subject can be measured using, for example, MRI (see (1) in FIG. 66). In other words, by not using the correspondence between the head surface position and the brain surface position of the subject in the procedure 2, in this embodiment, the signal observation point of the scalp and the brain function are not used without using the MRI data of the subject. It is possible to estimate the correspondence.

  FIG. 25 shows a processing procedure for estimating a standard brain brain surface position corresponding to a signal observation point on the head surface of the subject in the form of a flowchart.

  First, each head surface of the subject and the standard brain is divided into partial (three-dimensional) spaces (step S11).

  One subspace is formed by selecting three arbitrary points from the reference position on the head surface obtained in the procedure 1. By repeating this, it can be divided into about 25 partial spaces. The shape of the subspace changes depending on how the points are selected. FIG. 26 shows a state in which each head surface of the subject and the standard brain is divided into partial spaces. Details of the method of dividing the head table into a plurality of partial spaces will be described later.

  Also, coordinates are assigned to each partial space obtained by dividing the head table. Various methods can be considered for the coordinate assignment. In the present embodiment, an oblique coordinate system is assigned. One of the three points forming the space is set as the origin, and vectors from the other two points are set as the X axis and the Y axis, respectively. The unit vector length of each axis is the distance between two points. The direction of the Z axis was the outer product of the plane formed by three points, and the unit vector length was the square root of the solution obtained by the outer product (that is, the average of the unit vector lengths of the X axis and the Y axis).

  Next, the three-dimensional position of the signal observation point set on the subject's head surface is measured, and the partial space including the signal observation point is specified from the subject's head surface (step S12).

  The operator measures the three-dimensional position of the signal observation point on the head surface of the subject using the three-dimensional position measuring device. On the computer side, when the three-dimensional position information of the signal observation point is input from the three-dimensional position measuring device, it is checked in which subspace the coordinate position is included. Various methods are conceivable for specifying the subspace. In this embodiment, a point where the XY plane of each subspace and the signal observation point intersect perpendicularly is obtained, and the obtained points are three points in the subspace. The degree of proximity to the enclosed area is examined, and the closest one is determined as the subspace containing the observation point.

  27A and 27B show a state in which a partial space on the head surface of the subject including the signal observation point is specified. In the figure, the signal observation point is indicated by ● and the subspace including this is displayed with a color map. Each unit vector of XYZ that defines the specified subspace is displayed by an arrow.

  Then, the three-dimensional position of the signal observation point on the standard brain surface is obtained (step S13). Specifically, signal observation on the standard brain brain surface is performed by selecting a partial space corresponding to the partial space selected in step S12 from the standard brain brain surface and performing affine transformation between two oblique coordinates. You can get points. Details of the method for identifying the corresponding position on the standard brain surface from the signal observation point attached to the head surface will be described later.

  28A and 28B show screens for obtaining the positions of signal observation points on the standard brain surface. In the figure, the position of the signal observation point obtained on the standard brain surface is indicated by ●. In addition, the partial space including the signal observation point is displayed with a color map. Each unit vector of XYZ that defines the specified subspace is displayed by an arrow.

  In this way, the head surface position of the standard brain at the signal observation point is obtained. Then, as already described, the standard brain head surface position can be converted into the standard brain surface position using standard brain / standard brain head surface data such as MN1152. In the subsequent procedure 3, the brain function corresponding to the brain surface position of the standard brain can be specified using any method known in the art.

  As described so far, in this embodiment, the head surface position of the signal observation point on the subject's head is spatially mapped to the head surface position of the standard brain, so that the scalp of the scalp is not used without using the subject's MRI data. It should be fully understood that the correspondence between the signal observation point and the brain function site can be estimated.

To divide the head surface into multiple subspaces:
When a plurality of points of the international 10-20 system obtained by measurement are connected with a straight line so that a triangle can be formed between the points, a combination of a plurality of triangles as shown in FIG. 29 is completed.

  Different triangle combinations are possible depending on how they are tied, but this is not particularly important.

  In addition, the reference point when generating the triangle does not need to match the point defined in the international 10-20 system. An international 10-10 system may be used, and points (Fpz, Oz) not partially defined in FIG. 29 are used.

In the present embodiment, each triangle formed by selecting arbitrary three reference points is regarded as a partial space, and the head surface shape is regarded as consisting of a plurality of partial spaces. As an example, consider a triangle surrounded by points Cz, C3, and F3. A triangular plane ₄ surrounded by points Cz, C3, and F3 has a positional relationship as shown in FIG.

Here, as shown in FIG. 31, Cz is the origin, line Cz-F3 is the x ₁ axis unit vector, and line Cz-C3 is the y ₁ axis unit vector. The unit vector of z ₁ axis is the normal vector of plane _{4 and} the unit vector length is the average of the unit vector lengths of x ₁ axis and y ₁ axis. At this time, the space defined by the x ₁ y ₁ z ₁ axes is an oblique coordinate system in which the axes are not orthogonal to each other.

When the point P _xyz existing in the coordinate system of the xyz axis is viewed from the coordinate system of the x ₁ y ₁ z ₁ axis, and this is the point P _x1y1z1 , these relationships are expressed using a 4 × 4 mapping matrix M _1. It is expressed as the following formula.

  In this way, partial coordinates are generated by the number of triangles, and respective mapping matrices are prepared.

Next, similarly for the head surface of the standard brain, a combination of triangles is created to generate partial coordinates. Similarly to the above example, when the subspace surrounded by the points Cz, C3, and F3 in the standard brain brain surface is defined by the x ₂ y ₂ z ₂ axis, the point P _xyz 'existing in the coordinate system of the xyz axis is Similarly, it is expressed as the following equation.

Here, if P _x1y1z1 and P _x2y2z2 have the same value, it is derived that the following expression is established using the above two expressions.

The point P _xyz ′ is a result of multiplying the point P _xyz by two roadway matrices, and this is a result indicating which position on the standard brain head corresponds to the measured position on the head surface. Yes.

  The above conversion formula needs to be prepared for the number of subspaces.

To identify the corresponding position on the standard brain surface from signal observation points attached to the head surface:
A signal observation point for optical brain measurement is plotted by the operator using a three-dimensional position measurement device. For example, assuming that the point designated by the operator is the position of Q as shown in FIG. 32, the partial space is specified by the following calculation.

  A normal line passing through the point Q with respect to the xy plane in each partial space is obtained, and an intersection between the normal line and the xy plane and a distance to the xy plane are obtained. FIG. 33 shows an example in which processing is performed on a partial space surrounded by points Cz, C3, and F3.

  Next, it is checked whether or not the intersection obtained by the above-described calculation is in the triangle used for generating the subspace. If the intersection is in the triangle or is the nearest position of the triangle, the subspace is a candidate. If there is one candidate, it is selected. If there are a plurality of candidates, the one having the shortest distance to the xy plane is selected.

  When a subspace is selected, the position on the standard brain surface can be specified using the following formula derived earlier.

  FIG. 34 shows a state where the signal observation point Q ′ on the standard brain head surface is obtained from the signal observation point Q.

Operator operation support through user interface:
In this embodiment, when estimating the brain function from the head surface position of the signal observation point provided in the subject, the operator performs three-dimensional position measurement for the head surface shape measurement of the subject, the three-dimensional position measurement of the signal observation point, or the like. Equipment operation is also required. When such an operator operation is performed, the burden on the operator is reduced through the user interface. Below, the transition of the input assistance screen shown on the display of a computer at the time of performing procedure 1-2 is demonstrated.

  First, a screen prompting the operator to plot the left anterior pinna (LPA) is presented (see FIG. 35). The screen is composed of a display area for instructing an operator's operation and a three-dimensional screen display area for outputting measurement information. In the three-dimensional screen display area for outputting measurement information, the origin of measurement coordinates and the XYZ axes are shown. When the operator points the LPA at the three-dimensional position measuring device, a three-dimensional position cursor is displayed at the corresponding position. The three-dimensional position cursor updates and displays the three-dimensional position indicated by the operator in real time (see FIG. 36).

  When the operator finishes measuring the LPA, the position of the measured LPA is displayed three-dimensionally on the screen, and a plot of the right anterior pinna (RPA) is subsequently displayed in the display area for instructing the operator's operation. Prompt (see FIG. 37). When the RPA measurement is finished, the nasal root (Nz) and the occipital nodule (Iz) are prompted to be plotted and the reference points after the measurement are displayed three-dimensionally (see FIGS. 38 to 38). ).

  Then, when the measurement of these four reference points LPA, RPA, Nz, and Iz is completed, the screen is switched to a screen that prompts plotting of the central portion (Cz) (see FIG. 40). First, it is assumed that there is a uniform curve without distortion between Nz-Iz and LPA-RPA, and a temporary Cz input is prompted. Cz is a midpoint of a straight line drawn along the head from Nz to Iz, and a midpoint of a straight line drawn along the head from LPA to RPA. Two line segments Nz-Iz and LPA-RPA Then, the temporary measurement target position of Cz is displayed three-dimensionally. When the operator designates temporary Cz using the three-dimensional position measurement device, the distance between the current measurement position and the measurement target position is numerically displayed on the screen (see FIG. 41). As the distance from the measurement target position approaches, feedback is given such as changing the color of the character indicating the distance, for example, from yellow to orange to red, or to sound a sound according to the distance (see FIG. 42). ).

  When the provisional Cz is measured, the screen is switched to a screen for measuring the distance between Nz and provisional Cz-Iz based on the interpolation of discrete position information using a parametric curve (see FIG. 43). . On the same screen, a parametric curve passing through a total of three points of Nz, Iz, and Cz is displayed. The operator measures a plurality of three-dimensional positions along this auxiliary line. At this time, a number representing the distance between the current measurement position and the measurement target position is displayed in the above screen. In addition, as the distance from the measurement position to the measurement target position approaches, feedback is given such as changing the color of the character indicating the distance, for example, from yellow to orange to red, or sounding the sound according to the distance (Fig. 44-46).

  A parametric curve connecting Nz and Iz is generated via a plurality of measured points, and the distance is measured. As a result, the coordinates of the intermediate point of the parametric curve connecting Nz and Iz are determined, and this is the official Cz position. Further, the four points Fpz, Fz, Pz, and Oz distributed on the parametric curve obtained by measurement are also determined.

  The positions of the reference points Nz, Iz, LPA, RPA, Cz, Fpz, Fz, Pz, and Oz are determined by the three-dimensional position measurement work performed by the operator so far. Subsequently, parametric curves that connect LPA-Cz-RPA, Fpz-T3-Oz, and Fpz-T4-Oz are generated, and their distances are measured sequentially. And using these distance measurement results, each reference point C3, C4, T3, T4, on each parametric curve connecting LPA-Cz-RPA, Fpz-T3-Oz, and Fpz-T4-Oz. The positions of Fp1, Fp2, F7, F8, T5, T6, O1, and O2 are determined.

  FIG. 48 shows a screen obtained by measuring the distance measurement of A1-A2 using an auxiliary line in the same manner as A1-A2.

  FIG. 49 shows a screen after the distance measurement of Fp1-T3-Oz is measured using an auxiliary line in the same manner as A1-A2.

  FIG. 50 shows a screen after measuring the distance measurement of Fp1-T4-Oz using an auxiliary line in the same manner as A1-A2.

  As the final operator operation for measuring the scalp shape of the subject, the three-dimensional positions of the reference points F3, F4, P3, and P4 are measured.

  For example, when measuring the three-dimensional position of the reference point F3, it is a straight line connecting the midpoints of the line segments F7-Fz in the plane including the three reference points F7, Fz, F8 whose positions have already been determined. And the point which the operator measured using the three-dimensional position measuring device in the point which cross | intersects the head surface on this straight line is determined as the reference point F3. Here, the positions of these reference points are directly specified by one position measurement in consideration of the operator's work load.

  FIG. 51 shows a screen on which the measurement target position is displayed in order to measure F3.

  FIG. 52 shows a screen in the middle of moving the three-dimensional one cursor closer to the measurement target position in order to measure F3.

  FIG. 53 shows a screen immediately before F3 is measured.

  FIG. 54 shows a screen for measuring F4 as in F3.

  FIG. 55 shows a screen for measuring P3 as in F3.

  FIG. 56 shows a screen for measuring P4 as in F3.

  FIG. 57 shows a screen for confirming completion of measurement of the head surface shape of the subject.

  FIG. 58 shows a screen for storing measurement data of the head surface shape of the subject.

  When the measurement of the head surface shape of the subject is completed through the operation of the three-dimensional position measuring apparatus by the operator as described above in step 1, subsequently, in step 2, the scalp shape of the subject, that is, a plurality of standards on the measured head surface Using the coordinates of the position, it is checked which position on the head surface (standard brain head surface) of the standard brain (standard brain) the signal point attached to the subject's head surface corresponds to.

  First, each head surface of the subject and the standard brain is divided into partial (three-dimensional) spaces.

  FIG. 59 shows a screen on which the head surface shape of the subject is divided into a plurality of three-dimensional subspaces based on the measurement data, and similarly, the standard brain head table is divided into a plurality of three-dimensional subspaces, and these are displayed. ing.

  Next, the three-dimensional position of the signal observation point set on the subject's head surface is measured, and the subspace including the signal observation point is specified from the subject's head surface.

  FIG. 60 shows a screen that prompts the operator to measure the measurement observation point with the three-dimensional position measurement device.

  FIG. 61 shows a screen showing how the three-dimensional subspace is switched in accordance with the movement of the three-dimensional cursor.

  FIG. 62 shows a screen immediately after measuring the signal observation point.

  Then, the three-dimensional position of the signal observation point on the standard brain surface is obtained.

  FIG. 63 shows a screen on which a signal observation point of a subject is projected on the standard brain surface.

  FIG. 64 shows a screen displaying a state in which a plurality of signal observation points are projected onto the standard brain surface.

  FIG. 65 shows a screen for storing signal observation point data in a file.

  The present invention has been described in detail above with reference to specific embodiments. However, it is obvious that those skilled in the art can make modifications and substitutions of the embodiment without departing from the gist of the present invention.

  The present invention can be applied to the field of brain function measurement in which a signal observation point is provided at a specific position on the head surface, and it is possible to estimate brain function from the head surface position easily and with high accuracy. We can expect great development in the interpretation of the data obtained by

  The present invention has the potential to be widely applied in the field of non-invasive brain function measurement in the future. For example, it can be sufficiently applied to a non-invasive brain-machine interface.

  Moreover, although this specification demonstrated embodiment using the international 10-20 system, the summary of this invention is not limited to this. There are standards based on the international 10-20 system, such as the international 10-10 system that is an extension of the international 10-20 system, and any of these standards can be used as appropriate.

  In short, the present invention has been disclosed in the form of exemplification, and the description of the present specification should not be interpreted in a limited manner. In order to determine the gist of the present invention, the claims should be taken into consideration.

FIG. 1 is a diagram schematically showing a procedure of a brain function site estimation method according to the present invention. FIG. 2 is a diagram showing an overview configuration of a brain function site estimation system according to an embodiment of the present invention. FIG. 3 is a diagram schematically illustrating a hardware configuration example of a computer. FIG. 4 is a diagram schematically showing a functional configuration for processing the three-dimensional position information on the computer. FIG. 5 is a diagram showing a reference position defined by the international 10-20 system. FIG. 6 is a flowchart showing a procedure for measuring the scalp shape by measuring the reference position of the subject's head surface. FIG. 7A is a diagram showing a configuration example of an input support screen presented on a computer display when an operator performs a temporary measurement of Cz. FIG. 7B is a diagram illustrating a configuration example of an input support screen presented on the computer display when the operator performs a temporary measurement of Cz. FIG. 8A is a diagram showing a configuration example of an input support screen presented on a computer display when measuring a distance between Nz and provisional Cz-Iz. FIG. 8B is a diagram illustrating a configuration example of an input support screen presented on the computer display when measuring the distance between Nz and provisional Cz-Iz. FIG. 9 is a diagram showing how two line segments Nz-Iz and LPA-RPA are defined from four reference points Nz, Iz, LPA, and RPA. FIG. 10 is a diagram showing a plane Π ₁ passing through the point m ₁ with the line segment LPA-RPA as a normal vector. FIG. 11 is a diagram illustrating a plane Π ₂ that passes through the point m ₂ with the line segment Nz−Iz as a normal vector. 12, along with any and all points on the intersection line L ₁ of the plane [pi ₁ and [pi ₂ are equidistant from the reference point LPA and RPA, showing how it is equidistant from the reference point Nz and Iz FIG It is. FIG. 13 is a diagram illustrating a state in which the distance is a straight line connecting the temporary Cz and each of the four reference points Nz, Iz, LPA, and RPA. FIG. 14 is a diagram illustrating a state in which the coordinates of the intermediate point of the parametric curve connecting Nz and Iz are the Cz position. FIG. 15 is a diagram showing a state in which three reference points LPA, Cz, and RPA are determined when the processing up to step S3 in the flowchart shown in FIG. 6 is completed. FIG. 16 is a diagram showing a state in which a line segment in a three-dimensional space passing through the reference points LPA, Cz, and RPA is visually presented to the operator. FIG. 17 is a diagram showing a plurality of points plotted discretely in a line segment passing through the reference points LPA, Cz, and RPA by using the three-dimensional position measurement apparatus. FIG. 18 is a diagram showing a result of interpolating a plurality of discretely plotted points shown in FIG. 17 with a parametric curve. FIG. 19 is a diagram illustrating how other reference points T3, C3, T4, and C4 are obtained on a parametric curve that passes through LPA, Cz, and RPA. FIG. 20 is a diagram showing how two line segments F7-Fz and F8-Fz are defined by three reference points F7, Fz, and F8. Figure 21 is a diagram of three reference points F7, Fz, a plane passing through the F8 [pi _3, 2 points F7, the midpoint of Fz showing how to define the m _3. FIG. 22 is a diagram showing a state where a straight line passing through the point m ₃ and perpendicularly intersecting with the line segment F7-Fz and belonging to the plane Π ₃ is defined as L ₂ . Figure 23 becomes the same distance all points on the straight line L ₂ from the point F7 and Fz, diagrams linear L ₂ is showing how to measure as a reference point F3 of the point of intersection with the head surface of the subject. FIG. 24A is a diagram illustrating a configuration example of an input support screen presented on the computer display when the operator performs the three-dimensional position measurement of the point F3. FIG. 24B is a diagram showing a configuration example of an input support screen presented on the computer display when the operator performs the three-dimensional position measurement of the point F3. FIG. 25 is a flowchart showing a processing procedure for estimating a standard brain surface position corresponding to a signal observation point on the head surface of a subject. FIG. 26 is a diagram showing a state in which each head surface of the subject and the standard brain is divided into partial spaces. FIG. 27A is a diagram showing a screen specifying a partial space on the head surface of a subject including a signal observation point. FIG. 27B is a diagram showing a screen in which the partial space on the head surface of the subject including the signal observation point is specified. FIG. 28A is a diagram showing a screen for obtaining the position of the signal observation point on the standard brain surface. FIG. 28B is a diagram showing a screen for obtaining the position of the signal observation point on the standard brain surface. FIG. 29 shows a combination of a plurality of triangles formed by connecting the points with a straight line so that a triangle can be formed between the points of the international 10-20 system obtained by measurement. It is a figure. FIG. 30 is a diagram showing the positional relationship of a triangular plane ₄ surrounded by points Cz, C3, and F3. Figure 31 is the origin of Cz, a line segment Cz-F3 unit vectors x ₁ axis, a line segment Cz-C3 as the unit vector of y ₁ axis unit vector z ₁ axis normal vector of the plane [pi ₄ FIG. FIG. 32 is a diagram illustrating a state in which the operator plots the point Q as a signal observation point by the three-dimensional position measurement device. FIG. 33 is a diagram illustrating an example in which processing is performed on the partial space surrounded by the points Cz, C3, and F3. FIG. 34 is a diagram showing a state where the signal observation point Q ′ on the standard brain head surface is obtained from the signal observation point Q. FIG. 35 is a diagram showing a screen that prompts the operator to plot the left anterior pinna (LPA). FIG. 36 is a diagram showing a screen that prompts the operator to plot the left anterior pinna point (LPA). FIG. 37 is a diagram showing a screen that prompts the operator to plot the right anterior pinna (RPA). FIG. 38 is a diagram showing a screen that prompts the operator to plot the nose root (Nz). FIG. 39 is a diagram showing a screen that prompts the operator to plot the occipital nodule (Iz). FIG. 40 is a diagram showing a screen that prompts the operator to plot the central portion (Cz). FIG. 41 is a diagram showing a screen that prompts the operator to plot the central portion (Cz). FIG. 42 is a diagram showing a screen that prompts the operator to plot the central portion (Cz). FIG. 43 is a diagram showing a screen for measuring the distance between Nz and provisional Cz-Iz. FIG. 44 is a diagram showing a screen in the middle of bringing the three-dimensional cursor closer to the auxiliary line. FIG. 45 is a diagram showing a screen when the three-dimensional cursor is closest to the auxiliary line. FIG. 46 is a diagram showing a screen after three-dimensional position measurement of five reference points LPA, RPA, Nz, Iz, and Cz on the auxiliary line. FIG. 47 is a diagram showing a screen immediately before the end of the three-dimensional position measurement on the auxiliary line. FIG. 48 is a diagram showing a screen obtained by measuring the distance between A1 and A2 using auxiliary lines in the same manner as A1 and A2. FIG. 49 is a diagram illustrating a screen after the distance measurement of Fp1-T3-Oz is measured using an auxiliary line in the same manner as A1-A2. FIG. 50 is a diagram illustrating a screen after measuring the distance measurement of Fp1-T4-Oz using an auxiliary line in the same manner as A1-A2. FIG. 51 is a diagram showing a screen on which a measurement target position is displayed in order to measure F3. FIG. 52 is a diagram showing a screen in the middle of bringing the three-dimensional one cursor closer to the measurement target position in order to measure F3. FIG. 53 is a diagram showing a screen immediately before F3 is measured. FIG. 54 is a diagram showing a screen for measuring F4, similar to F3. FIG. 55 is a diagram showing a screen for measuring P3, similar to F3. FIG. 56 is a diagram showing a screen for measuring P4, similar to F3. FIG. 57 is a diagram showing a screen for confirming the completion of measurement of the head surface shape of the subject. FIG. 58 is a diagram showing a screen for storing measurement data of the head surface shape of the subject. FIG. 59 is a view showing a screen displaying the head surface shape and the standard brain head surface of the subject divided into a plurality of three-dimensional subspaces. FIG. 60 is a diagram illustrating a screen that prompts the operator to perform an operation of measuring the measurement observation point with the three-dimensional position measurement device. FIG. 61 is a view showing a screen showing a state in which the three-dimensional partial space is switched in accordance with the movement of the three-dimensional cursor. FIG. 62 is a diagram showing a screen immediately after measuring the signal observation point. FIG. 63 is a diagram showing a screen on which a signal observation point of a subject is projected on the standard brain surface. FIG. 64 is a diagram showing a screen displaying a state in which a plurality of signal observation points are projected on the standard brain surface. FIG. 65 is a diagram showing a screen for storing signal observation point data in a file. FIG. 66 is a diagram schematically illustrating an example of a brain function measuring method. FIG. 67 is a diagram schematically showing another example of the brain function measuring method.

Claims (13)

A brain functional region estimation system that estimates brain function from a subject's head surface position,
From the relationship between the measured head surface coordinates of the subject and the head surface coordinates of the standard brain, a head surface position converting means for converting a specific head surface position of the subject into a specific head surface position of the standard brain by geometric deformation,
A brain surface position searching means for determining a brain surface position closest to the head surface position of the standard brain by a search algorithm using MRI data including the standard brain head surface and the standard brain;
A brain function estimation means for referring to a brain function table assigned to each coordinate of the standard brain and estimating which brain function a specific standard brain position indicates;
A brain functional region estimation system comprising: In a brain function site estimation system constructed on a computer, a brain function site estimation method for estimating brain function from a head surface position of a subject,
The head surface position conversion means provided in the computer converts a specific head surface position of the subject to a specific head surface position of the standard brain by geometric deformation based on the relationship between the measured head surface coordinates of the subject and the head surface coordinates of the standard brain. A head surface position conversion step to convert;
The brain surface position searching means provided in the computer uses a search algorithm to find a brain surface position closest to the head surface position of the standard brain using MRI data including the standard brain head table and the standard brain. Steps,
The brain function estimation means provided in the computer refers to a brain function table assigned to each coordinate of the standard brain, and estimates a brain function indicating which brain function a specific standard brain position indicates;
The brain functional region estimation method characterized by comprising. A computer program written in a computer-readable format to execute a process for estimating a brain function from a head surface position of a subject on a computer, the computer comprising:
From the relationship between the measured head surface coordinates of the subject and the head surface coordinates of the standard brain, a head surface position converting means for converting a specific head surface position of the subject into a specific head surface position of the standard brain by geometric deformation,
A brain surface position searching means for determining a brain surface position closest to the head surface position of the standard brain by a search algorithm using MRI data including the standard brain head surface and the standard brain;
A brain function estimation means for referring to a brain function table assigned to each coordinate of the standard brain and estimating which brain function a specific standard brain position indicates;
Computer program to function as A brain functional region estimation system that estimates brain function from a subject's head surface position,
A subject head surface shape acquisition means for acquiring information on the head surface shape of the subject consisting of three-dimensional position information at a plurality of reference points set on the head surface of the subject;
A head surface position converting means for converting the three-dimensional position information of the signal observation point attached to the subject's head surface into a corresponding position on the standard brain head surface based on the subject head surface shape;
A brain surface position estimating means for estimating a brain surface position of a standard brain from a standard brain head surface position associated with a signal observation point on a subject brain head surface by the head surface position converting means;
A brain function estimating means for estimating a brain function corresponding to the brain surface position of the standard brain estimated by the brain surface position estimating means;
A brain functional region estimation system comprising: The head surface position converting means includes:
Means for selecting an arbitrary three reference points and repeating the process of forming a subspace to divide each of the subject and the head of the standard brain into a plurality of subspaces and assign an oblique coordinate system to each subspace; ,
Means for identifying a first subspace in which the coordinate position of the signal observation point is included from the subject's head surface;
Selecting a partial space corresponding to a second partial space on the standard brain brain surface including the coordinate position of the signal observation point, and performing an affine transformation between the oblique coordinates of the first and second partial spaces; A means of obtaining signal observation points on the standard brain surface;
The brain functional region estimation system according to claim 4, further comprising: The subject head surface shape acquisition means acquires information on the head surface shape of the subject by specifying a plurality of reference positions defined by the international 10-20 system or a standard based on the international 10-20 system on the head surface of the subject. To
The brain functional region estimation system according to claim 4, wherein: On a brain function site estimation system constructed using a computer, a brain function site estimation method for estimating brain function from a head surface position of a subject,
The subject head surface shape acquisition means provided in the computer acquires a subject head surface shape acquisition step for acquiring information related to the head surface shape of the subject consisting of three-dimensional position information at a plurality of reference points set on the subject's head surface;
The head surface position converting means provided in the computer converts the three-dimensional position information of the signal observation point attached to the subject's head surface into a corresponding position on the standard brain head table based on the subject head surface shape. A head surface position converting step,
The brain surface position estimating means provided in the computer estimates the brain surface position of the standard brain from the standard brain head surface position associated with the signal observation point on the subject brain head surface by the head surface position converting means. An estimation step;
The brain function estimation means provided in the computer estimates a brain function corresponding to the brain surface position of the standard brain estimated by the brain surface position estimation means;
The brain functional region estimation method characterized by comprising. The head surface position conversion step includes:
Repeating the process of selecting any three reference points to form a subspace, dividing each of the subject and the head of the standard brain into a plurality of subspaces, and assigning an oblique coordinate system to each subspace; ,
Identifying a first subspace in which the coordinate position of the signal observation point is included from the subject's head surface;
Selecting a partial space corresponding to a second partial space on the standard brain brain surface including the coordinate position of the signal observation point, and performing an affine transformation between the oblique coordinates of the first and second partial spaces; Obtaining a signal observation point on the standard brain surface;
The brain functional region estimation method according to claim 7, further comprising: In the subject head surface shape acquisition step, information related to the head surface shape of the subject is acquired by specifying a plurality of reference positions determined by the international 10-20 system or a standard based on the international 10-20 system on the head surface of the subject. To
The brain functional site estimation method according to claim 7. A computer program written in a computer-readable format to cause a computer to execute a process for estimating brain function from a head surface position of a subject, the computer comprising:
A subject head surface shape acquisition means for acquiring information on the head surface shape of the subject consisting of three-dimensional position information at a plurality of reference points set on the head surface of the subject;
A head surface position converting means for converting the three-dimensional position information of the signal observation point attached to the subject's head surface into a corresponding position on the standard brain head surface based on the subject head surface shape;
A brain surface position estimating means for estimating a brain surface position of a standard brain from a standard brain head surface position associated with a signal observation point on a subject brain head surface by the head surface position converting means;
A brain function estimating means for estimating a brain function corresponding to the brain surface position of the standard brain estimated by the brain surface position estimating means;
Computer program to function as A scalp shape measurement support device for supporting a scalp shape measurement operation by specifying a plurality of reference positions defined by an international 10-20 system or a standard based on the international 10-20 system on a subject's head surface,
3D position measurement means for measuring 3D position information in space;
Arithmetic processing means for arithmetically processing the three-dimensional position information output from the three-dimensional position measuring device;
A display that presents a screen related to the three-dimensional position information that is measured by the three-dimensional position measuring means or that has been arithmetically processed by the arithmetic processing means;
Four reference positions Nz (nasal root), Iz (protrusion tip of the posterior skull), LPA (left auricle point), RPA (right ear) measured by the operator on the head surface of the subject using the three-dimensional position measuring means. Means for maintaining the position of the intermediary point);
When a temporary measurement is performed using Cz (center portion) as a point where a straight line connecting the midpoint of two line segments of Nz-Iz and LPA-RPA intersects the head surface, 2 of Nz-Iz and LPA-RPA is displayed on the display. A Cz temporary measurement support means for displaying a relationship between a temporary Cz measurement target position and a current position measured using the three-dimensional position measurement means;
Means for holding a temporary Cz position measured by an operator through support by the Cz temporary measurement support means;
When measuring the distance between Nz-provisional Cz-Iz, the three reference lines Nz, Iz, LPA, RPA, and the straight line connecting Nz-provisional Cz-Iz are displayed on the display in three dimensions. , Nz, Iz, and Cz, the operator can measure a plurality of points at a head surface position on a straight line passing through a total of three points, and the operator can use the three-dimensional position measuring means to measure the head surface position on the straight line. Nz-provisional Cz-Iz distance measurement support means for generating a parametric curve connecting Nz and Iz via a plurality of points measured in step 3D and displaying them three-dimensionally;
The intermediate point of the parametric curve connecting Nz and Iz is determined as a formal Cz position, and four reference points Fpz, Fz, Pz, and Oz distributed on the parametric curve are determined. Cz-Iz distance measuring means;
Means for holding the position of the determined (formal) Cz and the four reference points Fpz, Fz, Pz and Oz;
For each of the three straight lines LPA-Cz-RPA, Fpz-T3-Oz, and Fpz-T4-Oz using the already determined reference points Nz, Iz, LPA, RPA, Cz, Fpz, Fz, Pz, Oz. In addition to supporting the operator's measurement by displaying a three-dimensional line on the display, a parametric curve is generated by connecting a plurality of points measured by the operator at the head surface position on the line, and the distance is measured. LPA-Cz-RPA, Fpz-T3-Oz, Fpz-T4-Oz distance measuring means,
Based on the measurement results of the LPA-Cz-RPA, Fpz-T3-Oz, Fpz-T4-Oz distance measuring means, the LPA-Cz-RPA, Fpz-T3-Oz, Fpz-T4- Means for determining the position of each reference point C3, C4, T3, T4, Fp1, Fp2, F7, F8, T5, T6, O1, O2 on each parametric curve connecting Oz;
Means for holding the position of each of the determined reference points C3, C4, T3, T4, Fp1, Fp2, F7, F8, T5, T6, O1, O2;
A point measured by the operator using the three-dimensional position measuring means at a point where the operator crosses the scalp on a straight line connecting the intermediate points of the line segments F7-Fz in a plane including the three reference points F7, Fz, F8 is a reference point F3. The point measured by the operator using the three-dimensional position measuring means at a point where the operator crosses the scalp on a straight line connecting the midpoints of the line segments F8-Fz in a plane including the three reference points F7, Fz, F8. Is determined as a reference point F4, and the operator uses the three-dimensional position measurement means at a point where the operator crosses the scalp on a straight line connecting the midpoints of the line segments T5-Pz in a plane including the three reference points T5, Pz, T6. The measured point is determined as a reference point P3, and the operator moves the three-dimensional position at a point where the operator intersects the scalp on a straight line connecting the midpoints of the line segments T6-Pz in a plane including the three reference points T5, Pz, T6. Measuring hand It means for determining the point of measurement as a reference point P4 with,
Means for holding each determined reference point F3, F4, P3, and P4;
A scalp shape measurement support apparatus comprising: On the scalp shape measurement support system constructed using a computer, the operator uses the three-dimensional position measuring means for measuring the three-dimensional position information of the space on the subject's head surface based on the international 10-20 system or the system. A scalp shape measurement support method for supporting a scalp shape measurement operation by specifying a plurality of reference positions defined by the standard,
The holding means included in the computer includes four reference positions Nz (nasal root), Iz (protrusion tip of the posterior skull), LPA (left ear) measured by the operator on the head surface of the subject using the three-dimensional position measuring means. A step of maintaining the position of the RPA (right auricle point);
When the temporary measurement support means included in the computer performs temporary measurement with Cz (center portion) as a point where the straight line connecting the midpoint of the two line segments of Nz-Iz and LPA-RPA intersects the head surface, The three-dimensional display of the straight line connecting the midpoints of the two line segments of Nz-Iz and LPA-RPA at the same time, and the temporary Cz measurement target position and the current position measured using the three-dimensional position measurement means Cz provisional measurement support step showing the relationship;
A holding means provided in the computer holds the position of the temporary Cz measured by the operator through support by the Cz temporary measurement support means;
When the Nz-temporary Cz-Iz distance measurement support means included in the computer measures the distance between Nz-temporary Cz-Iz, four reference positions Nz, Iz, LPA, RPA, In addition, a straight line connecting Nz-temporary Cz-Iz is displayed in three dimensions, and the operator can measure a plurality of points at a head surface position on a straight line passing through a total of three points of Nz, Iz, and Cz. An operator generates a parametric curve connecting Nz and Iz via a plurality of points measured at the head surface position on the straight line by using the three-dimensional position measuring means, and displays it in a three-dimensional manner. Iz distance measurement support step;
The Nz-temporary Cz-Iz distance measuring means provided in the computer determines an intermediate point of the parametric curve connecting Nz and Iz as a formal Cz position, and is distributed on the parametric curve. Nz-temporary Cz-Iz distance measuring step for determining reference points Fpz, Fz, Pz, and Oz;
Holding means included in the computer holds the determined (formal) Cz and the positions of the four reference points Fpz, Fz, Pz, and Oz;
The LPA-Cz-RPA, Fpz-T3-Oz, and Fpz-T4-Oz distance measuring means included in the computer are the reference points Nz, Iz, LPA, RPA, Cz, Fpz, Fz, For each of the three straight lines LPA-Cz-RPA, Fpz-T3-Oz, and Fpz-T4-Oz using Pz and Oz, the three-dimensional display of the straight line on the display supports the operator's measurement. Distances between LPA-Cz-RPA, Fpz-T3-Oz, and Fpz-T4-Oz that generate parametric curves connected via a plurality of points measured by the operator at the head surface position on a straight line and measure the distances Measuring steps;
Based on the measurement results by the distance measuring means between the LPA-Cz-RPA, between Fpz-T3-Oz, and Fpz-T4-Oz, the determining means provided in the computer is between FPA-Cz-RPA, Fpz-T3. Means for determining the position of each reference point C3, C4, T3, T4, Fp1, Fp2, F7, F8, T5, T6, O1, O2 on each parametric curve connecting between -Oz and Fpz-T4-Oz ,
Holding means provided in the computer holds the positions of the determined reference points C3, C4, T3, T4, Fp1, Fp2, F7, F8, T5, T6, O1, O2,
The determination means provided in the computer uses the three-dimensional position measurement means at a point where the determination means included in the computer intersects the scalp on a straight line connecting the midpoints of the line segments F7-Fz in a plane including three reference points F7, Fz, F8. The point measured in this manner is determined as a reference point F3, and the operator moves the three-dimensional position at a point where the operator crosses the scalp on a straight line connecting the midpoints of the line segments F8-Fz in a plane including three reference points F7, Fz, F8. A point measured using the measuring means is determined as a reference point F4, and the operator intersects with the scalp on a straight line connecting the midpoints of the line segments T5-Pz in a plane including three reference points T5, Pz, T6. A point measured using the three-dimensional position measuring means is determined as a reference point P3, and intersects with the scalp on a straight line connecting intermediate points of line segments T6-Pz in a plane including three reference points T5, Pz, T6. To the point Determining a point at which the operator was determined using the three-dimensional position measuring means as a reference point P4 Te,
A holding means included in the computer holds the determined reference points F3, F4, P3, and P4;
A scalp shape measurement support method comprising: By specifying a plurality of reference positions defined by an international 10-20 system or a standard based on the international 10-20 system on the head surface of a subject using a three-dimensional position measuring means for measuring three-dimensional position information of a space by an operator A computer program written in a computer-readable format so as to execute processing for supporting the scalp shape measurement operation on a computer, the computer comprising:
Four reference positions Nz (nasal root), Iz (protrusion tip of the posterior skull), LPA (left auricle point), RPA (right ear) measured by the operator on the head surface of the subject using the three-dimensional position measuring means. Means for maintaining the position of the intermediary point);
When a temporary measurement is performed using Cz (center portion) as a point where a straight line connecting the midpoint of two line segments of Nz-Iz and LPA-RPA intersects the head surface, 2 of Nz-Iz and LPA-RPA is displayed on the display. A Cz temporary measurement support means for displaying a relationship between a temporary Cz measurement target position and a current position measured using the three-dimensional position measurement means;
Means for holding a temporary Cz position measured by an operator through support by the Cz temporary measurement support means;
When measuring the distance between Nz-provisional Cz-Iz, the three reference lines Nz, Iz, LPA, RPA, and the straight line connecting Nz-provisional Cz-Iz are displayed on the display in three dimensions. , Nz, Iz, and Cz, the operator can measure a plurality of points at a head surface position on a straight line passing through a total of three points, and the operator can use the three-dimensional position measuring means to measure the head surface position on the straight line. Nz-provisional Cz-Iz distance measurement support means for generating a parametric curve connecting Nz and Iz via a plurality of points measured in step 3D and displaying them three-dimensionally;
The intermediate point of the parametric curve connecting Nz and Iz is determined as a formal Cz position, and four reference points Fpz, Fz, Pz, and Oz distributed on the parametric curve are determined. Cz-Iz distance measuring means;
Means for holding the position of the determined (formal) Cz and the four reference points Fpz, Fz, Pz and Oz;
For each of the three straight lines LPA-Cz-RPA, Fpz-T3-Oz, and Fpz-T4-Oz using the already determined reference points Nz, Iz, LPA, RPA, Cz, Fpz, Fz, Pz, Oz. In addition to supporting the operator's measurement by displaying a three-dimensional line on the display, a parametric curve is generated by connecting a plurality of points measured by the operator at the head surface position on the line, and the distance is measured. LPA-Cz-RPA, Fpz-T3-Oz, Fpz-T4-Oz distance measuring means,
Based on the measurement results of the LPA-Cz-RPA, Fpz-T3-Oz, Fpz-T4-Oz distance measuring means, the LPA-Cz-RPA, Fpz-T3-Oz, Fpz-T4- Means for determining the position of each reference point C3, C4, T3, T4, Fp1, Fp2, F7, F8, T5, T6, O1, O2 on each parametric curve connecting Oz;
Means for holding the position of each of the determined reference points C3, C4, T3, T4, Fp1, Fp2, F7, F8, T5, T6, O1, O2;
A point measured by the operator using the three-dimensional position measuring means at a point where the operator crosses the scalp on a straight line connecting the intermediate points of the line segments F7-Fz in a plane including the three reference points F7, Fz, F8 is a reference point F3. The point measured by the operator using the three-dimensional position measuring means at a point where the operator crosses the scalp on a straight line connecting the midpoints of the line segments F8-Fz in a plane including the three reference points F7, Fz, F8. Is determined as a reference point F4, and the operator uses the three-dimensional position measurement means at a point where the operator crosses the scalp on a straight line connecting the midpoints of the line segments T5-Pz in a plane including the three reference points T5, Pz, T6. The measured point is determined as a reference point P3, and the operator moves the three-dimensional position at a point where the operator intersects the scalp on a straight line connecting the midpoints of the line segments T6-Pz in a plane including the three reference points T5, Pz, T6. Measuring hand It means for determining the point of measurement as a reference point P4 with,
Means for holding each determined reference point F3, F4, P3, and P4;
Computer program to function as