JP2004160086A - Brain function measuring system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a brain function measuring system providing various visual stimulations suited to a brain function measurement and saving a space. <P>SOLUTION: This brain function measuring system comprises a shielded room 21 electromagnetically shielded and installed with an MRI (magnetic resonance imaging) body 1, a control room 23 adjoining with the shielded room and installed with a control device 22, and an operation room 25 performing an operation. The control room is disposed with a projection device 27 for visual stimulation images, the shielded room is disposed with a screen device 28 screening the projected visual stimulation images, and a projection light opening part 70 is provided in a boundary wall between the control room 23 and the shielded room 21. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an MRI system for measuring brain magnetism when a visual stimulus is applied using a magnetic resonance imaging apparatus (MRI), and more particularly to a technique for realizing a suitable measurement without affecting a measurement result. Things.
[0002]
[Prior art]
2. Description of the Related Art In various medical situations, magnetic resonance imaging (MRI) has been used, and its measurement accuracy has been improved. For research purposes, an MRI having a specific function called fMRI (functional MRI) is used.
For example, in order to study the brain function of a subject, a visual stimulus is given to the subject, and the activated site of the brain at that time is measured using MRI. Conventionally, in order to give a visual stimulus, a display device for a visual stimulus is arranged in a shielded room in which an MRI is provided, and measurement is performed while a subject visually observes the display device.
[0003]
As a conventional technique, in a brain function measurement apparatus disclosed in Japanese Patent Application Laid-Open No. 8-173398, after mounting a mask on the subject's head, an eye cap for opening a space in front of eyes is attached to stimulate a visual stimulus. The light is transmitted from the generator to the mask through an optical fiber, and the stimulus hits the eye of the subject using a mirror.
Also, as another embodiment, a method of directly applying light of a light emitting diode to an eye to provide a visual stimulus is disclosed.
[0004]
However, in such a conventional method, it is difficult to present various images necessary for the measurement of the brain function or to precisely adjust a part where the stimulus is presented, so that a sufficiently effective measurement cannot be performed.
On the other hand, the MRI reverses a high magnetic field at a high speed and generates a strong electromagnetic wave. Therefore, the MRI is installed in a shield room for preventing leakage to the outside. Therefore, there is a limit to the space to be installed, and it is necessary to take care not to reduce the shielding effect, and the visual stimulus device that can be installed does not affect MRI, and there is a big restriction that there is no influence by electromagnetic waves. Imposed.
For this reason, it has been difficult to present a visual stimulus suitable for the measurement of brain function as described above.
[0005]
[Problems to be solved by the invention]
The present invention has been made in view of the above-mentioned problems of the related art, and is capable of providing various visual stimuli suitable for brain function measurement, and at the same time, realizing a space-saving brain function measurement system. The purpose is to provide.
[0006]
[Means to solve the problem]
In order to achieve the above object, the brain function measurement system of the present invention has the following features.
That is, a brain function measurement system that measures a brain function when a visual stimulus is applied using a magnetic resonance imaging apparatus (MRI), wherein the brain function measurement system is electromagnetically shielded and an MRI main body is installed. The control room is provided with an MRI control device adjacent to the shield room, and an operation room for operating the MRI.
In the control room, a projection device for projecting the visual stimulus image is arranged, and in the shield room, a projection device for projecting the projected visual stimulus image is arranged.In a boundary wall between the control room and the shield room, An opening for projection light is provided.
[0007]
In a configuration in which the control room is adjacent to the subject substantially to the left or to the right of the shield room with the subject lying on the bed portion in the MRI main body, the projection device is provided above the subject, and is provided in the body axis direction of the subject. Provided is a brain function measurement system including a reflector that refracts and reflects a projected light beam, a screen plate that reflects the reflected light beam, and a visual reflector that is provided so that the screen plate can be viewed immediately in front of the subject's eyeball. May be.
[0008]
As another configuration, in a configuration in which the control room is adjacent to the subject substantially above the shield room in a state where the subject lies on the bed portion in the MRI main body, the projection light beam opening is provided above the subject in the body axis direction, While projecting the visual stimulus image toward the body axis from the projection device, a projection device is provided above the subject, and a screen plate that projects the projected visual stimulus image, and the screen plate in front of the subject's eyeball portion. A brain function measurement system constituted by a viewing reflector provided so as to be visible may be provided.
[0009]
As another configuration, in a state in which the subject lies on the bed portion in the MRI main body, in a configuration in which the control room is adjacent substantially below the subject in the shield room, the projection light beam opening is provided below the subject in the body axis direction, While projecting the visual stimulus image from the projection device toward the body axis, a projection device is provided below the subject, and a screen plate that projects the projected visual stimulus image, and the screen plate in front of the subject's eyeball portion. A brain function measurement system constituted by a viewing reflector provided so as to be visible may be provided.
[0010]
Here, the projection device may include a reproducing unit that reproduces a storage medium on which the visual stimulus image is recorded in advance, and a projector unit that projects the reproduced image.
[0011]
Alternatively, the projection device may include image processing means for generating a visual stimulus image, and projector means for projecting the generated image.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described based on an example shown in the drawings. The embodiments can be appropriately modified without departing from the gist of the present invention.
An MRI apparatus (magnetic resonance imaging apparatus) is an apparatus that obtains a tomographic image of a substance by utilizing the fact that a nuclear spin placed in a static magnetic field absorbs a high-frequency magnetic field that satisfies a resonance condition of nuclear magnetic resonance. Widely used in the medical field. In recent years, development of a functional magnetic resonance imaging apparatus (functional MRI; hereinafter, referred to as fMRI) for measuring biological information such as brain function using such MRI has been promoted. It has been practiced to provide a specific visual stimulus and to study the activated area of the brain at that time.
[0013]
FIG. 1 is a partial perspective view of fMRI (1) used in the present invention. The subject lies on the bed (2) and places his head in the head coil (3). The bed (2) is slidable in the horizontal body axis direction, and the bed (2) is inserted into the hole of the gantry (4) for measurement.
[0014]
The head coil (3) includes an upper coil section (3a) and a lower coil section (3b). The subject places his / her head on the lower coil part (3b) with the upper coil part (3a) standing up as shown in FIG. 1, and then falls down on the upper coil part (3a) to cover the head.
The subject can visually recognize the outside from the window (3c) provided in the upper coil (3a).
[0015]
FIG. 2 shows an overall plan view of the brain function measurement system according to the present invention. The system (20) includes a shield room (21) in which a main body of the fMRI (1) is disposed, a control room (23) in which a control device (22) of the fMRI (1) is installed, and a measurer who uses the fMRI (1). ), And an operation room (25) in which a terminal device (24) for performing the operation of (1) is installed. In the shield room (21), the longitudinal direction of the bed (2) is arranged in the left-right direction of FIG. 2, and the subject is measured while lying down so that the head is on the right side.
[0016]
In the present embodiment, an operation room (25) is arranged adjacent to the foot side of the subject in the shield room (21), and a control room (23) is arranged on the left side of the subject. Such an arrangement is publicly known and can be appropriately constructed at the time of system construction according to the installation location.
[0017]
The fMRI (1) main body generates a strong magnetic field and strong electromagnetic waves by a static magnetic field magnet, a gradient magnetic field coil, an irradiation coil for generating a high-frequency magnetic field, and the like. Since it is necessary to shield noise of the electromagnetic wave, it is installed in a shield room (21) surrounded by a partition for shielding electromagnetic waves.
The shield room (21) is provided with an entrance (26) through which a subject or the like enters and exits, and a sufficient shield is applied to the door portion.
[0018]
Therefore, constructing the shield room (21) excessively large not only requires an installation area, but also is technically difficult, and is sufficient and minimum necessary for installing the fMRI (1). It is desirable to use a shield room (21).
However, when the brain function is measured while giving a visual stimulus to the subject as the object of the present invention, since the device for presenting the stimulus has been conventionally installed in the shield room (21), the installation position is extremely large. Not only had to be restricted, but the influence of strong magnetic fields and strong electromagnetic waves on the equipment was unavoidable, and the types of equipment were also greatly restricted.
[0019]
Therefore, the present invention adopts a configuration in which a visual stimulus image used when presenting a stimulus is projected by a projector device and projected on a screen, and the projector device (27) is placed in a control room (23) to provide a screen (28) as a projection device. ) And a mirror (29) were installed in the shield room (21), respectively, to solve the above problem.
[0020]
That is, since the shield room (21) has the above-mentioned problems of installation space and electromagnetic waves, it is a non-magnetic material and does not affect the measurement, and the screen (28) and the mirror (29) do not take up space. Only place. On the other hand, by disposing the projector device (27) in the control room (23) in which the temperature and humidity are sufficiently managed for the control device (22) to be placed, the operating environment of the projector device (27) is reduced. In addition to being extremely well-maintained, since it is outside the shielded room, malfunctions due to electromagnetic waves and noise do not occur.
[0021]
The measurer generates a visual stimulus image using the terminal device (24) in the operation room (25) at the time of measurement, and projects it from the projector device (27). In this embodiment, since the control room (23) is adjacent to the left side of the subject, the light is projected from the left side.
The projected light beam passes through an optical path (30), is reflected by a mirror (29), is refracted by 90 degrees, and becomes an optical path (31). The visual stimulus image is projected on a screen (28) provided on the optical path (31).
A reflection device (50) as shown in FIG. 6 is provided on a window (3c) provided in the head coil (3), and a subject can visually recognize an image reflected on the reflection device (50).
[0022]
FIG. 7 shows an optical path explanatory diagram of the visual stimulus image when viewed from the side of the subject at this time. A visual stimulus image is projected on the screen (29), and the visual stimulus image is presented on the eyeball (55) of the subject by an optical path indicated by a dotted line.
As shown in the perspective view of FIG. 6, the reflecting device (50) is configured such that inclined bearings (52) (52) attached to both ends of a horizontally long rectangular mirror portion (51) are substantially T-shaped supporting members (53) ( 53).
The support members (53) and (53) are attached by fixtures (54) and (54) near the left and right ends of the subject in the upper coil portion (3a), respectively.
[0023]
Such a reflection device (50) is known, and for example, Japanese Patent Application No. 2002-202421 filed by the present applicant discloses a configuration of a reflection device using a dichroic mirror.
[0024]
In the present invention, the measurer performs an operation from the operation room (25) to measure brain magnetism by fMRI (1) while presenting a visual stimulus suitable for measurement. This makes it possible to measure brain functions from the relationship between visual stimulation and brain magnetism.
[0025]
FIGS. 3, 4, and 5 show another embodiment according to the present invention.
The system (20) shown in FIG. 3, FIG. 4, and FIG. 5 also has a shield room (21) in which the main body of the fMRI (1) is disposed, and a control device (22) for the fMRI (1). ) Is installed in the control room (23), and an operation room (25) is installed in the terminal room (24) where the measurer operates the fMRI (1). The shield room (21) is provided with a well-shielded entrance (26).
In the shield room (21), the longitudinal direction of the bed (2) is arranged in the left-right direction of FIGS. 3 to 5, and the subject is measured while lying down so that the head is on the right side.
[0026]
In the embodiment of FIG. 3, an operation room (25) is arranged adjacent to the subject's foot side of the shield room (21), and a control room (23) is arranged on the right side of the subject. In this configuration, similarly to the above, a visual stimulus image is projected from the projector device (27), reflected on the mirror (29) via the optical path (40), refracted by 90 degrees, and the screen (28) on the optical path (41). Projected to
The subject looks through the mirror device (50) shown in FIG.
[0027]
In the embodiment of FIG. 4, the operation room (25) is arranged adjacent to the subject's foot side of the shield room (21), and the control room (23) is arranged above the subject. In this configuration, only the screen (28) is used as the projection device, and a projection image (optical path (42)) from the projector device (27), which is a projection device, is directly projected.
The configuration that the subject visually observes uses the mirror device (50) as in the above two embodiments.
[0028]
In the embodiment of FIG. 5, the control room (23) is arranged adjacent to the subject's foot side of the shield room (21), and the operation room (25) is arranged above the subject. In this configuration, only the screen (28) is used as the projection device, and unlike the above embodiment, the screen (28) is arranged immediately below the subject.
The projection image (optical path (43)) from the projector device (27), which is a projection device, is directly projected on the screen, and the subject uses the mirror device (50) in the same manner as in the above embodiment. It is needless to say that the mirror part (51) of the above is different from the direction shown in FIG. The present invention can also be implemented by this configuration.
[0029]
The mirror (29) used here is a substantially flat body having a length of 800 mm, a width of 1700 mm, and a thickness of 150 mm. A non-magnetic honeycomb member is used inside, and a non-magnetic reflection member is provided on one surface. Stick it. By adopting a honeycomb structure, the weight is reduced while securing the strength. Examples of the material of the nonmagnetic material include synthetic resin materials, wood, and nonmagnetic metals, and any material can be used.
The mirror (29) having the above size has an effective reflection area of 700 mm in length and 1600 mm in width, and the center of the mirror (29) is installed at a position 1200 mm away from the gantry (4).
[0030]
The screen (28) is also made of a non-magnetic translucent member, and has a size of 1100 mm in height and 2170 mm in width, and an effective projection range of 640 mm in height and 1270 mm in width.
The embodiment of the present invention can be arbitrarily changed and is not limited to the above size. However, the size of the gantry (4) of the fMRI (1) and the effect of the visual stimulus may cause the mirror (29) to fail. And the size of the screen (28) is preferred.
[0031]
The present invention is characterized in that the projector device (27) is disposed in the control room (23). Finally, the projection light beam opening (70) is provided between the control room (23) and the shield room (21). Will be described. FIG. 8 is a perspective view of the opening (70) as viewed from the inside of the shield chamber (21).
As is apparent from the figure, the projection light beam opening (70) is formed in a rectangular shape at a height of 100 cm to 150 cm from the floor surface, and in this embodiment, each of the two projector devices (27) is formed from the same. The lens portions (71) and (72) protrude.
[0032]
The openings (70) other than the lens portions (71) and (72) are completely fitted with a shield plate and have a sufficient shielding effect, and the lens portions (71) and (72) are also made of a non-magnetic material. Care is taken not to affect the measurement.
Here, the two lens units (71) and (72) are provided for separately projecting visual stimuli to be presented to the left and right eyes, and are provided from the terminal device (24) in the operation room (25). Collectively controlled. In the present invention, it is not always necessary to provide two lens units, and one may be provided. Alternatively, a configuration may be adopted in which a transparent or translucent member having a shielding effect is provided in the opening (70) without projecting the lens portions (71) and (72), and the light is projected from the control room (23) through the member.
[0033]
In the present invention, the projector device (27) is used as the projection device. Here, the function of generating a visual stimulus image on the projection device or the visual stimulus image previously recorded on an arbitrary storage medium, for example, a video tape or a DVD is used. A configuration may be provided in which a function for reproducing is provided, and a visual stimulus image is projected by operating the terminal device (24).
[0034]
Also, the visual stimulus image can be generated and reproduced by the terminal device (24). In that case, it is simple to use a well-known personal computer for the terminal device (24), whereby a precise visual stimulus image can be generated or reproduced. In addition, as long as the visual stimulus image is simply reproduced repeatedly, a known video player can be used.
[0035]
【The invention's effect】
The present invention has the above-described configuration, and thus has the following effects.
That is, the configuration in which the projection device of the visual stimulus image created by the present invention is arranged in the control room and the projection device is arranged in the shield room is large enough to present the visual stimulus while installing the MRI with a small installation area. Thus, a suitable brain function can be measured using a projection device that can project a visual stimulus image.
[0036]
Further, by providing the reflection plate, not only can the positions of the projection device and the projection device be set freely, but also a sufficient optical path length can be obtained and the image from the projection device can be projected onto the projection device having a sufficient area.
[0037]
Furthermore, according to the present invention, it is only necessary to install a non-magnetic projection device in a shield room where it is necessary to enhance the shielding effect and improve the measurement accuracy. Since a projection device with strict conditions can be installed, and a measurer can perform measurement in an operation room with an office living room environment, members and personnel suitable for each environment can be arranged, thereby contributing to suitable measurement of brain function.
[Brief description of the drawings]
FIG. 1 is an explanatory perspective view of an MRI apparatus according to the present invention.
FIG. 2 is an overall plan view of the brain function measurement system.
FIG. 3 shows another embodiment.
FIG. 4 shows another embodiment.
FIG. 5 shows another embodiment.
FIG. 6 is a perspective view of a reflection device according to the present invention.
FIG. 7 is a side view illustrating an optical path of a visual stimulus image when the reflection device is used.
FIG. 8 is a perspective view of a projection light beam opening according to the present invention.
[Explanation of symbols]
1 fMRI
2 Bed 3 Head Coil 4 Gantry 20 Brain Function Measurement System 21 Shield Room 22 Control Device 23 Control Room 24 Terminal Device 25 Operation Room 26 Doorway 27 Projector Device 28 Screen 29 Mirror 30 Optical Path 31 Optical Path 70 Projection Ray Opening

Claims (6)

A brain function measurement system that measures a brain function when a visual stimulus is applied using a magnetic resonance imaging apparatus (MRI), wherein the brain function measurement system includes:
An electromagnetically shielded shield room in which the MRI body is installed,
A control room adjacent to the shield room, where the control device for the MRI is installed;
And an operation room for operating the MRI.
In the control room, a visual stimulus image projection device is arranged,
In the shield room, a projection device that projects the projected visual stimulus image is arranged,
A brain function measurement system, wherein an opening for a projected light beam is provided in a boundary wall between the control room and the shield room. In a configuration in which the subject is lying on the bed portion in the MRI main body, the control room is adjacent to the subject substantially to the left or to the right of the shield room,
The projection device,
A reflector provided above the subject and refracting and reflecting the projected light beam in the body axis direction of the subject,
A screen plate that reflects the reflected light rays,
The brain function measurement system according to claim 1, further comprising: a visual reflector provided so as to be able to visually recognize the screen plate immediately before the eyeball of the subject. In a configuration in which the subject is lying on the bed portion in the MRI main body and the control room is adjacent to the subject substantially above the shield room,
The projection light beam opening is provided above the subject in the body axis direction, and projects a visual stimulus image toward the body axis from the projection device,
The projection device,
A screen plate provided above the subject and projecting the projected visual stimulus image,
The brain function measurement system according to claim 1, further comprising: a visual reflector provided so as to be able to visually recognize the screen plate immediately before the eyeball of the subject. In a configuration in which the subject is lying on the bed portion in the MRI main body and the control room is adjacent to the subject substantially below the shield room,
The projection light beam opening is provided below the body axis direction of the subject, and while projecting a visual stimulus image from the projection device toward the body axis,
The projection device,
A screen plate provided below the subject and projecting the projected visual stimulus image,
The brain function measurement system according to claim 1, further comprising: a visual reflector provided so as to be able to visually recognize the screen plate immediately before the eyeball of the subject. The projection device,
Playback means for playing back a storage medium on which a visual stimulus image has been recorded in advance;
5. The brain function measurement system according to claim 1, further comprising a projector for projecting the reproduced image. The projection device,
Image processing means for generating a visual stimulus image;
5. The brain function measurement system according to claim 1, further comprising a projector for projecting the generated image.

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