JP2619437B2 - Inspection equipment using nuclear magnetic resonance - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection apparatus using nuclear magnetic resonance, and more particularly, to an inspection apparatus using nuclear magnetic resonance suitable for a subject to be inspected comfortably. .

[Prior Art] In a conventional apparatus, a magnet surrounds a subject as described in JP-A-58-1437.

Also, for a motor using a piezoelectric element, as described in Nikkei Electronics No. 423 (June 15, 1987), pp. 111 to 117, it is possible to generate a rotational motion using a standing wave by a piezo element. it can.

[Problems to be solved by the invention]

In the above-mentioned prior art, no consideration has been given to the fact that the temperature inside the bore of the magnet is increased by the gradient magnetic field generating coil or the like, or that the subject feels hot because the heat does not accumulate and diffuse therein.

Further, there is a problem that the DC and AC motors do not operate in the magnet bore due to the influence of the strong magnetic field.

An object of the present invention is to allow a subject to feel comfortable and to receive a test without feeling hot by blowing air by a motor or the like that operates even in a magnet bore and releasing heat in the magnet bore. It is in.

[Means for solving the problem]

The above object is achieved by operating a fan using a non-magnetic material such as plastic with a motor using a piezoelectric element or a bimorph, thereby releasing heat generated by blowing air into the magnet bore to the outside of the magnet, and trapping heat inside the magnet. This is achieved by preventing

[Action]

A motor using a piezoelectric element made of a nonmagnetic material can operate under a strong magnetic field in a magnet bore. Using this motor, a fan made of a non-magnetic material can be operated to blow air. By blowing air into the magnet bore with a fan operable in the magnet bore, heat generated in the magnet bore can be released outside the magnet.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. First
The figure is a sectional view of the magnet. The subject 2 is placed inside the bore of the magnet 1 that generates a static magnetic field and a gradient magnetic field.

At this time, the fan 3 driven by the piezoelectric element is installed in both sides of the magnet 1. The outside air is blown into the magnet 1 by the fan 3, and the air inside the magnet 1 is exhausted to the outside. FIG. 2 shows an embodiment of the fan 3 shown in FIG. 1 and includes a blade 31 and a piezoelectric motor 32. Piezoelectric motor 3
By using 2, operation is possible without the influence of the magnetic field of the magnet 1.

According to the present embodiment, there is an effect that the subject 2 can be inspected with a simple and inexpensive configuration without feeling the heat.

Fig. 3 shows a bimorph case in which fan 3 is connected to blade 3.
1, an embodiment is shown in which a piezoelectric element 33 is used, and the vibration of the piezoelectric element 33 is made to reciprocate the blades 31 to blow air.

 The material used above is a non-magnetic material.

In this embodiment, an example in which the fan 3 is installed near the magnet 1 has been described. However, although not inexpensive, the following embodiment is also possible. That is, it is also possible to blow air into the magnet through the duct by a fan installed in a place where the DC and AC motors operate at a magnetic field strength. At this time, the air to be blown may be cooled.

In FIG. 4, as another embodiment, an armature 4 is used in which the static magnetic field generated by the magnet 1 is used instead of the magnet outside the DC motor.
A motor can also be constituted only by this.

The air can be blown by converting the rotation of the armature 4 to a desired direction and rotating the blade 31.

In the above-described embodiment, the discomfort of the subject entering the magnet bore of the nuclear magnetic resonance inspection apparatus by blowing air is reduced, but the inside of the magnet bore becomes a narrow space for the purpose of making the magnetic field uniform and the like. Light and sound are difficult to reach, often causing anxiety to the subject. Therefore, improvement in these points will be described below.

As a means for transmitting and receiving light to and from the magnet bore, light transmission by an optical fiber can be performed without being affected by a magnetic field. Therefore, the inside of the magnet bore can be brightened, the state of the subject can be monitored, and the anxiety of the subject can be reduced.

By using a speaker utilizing the piezoelectric phenomenon instead of the speaker as a means for transmitting sound into the magnet bore, the influence of the magnetic field can be eliminated. In addition, the sound emitted by the subject in the magnet bore measures the position change of the detector due to the sound pressure with light, or uses a static magnetic field generated by a magnet instead of the external magnetic field of a normal microphone to induce the induction in the coil section. By converting it into an electromotive force, it can be extracted outside without being affected by a magnetic field.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 5 is a schematic configuration diagram of one embodiment for transmitting light into the magnet bore.
The optical fiber 13 sends light from the outside to the subject 2 installed in the bore of the magnet 1 to illuminate the subject 2 and brighten the inside of the magnet bore to reduce anxiety during the inspection.

FIG. 6 schematically shows an embodiment of the optical transmission by the optical fiber 13, in which the light from the light source 14 (the life of the light source 14 is less deteriorated by the magnetic field) placed in a place where the influence of the magnetic field is small is emitted. This is a transmission method using the fiber 3.

FIG. 7 is a schematic configuration diagram of one embodiment for monitoring the state of a subject at a remote place. In the present embodiment, the subject 2
Is reflected by the lens 15 and is incident on the optical fiber 13, and is guided by the optical fiber 13 to a camera 16 at a remote place. In the camera 16, the light passing through the optical fiber 13 is imaged on a photoelectric surface 62 by a lens 61. The image is displayed on the monitor using the signal of the photocathode 62. Thus, the subject can be monitored without being affected by the magnetic field. In this embodiment, the optical fiber 13 is used to guide to the camera 16, but when the camera 16 uses a solid-state imaging device, it can be installed near the magnet bore by being housed in a housing made of a non-magnetic material. It is. Further, a system in which an optical fiber is shared for transmitting and receiving light is also possible.

FIG. 8 shows one embodiment of transmitting sound into a magnet bore without being affected by a magnetic field. In this embodiment, the thin film piezoelectric speaker 17 is used.
Is attached to the inner surface of the magnet bore to transmit a sound from the outside to the subject 2 to reduce the anxiety of the subject 2.

9 and 10 show an embodiment in which the sound emitted from the subject 2 is taken out of the magnet without being affected by the magnetic field.
In one embodiment shown in FIG. 9, the sound emitted by the subject 2 causes the reflector 18 to vibrate.

Using an external light source 14, the light source 14 is guided into the magnet bore via the optical fiber 13, and is applied to the reflector 8. The light striking the reflecting plate 18 is reflected and again enters the detector 19 through the optical fiber 13. When the reflection plate 18 vibrates minutely, the reflectivity changes from the viewpoint of the detector 19 due to the minute vibration, and the signal of the detector 19 increases and decreases as the light intensity increases and decreases. This is measured by the arithmetic circuit 20 and the output of the arithmetic circuit 20 is used as a speaker.
The sound emitted by the subject 2 can be taken out by driving the device 21. It can also be achieved by a method using coherent light such as laser light as the light source 4 and utilizing interference between light incident on the reflector 8 and reflected light.

In Fig. 10, the magnetic field created by magnet 1 is
This is an example in which a sound emitted from the subject 2 is detected using 23 external magnetic fields. The diaphragm 131 of the microphone 23 vibrates with the sound emitted from the subject 2. The coil 132 connected to the diaphragm 131 vibrates together with the diaphragm 131. When the coil 132 vibrates, an induced electromotive force is generated in the coil 132. By amplifying this signal by the amplifier 12 and driving the speaker 21, the sound emitted from the subject 2 can be monitored externally.

By combining the above embodiments, the subject and the outside can be simultaneously connected by light and sound, and the anxiety of the subject can be reduced.

[Effects of the Invention] As described above, according to the present invention, there is an effect that a subject can be comfortably subjected to an examination.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of one embodiment of the present invention, and FIGS.
FIG. 4 and FIG. 4 are sketches of an embodiment of the blowing means, respectively.
FIG. 5 is a block diagram of one embodiment of the optical transmission / reception of the present invention, and FIG.
FIG. 5 is a diagram showing an example of the light transmitting means in FIG. 5, FIG. 7 is a diagram showing an example of the light receiving means in FIG. 5, FIG. The figure is a block diagram of the means for receiving sound. 1 ... magnet, 2 ... subject, 3 ... fan, 31 ... blade, 32 ... piezoelectric motor, 33 ... piezoelectric element, 4 ... armature.

Continuing on the front page (72) Inventor Yoshiki Murakami 1-280 Higashi Koikekubo, Kokubunji-shi, Tokyo Inside Hitachi, Ltd. Central Research Laboratory (72) Inventor Hideki Kono 1-280 Higashi Koikebo, Kokubunji-shi, Tokyo Inside Hitachi, Ltd. Central Research Laboratory (56) References JP-A-60-232139 (JP, A) JP-A-63-203148 (JP, A) JP-A-63-262146 (JP, A) JP-A-59-184808 (JP, U) Opened Sho 62-74810 (JP, U) Opened Sho 63-88309 (JP, U)

Claims (1)

(57) [Claims] An inspection apparatus using nuclear magnetic resonance, comprising: magnetic field generating means for generating a static magnetic field, a gradient magnetic field, and a high-frequency magnetic field; and signal detecting means for detecting a nuclear magnetic resonance signal from an object to be inspected. In the vicinity of the opening of the bore for generating the static magnetic field and the gradient magnetic field, a fan driven by a piezoelectric element is provided,
An inspection apparatus using nuclear magnetic resonance, which blows air into the bore and reduces discomfort felt by the inspection target placed inside the bore.