JP3530912B2 - Dewar for biomagnetic measurement - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biomagnetic measuring dewar, and more particularly to a biomagnetic measuring dewar that can accurately recognize a measurement location by looking at a tail portion.

[0002]

2. Description of the Related Art FIG. 4 of Japanese Patent Laid-Open No. 10-155758
Discloses a biomagnetic measuring dewar in which magnetic sensors are arranged in a lattice shape on a small-diameter cylindrical tail portion. Further, in FIG. 5 of JP-A-10-155758, a living body in which a part of the circumference of a large-diameter cylindrical tail portion is linearly deformed and magnetic sensors are arranged in a lattice along the straight line A magnetic measuring dewar is disclosed.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the biomagnetic measuring dewar having a small-diameter cylindrical tail portion disclosed in FIG. 4 of Japanese Patent No. 5758, the bottom portion of the tail portion has a circular shape, and the magnetic sensor array has a lattice shape. The distance from the edge of the to the magnetic sensor is not constant. Therefore, the operator cannot estimate the position of the magnetic sensor by looking at the peripheral edge of the bottom surface of the tail portion. That is, there is a problem in that the measurement location cannot be accurately recognized even when looking at the tail portion. On the other hand, in the biomagnetism measuring dewar having a large-diameter cylindrical tail portion partially deformed into a linear shape disclosed in FIG. 5 of Japanese Patent Laid-Open No. 10-155758, along the linear portion of the tail portion. Since the magnetic sensors are arranged in a grid pattern, it can be estimated whether or not the magnetic sensors are near the target portion based on the positional relationship between the target portion and the linear portion on the peripheral edge of the bottom surface of the tail portion. However, in the part of interest where the magnetic sensor is not close, it is difficult to know how far the magnetic sensor is, so that there is still the problem that the measurement location cannot be accurately recognized even when looking at the tail part. Further, since the biomagnetic measurement dewar disclosed in FIG. 5 of Japanese Patent Laid-Open No. 10-155758 has a large diameter, it cannot be adhered to the curved head.
There is a problem that it is not possible to deal with elongated parts such as arms, legs, spinal cord and parts with irregularities (for example, irregularities such as the shoulder blades prevent access to the measurement site). Therefore, it is a first object of the present invention to provide a biomagnetic measurement dewar that can easily and accurately recognize the measurement location by looking at the tail portion. A second object of the present invention is to provide a biomagnetism measuring dewar that can be used for curved surfaces, elongated portions, and uneven portions.

[0004]

According to a first aspect of the present invention, there is provided an inner container for holding a refrigerant, and an inner container tail portion having a quadrangular bottom surface protruding cylindrically from a bottom portion of the inner container. A large number of magnetic sensors arranged on the bottom surface of the quadrangular shape along the sides of the bottom surface, an outer container surrounding the inner container and forming a gap for heat insulation with the inner container, and a bottom portion of the outer container. A biomagnet comprising a cylindrical outer container tail portion projecting in a cylindrical shape from the outer circumference of the inner container tail portion, surrounding the inner container tail portion, forming a heat insulating space between the inner container tail portion and the inner container tail portion. Provides a measuring dewar. In the dewar for biomagnetism measurement according to the first aspect, the bottom surface of the tail portion has a quadrangular shape, and a large number of magnetic sensors are arranged along the sides thereof. That is, since the magnetic sensor always exists near the side of the bottom surface of the tail portion, the measurement location can be easily and accurately recognized by looking at the tail portion.

According to a second aspect of the present invention, in the biomagnetic measuring dewar having the above structure, the bottom of the tail portion of the outer container is a small square with a side of 12 cm or less. I will provide a. Since the biomagnetic measuring dewar according to the second aspect is small, it can be measured by bringing the tail portion into close contact with the body surface of the subject without being hindered by the curvature and unevenness of the body of the subject. Furthermore, by measuring while moving the dewar or the subject, it is possible to deal with a wide area such as the chest and an elongated portion such as the arm, leg or spinal cord. Further, since the bottom surface of the tail portion is formed in a quadrangular shape and a large number of magnetic sensors are arranged along the sides of the bottom surface, when measuring while moving, the measurement points do not overlap and the sensor distribution is uniform. Therefore, efficient measurement can be performed.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in more detail with reference to the embodiments shown in the drawings. The present invention is not limited to this.

First Embodiment FIG. 1 is a sectional view showing a biomagnetic measuring dewar 100 according to a first embodiment of the present invention. Further, FIG. 2 is a bottom view thereof. This biomagnetic measurement dewar 100 is
An inner container 1 that holds, for example, liquid helium (4.2K) as the refrigerant 10, an inner container tail portion 1t that projects from the bottom of the inner container 1 into a square tubular section, and has a square bottom.
A large number of magnetic sensors 3 arranged in a lattice shape along the sides of the square bottom surface of the inner container tail portion 1t, and a space Dn for insulating the inner container 1 from the surrounding and surrounding the inner container 1.
And an outer container 2 which forms a funnel-shaped projection from the bottom of the outer container 2 to surround the inner container tail 1t and to form a heat insulating space between the inner container tail 1t and a bottom surface of 4 cm × It is configured by including a 4 cm square outer container tail portion 2t and a lid 5 of the inner container 1. In addition,
The inner container tail portion 1t and the outer container tail portion 2t.
Is called a tail portion T. The quadrangular corner of the bottom surface of the tail portion T has a radius of curvature of 2 mm from the viewpoint of pressure resistance.
It is preferable to have the above roundness.

The magnetic sensor 3 is, for example, a SQUID.
(Superconducting Quantum Interference Device).

A heat insulating material (not shown) is filled in the space Dn, and the space is evacuated. The heat insulating material is, for example, a stack of aluminum vapor-deposited polyester films.

FIG. 3 shows the biomagnetic measurement dewar 100.
It is explanatory drawing in the case of moving the tail part T and measuring the biomagnetism of the spinal cord of a subject. Since the bottom surface of the tail portion T has a square shape with a side length of 4 cm, the tail portion T can be moved in close contact with the back of the subject without being hindered by the left and right shoulder blades ke. In addition, since the magnetic sensors 3 are arranged along the bottom surface of the tail portion T in the vicinity thereof, by observing the outer edge of the bottom surface of the tail portion T, it is possible to accurately recognize the site being measured. Furthermore, since the measurement locations can be made uniform and the sensor distribution can be made uniform, efficient measurement can be performed.

FIG. 4 shows the dewar 100 for measuring the biomagnetism.
FIG. 7 is an explanatory diagram in the case of measuring the biomagnetism of the head of the subject by means of FIG. Since the bottom surface of the tail portion T has a square shape with a side of 4 cm, even if the skull zu is curved, it can be brought into close contact with the measurement point to collect signals only at the measurement point.

-Second Embodiment- FIG. 5 is a sectional view showing a biomagnetic measurement dewar 200 according to a second embodiment of the present invention. Further, FIG. 6 is a bottom view thereof. This biomagnetic measurement dewar 200 is
An inner container 6 that holds, for example, liquid helium (4.2K) as the coolant 10, an inner container tail portion 6t that projects from the bottom of the inner container 6 into a rectangular tubular shape in cross section and has a rectangular bottom surface,
A large number of magnetic sensors 3 arranged in a grid pattern along the sides of the rectangular bottom surface of the inner container tail portion 6t, and a space Dn for enclosing the inner container 6 and insulating the inner container 6 from each other.
And an outer container 7 that forms a rectangular cross-section from the bottom of the outer container 7 to surround the inner container tail 6t and to form a heat insulating space between the inner container tail 6t and the bottom. The outer container tail portion 7t having a rectangular shape of 5 cm × 10 cm and the lid 5 of the inner container 6 are provided. The inner container tail portion 6t and the outer container tail portion 7t are referred to as a tail portion T.

The tail portion T of the biomagnetism measuring dewar 200 can be moved to measure the biomagnetism of an elongated portion of the subject's spinal cord, arm, leg or the like, but the bottom surface of the tail portion T is rectangular. Because of the shape, the tail portion T can be moved by being brought into close contact with the subject without being hindered by the unevenness of the subject's body. In addition, since the magnetic sensors 3 are arranged along the bottom surface of the tail portion T in the vicinity thereof, by observing the outer edge of the bottom surface of the tail portion T, it is possible to accurately recognize the site being measured. Further, it is possible to make the measurement points non-overlapping and have a uniform distribution.

[0014]

According to the biomagnetic measuring dewar of the present invention, the following effects can be obtained. (1) Since the bottom surface of the tail portion is formed in a quadrangular shape and a large number of magnetic sensors are arranged along the sides of the bottom surface, the magnetic sensor always exists near the side of the bottom surface of the tail portion. Therefore, by looking at the tail portion, the measurement location can be easily and accurately recognized. (2) If the size is made small, the tail portion can be brought into close contact with the body surface of the subject without being hindered by the curvature and unevenness of the subject's body. Also,
By measuring while moving, it can be applied to a wide area such as the chest, and to long and narrow areas such as the arms, legs and spinal cord. At that time, since the bottom surface of the tail portion is formed in a quadrangular shape and the magnetic sensors are arranged along the sides thereof, it is easy to obtain a uniform sensor distribution without overlapping measurement points.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a biomagnetic measurement dewar according to a first embodiment.

FIG. 2 is a bottom view of the biomagnetic measurement dewar according to the first embodiment.

FIG. 3 is an explanatory diagram of a case where a biomagnetism measurement dewar according to the first embodiment is moved to measure biomagnetism of a spinal cord of a subject.

FIG. 4 is an explanatory diagram of a case where the biomagnetism of the head of the subject is measured by the biomagnetism measurement dewar according to the first embodiment.

FIG. 5 is a vertical cross-sectional view of a biomagnetic measurement dewar according to a second embodiment.

FIG. 6 is a bottom view of the biomagnetism measurement dewar according to the second embodiment.

[Explanation of symbols]

100,200 Dewar for biomagnetic measurement 1,6 inner container 2,7 outer container 3 Magnetic sensor 1t, 6t inner container tail 2t, 7t Outer container tail 5 lid 10 Refrigerant Dn void

Claims (2)

(57) [Claims] 1. An inner container that holds a refrigerant, an inner container tail portion that projects cylindrically from the bottom of the inner container and has a rectangular bottom surface, and is arranged on the rectangular bottom surface along the sides of the bottom surface. A plurality of magnetic sensors, an outer container that surrounds the inner container and forms a space for heat insulation between the inner container and the outer container, and cylindrically projects from the bottom of the outer container to surround the inner container tail portion and A biomagnetic measuring dewar, characterized in that a void for heat insulation is formed between the inner container tail portion and the outer container tail portion having a square bottom surface. 2. The demagnetizer for biomagnetic measurement according to claim 1, wherein the bottom of the tail portion of the outer container has a small square shape with a side of 12 cm or less.