JPH0295336A - Biomagnetic measuring device - Google Patents

Abstract

PURPOSE:To execute measurement from a side surface direction in a condition in which a subject is in an natural attitude such as standing and sitting by forming the bottom surface of a cooling container so as to be inclined at a prescribed angle from the center axis of the cooling container and arranging many detecting coils along the bottom surface. CONSTITUTION:Since, in a Dewar 2, the bottom surface is inclined at 45 deg. and simultaneously, it is the recessed surface in a spherical shape, many detecting coils 42 are arranged along the recessed surface at 45 deg.. The bottom surface of the Dewar 2, the bottom surface of a Dewar 3 and the bottom surface of a Dewar 4 are applied onto the right side surface, left side surface and rear side surface of the cranium of a subject 6, respectively. Onto the upper surface of the cranium, the bottom surface of a Dewar 5 is applied. Since the bottom surfaces are made into the recessed surfaces in the spherical shape, respectively, they are made into contact with the cranium in wrapping it. For such a reason, respectively nineteen detecting coils 42 are made to approach the cranium all, and the whole of the cranium is covered with total seventy-two detecting coils 42. For such a reason, a biomagnetic multichannel simultaneous measurement can be executed, and brain magnetic diagram and an equal magnetic field curve obtained from the data of seventy-two channels can be displayed on a monitor.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a biomagnetism measurement device that measures minute magnetism inside a living body.

[Conventional technology]

When a stimulus is applied to a living body, the polarization formed between cell membranes breaks down, causing an active current to flow. Such action currents are seen in the brain, heart, skeletal muscles, retina, etc., and are called electroencephalograms, electrocardiograms, electromyograms, M-reticular electrograms, etc., respectively. Records of magnetic fields caused by the flow of electric current are called magnetoencephalography, magnetocardiography, magnetomyography, magnetoretinography, etc., respectively. In recent years, SQU has been used as a device to measure magnetism in living organisms.
I D (Superconducting Quan)
tum l] surfaceDevice: superconducting quantum interference device) has been developed, and it has become easier to measure minute magnetic fields in living organisms (Trigger special volume p155-163. December 1987, Parity special volume N
o, 1. p26-38.1986. Medical System News vol. 1.9 No. 4 No. 100 p26-
27.1988). This SQUID needs to be cooled with liquid helium to maintain its superconducting state, and is usually immersed in liquid helium filled in a container called a dewar. The conventional dewar has a cylindrical shape, and its bottom surface is approximately perpendicular to its central axis. A detection coil is placed near the bottom surface, and the dewar is suspended from above so that the detection coil and 5QUID unit near the bottom surface are always immersed in liquid helium.

[Problem to be solved by the invention]

In this way, in the conventional biomagnetic measurement device, the 5QUID
Since the sensor is placed in a dewar and immersed in liquid helium, there is a problem in that it cannot measure the living body from a horizontal direction. In other words, in order to take measurements from the horizontal direction, the detection surface (the bottom surface) must be vertical and as close as possible to the side of the subject. This is because it cannot be taken as long as it is included. Therefore, in the past, when trying to measure the skull from the side, for example, it was necessary to lay the subject lying down and apply the bottom of the dewar from above. It is not possible to measure by having the patient take a standing or sitting position. An object of the present invention is to provide a biomagnetic measurement device that enables measurement from the side of a subject while the subject is in a natural body position such as standing or sitting.

[Means to solve the problem]

In order to achieve the above object, the present invention comprises a large number of detection components,
In a living wood magnetic measurement device in which a large number of 5QUID units connected to each detection coil are housed in a cooling container, the bottom surface of the cooling container is formed by tilting at a predetermined angle from the central axis of the cooling container, and a large number of 5QUID units connected to each detection coil are A feature is that the detection coil is arranged along this bottom surface.

[For production]

Since the bottom surface of the cooling container is inclined, even if the bottom surface is made vertical, the 5QUID unit and the detection coil remain immersed in the cooling medium in the cooling container. Therefore, it is possible to bring this bottom vertically close to the side of the subject, so even when measuring from the side of the skull, the subject remains in a natural body position such as standing or sitting. Measurements can be made. Therefore, it is suitable for measuring the magnetic field of the brain.

【Example】

Next, an embodiment of the present invention will be described with reference to the drawings. Figures A and B show the entire system.
As shown in these figures, four dewars 2 to 5 are suspended from the ceiling of the eddy current shield room 1, and their bottom surfaces are placed against the skull of the subject 6 so as to surround it. There is. Further, in this eddy current shield room 1, a stimulus and pattern display device 7 for stimulating the subject 6 is arranged. These dewars 2 to 5 each have an arm 2 extending and contracting from a base 21, as shown in FIG.
2 is held by a belt 24 via a shaft 23. The dewars 2 to 5 have a generally cylindrical shape, and by loosening a fixing device (not shown) on the belt 24, the dewars can be opened.
2 to 5 can rotate about their central axes. Further, this belt 24 is rotatably attached to the tip of the arm 22 by a shaft 23. Further, the base 21 is movable along a rail (not shown) provided on the ceiling and is rotatable about a vertical axis. With such a hanging mechanism, each dewar 2 to 5
can freely set the horizontal force and position in the vertical direction, and can also freely set the direction in the horizontal plane, freely set the inclination angle with respect to the vertical axis, and can also rotate around its own central axis. can. As shown in FIGS. 2 and 3, the bottom surfaces of the dewars 2 to 4 are inclined at about 45 degrees from their central axes. dewar
The bottom surface of 5 is approximately perpendicular to its central axis, similar to the usual one. These bottom surfaces are all concave so that when placed against the skull of the subject 6, they come into closer contact. The interior of dewars 2 to 5 is constructed as shown in FIG. Dewars 2 to 4 are exactly the same, except that dewar 5 has a nearly right-angled bottom.
Therefore, only Dewar-2 is shown in Figure 3.
The internal structure of the dewar 2 will be explained. Deyuwa-2 is
It consists of a liquid helium container 32 into which liquid helium 41 is placed, and an envelope 31 that covers the outside thereof. This envelope 3
There is a vacuum 33 inside 1, and a liquid helium container 32
A super insulation layer 35 serving as a heat insulating material and a vapor cooling metal strip 34 are arranged so as to surround it. A number of detection coils 42 are arranged at the bottom of the liquid helium container 32 . Each of the detection coils 42 is wound around a quartz bobbin. In this dewar-2, the bottom is 45
Since it has a spherical concave surface inclined at an angle of 45 degrees, a large number of detection coils 42 are arranged along this concave surface of 45 degrees. In the case of the dewar 5, the bottom surface is a substantially right-angled spherical concave surface, and a large number of detection coils are arranged along the bottom surface. In either case, the detection coil 42
When viewed from the front, they are arranged at equal intervals as shown in FIG. 4, and are directed toward the center of curvature of the spherical concave surface. Here, 19 detection coils 42 are arranged for each dewar as shown in FIG.
It is connected to nine [)C8QUID units 43. These detection coil 42 and DC3QUID unit 43 are supported by a support tube 44. This support tube 4
A heat radiation shield 45 is attached to the top of 4. The DC3QUID unit 43 is connected to an external electronic circuit via a preamplifier unit 51 attached to the outside of the dewar 5.
k Loop). The magnetic flux detection outputs of the 19 channels obtained in this way are each digitized by 19 A/D converters, and once stored in memory,
Necessary processing is performed. In this example, a dewar 2 is attached to the right side of the skull of the subject 6.
The bottom surface of the dewar 3 is placed on the left side, and the bottom surface of the dewar 4 is placed on the rear side. Further, the bottom surface of the dewar 5 is placed on the top surface of the skull. Each of these bottom surfaces has a spherical concave surface, so they fit tightly around the skull. Therefore, all 19 detection coils 42 are brought close to the cranium, and the entire cranium is covered by a total of 72 detection coils 42. Therefore, biomagnetism can be measured simultaneously in multiple channels, and magnetoencephalograms and isomagnetic field curves obtained from the data of these 72 channels can be displayed on a monitor device. As a result, images can be observed in real time, with excellent immediacy. (As a result, the time the subject is detained becomes longer, and real-time observation is not possible, resulting in a lack of immediacy).

【Effect of the invention】

According to the biomagnetic field measuring device of the present invention, the subject is placed in a standing position,
Measurements can be taken from the side while the body is in a natural position such as sitting.

[Brief explanation of drawings]

1A and 1B are schematic diagrams of the entire embodiment; FIG. 1A is a front view, FIG. 1B is a side view, and FIG. 2 is an enlarged front view;
FIG. 3 is a sectional view, and FIG. 4 is a front view showing the arrangement of the detection coils. 1... Eddy current shield room, 2-5... Dewar-16
... Subject, 7... Stimulus and pattern display device, 2
1...Base, 22...Arm, 23...Axis, 2
4... Belt, 31... Envelope, 32... Liquid helium container, 33... Vacuum, 34... Vapor cooling metal strip, 35... Super insulation layer, 41... Liquid helium, 42...Detection coil, 4
3...DC3QUID unit, 44...support tube,
45... Heat radiation shield, 51... Preamplifier unit.

Claims (1)

[Claims] (1) In a biomagnetic measuring device in which a large number of detection coils and a large number of SQUID units connected to each detection coil are housed in a cooling container, the bottom surface of the cooling container is inclined at a predetermined angle from its central axis. formed by
A biomagnetism measuring device characterized in that a large number of detection coils are arranged along the bottom surface.