Dual-helmet magnetoencephalography measurement device

Abstract

A dual-helmet magnetoencephalography measuring device comprises: an inner container storing a liquid refrigerant; an outer container arranged to surround the inner container and comprising a first outer helmet and a second outer helmet arranged to be spaced apart from each other; a first sensor-mounted helmet arranged to surround the first outer helmet between the outer container and the inner container; a second sensor-mounted helmet arranged to surround the second outer helmet between the outer container and the inner container; a plurality of first SQUID sensor modules arranged on the first sensor-mounted helmet; and a plurality of second SQUID sensor modules arranged on the second sensor-mounted helmet.

Description

Technical Field

[0001] The present disclosure relates to a magnetoencephalography device, and more particularly, to a magnetoencephalography device provided with a dual helmet. Background Art

[0002] A magnetoencephalography device is a device for measuring magnetic signals generated by microcurrents of brain neural circuits, and is used to study brain functions and diagnose functional brain diseases.

[0003] Typically, brain magnetic signals have an amplitude of 10fT to 1pT and a frequency of 0.1kHz to 1kHz. Therefore, there is a need for magnetic sensors with improved sensitivity and technology to eliminate environmental magnetic noise. Currently, the most advantageous magnetic sensor in practice is a superconducting quantum interference device (SQUID) based on the low-temperature superconductor niobium (Nb).

[0004] Since the critical temperature of Nb used for low-temperature superconducting SQUID is 9K, liquid helium or a cryogenic refrigerator is required for cooling. General magnetoencephalography devices require replenishment of liquid helium. The structure, thickness, and installation method of the material need to be optimized to reduce the evaporation rate of the Dewar while reducing the thermomagnetic noise caused by the superinsulation and heat shield installed in the vacuum part of the Dewar. In addition, since helium easily passes through small gaps, high-density glass fiber reinforced plastic needs to be used as the material of the Dewar.

[0005] Since the strength of the magnetic signal from the magnetic field signal source decreases inversely with the square of the distance, the distance between the signal source and the pickup coil needs to be significantly reduced to improve the signal-to-noise ratio (SNR). This approach has been studied to develop and use a coil-in-vacuum (CIV) SQUID in which the pickup coil is arranged in a vacuum container.

[0006] In the CIV SQUID device, the pickup coil and the SQUID sensor are arranged to be maintained in a vacuum state. Therefore, only low-temperature refrigerant exists in the internal helium storage container for storing liquid refrigerant. Therefore, there is only a path for filling refrigerant. Therefore, the diameter of the neck of the internal helium storage container can be significantly reduced. Therefore, the evaporation rate of the liquid refrigerant can be reduced. Summary of the invention

[0007]

Technical issues

[0008] One aspect of the present disclosure is to provide a coil-in-vacuum and dual-helmet structure capable of measuring adults and children in a single magnetoencephalography device measurement apparatus.

[0009] Another aspect of the present disclosure is to provide a cooling device having a double-wall structure capable of blocking radiant heat.

[0010] Another aspect of the present disclosure is to provide a coolant tube structure having a coaxial double-tube structure capable of providing a rotational movement of a Dewar flask.

[0011] Another aspect of the present disclosure is to provide a cooling device capable of circulating a refrigerant.

[0012] Another aspect of the present disclosure is to provide a magnetoencephalography measuring device including two helmets.

[0013]

Technical solution

[0014] The dual-helmet magnetoencephalography measuring device according to the exemplary embodiment includes: an inner container storing a liquid refrigerant; an outer container arranged to surround the inner container and including a first outer helmet and a second outer helmet arranged to be spaced apart from each other; a first sensor-mounted helmet arranged to surround the first outer helmet between the outer container and the inner container; a second sensor-mounted helmet arranged to surround the second outer helmet between the outer container and the inner container; a plurality of first SQUID sensor modules arranged on the first sensor-mounted helmet; and a plurality of second SQUID sensor modules arranged on the second sensor-mounted helmet. The space between the outer container and the inner container is in a vacuum state.

[0015] In an example embodiment, the outer container may be branched in a T-form. The outer container may include a first branch and a second branch branched from a cylindrical outer container body portion in a T-form. Each of the first outer helmet and the second outer helmet may be connected to the first branch and the second branch, respectively. The first outer helmet and the second outer helmet may face each other and may have different sizes.

[0016] In an example embodiment, the dual-helmet magnetoencephalography measuring device may further include: a rotational motion unit that rotates the inner container and the outer container around a central axis of the rotational motion unit.

[0017] In an example embodiment, the inner container may include a neck portion in which a baffle insert is inserted and an inner body portion having an increased diameter compared to the neck portion. The neck portion may have a double-walled structure including an inner cylinder and an outer cylinder surrounding the inner cylinder.

[0018] In example embodiments, the neck may further include a heat insulating layer disposed between the inner cylinder and the outer cylinder.

[0019] In an example embodiment, the inner cylinder may further include a plurality of annular protrusions protruding outward from the inner cylinder. The heat anchors may be connected to the annular protrusions, respectively. The annular protrusions may be arranged to be spaced apart from each other. The outer cylinder may be separated, with the annular protrusions sandwiched therebetween.

[0020] In example embodiments, an outer circumferential surface of the annular protrusion and an inner circumferential surface of the heat anchor may be threadedly connected to each other.

[0021] In example embodiments, the heat anchor may include a cylindrical heat anchor connection portion and a disc-shaped heat anchor body portion disposed on an outer circumferential surface of the heat anchor connection portion. An inner circumferential surface of the heat anchor connection portion may be threadedly connected to an outer circumferential surface of the annular protrusion.

[0022] In an example embodiment, the inner container may include: a neck portion in which a baffle plug is inserted; and a main body portion having an increased diameter compared to the neck portion. The dual-helmet magnetoencephalography measurement device may also include: a refrigerant discharge pipe, which is arranged at the baffle plug and discharges vaporized refrigerant; a refrigerant injection pipe, which is arranged at the baffle plug and injects refrigerant; and a condenser, which is connected to the refrigerant discharge pipe and the refrigerant injection pipe, and condenses the vaporized refrigerant discharged through the refrigerant injection pipe. The refrigerant injection pipe may have a coaxial structure inserted in the refrigerant discharge pipe.

[0023] In example embodiments, each of the refrigerant discharge pipe and the refrigerant injection pipe may be a double pipe including an inner pipe and an outer pipe.

[0024] In an exemplary embodiment, the dual-helmet magnetoencephalography measurement device may further include: a C-shaped external container support portion that supports the lower surfaces of the first branch and the second branch; and a rotational motion unit that is connected to the external container support portion to provide rotational motion to the external container.

[0025] In an exemplary embodiment, the dual-helmet magnetoencephalography measuring device may further include: a vacuum sealing portion inserted into a through hole formed in a lower surface of each of the first branch and the second branch to seal a signal line, and arranged inside the external container support portion; and a signal line junction box arranged below the external container support portion and connecting the signal lines sealed by the vacuum sealing portion to each other. The rotational motion unit may further include: an upper base box arranged to surround the signal line junction box; a lower base box arranged below the upper base box; and a bearing portion arranged between the upper base box and the lower base box to provide rotational motion to the upper base box.

[0026] In an exemplary embodiment, the dual-helmet magnetoencephalography device may further include: a handle connected to the outer side of the upper base box.

[0027] In an example embodiment, the first outer helmet may include a connection portion provided with a long groove. The first outer helmet may be connected to one end of the first branch while rotating along the long groove in an aligned state. The second outer helmet may include a connection portion provided with a long groove. The second outer helmet may be connected to one end of the second branch while rotating along the long groove in an aligned state.

[0028] In an example embodiment, the inner container may include: a neck having a baffle insert inserted therein; a first body portion having an increased diameter compared to the neck; a second body portion having an increased diameter compared to the first body portion; and a third body portion having a decreased diameter compared to the second body portion.

[0029] In an exemplary embodiment, the dual-helmet magnetoencephalography measurement device may also include: a pair of first support parts, which are connected to the interface between the neck and the first main body part and extend in the direction of the first external helmet and the direction of the second external helmet, respectively; a pair of second support parts, which are connected to the interface between the first main body part and the second main body part and extend in the direction of the first external helmet and the direction of the second external helmet, respectively; a pair of third support parts, which are connected to the interface between the second main body part and the third main body part and extend in the direction of the first external helmet and the direction of the second external helmet, respectively; a first fixing ring, which is connected to the first support part, the second support part and the third support part in the direction of the first external helmet; a second fixing ring, which is connected to the first support part, the second support part and the third support part in the direction of the second external helmet; a first auxiliary fixing part, which connects the first fixing ring and the first helmet mounted with a sensor; and a second auxiliary fixing part, which connects the second fixing ring and the second helmet mounted with a sensor.

[0030] In an exemplary embodiment, each of the first supporting portion, the second supporting portion, and the third supporting portion may include a plurality of arc-shaped long grooves. A connecting member may be inserted into each of the arc-shaped long grooves to connect to the inner container.

[0031] In an exemplary embodiment, the first sensor-mounted helmet may include: a helmet body having an opening area for ensuring a field of vision, a lower brim arranged along an edge of a lower surface of the helmet body, an upper brim with a brim provided at the opening portion of the helmet body, a helmet fixing ring having an annular shape connected to the upper brim continuously from the lower edge at predetermined intervals, and a plurality of connecting columns vertically connecting the lower brim and the upper brim to each other.

[0032] In an exemplary embodiment, the dual-helmet magnetoencephalography measuring device may further include: a first auxiliary heat anchor, which is arranged on the lower surface of each of the upper brim and the lower brim of the first sensor-mounted helmet; a first internal 4K heat insulation portion, which is in thermal contact with the first auxiliary heat anchor and is arranged on the inner surface of the first sensor-mounted helmet; and a first external 4K heat insulation portion, which is in thermal contact with the first auxiliary heat anchor and is arranged on the outer surface of the first sensor-mounted helmet. The first auxiliary heat anchor, the first internal 4K heat insulation portion, and the first external 4K heat insulation portion may be in thermal contact with the main heat anchor through a litz wire.

[0033] In an example embodiment, each of the plurality of first SQUID sensor modules may be in thermal contact with a primary thermal anchor disposed on the lower surface of the inner container via a Litz wire. Each of the plurality of second SQUID sensor modules may be in thermal contact with a primary thermal anchor disposed on the lower surface of the inner container via a Litz wire.

[0034] In an example embodiment, the first SQUID sensor module may be cooled by a plurality of Litz wires. Portions of the plurality of Litz wires arranged around the first SQUID sensor module may be connected to the first SQUID sensor module, and the remainder of the plurality of Litz wires may be in thermal contact with a primary heat anchor.

[0035] In an example embodiment, the first SQUID sensor module may be cooled by six Litz wires. Of the six Litz wires, two Litz wires may be in thermal contact with the primary heat anchor, and four Litz wires arranged around the first SQUID sensor module may be connected to the first SQUID sensor module.

[0036] In an example embodiment, the inner container may include a neck in which a baffle insert is inserted. The neck may have a double-wall structure. First to third thermal anchors arranged in a washer shape vertically spaced from each other may be provided on the outside of the neck. The first thermal anchor may be connected to a 120K insulation layer. The second thermal anchor may be connected to an 80K insulation layer. The third thermal anchor may be connected to a 40K insulation layer.

[0037] In an example embodiment, the 40K thermal insulation layer may be arranged to surround the first sensor-mounted helmet and the second sensor-mounted helmet.

[0038] In an example embodiment, the first SQUID sensor module may be inserted into a through hole formed in the first sensor-mounted helmet to be fixed. The first SQUID sensor module may include a plurality of holes. Litz wires may be respectively inserted into the holes to cool the SQUID sensor.

[0039] In an example embodiment, the main heat anchor may include: a first heat transfer unit formed of oxygen-free copper and including a first plate, a first upper protrusion protruding from a central axis of the first plate to an upper surface of the first plate, and a first lower protrusion protruding from the central axis of the first plate to a lower surface of the first plate; a second heat transfer unit formed of oxygen-free copper and including a second plate, a second upper protrusion protruding from a central axis of the second plate to an upper surface of the second plate, and a second lower protrusion protruding from the central axis of the second plate to a lower surface of the second plate; a third heat transfer unit formed of oxygen-free copper and including a third plate, a third upper protrusion protruding from a central axis of the third plate to an upper surface of the third plate, and a third lower protrusion protruding from a central axis of the third plate to a lower surface of the third plate; a third lower protrusion protruding from the central axis of the fourth disk to the upper surface of the fourth disk; a fourth heat transfer unit formed of oxygen-free copper and including a fourth disk, a fourth upper protrusion protruding from the central axis of the fourth disk to the upper surface of the fourth disk, and a fourth lower protrusion protruding from the central axis of the fourth disk to the lower surface of the fourth disk; a fifth heat transfer unit formed of oxygen-free copper, connected to the fourth heat transfer unit, and having a plate shape; a first thermal expansion control unit formed of an insulating material and inserted between the first disk of the first heat transfer unit and the second disk of the second heat transfer unit; and a second thermal expansion control unit formed of an insulating material and inserted between the third disk of the third heat transfer unit and the fourth disk of the fourth heat transfer unit. The second upper protrusion of the second heat transfer unit may be provided with a groove for connecting to the first lower protrusion of the first heat transfer unit. The second lower protrusion of the second heat transfer unit may be provided with a groove for connecting to the third upper protrusion of the third heat transfer unit. The third lower protrusion of the third heat transfer unit may be provided with a groove for connecting to the fourth upper protrusion of the fourth heat transfer unit.

[0040] In an example embodiment, the first thermal expansion control unit may include: a first insulating body portion having a diameter equal to a first diameter of the first disk; a second insulating body portion embedded in a lower surface of the inner body and having a second diameter larger than the first diameter; and a third insulating body portion having a third diameter smaller than the second diameter. The third insulating body portion may be arranged to surround an outer circumferential surface of the second disk.

[0041] A magnetic field measuring device according to an example embodiment includes: an outer container; and a cylindrical inner container which stores a liquid refrigerant and is inserted into the outer container. The inner container includes: a neck in which a baffle insert is inserted; and a body having a diameter increased compared to the neck. The neck may have a double-walled structure including an inner cylinder and an outer cylinder surrounding the inner cylinder.

[0042] In an exemplary embodiment, the inner cylinder may further include a plurality of annular protrusions protruding outward from the cylinder body. The heat anchors may be connected to the annular protrusions, respectively. The annular protrusions may be arranged to be spaced apart from each other. The outer cylinder may be separated, with the annular protrusions sandwiched therebetween.

[0043] In example embodiments, the neck may further include a heat insulating layer disposed between the inner cylinder and the outer cylinder.

[0044] In example embodiments, an outer circumferential surface of the annular protrusion and an inner circumferential surface of the heat anchor may be threadedly connected to each other.

[0045] In an example embodiment, each heat anchor may include a disc-shaped heat anchor body portion disposed on a cylindrical heat anchor connection portion and an outer circumferential surface of the heat anchor connection portion. The inner circumferential surface of the heat anchor connection portion may be threadedly connected to the outer circumferential surface of the annular protrusion.

[0046] In an example embodiment, the thermal anchors may include first to third thermal anchors. The first thermal anchor may be connected to a 120K insulation layer, the second thermal anchor may be connected to an 80K insulation layer, and the third thermal anchor may be connected to a 40K insulation layer.

[0047] In an example embodiment, the magnetic field measuring device may further include: a refrigerant discharge pipe, which is arranged at the baffle plug-in and discharges vaporized refrigerant; a refrigerant injection pipe, which is arranged at the baffle plug-in and injects refrigerant; and a condenser, which is connected to the refrigerant discharge pipe and the refrigerant injection pipe, and condenses the vaporized refrigerant discharged through the refrigerant injection pipe. The refrigerant injection pipe is provided with a coaxial structure to be inserted into the refrigerant discharge pipe. Each of the refrigerant discharge pipe and the refrigerant injection pipe may be a double pipe including an inner pipe and an outer pipe.

[0048] The magnetic field measuring device according to the example embodiment includes: an outer container; a cylindrical inner container which stores liquid refrigerant and is inserted in the outer container; a baffle plug-in which is inserted in the inner container; a refrigerant discharge pipe which is arranged at the baffle plug-in and discharges vaporized refrigerant; a refrigerant injection pipe which is arranged at the baffle plug-in and injects refrigerant; and a condenser which is connected to the refrigerant discharge pipe and the refrigerant injection pipe and condenses the vaporized refrigerant discharged through the refrigerant injection pipe. The refrigerant injection pipe may have a coaxial structure inserted in the refrigerant discharge pipe. Each of the refrigerant discharge pipe and the refrigerant injection pipe may be a double pipe including an inner pipe and an outer pipe.

[0049] In an example embodiment, the inner container may include: a neck portion in which a baffle insert is inserted; and a body portion having an increased diameter compared to the neck portion. The neck portion may have a double-walled structure including an inner cylinder and an outer cylinder surrounding the inner cylinder.

[0050] A magnetic field measuring device according to an example embodiment includes: an outer container; a cylindrical inner container for storing a liquid refrigerant and inserted into the outer container; a main heat anchor arranged on a lower surface of the inner container; and a plurality of first SQUID sensor modules arranged outside the inner container. Each of the plurality of first SQUID sensor modules may be in thermal contact with the main heat anchor arranged on the lower surface of the inner container through a Litz wire.

[0051] In an example embodiment, the main heat anchor may include: a first heat transfer unit formed of oxygen-free copper and including a first plate and a first lower protrusion protruding from a central axis of the first plate to a lower surface of the first plate; a second heat transfer unit formed of oxygen-free copper and including a second plate, a second upper protrusion protruding from a central axis of the second plate to an upper surface of the second plate, and a second lower protrusion protruding from a central axis of the second plate to a lower surface of the second plate; a third heat transfer unit formed of oxygen-free copper and including a third plate, a third upper protrusion protruding from a central axis of the third plate to an upper surface of the third plate; A fourth heat transfer unit is formed of oxygen-free copper and includes a fourth disk and a fourth upper protrusion protruding from the central axis of the fourth disk to the upper surface of the fourth disk; a first thermal expansion control unit is formed of an insulating material and inserted between the first disk of the first heat transfer unit and the second disk of the second heat transfer unit; and a second thermal expansion control unit is formed of an insulating material and inserted between the third disk of the third heat transfer unit and the fourth disk of the fourth heat transfer unit. The second upper protrusion of the second heat transfer unit may be provided with a groove for connecting to the first lower protrusion of the first heat transfer unit. The second lower protrusion of the second heat transfer unit may be provided with a groove for connecting to the third upper protrusion of the third heat transfer unit. The third lower protrusion of the third heat transfer unit may be provided with a groove for connecting to the fourth upper protrusion of the fourth heat transfer unit.

[0052] In an example embodiment, the first thermal expansion control unit may include: a first insulating body portion having a diameter equal to a first diameter of the first disk; a second insulating body portion embedded in a lower surface of the inner body and having a second diameter larger than the first diameter; and a third insulating body portion having a third diameter smaller than the second diameter. The third insulating body portion may be arranged to surround an outer circumferential surface of the second disk.

[0053]

Beneficial Effects

[0054] As described above, the magnetoencephalogram (MEG) measuring apparatus according to the exemplary embodiment can measure child MEG or adult MEG according to a rotation state using a helmet for children and a helmet for adults respectively arranged at both ends of a barrel-shaped Dewar flask placed horizontally in a narrow magnetic shielding room.

[0055] A magnetoencephalogram (MEG) measuring apparatus according to an example embodiment may effectively block radiant heat using a neck having a double-wall structure of a horizontally placed barrel-shaped Dewar flask.

[0056] A magnetoencephalogram (MEG) measuring apparatus according to an exemplary embodiment may measure a child's MEG or an adult's MEG according to a rotation state by installing a rotational motion unit on a floor of a horizontally arranged barrel-shaped Dewar flask and setting a rotational motion.

[0057] A magnetoencephalogram (MEG) measuring apparatus according to example embodiments may improve the efficiency of a condenser or a cooler by transferring a low-temperature refrigerant to a condenser while providing a rotational motion using a coaxial double-tube structure connecting the condenser and a Dewar flask to each other.

[0058] A magnetoencephalogram (MEG) measuring apparatus according to example embodiments may employ a coil-in-vacuum structure, and thus the distance between a SQUID sensor and a current source may be reduced to increase a signal-to-noise ratio (SNR).

[0059] The magnetoencephalogram measuring device according to the exemplary embodiment of the present disclosure may include a main heat anchor for cooling the SQUID sensor on the lower surface of the inner container storing the refrigerant. The main heat anchor may include a plurality of components to increase the thermal contact area while suppressing damage to the inner container caused by thermal expansion. Therefore, the Litz wire and the SQUID sensor may be effectively cooled. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The present disclosure will become more apparent in light of the accompanying drawings and the accompanying detailed description. The embodiments described herein are provided by way of example, rather than by way of limitation, wherein like reference numerals refer to the same or similar elements. The drawings are not necessarily drawn to scale, but emphasis is placed on illustrating various aspects of the present disclosure.

[0061] Figure 1 is a conceptual diagram showing a magnetoencephalographic measurement apparatus according to an exemplary embodiment of the present disclosure.

[0062] Figure 2 is a perspective view showing a magnetoencephalography measuring device.

[0063] Figure 3 It is along Figure 2 A cross-sectional view taken along line AA'.

[0064] Figure 4 is a perspective view showing an inner container and a helmet with sensors mounted thereon.

[0065] Figure 5 is an exploded perspective view showing a rotational motion unit that supports an outer container and provides rotational motion.

[0066] Figure 6 It is an enlarged cross-sectional view of the inner container of the magnetoencephalography measuring device.

[0067] Figure 71 is a perspective view showing a support portion of a helmet on which a sensor of a magnetoencephalography measuring device is mounted.

[0068] Figure 8 This is a diagram viewed from the bottom surface of the inner container of the magnetoencephalography measurement device.

[0069] Fig. 9 is a perspective view showing a helmet on which a sensor is mounted according to an exemplary embodiment of the present disclosure.

[0070] Fig.10 yes Fig. 9 A cross-sectional view of a helmet with sensors installed.

[0071] Fig.11 is a conceptual diagram illustrating a connection relationship between a primary heat anchor and a SQUID sensor module according to an example embodiment of the present disclosure.

[0072] Fig.12 It is a cross-sectional view of the main thermal anchor.

[0073] Fig.13A is a perspective view showing a SQUID sensor module according to an example embodiment of the present disclosure.

[0074] Fig. 13B It shows Fig.13A Exploded perspective view of the SQUID sensor module.

[0075] Fig. 13C is a cross-sectional view showing a SQUID sensor module according to an example embodiment of the present disclosure.

[0076] Fig.14 is a perspective view showing a SQUID sensor module according to another example embodiment of the present disclosure. DETAILED DESCRIPTION

[0077] According to an exemplary embodiment, a technique of directly recondensing helium using a refrigerator and resending the recondensed helium to a dewar is applied. Since the magnetic noise and vibration noise caused by the refrigerator and the refrigerant delivery pipe are very large, a special dewar structure and a special SQUID arrangement method are required to prevent the SQUID from reacting to vibration. In particular, a stable structure for supporting a helmet on which the SQUID is mounted is required.

[0078] With the recent increase in helium prices, a technology is required to directly recondense helium using a refrigerant and resend the recondensed helium to the magnetoencephalogram dewar. The vaporized helium is supplied to the refrigerator through a refrigerant discharge pipe, and the liquefied refrigerant is supplied to the dewar through a refrigerant injection pipe. When the refrigerant discharge pipe and the refrigerant injection pipe include a single pipe, ice condenses on the baffle insert cover. This ice prevents optimal sealing, resulting in a large amount of external heat inflow.

[0079] The CIV SQUID according to the example embodiment solves the problem of ice condensation on the baffle plug cover using a coaxial double-tube structure. The refrigerant discharge pipe and the refrigerant injection pipe have a coaxial structure, and the refrigerant discharge pipe and the refrigerant injection pipe both have a double-tube structure. The double-tube structure can prevent water vapor condensation from occurring on the upper plate surface of the Dewar flask. Therefore, a sealing member such as an O-ring can be used to provide rotation of the Dewar flask. In addition, the double-tube structure can transmit the temperature of the evaporated helium to the cooler in a cold state, thereby improving the efficiency of the cooler.

[0080] In the CIV SQUID, the Dewar flask includes an inner container and an outer container surrounding the inner container. However, the inner container absorbs radiant heat from the outside, thereby increasing the consumption of refrigerant.

[0081] In the CIV SQUID, the Dewar flask uses a double-wall structure in the neck of the inner container in which the baffle insert is inserted. This double-wall structure improves the mechanical stability caused by thermal expansion. In addition, the heat insulation layer arranged between the double walls reduces the inflow of radiant heat. In addition, the heat anchor arranged outside the double-wall structure uses a threaded connection to reduce damage caused by thermal expansion while thermally contacting the inner wall of the inner container having the double-wall structure through a large contact area. The double-wall structure can reduce the evaporation rate of the refrigerant and can stably support the internal structure with a high load, thereby reducing the internal vibration caused by the evaporation of the refrigerant.

[0082] The magnetoencephalogram (MEG) signal depends on the distance between the SQUID sensor and the brain. Therefore, MEG helmets for adults are not suitable for measuring MEG in children. Therefore, there is a need for a dual helmet in which a single MEG device can measure both adults and children.

[0083] A helmet for children can provide 144 channels, and a helmet for adults can provide 192 channels. Therefore, as a structure that is most suitable for the head size, it is expected that the quality of MEG signals, especially for children, will be improved. It is advantageous to measure the development process of brain function of children to that of adults.

[0084] The magnetoencephalography apparatus according to the exemplary embodiment has a structure in which two helmets are arranged on a single dewar flask. A helmet for children and a helmet for adults having different sizes are installed to face each other.

[0085] In the magnetoencephalogram device according to the example embodiment, both the helmet for children and the helmet for adults can measure the magnetoencephalogram in a lying state according to the rotation state of the dewar flask. In order to provide the rotational movement of the dewar flask, the rotational movement unit can use a non-metallic bearing to provide the rotational movement of the dewar flask. The rotational movement unit may include a signal line junction box in which the signal line is connected.

[0086] The magnetoencephalography device according to the example embodiment includes a main heat anchor disposed on the lower surface of the inner container. The main heat anchor includes a plurality of heat transfer parts threadedly connected to each other, and a thermal expansion control part formed of an insulating material and controlling a sealing failure caused by thermal expansion between the heat transfer parts and the inner container. When the plurality of heat transfer parts are connected to each other, a pair of thermal expansion control parts arranged to be embedded in the outer surface and the inner surface of the inner container are compressed to prevent damage to the components caused by the sealing and thermal expansion.

[0087] Hereinafter, the embodiments of the present disclosure will be described more fully with reference to the accompanying drawings. However, the present disclosure can be implemented in different forms and should not be constructed to be limited to the embodiments set forth herein. On the contrary, these embodiments are provided to make the present disclosure thorough and complete and to fully convey the scope of the present invention to those skilled in the art.

[0088] Figure 1 is a conceptual diagram showing a magnetoencephalographic measurement apparatus according to an exemplary embodiment of the present disclosure.

[0089] Figure 2 is a perspective view showing a magnetoencephalography measuring device.

[0090] Figure 3 It is along Figure 2 A cross-sectional view taken along line AA'.

[0091] Figure 4 is a perspective view showing an inner container and a helmet with sensors mounted thereon.

[0092] Figure 5 is an exploded perspective view showing a rotational motion unit that supports an outer container and provides rotational motion.

[0093] Figure 6 It is an enlarged cross-sectional view of the inner container of the magnetoencephalography measuring device.

[0094] Reference Figures 1 to 6The magnetoencephalogram measuring device 300 includes: an inner container 360 storing a liquid refrigerant; an outer container 310 arranged to surround the inner container 360 and including a first outer helmet 320 and a second outer helmet 330 arranged to be spaced apart from each other; a first sensor-mounted helmet 322 arranged to surround the first outer helmet 320 between the outer container 310 and the inner container 360; a second sensor-mounted helmet 332 arranged to surround the second outer helmet 330 between the outer container 310 and the inner container 360; a plurality of first SQUID sensor modules 103a arranged on the first sensor-mounted helmet 322; and a plurality of second SQUID sensor modules 103b arranged on the second sensor-mounted helmet 332. The space between the outer container 310 and the inner container 360 is in a vacuum state.

[0095] Each of the plurality of first SQUID sensor modules 103a is in thermal contact with a main heat anchor 170 disposed on the lower surface of the inner container 360 through a litz wire 12. Each of the plurality of second SQUID sensor modules 103b is in thermal contact with a main heat anchor 170 disposed on the lower surface of the inner container 360 through a litz wire 12. The space between the outer container 310 and the inner container 360 is in a vacuum state. The SQUID sensors of the first sensor-mounted helmet 322 and the second sensor-mounted helmet 332 can be effectively cooled by the litz wire 12.

[0096] The magnetoencephalography measuring device 300 may be arranged inside the magnetic shielding room 11 .

[0097] The outer container 310 may be branched in a T-form. The outer container 310 may include a first branch 312 and a second branch 314 branched in a T-form from a cylindrical outer container body 316. Each of the first outer helmet 320 and the second outer helmet 330 may be connected to the first branch 312 and the second branch 314, respectively. The first outer helmet 320 and the second outer helmet 330 may face each other and may have different sizes. The diameter of each of the first branch 312 and the second branch 314 may be greater than the diameter of the outer container body 316. The first outer helmet 320 may include an opening 321 for ensuring a field of view. The outer container body 316 may be arranged vertically, and the first branch 312 and the second branch 314 may be arranged horizontally. The outer container 310 may be a glass fiber reinforced plastic such as G10 epoxy resin.

[0098] The outer container body 316 may have a cylindrical shape and may rotate around its central axis. The first outer helmet 320 or the second outer helmet 330 may measure a magnetoencephalogram signal of a child or an adult according to a rotation state of the outer container 310 .

[0099] The rotational movement unit 340 may be connected to the lower surfaces of the first branch 312 and the second branch 314 . The rotational movement unit 340 may include a bearing formed of a non-conductive material. The rotational movement unit 340 may be installed on the bottom surface of the magnetic shielding room 11 .

[0100] The first external helmet 320 may be provided with a long groove 320a in a portion connected to the first branch 312. The first external helmet 320 may be rotated along the long groove 320a to be connected to one end of the first branch 312 in an aligned state therewith. The long groove 320a may provide alignment between the first external helmet 320 and the first sensor-mounted helmet 322. The first external helmet 320 may include an opening portion 321 for ensuring a field of view.

[0101] The second outer helmet 330 may be provided with a long groove in a portion connected to the second branch 314. The second outer helmet 330 may be rotated along the long groove to be connected to one end of the second branch 314 in an aligned state therewith.

[0102] The inner container 360 may store liquid refrigerant and may cool the SQUID sensor modules 103a and 103b through the main heat anchor 170 and the Litz wire 12. The material of the inner container 360 may be glass fiber reinforced plastic such as G10 epoxy resin.

[0103] The inner container 360 may include a neck 362 in which the baffle insert 150 is inserted, a first body portion 364 having an increased diameter compared to the neck 362, a second body portion 366 having an increased diameter compared to the first body portion 364, and a third body portion 368 having a reduced diameter compared to the second body portion. The inner container 360 may include a body portion and a neck 362 in which the baffle insert 150 is inserted. The body portion may include a first body portion 364 having an increased diameter compared to the neck 362, a second body portion 366 having an increased diameter compared to the first body portion, and a third body portion 368 having a reduced diameter compared to the second body portion.

[0104] The neck portion 362 may have a double-walled structure including an inner cylinder and an outer cylinder surrounding the inner cylinder. The first body portion 364 may be continuously connected to the neck portion 362. The second body portion 366 may be continuously connected to the first body portion 364. The second body portion 366 may have a larger diameter than the first body portion 364. The third body portion 368 may be continuously connected to the second body portion 366. The third body portion 368 may have a smaller diameter than the second body portion 366. The first body portion 364 and the third body portion 368 may have equal diameters.

[0105] The first sensor-mounted helmet 322 and the second sensor-mounted helmet 332 are symmetrically arranged with respect to the first body portion 364, the second body portion 366, and the third body portion 368 to provide mechanical stability and symmetry for cooling.

[0106] The lower surface 368a of the third body part 368 may include a plurality of getter grooves 368b having a fan shape in a direction toward the lower surface or the vacuum side. A getter that collects residual gas in a vacuum state may be arranged in the getter grooves 368b.

[0107] The neck 362 may include an inner cylinder 162a and an outer cylinder 162b surrounding the inner cylinder 162a. A heat insulating layer 162c may be arranged between the inner cylinder 162a and the outer cylinder 162b. The heat insulating layer 162c may have a multilayer structure in which a metal film having high reflectivity and low emissivity and a very thin non-woven fabric having low thermal conductivity are sequentially stacked.

[0108] The inner cylinder 162a may further include a plurality of annular protrusions 162a' protruding outward from the cylinder body. The annular protrusions 162a' may have a cylindrical ring shape and may be formed integrally with the inner cylinder 162a. Screws for threaded connection may be formed on the outer circumferential surface of the annular protrusions 162a'.

[0109] The annular protrusions 162a' may be arranged to be spaced apart from each other. The outer cylinder 162b may be separated, with the annular protrusion 162a' sandwiched therebetween. That is, the outer cylinder 162b may include a plurality of cylindrical parts separated from each other. The distance between the outer cylinder 162b and the inner cylinder 162a may be within a few millimeters (mm). Each of the outer cylinders 162a may have a raised point to surround the heat anchor connection portion 106a" and the annular protrusion 162a'. The outer cylinder 162b may be connected to surround the annular protrusion 162a', and the connection may be fixed and sealed with an adhesive such as epoxy resin.

[0110] The heat anchors 106a, 106b, and 106c may be connected to the annular protrusion 162a', respectively. The outer circumferential surface of the annular protrusion 162a' and the inner circumferential surfaces of the heat anchors 106a, 106b, and 106c may be threadedly connected to each other. Each of the heat anchors 106a, 106b, and 106c may have a circular washer shape. Each of the heat anchors 106a, 106b, and 106c may include copper (Cu) or aluminum (Al).

[0111] The heat anchor 106a may include a cylindrical heat anchor connecting portion 106a" and a disc-shaped heat anchor body portion 106a' arranged on the outer circumferential surface of the connecting portion. The inner circumferential surface of the heat anchor connecting portion 106a" may be threadedly connected to the outer circumferential surface of the annular protrusion 162a'. Therefore, the heat anchors 106a, 106b, and 106c may be stably fixed to the inner container and may be cooled while being in thermal contact with each other through a large area.

[0112] The threaded connection of the annular protrusion 162a' and the thermal anchor 106a may improve mechanical stability while providing effective thermal contact due to thermal expansion.

[0113] The double-wall structure can prevent radiant heat from flowing into the inner container 360 from an external entity. When the inner container is cooled by the refrigerant, the space between the inner cylinder and the outer cylinder can be maintained in a vacuum state. Therefore, the heat inflow caused by heat transfer can be blocked, and the heat insulation layer 162c can additionally block the inflow of radiant heat. Therefore, compared with the neck of the single-wall structure, the neck of the double-wall structure can provide high mechanical stability and high thermal insulation performance.

[0114] The thermal anchors 106a, 106b, and 106c may include a first thermal anchor 106a, a second thermal anchor 106b, and a third thermal anchor 106c that are sequentially arranged. The first thermal anchor 106a may be arranged at the uppermost side of the neck portion 362 and may be connected to the 120K thermal insulation layer 107a. The second thermal anchor 106b may be arranged below the first thermal anchor 106a and connected to the 80K thermal insulation layer 107b. The third thermal anchor 106c may be arranged at the lower side of the second thermal anchor 106b and may be connected to the 40K thermal insulation layer 107b. The outer diameter of the first thermal anchor 106a may be greater than the outer diameter of the second thermal anchor 106b.

[0115] The first heat anchor 106a may be spaced farthest from the refrigerant to maintain the highest temperature, and the third heat anchor 106c may be closest to the refrigerant to maintain the lowest temperature. The first heat anchor 106a, the second heat anchor 106b, and the third heat anchor 106c may be in thermal contact with the vaporized refrigerant to be cooled. The 40K heat insulation layer 107c may be connected to the outer circumferential surface of the third heat anchor 106c, and may be arranged to surround the inner container 360 to block the inflow of radiant heat. The 40K heat insulation layer 107c may include an insulating layer and a metal mesh woven by metal wires that are thermally insulated from each other. The 40K heat insulation layer 107c may be branched in a T-shape to surround the first sensor-mounted helmet 322 and the second sensor-mounted helmet 332, and then may surround the first sensor-mounted helmet 322 and the second sensor-mounted helmet 332.

[0116] The 80K insulation layer 107b may be connected to the outer circumferential surface of the second heat anchor 106b, and may be arranged to surround the 40K insulation layer 107c and block the inflow of radiant heat. The 80K insulation layer 107b may include an insulation layer and a metal mesh woven by metal wires that are thermally insulated from each other. The 80K insulation layer 107b may be branched in a T-shape to surround the first sensor-mounted helmet 322 and the second sensor-mounted helmet 332. The 80K insulation layer 107b may extend in the direction of the edge of the first sensor-mounted helmet 322, and may extend in the direction of the edge of the second sensor-mounted helmet 332.

[0117] The 120K insulation layer 107a may be connected to the outer circumferential surface of the first heat anchor 106a and may be arranged to surround the 80K insulation layer 107b and block the inflow of radiant heat. The 120K insulation layer 107a may include an insulation layer and a metal mesh woven by metal wires that are thermally insulated from each other. The 120K insulation layer 107a may be branched in a T-shape to surround the first sensor-mounted helmet 322 and the second sensor-mounted helmet 332.

[0118] Each of the first heat anchor 106a, the second heat anchor 106b, and the third heat anchor 106c may have an opening in a direction toward the outer container support portion 341. These openings may be arranged so as not to overlap each other. Therefore, the signal line may pass through the openings of the first heat anchor 106a, the second heat anchor 106b, and the third heat anchor 106c in a zigzag shape to pass through the vacuum seal portion 344.

[0119] The space between the inner container 360 and the outer container 310 may be maintained in a vacuum state. The outer container cover 311 may include a discharge port 311a connected to a vacuum pump. The discharge port 311a may be formed of a G-10 epoxy resin tube.

[0120] The baffle insert 150 may be arranged to be inserted into the neck 362 of the inner container 360. The baffle insert 150 may include an insert upper plate 151, a baffle 156 arranged below the insert upper plate, and a plurality of guide rods 154 supporting the baffle 156 and fixed to the insert upper plate 151.

[0121] The plug-in upper plate 151 may have a disc shape and may be formed of G-10 epoxy resin. The plug-in upper plate 151 may be fixed to the outer container cover 311. The guide rod 154 is formed of G-10 epoxy resin and may have a rod shape or a tubular shape. The guide rod 154 may support the baffle 156. The baffle 156 may include polystyrene foam with improved heat retention and a conductive plate. The conductive plate may include an aluminum-plated polyester film layer and a copper layer stacked in sequence to block radiant heat.

[0122] The refrigerant discharge pipe 153 may be arranged on the plug-in upper plate of the baffle plug-in 150, and may discharge the vaporized refrigerant. The refrigerant injection pipe 152 may be arranged on the plug-in upper plate 151 of the baffle plug-in 150, and may inject the refrigerant. Each of the refrigerant discharge pipe 153 and the refrigerant injection pipe 152 may be a double pipe including an inner pipe and an outer pipe. In the double pipe, the space between the inner pipe and the outer pipe may be maintained in a vacuum state during cooling. The refrigerant injection pipe 152 may have a coaxial structure inserted into the refrigerant discharge pipe 153. The refrigerant discharge pipe 153 and the refrigerant injection pipe 152 may be formed of G-10 epoxy resin.

[0123] The coaxial double tubes 152 and 153 can reduce the thermal contact with the plug-in upper plate 151 to reduce the icing of the plug-in upper plate 151. When the refrigerant discharge pipe and the refrigerant injection pipe are single pipes, the plug-in upper plate 151 and the refrigerant discharge pipe may be frozen, thereby hindering the sealing of the outer container cover 111 and the plug-in upper plate 151 and increasing the inflow of external heat. The coaxial double tubes 152 and 153 may be arranged on the central axis of the plug-in upper plate 151. One end of the refrigerant discharge pipe 153 may be arranged at a higher position than the first heat anchor 106a. When the outer container 310 and the inner container 360 rotate, the coaxial double tubes 152 and 153 may not rotate while maintaining the seal using a sealing device such as an O-ring.

[0124] The condenser 159 may be connected to the refrigerant discharge pipe 153 and the refrigerant injection pipe 152, and may condense the vaporized refrigerant discharged through the refrigerant injection pipe 153. The condenser 159 may be disposed outside the magnetic shield room 11.

[0125] The rotational movement unit 340 may be connected to lower surfaces of the first branch 312 and the second branch 314. The rotational movement unit 340 may provide a rotational movement of the outer container 310.

[0126] The rotational movement unit 340 may include an outer container support portion 341 , an upper support box 342 , a lower support box 347 , and a bearing portion 346 .

[0127] The outer container support part 341 may be in the form of a C, and may support lower surfaces of the first branch 312 and the second branch 314. The outer container support part 341 may have a through hole at the center thereof.

[0128] The vacuum seal 344 may be inserted into a through hole formed in the lower surface of the first branch 312 and the second branch 314 to seal the signal line, and disposed inside the outer container support 341. The vacuum seal 344 may seal the outer container 310 in a vacuum state and the outside in an atmospheric pressure state from each other.

[0129] The signal line junction box 345 may be disposed below the outer container support portion 341, and may connect the sealed signal lines 15 to each other through the vacuum sealing portion 344. The signal line junction box 345 may be disposed inside the upper support box 342.

[0130] The upper support box 342 may be arranged to surround the signal line junction box 345 and may have a cylindrical shape. The upper support box 342 may support the outer container support portion 341. The handle 343 may be connected to the outside of the upper support box 342. The user may rotate the handle 343 to select the rotation state of the magnetoencephalogram measurement device.

[0131] The lower support box 347 may be disposed below the upper support box 342 .

[0132] The bearing portion 346 may be disposed between the upper support case 342 and the lower support case 347 to provide rotational movement of the upper support case 342 .

[0133] Figure 7 1 is a perspective view showing a support portion of a helmet on which a sensor of a magnetoencephalography measuring device is mounted.

[0134] Figure 8 This is a diagram viewed from the bottom surface of the inner container of the magnetoencephalography measurement device.

[0135] Fig. 9 is a perspective view showing a helmet on which a sensor is mounted according to an exemplary embodiment of the present disclosure.

[0136] Fig.10 yes Fig. 9 A cross-sectional view of a helmet with sensors installed.

[0137] Reference Figures 7 to 10 The first sensor-mounted helmet 322 may be configured to cover the head and may include an opening to ensure the field of view of the subject. The first sensor-mounted helmet 322 may include a brim 322a' and a brim 322a" on its edge, and the brim 322a' and the brim 322a" may be connected to a fixing device for fixing the first sensor-mounted helmet 322.

[0138] The second sensor-mounted helmet 332 may be configured to cover the head and include an opening to ensure a field of view of the subject. The second sensor-mounted helmet 332 may include a brim on its edge. The brim may be connected to a fixing device for fixing the second sensor-mounted helmet 332.

[0139] A pair of first support portions 382 may be connected to the interface between the neck 362 and the first body portion 364, and may extend in the direction of the first external helmet 320 and the direction of the second external helmet 330, respectively. The first support portion 382 may include a C-shaped portion 382c connected to the interface between the neck 362 and the first body portion 364, and a pair of pillars 382b extending parallel to the direction of the corresponding external helmet. The C-shaped portion 382c may have a plurality of arc-shaped long grooves 382a. A fixing device may be connected to each arc-shaped long groove 382a to provide alignment with the corresponding sensor-mounted helmet.

[0140] A pair of second support portions 384 may be connected to the interface between the first body portion 364 and the second body portion 366, and extend in the direction of the first external helmet 320 and the direction of the second external helmet 330, respectively. The second support portion 384 may include a C-shaped portion connected to the interface between the first body portion 364 and the second body portion 366, and a pair of pillars extending parallel to the direction of the corresponding external helmet. The C-shaped portion may include a plurality of arc-shaped long grooves 384a. A fixing device may be connected to each arc-shaped long groove 384a to provide alignment with the corresponding sensor-mounted helmet.

[0141] A pair of third support portions 386 may be connected to the interface between the second body portion 366 and the third body portion 368, and may extend in the direction of the first external helmet 320 and the direction of the second external helmet 330, respectively. The second support portion 384 may include a C-shaped portion connected to the interface between the second body portion 366 and the third body portion 368, and a pair of pillars extending parallel to the direction of the corresponding external helmet. The C-shaped portion may include a plurality of arc-shaped long grooves 386a. A fixing device may be connected to the arc-shaped long groove to provide alignment with the corresponding sensor-mounted helmet.

[0142] The first fixing ring 387 may be connected to the first supporting portion 382 , the second supporting portion 384 , and the third supporting portion 386 in the direction of the first outer helmet 320 .

[0143] The second fixing ring 388 may be connected to the first support portion 382 , the second support portion 384 , and the third support portion 386 in the direction of the second outer helmet 330 .

[0144] The first auxiliary fixing part 323 may connect the first fixing ring 387 and the first sensor-mounted helmet 322 to each other. The first auxiliary fixing part 323 may include an upper ring 323a, a lower ring 323c spaced apart from the upper ring 323a, and a plurality of support rods 323b connecting the upper ring 323a and the lower ring 323c to each other.

[0145] The second auxiliary fixing part 333 may connect the second fixing ring 388 and the second sensor-mounted helmet 332 to each other. The second auxiliary fixing part 333 may include an upper ring, a lower ring spaced apart from the upper ring, and a plurality of support rods connecting the upper ring and the lower ring to each other.

[0146] The first sensor-mounted helmet 322 may include a brim 322a' and 322a". on its edge. The first sensor-mounted helmet 322 may have the same structure as the second sensor-mounted helmet 332, but the first sensor-mounted helmet 322 may be different from the second sensor-mounted helmet 332 in size and the number of SQUID sensor modules. The first sensor-mounted helmet 322 may have a first through hole 322b for mounting a SQUID sensor module, a second through hole 322c for placing a signal line, and a third through hole for mounting a fixing member for fixing the SQUID sensor module 103a.

[0147] The first sensor-mounted helmet 322 may include a helmet body 322' having an opening area for ensuring a field of view, a lower brim 322a' arranged along an edge of a lower surface of the helmet body, an upper brim 322a" having a brim provided at the opening portion of the helmet body, a helmet fixing ring 322f having an annular shape connected to the upper brim 322a" from the lower brim 322a' at predetermined intervals and continuously, and a plurality of connecting columns 322e connecting the lower brim 322a' and the upper brim 322a" vertically to each other. The brim of the first sensor-mounted helmet 322 may include an upper brim arranged in the opening portion to ensure a field of view and a lower brim surrounding an occipital area of ​​a subject.

[0148] The first auxiliary heat anchor 185 may be arranged on the lower surface of the brim 322a of the first sensor-mounted helmet 322. The first auxiliary heat anchor 185 may be divided into a plurality of parts 185a to 185d. The first auxiliary heat anchor 185 may be manufactured using oxygen-free copper tape. The separated first auxiliary heat anchor 185 may be divided into four parts to reduce eddy current noise caused by high-frequency magnetic noise and thermal noise caused by free electrons of the metal, and may provide a uniform position-dependent temperature gradient. The first auxiliary heat anchor 185 may be in thermal contact with the main heat anchor 170 through the Litz wire 12.

[0149] The first inner 4K insulation portion 124 may be in thermal contact with the first auxiliary heat anchor 185 and may be disposed on the inner side surface of the first sensor-mounted helmet 322. The first inner 4K insulation portion 124 may be disposed to surround the SQUID sensor module 103a and may include an insulating coated metal mesh.

[0150] The first external 4K insulation portion 126 may be in thermal contact with the first auxiliary heat anchor 185 and may be arranged on the outer side surface of the first sensor-mounted helmet 322. The first external 4K insulation portion 126 may be arranged to surround the outer side surface of the first sensor-mounted helmet 322. The first external 4K insulation portion 126 may include an insulating coated metal mesh. Therefore, the first auxiliary heat anchor 185, the first internal 4K insulation portion 124, and the first external 4K insulation portion 126 may be in thermal contact with the main heat anchor 170 through the Litz wire 12.

[0151] The second auxiliary thermal anchor may be disposed on the lower surface of the brim of the second sensor-mounted helmet 332. The second inner 4K thermal insulation portion may be in thermal contact with the second auxiliary thermal anchor and may be disposed on the inner surface of the second sensor-mounted helmet 332. The second outer 4K thermal insulation portion may be in thermal contact with the second auxiliary thermal anchor and may be disposed on the outer surface of the second sensor-mounted helmet. The second auxiliary thermal anchor, the second inner 4K thermal insulation portion, and the second outer 4K thermal insulation portion may be in thermal contact with the main thermal anchor 170 through the Litz wire 12.

[0152] Fig.11 is a conceptual diagram illustrating a connection relationship between a primary heat anchor and a SQUID sensor module according to an exemplary embodiment of the present disclosure.

[0153] Fig.12 It is a cross-sectional view of the main thermal anchor.

[0154] Reference Fig.11 and Fig.12 , each of the plurality of first SQUID sensor modules 103a may be in thermal contact with a main heat anchor 170 disposed on the lower surface of the inner container 360 via a Litz wire 12. Each of the plurality of second SQUID sensor modules 103b may be in thermal contact with a main heat anchor 170 disposed on the lower surface of the inner container 360 via a Litz wire 12.

[0155] The main heat anchor 170 may include a first heat transfer unit 171, a second heat transfer unit 172, a third heat transfer unit 173, a fourth heat transfer unit 174, a fifth heat transfer unit 175, a first thermal expansion control unit 176, and a second thermal expansion control unit 177. The main heat anchor 170 may include a plurality of components to increase a thermal contact area while preventing damage to an inner container caused by thermal expansion, and thus may effectively cool the Litz wire 12 and the SQUID sensor.

[0156] The first thermal expansion control unit 176 may be connected to a double groove having two radii formed on the inner side of the lower surface of the inner container, and the second thermal expansion control unit 177 may be connected to a double groove having two radii formed on the outer side of the lower surface of the inner container.

[0157] The first heat transfer unit 171 may be formed of oxygen-free copper and may include a first plate 171a and a first lower protrusion 171b protruding from the central axis of the first plate 171a to the lower surface of the first plate 171a. The first heat transfer unit 171 may also include a first upper protrusion 171c protruding from the central axis of the first plate 171a to the upper surface of the first plate 171a.

[0158] The second heat transfer unit 172 may be formed of oxygen-free copper, and may include a second plate 172a, a second upper protrusion 172b protruding from the central axis of the second plate 172a to the upper surface of the second plate 172a, and a second lower protrusion 172c protruding from the central axis of the second plate 172a to the lower surface of the second plate 172a. The second upper protrusion 172b of the second heat transfer unit 172 may include a threaded groove 172d for connecting to the first lower protrusion 171b of the first heat transfer unit 171. The second lower protrusion 172c of the second heat transfer unit 172 may have a threaded groove 172e for connecting to the third upper protrusion 173b of the third heat transfer unit 173.

[0159] The third heat transfer unit 173 may be formed of oxygen-free copper and may include a third plate 173a, a third upper protrusion 173b protruding from the central axis of the third plate 173a to the upper surface of the third plate 173a, and a third lower protrusion 173c protruding from the central axis of the third plate 173a to the lower surface of the third plate 173a. The third lower protrusion 173c of the third heat transfer unit 173 may have a threaded groove 173d for connecting to the fourth upper protrusion 174b of the fourth heat transfer unit 174.

[0160] The fourth heat transfer unit 174 may be formed of oxygen-free copper and may include a fourth tray, a fourth upper protrusion 174b protruding from the central axis of the fourth tray to the upper surface of the fourth tray, and a fourth lower protrusion 174c protruding from the central axis of the fourth tray to the lower surface of the fourth tray.

[0161] The fifth heat transfer unit 175 may be formed of oxygen-free copper and may include a C-shaped plate. The fifth heat transfer unit 175 may be connected to the fourth lower protrusion 174c of the fourth heat transfer portion 174. The lower surface of the fifth heat transfer unit 175 may be connected to the fixture 178. The fixture 178 may fix and cool the Litz wire 12 connected to the SQUID sensor module 103a.

[0162] The first thermal expansion control unit 176 may be formed of a heat insulating material, or may be interposed between the first plate 171a of the first heat transfer unit 171 and the second plate 172b of the second heat transfer unit 172. The first thermal expansion control unit 176 may include the same material as the inner container.

[0163] The second thermal expansion control unit 177 may be formed of an insulating material and may be interposed between the third plate 173a of the third heat transfer unit 173 and the fourth plate 174a of the fourth heat transfer unit 174. The second thermal expansion control unit 177 may include the same material as the inner container.

[0164] The first thermal expansion control unit 176 may include: a first insulating body portion 176a having a diameter equal to the first diameter D1 of the first disk 171a; a second insulating body portion 176b embedded in the lower surface of the inner body and having a second diameter D2 larger than the first diameter D1; and a third insulating body portion 176c having a third diameter D3 smaller than the second diameter D2. The third insulating body portion 176c may be arranged to surround the outer circumferential surface of the second disk 172a. The outer circumferential surface of the third insulating body portion 176c may be provided with a threaded groove.

[0165] The second thermal expansion control unit 177 may have the same structure as the first thermal expansion control unit 176 .

[0166] When the first to fourth heat transfer units 171 to 174 are connected to each other, the first thermal expansion control unit 176 and the second thermal expansion control unit 177 may be pressed to seal with the inner container. In addition, the first plate 171a and the fourth plate 174a may be sealed by pressing the first thermal expansion control unit 176 and the second thermal expansion control unit 177.

[0167] The primary heat anchor 170 may cool the first SQUID sensor module 103a and the second SQUID sensor module 103b via the Litz wires.

[0168] Each of the first SQUID sensor modules 103a may be cooled by the plurality of Litz wires 12. A portion of the plurality of Litz wires 12 may be provided to an adjacent first SQUID sensor module 103a. The remaining portion of the plurality of Litz wires 12 may be in thermal contact with the primary heat anchor 170.

[0169] Each of the first SQUID sensor modules 103a may be cooled by six Litz wires 12. Two of the Litz wires 12 may be in thermal contact with the primary heat anchor 170, and the remaining four Litz wires 12 may be connected to adjacent first SQUID sensor modules 103a.

[0170] Each of the first SQUID sensor modules 103a may be inserted into a through-hole formed in the first sensor-mounted helmet 322 to be fixed.

[0171] The first SQUID sensor module 103a may have a plurality of holes 611. Litz wires 12 may be inserted into the holes 611 to cool the SQUID sensor 646.

[0172] Fig.13A is a perspective view showing a SQUID sensor module according to an example embodiment of the present disclosure.

[0173] Fig. 13B It shows Fig.13A Exploded perspective view of the SQUID sensor module.

[0174] Fig. 13C is a cross-sectional view showing a SQUID sensor module according to an example embodiment of the present disclosure.

[0175] Reference FIG. 13A to FIG. 13C , the SQUID sensor module 103a / 103b may include: a fixed occluder 610 having one end fixed to a helmet 322 / 332 on which a sensor is mounted; a bobbin 630, one end of which is connected to the other end of the fixed occluder 610 and is provided with a groove around the pickup coil 601; a bobbin fixing device 650, which is fixed to the other end of the fixed occluder 610 via a through hole formed in the center of the bobbin 630; a superconducting quantum interference device (SQUID) printed circuit board (PCB) 640, which is arranged on the upper side surface of the bobbin 630 and includes a SQUID sensor 646; and a signal line connection PCB 620, which is inserted into the outer circumferential surface of the fixed occluder 610 and transmits the signal detected by the SQUID sensor 646 to an external circuit.

[0176] The sensor-mounted helmet 322 and the sensor-mounted helmet 332 may be mounted with a SQUID sensor module and may be arranged in a vacuum space between an outer container and an inner container. The sensor-mounted helmet 322 and the sensor-mounted helmet 332 may be formed of a non-magnetic material. The sensor-mounted helmet 322 and the sensor-mounted helmet 332 may include a first sensor-mounted helmet 322 and a second sensor-mounted helmet 332 mounted with a SQUID sensor module.

[0177] The fixed occluder 610 may be formed in one piece from a non-magnetic material such as G10 epoxy resin. The fixed occluder 610 may be inserted into a through hole 322b formed in a helmet on which a sensor is mounted to be fixed by an adhesive. The fixed occluder 610 may include a fixed occluder protrusion 612, a fixed occluder threshold portion 614, a fixed occluder main body portion 616, and a fixed occluder extension portion 618. The fixed occluder 610 may have a plurality of holes 611 in the direction of the central axis into which Litz wires for cooling are inserted. Litz wires are inserted into each of the plurality of holes 611 to cool the SQUID sensor 646.

[0178] The fixing blocking protrusion 612 may have a disc shape and may be connected to a groove or through hole 322b formed in the helmet on which the sensor is mounted. In addition, the fixing blocking protrusion 612 may be fixed to the through hole by an adhesive.

[0179] The fixed occlusion threshold portion 614 may have a disc shape and may be continuously connected to the fixed occlusion protrusion 612. The fixed occlusion threshold portion 614 may have a larger diameter than the fixed occlusion protrusion 612. The fixed occlusion threshold portion 614 may have a planar side surface 614a. One side surface 614a of the fixed occlusion threshold portion 614 may be a plane having a predetermined first vertical distance from the central axis having a cylindrical shape. The fixed occlusion threshold portion 614 may be used to perform alignment in the central axis direction. A through hole 619 may be formed outside the fixed occlusion threshold portion 614.

[0180] The fixed occlusion body part 616 may be a part connected to the signal line connection PCB 620. The signal line connection PCB 620 may be arranged to be inserted in the outer peripheral surface of the fixed occlusion body part 616. The signal line connection PCB 620 may include a hole 623 on its periphery. The through hole 619 of the fixed occlusion threshold part 614 may be aligned with the hole 623 of the signal line connection PCB 620. A fixing device may be inserted into the through hole 619 of the fixed occlusion threshold part 614 and the hole 623 of the signal line connection PCB 620 to fix the fixed occlusion threshold part 614 and the signal line connection PCB 620 to each other. The inner diameter of the signal line connection PCB 620 may be substantially the same as the outer diameter of the fixed occlusion body part 616. In addition, the outer diameter of the signal line connection PCB 620 may be substantially the same as the outer diameter of the fixed occlusion threshold part 614.

[0181] The signal line connection PCB 620 has a washer shape with a central through hole therein. When the signal line connection PCB 620 is connected to the outer circumferential surface of the fixed occlusion 610, one side of the central through hole may be flat to prevent rotational movement. The signal line connection PCB 620 may include a first connector 622. The first connector 622 may be a female connector. The first connector 622 may be arranged on the edge of the lower surface of the signal line connection PCB 620. The connection terminal 624 and the wiring may be arranged on the upper surface of the signal line connection PCB 620. The connection terminal 624 may be connected to the first connector 622 by wiring. The connection wiring connected to the external circuit may be connected to the connection terminal 624.

[0182] The fixed occlusion body portion 616 may have a disc shape and may be continuously connected to the fixed occlusion threshold portion 614. The fixed occlusion body portion 616 may have a smaller diameter than the fixed occlusion threshold portion 614 and may have a plane side surface 616a. One side surface 616a of the fixed occlusion body portion 616 may be a plane having a predetermined second vertical distance from the central axis having a cylindrical shape.

[0183] The fixed occluder extension 618 may have the same diameter as the fixed occluder body 616 and may have a planar side surface 618a. The side surface 618a may be a plane having a predetermined third vertical distance from the central axis having a cylindrical shape. The third vertical distance may be less than the second vertical distance.

[0184] A side surface 614a of one plane of the fixed occlusion threshold portion 614 and a side surface 616a of one plane of the fixed occlusion body portion 616 may be connected to each other. A side surface 616a of the fixed occlusion body portion 616 and a side surface 618a of the fixed occlusion extension portion 618 may be spaced apart from each other to be parallel to each other. A vertical distance between the central axis and a side surface of the fixed occlusion extension portion 618 may be smaller than a vertical distance between the central axis and a side surface of the fixed occlusion body portion 616.

[0185] The bobbin 630 may be formed of a non-magnetic material such as G10 epoxy. The bobbin 630 may have a cylindrical shape. The bobbin 630 includes: a first planar portion 634 formed on an upper surface having a first vertical distance from the central axis; and a second planar portion 636 formed on a lower surface having a second vertical distance greater than the first vertical distance. The bobbin 630 may have a groove 632 formed around its lower surface. The groove may form a closed loop. The pickup coil 601 may be wound around the groove 632. A hole 635 may be formed in the first planar portion 634. The hole 635 may be connected to a fixing device for fixing the SQUID PCB 640. The SQUID PCB 640 may be arranged on the first planar portion 634. Both ends of the pickup coil 601 may be fixed on the second planar portion 636 by an adhesive. The pickup coil 601 may be electrically connected to the SQUID sensor 646 by a connecting wire 648 formed of a superconductor material. The connection line 648 may include a material of niobium (Nb).

[0186] The SQUID PCB 640 may include a second connector 642 and a SQUID sensor 646, and is arranged on a PCB substrate 644. The SQUID sensor 646 may be in the form of a semiconductor chip. The SQUID sensor 646 may include an input coil and a Josephson junction. The SQUID sensor 646 may include a conductive pad for electrically connecting to the pickup coil 601. The conductive pad may connect the pickup coil 601. The second connector 642 may be electrically connected to another conductive pad. The second connector 642 may be a pin-type male connector. Therefore, the second connector 642 may be separated from the first connector 622 or connected to the first connector 622.

[0187] The pickup coil 601 can be a first-order axial gradiometer. Therefore, the length of the bobbin around which the pickup coil 601 is wound can be increased. The pickup coil 601 can include a pair of single-turn coils that are continuously connected and wound in directions opposite to each other. The pickup coil 601 and the SQUID sensor 646 are joined to be directly connected to each other using a connecting wire 648 of a superconductor material after heat treatment, and an integrated QUID magnetometer can be manufactured. The material of the pickup coil 601 can be a niobium tantalum (NbTi) wire.

[0188] The connecting wire of niobium (Nb) material used for bonding can be vacuum heat treated at a temperature of 1900 degrees Celsius to increase ductility. Superconducting bonding can be performed using an ultrasonic wedge bonder. The two ends of the pickup coil can be twisted together. Therefore, the noise of the pickup coil can be significantly reduced. The pickup coil can be a first-order gradiometer or a magnetometer.

[0189] The bobbin fixture 650 may be inserted into the through hole 638 passing through the central axis of the bobbin 630. Thus, the bobbin fixture 650 may be fixed to the lower surface of the fixing occluder 610. The bobbin fixture 650 may include a non-magnetic material such as G10 epoxy.

[0190] When the SQUID PCB 640 fails, the bobbin fixture 650 can be removed to replace the SQUID PCB 640. In this case, the bobbin 630 and the fixing occlusion 610 can be separated from each other. Therefore, the failed SQUID PCB can be simply replaced with a new SQUID PCB. Therefore, maintenance can be facilitated.

[0191] The SQUID sensor module 103a / 103b may include: a fixed occluder 610, one end of which is fixed to a support portion; a bobbin 630, one end of which is connected to the other end of the fixed occluder 610 and has a groove, around which the pickup coil 601 is surrounded; a bobbin fixing device, which is fixed to the other end of the fixed occluder 610 via a through hole formed in the center of the bobbin 630; a superconducting quantum interference device (SQUID) printed circuit board (PCB) 640, which includes a SQUID sensor; and a signal line connection PCB 620, which is inserted into the outer circumferential surface of the fixed occluder 610 and transmits a signal detected by the SQUID sensor to an external circuit.

[0192] Fig.14 is a perspective view showing a SQUID sensor module according to another example embodiment of the present disclosure.

[0193] Reference Figure 3 and Fig.14 , the first reference SQUID sensor module 105a can be arranged on the first sensor-mounted helmet 322, and the second reference SQUID sensor module 105b can be arranged on the second sensor-mounted helmet 332. The first reference SQUID sensor module 105a can be used as a sensor for measuring the background magnetic field when the second SQUID sensor module 103b is in operation. The second reference SQUID sensor module 105b can be used as a sensor for measuring the background magnetic field when the first SQUID sensor module 103a is in operation.

[0194] Each of the first reference SQUID sensor module 105a and the second reference SQUID sensor module 105b may be a three-axis magnetic field sensor. Each of the first reference SQUID sensor module 105a and the second reference SQUID sensor module 105b may include a first pickup coil 743a for detecting a magnetic field component in the x-axis direction, a second pickup coil 743b for detecting a magnetic field component in the y-axis direction, and a third pickup coil 743c for detecting a magnetic field component in the z-axis direction. Each of the first pickup coil 743a to the third pickup coil 743c may be connected to a SQUID sensor 746.

[0195] The first reference SQUID sensor module 105a may include a cylindrical fixed occluder 741 and a bobbin 742 in which a pickup coil connected to the fixed occluder 741 is arranged. The bobbin 742 may have a rectangular parallelepiped shape. The fixed occluder 741 may have through holes in multiple central axis directions, and the Litz wire 12 may be inserted into the through holes. The Litz wire 12 may be connected to the main heat anchor 170.

[0196] Although the present disclosure and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the disclosure as defined by the appended claims.

Claims

1. A dual-helmet magnetoencephalography measuring device, comprising: an inner container storing a liquid refrigerant; an outer container arranged to surround the inner container and comprising a first outer helmet and a second outer helmet arranged to be spaced apart from each other; a first sensor-mounted helmet disposed to surround the first outer helmet between the outer container and the inner container; a second sensor-mounted helmet disposed to surround the second outer helmet between the outer container and the inner container; a plurality of first SQUID sensor modules arranged on the first sensor-mounted helmet; as well as a plurality of second SQUID sensor modules disposed on the second sensor-mounted helmet; wherein the space between the outer container and the inner container is in a vacuum state, wherein each of the plurality of first SQUID sensor modules is in thermal contact with a primary thermal anchor disposed on a lower surface of the inner container via a Litz wire, and Each of the plurality of second SQUID sensor modules is in thermal contact with the primary heat anchor disposed on a lower surface of the inner container via a Litz wire.

2. The dual-helmet magnetoencephalography measuring device according to claim 1, wherein: The outer container branches in a T-form, The outer container includes a first branch and a second branch branching from a cylindrical outer container body in a T-form. The first external helmet and the second external helmet are each connected to the first branch and the second branch, respectively, and The first outer helmet and the second outer helmet face each other and have different sizes.

3. The dual-helmet magnetoencephalography measuring device according to claim 1, further comprising: A rotational motion unit rotates the inner container and the outer container around a central axis of the rotational motion unit.

4. The dual-helmet magnetoencephalography measuring device according to claim 1, wherein: The main heat anchor comprises: a first heat transfer unit formed of oxygen-free copper and including a first plate, a first upper protrusion protruding from a central axis of the first plate to an upper surface of the first plate, and a first lower protrusion protruding from the central axis of the first plate to a lower surface of the first plate; a second heat transfer unit formed of oxygen-free copper and including a second plate, a second upper protrusion protruding from a central axis of the second plate to an upper surface of the second plate, and a second lower protrusion protruding from the central axis of the second plate to a lower surface of the second plate; a third heat transfer unit formed of oxygen-free copper and including a third plate, a third upper protrusion protruding from a central axis of the third plate to an upper surface of the third plate, and a third lower protrusion protruding from the central axis of the third plate to a lower surface of the third plate; a fourth heat transfer unit formed of oxygen-free copper and including a fourth plate, a fourth upper protrusion protruding from a central axis of the fourth plate to an upper surface of the fourth plate, and a fourth lower protrusion protruding from the central axis of the fourth plate to a lower surface of the fourth plate; a fifth heat transfer unit formed of oxygen-free copper, connected to the fourth heat transfer unit, and having a plate shape; a first thermal expansion control unit formed of an insulating material and interposed between the first plate of the first heat transfer unit and the second plate of the second heat transfer unit; and a second thermal expansion control unit formed of an insulating material and inserted between the third plate of the third heat transfer unit and the fourth plate of the fourth heat transfer unit, and wherein the second upper protrusion of the second heat transfer unit is provided with a groove for connecting to the first lower protrusion of the first heat transfer unit, The second lower protrusion of the second heat transfer unit is provided with a groove for connecting to the third upper protrusion of the third heat transfer unit, and The third lower protrusion of the third heat transfer unit is provided with a groove for connecting to the fourth upper protrusion of the fourth heat transfer unit.

5. The dual-helmet magnetoencephalography measuring device according to claim 4, wherein: The first thermal expansion control unit comprises: a first insulating body portion having a diameter equal to a first diameter of the first disk; a second insulating body portion embedded in a lower surface of the inner container and having a second diameter greater than the first diameter; and a third insulating body portion having a third diameter smaller than the second diameter, and The third insulating body portion is arranged to surround the outer circumferential surface of the second disk.

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