A heat-conducting thermal insulation device for an atomic brain magnetometer probe

Abstract

The application provides a heat-conducting heat insulation device for an atomic brain magnetometer probe. The device combines the characteristics of brain magnetic measurement, and a heat-conducting layer made of non-magnetic high-thermal-conductivity material is clamped in the heat insulation layer of the skin contact surface of the brain magnetometer probe, and the heat-conducting layer is communicated to a heat dissipation shell arranged at the non-contact surface of the skin. Through the above structural design, while ensuring the high-temperature requirement of the atomic bubble inside the atomic brain magnetometer probe, most of the total heat flow transmitted from the internal high-temperature area to the human body is transmitted to the heat dissipation shell through the heat-conducting layer, so as to reduce the heat transmission to the human body, so that the atomic brain magnetometer probe can meet the skin contact safety temperature requirement of the medical electrical equipment, the distance between the atomic bubble and the brain magnetic source can be shortened, the attenuation of the brain magnetic signal is reduced, and the precise detection of the weak brain magnetic signal is of great significance.

Description

Technical Field

[0001] This invention belongs to the field of precision measurement of weak magnetic fields, and specifically relates to a thermally conductive insulation device for an atomic magnetoencephalometer probe. Background Technology

[0002] Magnetoencephalography (MEG) is an extremely weak magnetic field generated by electrical signals in the brain's nerves. This magnetic field is typically on the order of hundreds of fT and decays rapidly with increasing distance.

[0003] The atomic magnetoencephalometer is recognized as the next generation of magnetoencephalometers. The magnetic probe uses an atomic magnetometer, which measures brain magnetism based on the Larmor precession of polarized alkali metal atoms in a magnetic field.

[0004] The atomic bubble is the magnetically sensitive device of the atomic magnetoencephalography (MEG) probe. To meet the requirements of MEG measurement, the atomic bubble of the MEG probe usually needs to be heated to 150-200℃ so that the alkali metal atoms in the bubble can reach the spin-exchange relaxation-free (SERF) state.

[0005] The atomic magnetoencephalography (MEG) instrument has the following requirements for the heat insulation device of the probe:

[0006] First, the distance between the magnetoencephalogram (MEG) and the head must be small enough. Magnetic resonance imaging (MRI) can be approximated by a magnetic moment model, and the magnetic field decays with the cube of the distance. Therefore, distance has a crucial impact on the MEG measurement performance; for every 1mm increase in the distance between the MEG and the head, the MEG signal drops sharply.

[0007] Secondly, to meet safety requirements, the temperature of the part of the magnetoencephalography (MEG) probe in contact with the head should not exceed 43°C [Section 11.1 of GB9706.1-2020 standard "Medical Electrical Equipment - Part 1: General Requirements for Basic Safety and Basic Performance"]. Since the operating temperature of the atomic bulb inside the MEG probe is typically higher than 150°C, and the temperature difference between the inside and outside is greater than 100°C, this places very high demands on the thermal insulation performance of the insulation device.

[0008] Finally, because magnetoencephalography (MEG) measurement devices require non-magnetic and insulating materials, commonly used metallic materials and conductive non-metallic materials (such as graphene) cannot be used in atomic MEG probes.

[0009] In summary, the contradiction between thin insulation thickness and high insulation performance, as well as the requirement for non-magnetic and insulating properties, determine the special characteristics of the thermal insulation device for the atomic brain magnetometer probe.

[0010] Existing atomic magnetometer insulation designs typically only consider their thermal insulation performance while neglecting the distance between the atomic bubble and the magnetic field source. Although such insulation devices can ensure good thermal insulation, they often leave a relatively thick insulation layer between the atomic bubble and the magnetic field source (e.g., the human or animal head), which leads to significant attenuation of the brain magnetic signal. The accuracy of magnetic source positioning and the detection of weak magnetic signals place high demands on the sensor distance, thus hindering the detection and precise positioning of weak brain magnetic waves. For example, one approach involves a double-layered hollow cylindrical sleeve (CN113093066A) between a heating top cover and a heating bottom cover. Porous silica insulation material is filled between the inner and outer hollow cylindrical sleeves, and a heating film is attached to the hollow inner wall of the inner sleeve. A spherical alkali metal atom gas chamber is placed at the center of the sleeve. This double-layered cylindrical uniform heating furnace device for SERF atomic magnetometers requires a thick insulation layer to ensure a low temperature on the outer surface of the magnetometer, which is detrimental to magnetoencephalography (MEG) measurements. Another approach is vacuum insulation technology [DOI:10.1109 / FREQ.2010.5556310]. This involves designing vacuum leads and non-magnetic vacuum valves to extract air from the atomic magnetometer probe, achieving insulation through a vacuum. This method requires additional structures to simultaneously meet the probe's sealing and wiring requirements, significantly increasing the structural complexity of the atomic magnetometer and reducing the device's reliability (e.g., leakage).

[0011] Existing heat-conducting structures typically aim to reduce the temperature of core components, while the requirement for atomic magnetoencephalography (MEG) probes is to maintain the high temperature of core components. Traditional high-temperature devices typically employ thick insulation layers, but the high-temperature components of MEG probes need to reduce insulation thickness. In the application scenario of MEG probes, the key issues are reducing insulation thickness, maintaining the high temperature of core components, and reducing surface temperature—all of which need to be addressed simultaneously. These conflicting requirements lack suitable solutions in traditional approaches. Summary of the Invention

[0012] In view of this, and in view of the defects or deficiencies of the prior art, the present invention provides a thermally conductive insulation device for an atomic magnetoencephalography probe.

[0013] To achieve the above objectives, the specific solution adopted by the present invention is as follows:

[0014] A thermally conductive insulation device for an atomic brain magnetoencephalography (MEG) probe includes a heating furnace covering the outside of the atomic bubble. The heating furnace is covered with an insulation component. The thickness of the top and sides of the insulation component is greater than the thickness of the bottom of the insulation component. An intermediate thermally conductive layer is connected to the bottom surface of the insulation component. A thermally insulating bottom layer is provided on the bottom surface of the intermediate thermally conductive layer. The bottom surface of the thermally insulating bottom layer is in contact with the head. A heat dissipation shell is covered outside the insulation component, and the bottom opening of the heat dissipation shell is connected to the perimeter of the intermediate thermally conductive layer. Non-magnetic heating elements are provided on the outer surfaces of a pair of opposite side walls of the heating furnace.

[0015] As described above, a pair of opposite sidewalls of the heating furnace are provided with light-transmitting holes at their centers. The heat insulation component is provided with two light-transmitting channels corresponding to the two light-transmitting holes. The non-magnetic heating elements inside the two light-transmitting channels are provided with heating element openings at corresponding positions. The two light-transmitting holes, the two heating element openings, and the two light-transmitting channels are located on the same straight line. The diameters of the heating element openings and the light-transmitting holes are the same and aligned. A sealing through-hole is provided at the center of the top of the heating furnace. The heat insulation component is provided with a sealing cooling channel corresponding to the position of the sealing through-hole. The glass seal of the atomic bubble extends through the sealing through-hole into the sealing cooling channel. The heat insulation component is solid except for the two light-transmitting channels and the sealing cooling channel.

[0016] As described above, the laser used in the atomic magnetoencephalography (MEG) probe passes through the top of the heat dissipation shell from top to bottom via an optical fiber, then sequentially through an optical fiber coupler, a beam expander, a polarizing beam splitter, and a quarter-wave plate. After being reflected by the first reflecting prism, it enters the atomic bubble through the light transmission channel of the incident path, the opening of the heating plate, and the light transmission hole. After passing through the light transmission hole, the opening of the heating plate, and the light transmission channel of the exit path, it enters the second reflecting prism and is then reflected by the second reflecting prism to the photodetector. The photodetector is connected to the signal transmission line, which passes upward through the heat dissipation shell.

[0017] As mentioned above, the heating furnace, intermediate heat-conducting layer and heat dissipation shell are all made of hexagonal boron nitride ceramic, and the heat insulation components and heat insulation bottom layer are made of aerogel.

[0018] As mentioned above, the heat insulation component and the intermediate heat-conducting layer, as well as the intermediate heat-conducting layer and the heat insulation base layer, are bonded and fixed with high-temperature resistant adhesive.

[0019] As mentioned above, the thickness of the top and sides of the insulation component is 8-12 mm, and the thickness of the bottom is 2-4 mm.

[0020] As mentioned above, there is an air gap between the four sides of the heat insulation component and the four sides of the heat dissipation shell, and there is an air gap between the top of the heat insulation component and the top of the heat dissipation shell.

[0021] As mentioned above, the thickness of the intermediate heat-conducting layer is 0.8-1.2 mm.

[0022] As mentioned above, the thickness of the heat insulation layer is 1.5-2.5mm, and the length and width of the heat insulation layer are consistent with the length and width of the middle heat-conducting layer, respectively.

[0023] A slit is made on the top of the heat insulation component located above the non-magnetic heating element as described above, and the lead wire of the non-magnetic heating element passes through the slit and exits the heat insulation component; a temperature sensor is installed on the outer wall of the heating furnace near the sealing through hole, and the lead wire of the temperature sensor passes through the sealing cooling channel of the heat insulation component and exits the heat insulation component; both the lead wire of the non-magnetic heating element and the lead wire of the temperature sensor pass through the signal transmission line hole provided on the top of the heat dissipation shell and exit the heat dissipation shell.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] This invention, combining the characteristics of magnetoencephalography (MEG) measurement, incorporates an intermediate thermally conductive layer made of a non-magnetic, high-thermal-conductivity material sandwiched within the thermal insulation layer of the MEG probe's skin-contact surface. This non-magnetic thermally conductive and insulating material, along with a double-layered thermal insulation structure, connects the intermediate thermally conductive layer to the heat dissipation shell located on the non-skin-contact surface. Through this structural design, while ensuring the high-temperature requirements of the atomic bubble within the MEG probe, a significant portion of the total heat flow from the high-temperature region to the body is transferred through the intermediate thermally conductive layer to the heat dissipation shell, thus reducing heat transfer to the body. This allows the MEG probe to meet the skin-contact safety temperature requirements for medical electrical equipment while shortening the distance between the atomic bubble and the brain's magnetic source, thereby reducing MEG signal attenuation. This is of great significance for the precise detection of weak MEG signals, such as the localization of the MEG magnetic source and the detection of weak MEG signals.

[0026] In addition, the device of the present invention has a simple structure and can be applied to other application scenarios of atomic magnetometers, such as zero-field to ultra-low-field nuclear magnetic resonance, magnetic nanoparticle detection, etc., reducing the influence of atomic magnetometer on sample temperature. Attached Figure Description

[0027] Figure 1 This is a cross-sectional schematic diagram of the present invention;

[0028] Figure 2 This is a schematic diagram of a specific embodiment of the present invention;

[0029] Figure 3 This is a local equivalent thermal resistance model of the device of the present invention;

[0030] In the diagram: 1-bubble, 2-heating furnace, 3-insulation component, 4-intermediate heat-conducting layer, 5-heat dissipation shell, 6-insulation bottom layer, 7-light transmission hole, 8-glass seal, 9-sealing through hole, 10-non-magnetic heating element, 11-temperature sensor, 12-optical fiber, 13-optical fiber coupler, 14-beam expander, 15-polarizing beam splitter, 16-quarter-wave plate, 17-first reflecting prism, 18-head, 19-second reflecting prism, 20-photodetector, 21-signal transmission line. Detailed Implementation

[0031] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. The following embodiments or accompanying drawings... Figure 1 —Appendix Figure 3 This invention is used to illustrate the invention, but is not intended to limit the scope of the invention.

[0032] A thermally conductive insulation device for an atomic magnetoencephalography (MEG) probe includes: a heating furnace 2, a heat insulation component 3, an intermediate thermally conductive layer 4, a heat dissipation shell 5, and a heat insulation bottom layer 6.

[0033] Atomic bubble 1 is located at the innermost part of the entire heat insulation device. Atomic bubble 1 is enclosed within heating furnace 2. Heating furnace 2 is externally covered by heat insulation component 3. The thickness of the top and sides of heat insulation component 3 is greater than the thickness of its bottom, thus forming an asymmetrical structure. The top thickness of heat insulation component 3 is the distance from its inner top surface in contact with heating furnace 2 to its outer top surface; the side thickness is the distance from its inner side surface in contact with heating furnace 2 to its outer side surface; and the bottom thickness is the distance from its inner bottom surface in contact with heating furnace 2 to its outer bottom surface. This asymmetrical structure causes heat to dissipate primarily from the bottom of heat insulation component 3. An intermediate heat-conducting layer 4 is connected to the bottom surface of heat insulation component 3. A bottom insulating layer 6 is disposed on the bottom surface of the intermediate heat-conducting layer 4, and the bottom surface of the bottom insulating layer 6 contacts the head 18, such as... Figure 2 As shown. The heat dissipation shell 5 is covered outside the heat insulation component 3, and the bottom opening of the heat dissipation shell 5 is connected to the periphery of the intermediate heat-conducting layer 4. An air gap is left between the periphery of the heat insulation component 3 and the periphery of the heat dissipation shell 5, and an air gap is left between the top of the heat insulation component 3 and the top of the heat dissipation shell 5. Non-magnetic heating elements 10 are attached to the outer surfaces of a pair of opposite sidewalls of the heating furnace 2.

[0034] Both the intermediate heat-conducting layer 4 and the heat dissipation shell 5 are heat-conducting layers, while the heat insulation component 3 and the bottom heat insulation layer 6 are heat insulation layers. The heating furnace 2, the intermediate heat-conducting layer 4, and the heat dissipation shell 5 are all made of a preferred high thermal conductivity hexagonal boron nitride ceramic material, while the heat insulation component 3 and the bottom heat insulation layer 6 are made of a preferred aerogel material with a thermal conductivity between 0.018 and 0.024 W / (m·K). This heat insulation device meets the requirements for both heat conduction and insulation while avoiding interference from magnetic noise generated by the materials on the measurement of magnetoencephalography (MEG) signals.

[0035] The atomic bubble 1 of the atomic magnetoencephalography (MEG) probe is heated by a non-magnetic heating element 10. The non-magnetic heating element 10 generates heat flow. Since the two sides of the non-magnetic heating element 10 are a heating furnace 2 made of a high thermal conductivity material (e.g., hexagonal boron nitride) and a heat insulation element 3 made of a low thermal conductivity material (e.g., aerogel), almost all the heat flow is directed towards the heating furnace 2 to maintain the high operating temperature of the atomic bubble 1. Because the bottom of the heat insulation element 3 is relatively thin, some of the heat from the heating furnace 2 will escape from the bottom of the heat insulation element 3. This portion of heat flowing towards the human head 18 is intercepted by the intermediate heat-conducting layer 4 and diffused within the intermediate heat-conducting layer 4, preventing localized overheating caused by concentrated heat. Meanwhile, due to the presence of the heat dissipation shell 5 and the heat insulation bottom layer 6, the diffused heat will be redistributed. After being blocked by the heat insulation bottom layer 6 and the design of the intermediate heat-conducting layer 4 connecting the heat dissipation shell 5, most of this heat will be dissipated through air convection on the surface of the heat dissipation shell 5, with only a small portion flowing to the human body, thereby ensuring that the temperature at the bottom of the atomic brain magnetometer probe remains within a safe range for direct contact with human skin.

[0036] like Figure 2The diagram illustrates a specific embodiment of the present invention used in an atomic magnetoencephalography (MEG) probe. For clarity, the contact surface between the head 18 and the heat insulation device is defined as the bottom, and does not represent the actual spatial orientation in use. The outermost part of the MEG probe is a heat dissipation shell 5 preferably made of hexagonal boron nitride (e.g., a hollow, bottomless sleeve of a cuboid, cube, or other shape). The bottom of the heat dissipation shell 5 is an intermediate heat-conducting layer 4 preferably made of hexagonal boron nitride. A heat insulation bottom layer 6 preferably made of aerogel is attached to the bottom of the intermediate heat-conducting layer 4. A heat insulation element 3 preferably made of aerogel is attached to the upper center of the intermediate heat-conducting layer 4. A heating furnace 2 made of hexagonal boron nitride (e.g., a hollow structure of a cuboid, cube, or other shape) is disposed inside the heat insulation element 3, and an atomic bubble 1 is placed inside the heating furnace 2. A light-transmitting hole 7 is provided at the center of a pair of opposite sidewalls of the heating furnace 2. Two light-transmitting channels are respectively provided on the heat insulation component 3 at the two light-transmitting holes 7. A heating element opening is provided at the corresponding position on the non-magnetic heating element 10 inside the two light-transmitting channels. The two light-transmitting holes 7, the two heating element openings, and the two light-transmitting channels are all aligned on a straight line. The heating element openings have the same diameter as the light-transmitting holes 7 and are aligned and adhered. A sealing through-hole 9 is provided at the center of the top of the heating furnace 2. A temperature sensor 11 (e.g., platinum resistance thermometer) is provided on the outer wall of the heating furnace 2 near the sealing through-hole 9. A sealing cooling channel is provided on the heat insulation component 3 corresponding to the position of the sealing through-hole 9. The glass seal 8 of the atomic bubble 1 extends through the sealing through-hole 9 into the sealing cooling channel. The heat insulation component 3 is solid except for the two light-transmitting channels and the sealing cooling channel.

[0037] Furthermore, the top of the heat dissipation housing 5 has circular holes (one for optical fiber and one for signal transmission line) to allow the optical fiber 12 and signal transmission line 21 to extend into the heat dissipation housing 5. The optical fiber coupler 13, beam expander 14, polarization beam splitter 15, quarter-wave plate 16, first reflecting prism 17, second reflecting prism 19, and photodetector 20 are all disposed inside the heat dissipation housing 5. The laser used by the atomic magnetoencephalography (MEG) probe passes through the top of the heat dissipation housing 5 from top to bottom via the optical fiber 12, and then sequentially passes through the optical fiber coupler 13, beam expander 14, polarization beam splitter 15, and quarter-wave plate 16. After being reflected by the first reflecting prism 17, it enters the atomic bulb 1 through the light transmission channel of the incident path, the opening of the heating plate, and the light transmission hole 7. After passing through the light transmission hole 7, the opening of the heating plate, and the light transmission channel of the exit path, it enters the second reflecting prism 19 and is then reflected by the second reflecting prism 19 to the photodetector 20. The photodetector 20 is connected to the signal transmission line 21, which passes upward through the heat dissipation housing 5. The aforementioned optical fiber 12, optical fiber coupler 13, beam expander 14, polarization beam splitter 15, quarter-wave plate 16, first reflecting prism 17, second reflecting prism 19, photodetector 20, and signal transmission line 21 are optoelectronic components.

[0038] Furthermore, the thickness of the heat dissipation shell 5 is 1mm, and the internal cavity of the heat dissipation shell 5 is 60mm long, 50mm wide, and 60mm high. The heat dissipation shell 5 dissipates heat through external air convection.

[0039] Furthermore, the thickness of the intermediate heat-conducting layer 4 is 1 mm, and the length and width of the intermediate heat-conducting layer 4 are consistent with the length and width of the bottom opening of the heat dissipation shell 5. The intermediate heat-conducting layer 4 laterally diffuses the heat flow from the heating furnace 2 to the bottom of the heat insulation component 3, firstly serving as a heat flow distribution layer, guiding part of the heat flow into the heat dissipation shell 5, and secondly preventing the heat flow from concentrating and forming localized high-temperature areas.

[0040] Furthermore, the thickness of the heat insulation layer 6 is 2mm, and the length and width of the heat insulation layer 6 are consistent with the length and width of the intermediate heat-conducting layer 4. The heat insulation layer 6 blocks the heat flow to the human body after it has been diffused and distributed by the intermediate heat-conducting layer 4, thereby further reducing the temperature.

[0041] Furthermore, the atomic bubble 1 is made of high-temperature resistant glass. In this embodiment, boron-doped high-temperature resistant glass is used, with a glass thickness of 2 mm. The interior is sealed with helium, nitrogen, and a drop of alkali metal. The glass seal 8 at the top center of the atomic bubble 1 is a conical tip with a bottom diameter of 4 mm and a height of 3 mm.

[0042] Furthermore, the heating furnace 2 has a wall thickness of 1mm and an internal cavity that is 20mm long, 10mm wide, and 10mm high, which matches the size of the atomic bubble 1 to prevent the atomic bubble 1 from shaking.

[0043] Furthermore, the diameter of the sealing hole 9 is 4mm. The glass seal 8 extends into the air through the sealing hole 9, allowing alkali metal vapor to adhere to the glass seal 8 upon cooling, thus preventing rubidium atoms from adhering to other locations on the atomic bubble 1 and affecting the operation of the magnetoencephalography (MEG) device.

[0044] Furthermore, the light-transmitting hole 7 is a square hole with a side length of 5mm.

[0045] Furthermore, the bottom thickness of the heat insulation component 3 is less than the thickness of the top and sides. The top and sides of the heat insulation component 3 are 10mm thick, and the bottom thickness of the heat insulation component 3 is 3mm thick. The sides and top of the heat insulation component 3 are thicker to ensure a higher temperature for the internal heating furnace 2. At the same time, there is an air layer between the heat insulation component 3 and the heat dissipation shell 5 to reduce heat loss.

[0046] Furthermore, a slit is provided at the top of the heat insulation component 3 located above the non-magnetic heating element 10, through which the leads of the non-magnetic heating element 10 pass out of the heat insulation component 3; the leads of the temperature sensor 11 pass out of the heat insulation component 3 through the sealed cooling channel of the heat insulation component 3; all leads, namely the leads of the non-magnetic heating element 10 and the leads of the temperature sensor 11, pass out of the heat dissipation housing 5 through the signal transmission line circular hole located at the top of the heat dissipation housing 5. The non-magnetic heating element 10 adopts the microelectromechanical system (MEMS) manufacturing process, with reverse symmetrical wiring on both sides of the polyimide flexible film, thereby canceling the magnetic field generated by the current in the wires on both sides of the film, so no magnetic field is generated after current is passed through the non-magnetic heating element 10.

[0047] The intermediate heat-conducting layer 4 and the heat dissipation shell 5 can be manufactured as a single piece. The heat insulation component 3 and the intermediate heat-conducting layer 4, as well as the intermediate heat-conducting layer 4 and the heat insulation bottom layer 6, are fixed by bonding with high-temperature resistant adhesive. In this embodiment, the high-temperature resistant adhesive is high-temperature resistant epoxy resin structural adhesive.

[0048] Furthermore, both the heating furnace 2 and the heat insulation component 3 adopt a separate design. The heating furnace 2 is divided into two parts: the bottom of the heating furnace 2 (i.e., the bottom cover of the heating furnace) and the sides and top of the heating furnace 2 (i.e., the furnace body). After the atomic bubble 1 is installed into the furnace body, the bottom cover and the furnace body are glued together as a whole using high-temperature resistant adhesive. The heat insulation component 3 is also divided into two parts: the bottom of the heat insulation component 3 and the sides and top of the heat insulation component 3. The sides and top of the heat insulation component 3 are integrated. After the heating furnace 2 is installed, the bottom and sides of the heat insulation component 3 are glued together using high-temperature resistant adhesive. One side of the heat dissipation shell 5 is also designed separately from the adjacent side. After all the components inside the heat dissipation shell 5 are installed, it is glued together with the intermediate heat-conducting layer 4 as a whole. The order of installation and fixing of each component is as follows: 1) Install the heat dissipation shell 5 except for one side; 2) Install the intermediate heat-conducting layer 4, the heat insulation bottom layer 6, and the bottom of the heat insulation component 3; 3) After the atomic bubble 1 is installed into the furnace body, the furnace cover is closed and the furnace body and furnace cover of the heating furnace 2 are glued together; 4) The heating furnace 2 is installed inside the heat dissipation shell 5, and the non-magnetic heating element 10 and temperature sensor 11 are installed; 5) The side and top of the heat insulation component 3 are installed inside the heat dissipation shell 5; 6) The photoelectric component is installed inside the heat dissipation shell 5; 7) Install the remaining side wall of the heat dissipation shell 5.

[0049] The high thermal conductivity of the heating furnace 2 and its almost complete encapsulation of the atomic bulb 1 ensure the uniformity of heating of the atomic bulb 1. The heated atomic bulb 1 and the heating furnace 2 can be considered as isothermal bodies. The heat from the isothermal body will flow to the outside of the heat insulation component 3. Since the heat insulation layer on the top and sides of the heat insulation component 3 is relatively thick, the thermal resistance is relatively large, so the amount of heat flowing away is relatively small, and the temperature of the top and sides of the outer surface of the heat insulation component 3 is also relatively low. The formula modeling and analysis process will not be elaborated here. The following mainly analyzes the heat flowing to the bottom of the heat insulation component 3 and the temperature at the bottom of the magnetoencephalogram (MEG) device.

[0050] In the device of this invention, the simplified model of the equivalent thermal resistance between atomic bubble 1 and human head 18 is as follows: Figure 3 As shown in the thermal circuit diagram, the following equation can be derived based on the thermal resistance model:

[0051]

[0052]

[0053]

[0054] P1 = P2 + P3

[0055] Wherein, P1 is the heat flow from atomic bubble 1 and heating furnace 2 to the bottom of insulation component 3, P2 is the portion of heat flow transferred to the environment, P3 is the portion of heat flow to the human body, and T cell T represents the temperature of bubble 1. room Indicates ambient temperature, T body θ1 represents the thermal resistance at the bottom of the insulation component 3, θ2 represents the equivalent thermal resistance from the heat dissipation shell 5 to air convection, and θ3 represents the thermal resistance of the bottom insulation layer 6. body T1 represents the equivalent thermal resistance of the human skin layer, and T1 is the temperature of the intermediate heat-conducting layer 4 and the heat dissipation shell 5. To simplify the calculation, the thermal resistance of the intermediate heat-conducting layer 4 and the heat dissipation shell 5 is ignored, and the heating furnace 2 and the atomic bubble 1 are considered as isothermal bodies.

[0056] Solving for the given information yields:

[0057]

[0058] Specifically, because the heat dissipation casing 5 has a large contact area with the air and high convective heat transfer efficiency, the thermal resistance θ2 from the heat dissipation casing 5 to the air convection section is small compared to other thermal resistances. As can be seen from the above equation, the smaller θ2 is, the lower the thermal resistance T... cell The smaller the coefficient, the more sensitive the temperature T. feel The less it is affected by the high temperature inside atomic bubble 1.

[0059] If direct insulation is used, the temperature felt by the human body will be... With a fixed amount of insulation material, it is necessary to increase the thickness of the insulation material to increase the thermal resistance θ1+θ3, thereby reducing T. cell The coefficient.

[0060] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A thermally conductive insulation device for an atomic magnetoencephalography (MEG) probe, comprising a heating furnace (2) enclosing the atomic bubble (1), characterized in that, The heating furnace (2) is covered with a heat insulation component (3). The thickness of the top and sides of the heat insulation component (3) is greater than the thickness of the bottom of the heat insulation component (3). The bottom surface of the heat insulation component (3) is connected to an intermediate heat-conducting layer (4). The bottom surface of the intermediate heat-conducting layer (4) is provided with a heat insulation bottom layer (6). The bottom surface of the heat insulation bottom layer (6) is in contact with the head (18). The heat dissipation shell (5) is covered outside the heat insulation component (3), and the bottom opening of the heat dissipation shell (5) is connected to the periphery of the intermediate heat-conducting layer (4). A pair of opposite sidewalls of the heating furnace (2) are provided with non-magnetic heating plates (10). The heating furnace (2) has a light-transmitting hole (7) at the center of a pair of opposite sidewalls. The heat insulation component (3) has two light-transmitting channels at the corresponding positions of the two light-transmitting holes (7). The non-magnetic heating element (10) inside the two light-transmitting channels has a heating element opening at the corresponding position. The two light-transmitting holes (7), the two heating element openings, and the two light-transmitting channels are located on the same straight line. The diameter of the heating element opening is the same as that of the light-transmitting hole (7) and they are aligned. The heating furnace (2) has a sealing through hole (9) at the center of the top. The heat insulation component (3) has a sealing cooling channel corresponding to the position of the sealing through hole (9). The glass seal (8) of the atomic bubble (1) extends through the sealing through hole (9) into the sealing cooling channel. The heat insulation component (3) is solid except for the two light-transmitting channels and the sealing cooling channel. The thickness of the top and sides of the heat insulation component (3) is 8-12 mm, and the thickness of the bottom is 2-4 mm; The thickness of the intermediate heat-conducting layer (4) is 0.8-1.2 mm; The thickness of the heat insulation bottom layer (6) is 1.5-2.5 mm, and the length and width of the heat insulation bottom layer (6) are the same as the length and width of the intermediate heat-conducting layer (4).

2. The thermally conductive insulation device for an atomic magnetoencephalography (MEG) probe according to claim 1, characterized in that, The laser used by the atomic magnetoencephalography probe passes through the top of the heat sink shell (5) from top to bottom via an optical fiber (12), and then passes through the optical fiber coupler (13), beam expander (14), polarization beam splitter (15), and quarter-wave plate (16) in sequence. After being reflected by the first reflecting prism (17), it enters the atomic bubble (1) through the light transmission channel, heating plate opening, and light transmission hole (7) of the incident path. After passing through the light transmission hole (7), heating plate opening, and light transmission channel of the exit path, it enters the second reflecting prism (19) and is reflected by the second reflecting prism (19) to the photodetector (20). The photodetector (20) is connected to the signal transmission line (21), and the signal transmission line (21) passes upward through the heat sink shell (5).

3. The thermally conductive insulation device for an atomic magnetoencephalography (MEG) probe according to claim 1, characterized in that, The heating furnace (2), the intermediate heat-conducting layer (4) and the heat dissipation shell (5) are all made of hexagonal boron nitride ceramic, and the heat insulation component (3) and the heat insulation bottom layer (6) are made of aerogel.

4. The thermally conductive insulation device for an atomic magnetoencephalography (MEG) probe according to claim 1, characterized in that, The heat insulation component (3) and the intermediate heat-conducting layer (4), as well as the intermediate heat-conducting layer (4) and the heat insulation bottom layer (6) are bonded and fixed with high-temperature resistant adhesive.

5. The thermally conductive insulation device for an atomic magnetoencephalography (MEG) probe according to claim 1, characterized in that, An air gap is left between the periphery of the heat insulation component (3) and the periphery of the heat dissipation shell (5), and an air gap is left between the top of the heat insulation component (3) and the top of the heat dissipation shell (5).

6. The thermally conductive insulation device for an atomic magnetoencephalography (MEG) probe according to claim 1, characterized in that, A slit is made on the top of the heat insulation component (3) located above the non-magnetic heating element (10), and the lead wire of the non-magnetic heating element (10) passes through the slit and exits the heat insulation component (3); a temperature sensor (11) is provided on the outer wall of the heating furnace (2) near the sealing through hole (9), and the lead wire of the temperature sensor (11) passes through the sealing cooling channel of the heat insulation component (3) and exits the heat insulation component (3); the lead wire of the non-magnetic heating element (10) and the lead wire of the temperature sensor (11) both pass through the signal transmission line hole provided on the top of the heat dissipation shell (5) and exit the heat dissipation shell (5).

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