Superconducting magnet system for esophageal atresia traction anastomosis, and method

Abstract

Disclosed in the present invention are a superconducting magnet system for esophageal atresia traction anastomosis, and a method. The system comprises: a superconducting magnet device, a movable flat plate, a support, a ferromagnetic core and a permanent magnetic core, wherein the movable flat plate is movably arranged inside a central hole of the superconducting magnet device, the support is fixedly connected to the superconducting magnet device, and the ferromagnetic core and the permanent magnetic core are placed inside the central hole of the superconducting magnet device and are respectively located at a proximal esophageal end and a distal esophageal end of an esophageal atresia target; the superconducting magnet device is configured to generate a uniform magnetic field and a gradient magnetic field inside the central hole; and the ferromagnetic core and the permanent magnetic core are configured to provide opposite traction forces for the esophageal atresia target under the uniform magnetic field and the gradient magnetic field. According to the present application, by combining the uniform magnetic field, the gradient magnetic field, the ferromagnetic core and the permanent magnetic core, opposite traction forces that have adjustable magnitudes and that do not require directional adjustment are provided for the esophageal atresia target, thereby improving the traction force intensity, control flexibility and control precision.

Description

A superconducting magnet system and method for traction anastomosis of esophageal atresia Technical Field

[0001] This application relates to the field of superconducting magnet technology, and in particular to a superconducting magnet system and method for esophageal atresia traction anastomosis. Background Technology

[0002] The incidence of congenital esophageal atresia in newborns is approximately 1 / 2500 to 1 / 4000. Long-segment esophageal atresia refers to a distance exceeding 2 cm between the proximal and distal esophagus. Although various surgical methods exist, they cause severe damage to the physiological structure of newborns. Currently, some researchers have proposed using magnets to shorten the atresia distance, but this method generates insufficient traction when the atresia distance is large, failing to achieve the desired effect. Therefore, research and improvement of devices for traction anastomosis of esophageal atresia are necessary.

[0003] In the prior art, Chinese patent CN108606930A discloses a medical device and its preparation method for congenital esophageal atresia, including an upper guiding device, a lower guiding device, and a digital gaussmeter. The upper guiding device includes a first upper flexible tube and an upper magnetic attraction device disposed at the lower end of the first upper flexible tube. The lower guiding device includes a first lower flexible tube and a lower magnetic attraction device disposed at the upper end of the first lower flexible tube. This prior art can achieve synchronous growth and self-healing of the upper and lower blind ends of the esophagus, preserving the integrity of the child's own esophageal structure and function, avoiding surgical methods that require other organs to replace the esophagus. At the same time, the magnetic force enables the upper and lower blind ends of the esophagus to automatically anastomose and connect. The digital gaussmeter assists in observing the esophageal growth status, reducing the number of surgeries and minimizing the trauma caused by surgical treatment.

[0004] However, the aforementioned existing technologies have poor traction strength when faced with a large esophageal atresia distance, and it is difficult to adjust the magnitude and direction of the traction force, resulting in poor control flexibility and accuracy. Summary of the Invention

[0005] This application provides a superconducting magnet system and method for traction anastomosis of esophageal atresia, which solves the problems of poor traction strength, difficulty in adjusting the magnitude and direction of traction force, and poor control flexibility and accuracy of traction force when the esophageal atresia distance is large in the prior art.

[0006] On the one hand, this application provides a superconducting magnet system for esophageal atresia traction anastomosis, comprising: a superconducting magnet device, a movable plate, a support, a ferromagnetic core, and a permanent magnet core.

[0007] The movable plate is movably disposed inside the central hole of the superconducting magnet device. The bracket is fixedly connected to the superconducting magnet device. The ferromagnetic core and the permanent magnet core are placed inside the central hole of the superconducting magnet device and are respectively located at the proximal end and distal end of the esophagus of the esophageal atresia target.

[0008] The superconducting magnet device is used to generate a uniform magnetic field and a gradient magnetic field inside the central hole.

[0009] The movable plate is used to deliver the esophageal occlusion target into the central hole of the superconducting magnet device.

[0010] The bracket is used to support and fix the superconducting magnet device.

[0011] The ferromagnetic core and the permanent magnetic core are used to provide opposing traction forces for the esophageal atresia target under the uniform magnetic field and gradient magnetic field generated by the superconducting magnet device.

[0012] In one possible implementation, the superconducting magnet device includes: a uniform magnetic field winding, a uniform magnetic field frame, a gradient magnetic field winding, a gradient magnetic field frame, a connecting structure, a cold shield, an external Dewar, a suspension rod, and an axial rod.

[0013] The uniform magnetic field winding is wound on the uniform magnetic field frame, and the gradient magnetic field winding is wound on the gradient magnetic field frame. Both the uniform magnetic field winding and the gradient magnetic field winding are made of superconducting materials.

[0014] The connecting structure is fixedly connected to the uniform magnetic field skeleton and the gradient magnetic field skeleton, such that the uniform magnetic field skeleton is located outside or inside the gradient magnetic field skeleton, and both the uniform magnetic field skeleton and the gradient magnetic field skeleton are concentric with the central hole of the superconducting magnet device.

[0015] The uniform magnetic field winding, the uniform magnetic field frame, the gradient magnetic field winding, the gradient magnetic field frame, and the connecting structure constitute a superconducting coil winding structure.

[0016] The cold shield is wrapped around the outside of the superconducting coil winding structure.

[0017] The outer Dewar is wrapped around the outside of the cold screen.

[0018] The suspension rod is radially fixed to the superconducting coil winding structure and the external Dewar.

[0019] The axial tie rod is axially fixed to the superconducting coil winding structure and the external Dewar.

[0020] In one possible implementation, the uniform magnetic field winding includes: a pair of uniform magnetic field main windings.

[0021] In one possible implementation, the uniform magnetic field winding further includes at least one pair of uniform magnetic field auxiliary windings.

[0022] The uniform magnetic field auxiliary winding is located axially inside the uniform magnetic field main winding.

[0023] In one possible implementation, the gradient magnetic field winding includes: a pair of gradient magnetic field main windings.

[0024] In one possible implementation, the gradient magnetic field winding further includes at least one pair of gradient magnetic field auxiliary windings.

[0025] The gradient magnetic field auxiliary winding is located on the axial inner side of the gradient magnetic field main winding.

[0026] In one possible implementation, the uniform magnetic field winding is connected in series with a superconducting closed-loop switch.

[0027] The superconducting closed-loop switch uses a superconducting coil wound on a heating body and is connected in parallel with the power supply of the uniform magnetic field winding.

[0028] In one possible implementation, the superconducting magnet device further includes a refrigerator.

[0029] The refrigerator passes through the outer Dewar and the cold shield, and is connected to the uniform magnetic field winding and the gradient magnetic field winding for heat conduction.

[0030] In one possible implementation, the outer cylinder and the two end plates of the outer Dewar are made of ferromagnetic material.

[0031] On the other hand, this application provides a method for operating a superconducting magnet system for esophageal atresia traction anastomosis, comprising:

[0032] The superconducting magnet device was evacuated and cooled.

[0033] Ferromagnetic and permanent magnet cores are respectively placed at the proximal and distal ends of the esophagus of the esophageal atresia target.

[0034] The target of esophageal occlusion is inserted into the central hole of the superconducting magnet device via a movable plate.

[0035] When the uniform magnetic field winding of the superconducting magnet device is energized, a uniform magnetic field is generated inside the central hole, which magnetizes the ferromagnetic core to saturation.

[0036] When the gradient magnetic field winding of the superconducting magnet device is energized, a gradient magnetic field is generated inside the central hole, so that the ferromagnetic core and the permanent magnetic core provide opposing traction forces for the esophageal atresia target.

[0037] The magnitude of the traction force is controlled by adjusting the current flowing through the gradient magnetic field winding.

[0038] The superconducting magnet system and method for esophageal atresia traction anastomosis disclosed in this application have the following advantages:

[0039] By combining a uniform magnetic field, a gradient magnetic field, a ferromagnetic core, and a permanent magnetic core, a uniform magnetic field and a gradient magnetic field are generated inside the central hole of the superconducting magnet device. By adjusting the current flowing through the magnetic field, the magnitude of the opposing traction force provided to the esophageal atresia target is adjustable without requiring directional adjustment, thus improving traction force strength, control flexibility, and control precision. Furthermore, because the uniform and gradient magnetic fields exist throughout the entire central hole, the traction force remains constant regardless of changes in the positions of the ferromagnetic and permanent magnetic cores, improving traction force stability.

[0040] Both the proposed uniform magnetic field winding and gradient magnetic field winding use superconducting materials, which improves the magnetic field strength and thus the traction strength of the ferromagnetic core. At the same time, the superconducting material generates almost no heat during operation, has low power consumption, and can achieve long-term continuous operation, thereby shortening the overall working cycle.

[0041] The superconducting coil winding structure and the outer Dewar are fixedly connected radially by a suspension rod, and axially by a tie rod, which stabilizes the structure between the superconducting coil winding structure and the outer Dewar, thereby stabilizing the magnetic field and the traction force.

[0042] The invention proposes at least one pair of uniform magnetic field auxiliary windings, which are located axially inside the uniform magnetic field main winding. The uniform magnetic field generated by the uniform magnetic field main winding is adjusted by the uniform magnetic field auxiliary windings, thereby improving the uniformity of the magnetic field in the entire magnetic field space.

[0043] At least one pair of gradient magnetic field auxiliary windings are proposed. The gradient magnetic field auxiliary windings are located on the axial inner side of the gradient magnetic field main winding. The gradient magnetic field generated by the gradient magnetic field main winding is adjusted by the gradient magnetic field auxiliary windings, so that the magnetic field gradient of the entire magnetic field space is more consistent.

[0044] The proposed uniform magnetic field winding is connected in series with a superconducting closed-loop switch. The superconducting closed-loop switch uses a superconducting coil wound on the heating body and is connected in parallel with the power supply of the uniform magnetic field winding. When the power supply of the uniform magnetic field winding is energized and the required magnetic field strength is reached, the power supply of the uniform magnetic field winding can be short-circuited through the superconducting closed-loop switch. By utilizing the non-resistance current carrying capacity of the superconducting material, the magnetic field strength of the uniform magnetic field can be maintained without energizing the uniform magnetic field winding again, while reducing the heat leakage load caused by the power supply of the uniform magnetic field winding.

[0045] The proposed refrigerator passes through an external Dewar and a cold shield, and is connected to a uniform magnetic field winding and a gradient magnetic field winding for heat conduction. Compared with conventional liquid helium cooling, the refrigerator can be used simply by being powered on, making it more economical and convenient.

[0046] The outer cylinder and two end plates of the proposed outer Dewar are all made of ferromagnetic materials, which achieves magnetic shielding and improves safety. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 is a schematic diagram of a superconducting magnet system for esophageal atresia traction anastomosis provided in an embodiment of this application;

[0049] Figure 2 is a schematic diagram of the esophageal atresia target provided in an embodiment of this application;

[0050] Figure 3 is a schematic diagram of the uniform magnetic field winding and the gradient magnetic field winding provided in the embodiments of this application;

[0051] Figure 4 is a power supply schematic diagram of the uniform magnetic field winding and the gradient magnetic field winding provided in the embodiments of this application;

[0052] Figure 5 is a schematic diagram of a single uniform magnetic field distribution provided in an embodiment of this application;

[0053] Figure 6 is a schematic diagram of the individual gradient magnetic field distribution provided in an embodiment of this application;

[0054] Figure 7 is a schematic diagram of the superimposed distribution of uniform magnetic field and gradient magnetic field provided in an embodiment of this application;

[0055] Figure 8 is a schematic diagram of the traction force of the ferromagnetic core and permanent magnetic core provided in the embodiments of this application under a uniform magnetic field and a gradient magnetic field.

[0056] Explanation of reference numerals in the attached figures:

[0057] 1-Esophagus occlusion target, 2-Superconducting magnet device, 3-Movable plate, 4-Support, 201-Uniform magnetic field winding, 202-Uniform magnetic field frame, 203-Gradient magnetic field winding, 204-Gradient magnetic field frame, 205-Connecting structural component, 206-Cold shield, 207-External Dewar, 208-Refrigeration unit, 209-Suspension rod, 210-Axial rod, 101-Proximal end of esophagus, 102-Distal end of esophagus, 103-Ferromagnetic core, 104-Permanent magnetic core, 2011-Uniform magnetic field main winding, 2012-Uniform magnetic field auxiliary winding, 2031-Gradient magnetic field main winding, 2032-Gradient magnetic field auxiliary winding, 211-Uniform magnetic field winding power supply, 212-Gradient magnetic field winding power supply, 213-Superconducting closed-loop switch, 214-Heating element. Detailed Implementation

[0058] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0059] As shown in Figures 1 and 2, this application provides a superconducting magnet system for esophageal atresia traction anastomosis, including: a superconducting magnet device 2, a movable plate 3, a support 4, a ferromagnetic core 103, and a permanent magnet core 104.

[0060] The movable plate 3 is movably disposed inside the central hole of the superconducting magnet device 2. The bracket 4 is fixedly connected to the superconducting magnet device 2. The ferromagnetic core 103 and the permanent magnet core 104 are placed inside the central hole of the superconducting magnet device 2 and are respectively located at the proximal end 101 and distal end 102 of the esophagus of the esophageal occlusion target 1.

[0061] The superconducting magnet device 2 is used to generate a uniform magnetic field and a gradient magnetic field inside the central hole.

[0062] The movable plate 3 is used to send the esophageal occlusion target 1 into the central hole of the superconducting magnet device 2.

[0063] The bracket 4 is used to support and fix the superconducting magnet device 2.

[0064] The ferromagnetic core 103 and the permanent magnetic core 104 are used to provide opposing traction forces for the esophageal atresia target 1 under the uniform magnetic field and gradient magnetic field generated by the superconducting magnet device 2.

[0065] Specifically, when the ferromagnetic core 103 is positioned at the proximal esophagus 101 of the esophageal closure target 1, the permanent magnetic core 104 is positioned at the distal esophagus 102 of the esophageal closure target 1; when the ferromagnetic core 103 is positioned at the distal esophagus 102, the permanent magnetic core 104 is positioned at the proximal esophagus 101. In this embodiment, the ferromagnetic core 103 is positioned at the distal esophagus 102 of the esophageal closure target 1, and the permanent magnetic core 104 is positioned at the proximal esophagus 101 of the esophageal closure target 1. As shown in Figure 2, the distance between the proximal esophagus 101 and the distal esophagus 102 is L (i.e., the esophageal closure distance is L). When L is large, the prior art uses magnets to attract each other, resulting in a weak traction force. However, in this application, the ferromagnetic core 103 and the permanent magnetic core 104 are located in the magnetic field inside the central hole of the superconducting magnet device 2, and the traction force is independent of the magnitude of the esophageal closure distance L. In this embodiment, the target 1 of esophageal atresia adopts the neonatal model of esophageal atresia.

[0066] In this embodiment, the entire superconducting magnet system is set to be 0.6m long, 0.5m wide, and 1.5m high to meet the length of the esophageal atresia target 1. In other possible embodiments, the size of the superconducting magnet system can be set to other dimensions according to actual conditions.

[0067] For example, the superconducting magnet device 2 includes: a uniform magnetic field winding 201, a uniform magnetic field frame 202, a gradient magnetic field winding 203, a gradient magnetic field frame 204, a connecting structure 205, a cold shield 206, an external Dewar 207, a suspension rod 209, and an axial rod 210.

[0068] The uniform magnetic field winding 201 is wound on the uniform magnetic field frame 202, and the gradient magnetic field winding 203 is wound on the gradient magnetic field frame 204. Both the uniform magnetic field winding 201 and the gradient magnetic field winding 203 are made of superconducting materials.

[0069] The connecting structure 205 fixes the uniform magnetic field skeleton 202 and the gradient magnetic field skeleton 204, such that the uniform magnetic field skeleton 202 is located outside or inside the gradient magnetic field skeleton 204, and both the uniform magnetic field skeleton 202 and the gradient magnetic field skeleton 204 are concentric with the central hole of the superconducting magnet device 2.

[0070] The uniform magnetic field winding 201, the uniform magnetic field frame 202, the gradient magnetic field winding 203, the gradient magnetic field frame 204, and the connecting structure 205 constitute a superconducting coil winding structure.

[0071] The cold shield 206 is wrapped around the outside of the superconducting coil winding structure.

[0072] The outer Dewar 207 is wrapped around the outside of the cold screen 206.

[0073] The suspension rod 209 is radially fixed to the superconducting coil winding structure and the outer Dewar 207.

[0074] The axial tie rod 210 is axially fixed to the superconducting coil winding structure and the external Dewar 207.

[0075] Specifically, the connecting structure 205 is used to fix the positions of the uniform magnetic field frame 202 and the gradient magnetic field frame 204 and to provide a cooling effect; the cold shield 206 is used to reduce the radiative heat leakage of the superconducting coil winding structure; the external Dewar 207 is used to provide a vacuum environment for the superconducting coil winding structure; the suspension rod 209 and the axial rod 210 are used to prevent the superconducting coil winding structure from moving with the external Dewar 207 due to electromagnetic force and to reduce conductive heat leakage.

[0076] In this embodiment, both the uniform magnetic field winding 201 and the gradient magnetic field winding 203 are made of niobium-titanium alloy superconducting material. In other possible embodiments, other superconducting materials may also be used.

[0077] Specifically, the uniform magnetic field framework 202 can be located outside or inside the gradient magnetic field framework 204. In this embodiment, the uniform magnetic field framework 202 can be located outside the gradient magnetic field framework 204. In other possible embodiments, the uniform magnetic field framework 202 can also be located inside the gradient magnetic field framework 204.

[0078] As shown in Figure 3, the Z-axis is the axial direction of the superconducting magnet device 2, the R-axis is the radial direction of the superconducting magnet device 2, -Z1 to +Z1 are the axial positions of the center hole of the superconducting magnet device 2, and -R1 to +R1 are the radial positions of the center hole of the superconducting magnet device 2. The uniform magnetic field winding 201 is used to generate a uniform magnetic field in the cylindrical range inside the center hole of the superconducting magnet device 2, and the gradient magnetic field winding 203 is used to generate a gradient magnetic field in the cylindrical range inside the center hole of the superconducting magnet device 2.

[0079] As shown in Figure 3, by way of example, the uniform magnetic field winding 201 includes: a pair of uniform magnetic field main windings 2011.

[0080] For example, the uniform magnetic field winding 201 further includes at least one pair of uniform magnetic field auxiliary windings 2012.

[0081] The uniform magnetic field auxiliary winding 2012 is located on the axial inner side of the uniform magnetic field main winding 2011.

[0082] For example, the gradient magnetic field winding 203 includes: a pair of gradient magnetic field main windings 2031.

[0083] For example, the gradient magnetic field winding 203 further includes at least one pair of gradient magnetic field auxiliary windings 2032.

[0084] The gradient magnetic field auxiliary winding 2032 is located on the axial inner side of the gradient magnetic field main winding 2031.

[0085] Specifically, as shown in Figure 3, in this embodiment, the uniform magnetic field winding 201 includes a pair of uniform magnetic field main windings 2011 and a pair of uniform magnetic field auxiliary windings 2012, and the gradient magnetic field winding 203 includes a pair of gradient magnetic field main windings 2031 and a pair of gradient magnetic field auxiliary windings 2032. The uniform magnetic field main windings 2011 are used to generate a uniform magnetic field inside the central hole of the superconducting magnet device 2, and the uniform magnetic field auxiliary windings 2012 are used to adjust the uniform magnetic field, improving the magnetic field uniformity of the entire magnetic field space. The gradient magnetic field main windings 2031 are used to generate a gradient magnetic field inside the central hole of the superconducting magnet device 2, and the gradient magnetic field auxiliary windings 2032 are used to adjust the gradient magnetic field, making the magnetic field gradient more consistent throughout the magnetic field space. In other possible embodiments, other numbers of uniform magnetic field auxiliary windings 2012 and gradient magnetic field auxiliary windings 2032 can be provided according to actual conditions.

[0086] For example, the uniform magnetic field winding 201 is connected in series with a superconducting closed-loop switch 213.

[0087] The superconducting closed-loop switch 213 uses a superconducting coil wound on the heating body 214 and is connected in parallel with the power supply of the uniform magnetic field winding 201.

[0088] Specifically, as shown in Figure 4, the uniform magnetic field winding 201 is connected in series with the superconducting closed-loop switch 213 and the uniform magnetic field winding power supply 211, respectively, and the superconducting closed-loop switch 213 is connected in parallel with the uniform magnetic field winding power supply 211; the gradient magnetic field winding 203 is connected in series with the gradient magnetic field winding power supply 212. Among them, the uniform magnetic field winding power supply 211 and the gradient magnetic field winding power supply 212 are located outside the superconducting magnet device 2, and the superconducting closed-loop switch 213 is located inside the superconducting magnet device 2.

[0089] During the cooling phase of the superconducting magnet device 2, the superconducting closed-loop switch 213, along with the uniform magnetic field winding 201 and the gradient magnetic field winding 203, is cooled to below the superconducting critical temperature, entering the superconducting state. Before energizing the uniform magnetic field winding 201, the superconducting closed-loop switch 213 is heated by a heating element 214 to raise its temperature above the superconducting critical temperature, thus exiting the superconducting state. At this time, the uniform magnetic field winding power supply 211 energizes the uniform magnetic field winding 201. When the required magnetic field strength is reached (in this embodiment, the uniform magnetic field strength is...), the switch is energized. (With the magnetic field strength not exceeding 1T), heating of the superconducting closed-loop switch 213 is stopped. The superconducting closed-loop switch 213 gradually cools down and re-enters the superconducting state, short-circuiting the uniform magnetic field winding power supply 211. At this time, the uniform magnetic field winding power supply 211 is removed. Utilizing the unobstructed current-carrying capacity of the superconducting materials of the uniform magnetic field winding 201 and the superconducting closed-loop switch 213, the magnetic field strength of the uniform magnetic field can be maintained without energizing the uniform magnetic field winding 201, while reducing the heat leakage load caused by the uniform magnetic field winding power supply 211. In actual operation, the magnitude of the gradient magnetic field is controlled by controlling the magnitude of the current flowing through the gradient magnetic field winding 203, thereby controlling the magnitude of the traction force.

[0090] For example, the superconducting magnet device 2 further includes a refrigerator 208.

[0091] The refrigeration unit 208 passes through the outer Dewar 207 and the cold shield 206, and is connected to the uniform magnetic field winding 201 and the gradient magnetic field winding 203 for heat conduction.

[0092] Specifically, compared to conventional liquid helium cooling, the refrigerator 208 only requires power to operate, making it more economical and convenient. However, in other possible embodiments, liquid helium cooling can also be used to cool the uniform magnetic field winding 201 and the gradient magnetic field winding 203.

[0093] For example, the outer cylinder and the two end plates of the outer Dewar 207 are made of ferromagnetic material.

[0094] Specifically, in this embodiment, by using ferromagnetic materials for the outer cylinder and the two end plates of the outer Dewar 207 for magnetic shielding, the environmental leakage magnetic field within one meter around the superconducting magnet device 2 is much less than 5Gs, thus improving safety.

[0095] Specifically, when the uniform magnetic field winding 201 is energized alone, the distribution of the uniform magnetic field is shown in Figure 5. The Z-axis is the axial direction of the superconducting magnet device 2, the B-axis is the magnetic field strength, and +B1 is the magnetic field strength when the current flowing through the uniform magnetic field winding 201 is at its maximum. It can be seen that in the uniform magnetic field alone, the magnetic field strength remains constant along the axial direction of the superconducting magnet device 2. The direction of the magnetic field strength can be changed to -B1 by changing the direction of the current flowing through it. Simultaneously, the magnitude of the magnetic field strength can also be changed by changing the magnitude of the current flowing through it. The uniform magnetic field is mainly used for the magnetization of the ferromagnetic core 103.

[0096] Specifically, when the gradient magnetic field winding 203 is energized alone, the distribution of the individual gradient magnetic field is shown in Figure 6. The Z-axis is the axial direction of the superconducting magnet device 2, and the B-axis is the magnetic field strength. When the current flowing through the gradient magnetic field winding 203 is I1, the slope of the magnetic field strength (i.e., the magnetic field gradient) is K1. It can be seen that in the individual gradient magnetic field, the magnetic field gradient remains unchanged along the axial direction of the superconducting magnet device 2. The direction of the magnetic field gradient can be changed by changing the direction of the current, that is, the slope of the magnetic field strength changes from K1 to -K1. At the same time, the magnitude of the magnetic field gradient can also be changed by changing the magnitude of the current. When the current flowing through the gradient magnetic field winding 2031 increases from I1 to I2, the magnetic field gradient increases from K1 to K2.

[0097] Specifically, when the uniform magnetic field winding 201 and the gradient magnetic field winding 203 are simultaneously energized, the superimposed distribution of the uniform magnetic field and the gradient magnetic field is shown in Figure 7. The Z-axis is the axial direction of the superconducting magnet device 2, and the B-axis is the magnetic field strength. S1, S2, and S3 are the lines showing the relationship between the magnetic field strength and the axial direction of the superconducting magnet device 2 under three different conditions. Taking line S1 as a reference, the magnetic field gradient is K1. When the magnitude of the current flowing through the uniform magnetic field winding 201 is changed, the magnitude of the magnetic field strength changes while the magnetic field gradient remains unchanged. That is, line S1 will shift vertically, thus obtaining lines S2 and S3. In other words, changes in the magnitude of the magnetic field strength do not cause changes in the magnetic field gradient.

[0098] Specifically, in this embodiment, the traction force F of the ferromagnetic core 103 and the permanent magnetic core 104 is defined as follows:

[0099] F=V*mM*gradB

[0100] Where V represents the core volume, mM represents the magnetization intensity of the core, and gradB represents the magnetic field gradient (in this embodiment, the slope of the magnetic field intensity). It can be seen that the volumes V of both the ferromagnetic core 103 and the permanent magnetic core 104 are constants, and the magnetization intensity of the permanent magnetic core 104 is also constant. When the ferromagnetic core 103 is magnetized to saturation, its magnetization intensity is also constant. That is, the traction force F of the ferromagnetic core 103 and the permanent magnetic core 104 is linearly related to the magnetic field gradient gradB. In this embodiment, the magnitude and direction of the magnetic field gradient can be controlled by controlling the magnitude and direction of the current flowing through the gradient magnetic field winding 203, thereby controlling the magnitude and direction of the traction force of the ferromagnetic core 103. The formula for the traction force F also shows that the magnitude of the traction force F is independent of the position of the ferromagnetic core 103 and the permanent magnetic core 104 in the entire magnetic field space, and is not affected by the esophageal atresia distance L.

[0101] This application also provides a method for operating a superconducting magnet system for esophageal atresia traction anastomosis, including:

[0102] The superconducting magnet device 2 was evacuated and cooled.

[0103] Ferromagnetic core 103 and permanent magnet core 104 are respectively placed at the proximal end 101 and distal end 102 of the esophagus of the esophageal occlusion target 1.

[0104] The esophageal occlusion target 1 is inserted into the central hole of the superconducting magnet device 2 via the movable plate 3.

[0105] When the uniform magnetic field winding 201 of the superconducting magnet device 2 is energized, a uniform magnetic field is generated inside the central hole, which magnetizes the ferromagnetic core 103 to a saturated state.

[0106] When the gradient magnetic field winding 203 of the superconducting magnet device 2 is energized, a gradient magnetic field is generated inside the central hole, so that the ferromagnetic core 103 and the permanent magnetic core 104 provide opposing traction forces for the esophageal occlusion target 1.

[0107] The magnitude of the traction force is controlled by controlling the magnitude of the energizing current in the gradient magnetic field winding 203.

[0108] Specifically, in this embodiment, the vacuuming and cooling of the superconducting magnet device 2 includes: evacuating the interior of the outer Dewar 207; when the vacuum level inside the outer Dewar 207 reaches 1E-2Pa, turning on the refrigerator 208 to cool the uniform magnetic field winding 201, the gradient magnetic field winding 203, and the superconducting closed-loop switch 213 until the temperature of the uniform magnetic field winding 201, the gradient magnetic field winding 203, and the superconducting closed-loop switch 213 is lower than the superconducting critical temperature, entering the superconducting state and meeting the conditions for energization.

[0109] In this embodiment, a ferromagnetic core 103 is disposed at the distal end 102 of the esophagus of the esophageal closure target 1, and a permanent magnetic core 104 is disposed at the proximal end 101 of the esophagus of the esophageal closure target 1.

[0110] In this embodiment, before energizing the uniform magnetic field winding 201, the superconducting closed-loop switch 213 is heated by a heating element 214 to raise its temperature above the superconducting critical temperature, thus exiting the superconducting state. At this time, the uniform magnetic field winding power supply 211 energizes the uniform magnetic field winding 201. When the required magnetic field strength is reached (in this embodiment, the magnetic field strength of the uniform magnetic field does not exceed 1T), heating of the superconducting closed-loop switch 213 is stopped. The superconducting closed-loop switch 213 gradually cools and re-enters the superconducting state, short-circuiting the uniform magnetic field winding power supply 211. The uniform magnetic field winding power supply 211 is then removed. Utilizing the unobstructed current-carrying capacity of the superconducting materials of the uniform magnetic field winding 201 and the superconducting closed-loop switch 213, the magnetic field strength of the uniform magnetic field can be maintained without energizing the uniform magnetic field winding 201, while simultaneously reducing the heat leakage load caused by the uniform magnetic field winding power supply 211. Generally, a magnetic field strength not exceeding 1T is sufficient to magnetize the ferromagnetic core 103 to saturation.

[0111] As shown in Figure 8, in this embodiment, after the ferromagnetic core 103 is magnetized to saturation, the gradient magnetic field winding power supply 212 energizes the gradient magnetic field winding 203 of the superconducting magnet device 2. This causes the traction force of the ferromagnetic core 103 to point from the distal end 102 of the esophagus to the proximal end 101 of the esophagus (see F2 in Figure 8), and the traction force of the permanent magnetic core 104 to point from the proximal end 101 of the esophagus to the distal end 102 of the esophagus (see F1 in Figure 8). The magnitude of the magnetic field gradient can be controlled by controlling the magnitude of the current flowing through the gradient magnetic field winding 203, thereby controlling the magnitude of the traction forces of the ferromagnetic core 103 and the permanent magnetic core 104. Since the ferromagnetic core 103 and the permanent magnetic core 104 provide opposing traction forces to the esophageal occlusion target 1, simultaneously pulling the proximal end 101 and the distal end 102 of the esophagus closer together, there is no need to change the direction of the current flowing through the gradient magnetic field winding 203.

[0112] When the distance between the proximal esophagus 101 and the distal esophagus 102 approaches zero, the superconducting magnet device 2 can be removed. The ferromagnetic core 103 demagnetizes when the external uniform magnetic field is lost. Since the distance between the proximal esophagus 101 and the distal esophagus 102 is close to zero at this time, the permanent magnet core 104 produces a new magnetization effect on the demagnetized ferromagnetic core 103 (equivalent to the effect of a permanent magnet attracting iron in real life). The ferromagnetic core 103 and the permanent magnet core 104 continue to attract each other, causing ischemic necrosis of the esophageal tissue between them. The adjacent esophageal tissue heals and connects, realizing the anastomosis between the proximal esophagus 101 and the distal esophagus 102. This avoids the surgical safety risks and slow postoperative recovery problems caused by open-chest surgery or thoracoscopic surgery for the anastomosis between the proximal esophagus 101 and the distal esophagus 102.

[0113] In one possible comparative embodiment, the permanent magnetic core 104 is replaced with a ferromagnetic core 103 (i.e., both the proximal esophagus 101 and the distal esophagus 102 are provided with ferromagnetic cores 103). Since the two ferromagnetic cores 103 are magnetized in the same way under a uniform magnetic field, after the gradient magnetic field winding 203 generates a gradient magnetic field, the traction force of the two ferromagnetic cores 103 is in the same direction, which can only achieve traction on the proximal esophagus 101 or the distal esophagus 102 individually. In order to pull both the proximal esophagus 101 and the distal esophagus 102 closer together, it is necessary to change the direction of the current flowing through the gradient magnetic field winding 203, thereby changing the direction of the traction force. Therefore, when both the proximal esophagus 101 and the distal esophagus 102 are equipped with ferromagnetic cores 103, the actual esophageal traction time is twice that when both ferromagnetic cores 103 and permanent magnetic cores 104 are used, and the anastomosis between the proximal esophagus 101 and the distal esophagus 102 cannot be achieved. This application solves the problems of long traction time and inability to achieve esophageal anastomosis in the comparative embodiment by providing opposing traction forces for the esophageal occlusion target 1 under uniform and gradient magnetic fields by respectively equipping the proximal esophagus 101 with ferromagnetic cores 103 and the distal esophagus 102 with permanent magnetic cores 104.

[0114] In one possible comparative embodiment, the ferromagnetic core 103 is replaced with a permanent magnetic core 104 (i.e., both the proximal esophagus 101 and the distal esophagus 102 are provided with permanent magnetic cores 104). Scenario 1: If the magnetic poles of the two permanent magnetic cores 104 are aligned (S poles opposite N poles, N poles opposite S poles), the two permanent magnetic cores 104 will generate an attractive force towards each other. However, when the distance L between the proximal esophagus 101 and the distal esophagus 102 is relatively large, the attractive force generated by the two permanent magnetic cores 104 is small and cannot achieve a traction effect. Even with an external gradient magnetic field, because the magnetic poles of the two permanent magnetic cores 104 are aligned, the traction force in the gradient magnetic field is in the same direction, meaning it is impossible to pull the proximal esophagus 101 and the distal esophagus 102 closer together. Scenario 2: If the magnetic poles of the two permanent magnetic cores 104 are aligned (S poles opposite S poles, N poles opposite N poles), the two permanent magnetic cores 104 will generate a repulsive force towards each other. When the distance L between the proximal end 101 and the distal end 102 of the esophagus is relatively large, the repulsive force is negligible. At this time, when an external gradient magnetic field is applied, since the magnetic poles of the two permanent magnetic cores 104 are opposite, the traction force in the gradient magnetic field is also opposite, which can provide a traction force in opposite directions. However, when the distance between the proximal end 101 and the distal end 102 of the esophagus is close to zero, the repulsive force generated by the two permanent magnetic cores 104 gradually increases. It is necessary to keep the superconducting magnet device 2 running at all times and increase the current of the gradient magnetic field winding 203 to cope with the gradually increasing repulsive force of the two permanent magnetic cores 104, which consumes a lot of energy. Once the superconducting magnet device 2 is removed, the repulsive force of the two permanent magnetic cores 104 cannot make the proximal end 101 and the distal end 102 of the esophagus match. Therefore, the method of setting permanent magnetic cores 104 in both the proximal esophagus 101 and the distal esophagus 102 has the problem that the traction effect cannot be achieved when the magnetic poles are in the same direction, and the traction effect cannot be achieved when the magnetic poles are in opposite directions.

[0115] This embodiment of the application generates a uniform magnetic field and a gradient magnetic field inside the central hole of the superconducting magnet device 2 by combining a uniform magnetic field, a gradient magnetic field, a ferromagnetic core 103, and a permanent magnetic core 104. By adjusting the current flowing through the magnetic field, the magnitude of the opposing traction force provided to the esophageal atresia target 1 is adjustable without needing to adjust the direction, thus improving the traction force strength, control flexibility, and control accuracy. Furthermore, since the uniform magnetic field and gradient magnetic field exist throughout the entire central hole, the traction force does not change with the position of the ferromagnetic core 103 and the permanent magnetic core 104, thus improving the stability of the traction force.

[0116] The proposed uniform magnetic field winding 201 and gradient magnetic field winding 203 both use superconducting materials, which improves the magnetic field strength and thus improves the traction strength of the ferromagnetic core 103. At the same time, the superconducting material generates almost no heat during operation, has low power consumption, and can achieve long-term continuous operation, thereby shortening the total working cycle.

[0117] The superconducting coil winding structure and the outer Dewar 207 are radially fixedly connected by the suspension rod 209, and the superconducting coil winding structure and the outer Dewar 207 are axially fixedly connected by the axial rod 210, so that the structure between the superconducting coil winding structure and the outer Dewar 207 is stable, thereby stabilizing the magnetic field and the traction force.

[0118] At least one pair of uniform magnetic field auxiliary windings 2012 are proposed. The uniform magnetic field auxiliary windings 2012 are located on the axial inner side of the uniform magnetic field main winding 2011. The uniform magnetic field generated by the uniform magnetic field main winding 2011 is adjusted by the uniform magnetic field auxiliary windings 2012, thereby improving the magnetic field uniformity of the entire magnetic field space.

[0119] At least one pair of gradient magnetic field auxiliary windings 2032 are proposed. The gradient magnetic field auxiliary windings 2032 are located on the inner side of the gradient magnetic field main winding 2031 along the axis. The gradient magnetic field generated by the gradient magnetic field main winding 2031 is adjusted by the gradient magnetic field auxiliary windings 2032, so that the magnetic field gradient of the entire magnetic field space is more consistent.

[0120] The proposed uniform magnetic field winding 201 is connected in series with a superconducting closed-loop switch 213. The superconducting closed-loop switch 213 uses a superconducting coil wound on the heating body 214 and is connected in parallel with the power supply of the uniform magnetic field winding 201. When the power supply of the uniform magnetic field winding 201 is energized and the required magnetic field strength is reached, the power supply of the uniform magnetic field winding 201 can be short-circuited through the superconducting closed-loop switch 213. By utilizing the non-resistance current carrying capacity of the superconducting material, the magnetic field strength of the uniform magnetic field can be maintained without energizing the uniform magnetic field winding 201, while reducing the heat leakage load caused by the power supply of the uniform magnetic field winding 201.

[0121] The proposed refrigerator 208 passes through the outer Dewar 207 and the cold shield 206, and is connected to the uniform magnetic field winding 201 and the gradient magnetic field winding 203 for heat conduction. Compared with general liquid helium cooling, the refrigerator 208 can be used simply by being powered on, which is more economical and convenient.

[0122] The outer cylinder and two end plates of the proposed external Dewar 207 are made of ferromagnetic materials, which achieves magnetic shielding and improves safety.

[0123] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0124] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A superconducting magnet system for esophageal atresia traction anastomosis, characterized in that, include: Superconducting magnet device, movable plate, support, ferromagnetic core and permanent magnet core; The movable plate is movably disposed inside the central hole of the superconducting magnet device. The bracket is fixedly connected to the superconducting magnet device. The ferromagnetic core and the permanent magnet core are placed inside the central hole of the superconducting magnet device and are respectively located at the proximal end and distal end of the esophagus of the esophageal atresia target. The superconducting magnet device is used to generate a uniform magnetic field and a gradient magnetic field inside the central hole; The movable plate is used to deliver the esophageal occlusion target into the central hole of the superconducting magnet device; The bracket is used to support and fix the superconducting magnet device; The ferromagnetic core and the permanent magnetic core are used to provide opposing traction forces for the esophageal atresia target under the uniform magnetic field and gradient magnetic field generated by the superconducting magnet device.

2. The superconducting magnet system for esophageal atresia traction anastomosis according to claim 1, characterized in that, The superconducting magnet device includes: a uniform magnetic field winding, a uniform magnetic field frame, a gradient magnetic field winding, a gradient magnetic field frame, connecting structural components, a cold shield, an external Dewar, a suspension rod, and an axial rod; The uniform magnetic field winding is wound on the uniform magnetic field frame, and the gradient magnetic field winding is wound on the gradient magnetic field frame. Both the uniform magnetic field winding and the gradient magnetic field winding are made of superconducting materials. The connecting structure is fixedly connected to the uniform magnetic field skeleton and the gradient magnetic field skeleton, such that the uniform magnetic field skeleton is located outside or inside the gradient magnetic field skeleton, and both the uniform magnetic field skeleton and the gradient magnetic field skeleton are concentric with the central hole of the superconducting magnet device. The uniform magnetic field winding, the uniform magnetic field frame, the gradient magnetic field winding, the gradient magnetic field frame, and the connecting structure constitute a superconducting coil winding structure. The cold shield is wrapped around the outside of the superconducting coil winding structure; The outer Dewar is wrapped around the outside of the cold shield; The suspension rod is radially fixed to the superconducting coil winding structure and the external Dewar; The axial tie rod is axially fixed to the superconducting coil winding structure and the external Dewar.

3. A superconducting magnet system for esophageal atresia traction anastomosis according to claim 2, characterized in that, The uniform magnetic field winding includes: a pair of uniform magnetic field main windings.

4. A superconducting magnet system for esophageal atresia traction anastomosis according to claim 3, characterized in that, The uniform magnetic field winding further includes: at least one pair of uniform magnetic field auxiliary windings; The uniform magnetic field auxiliary winding is located axially inside the uniform magnetic field main winding.

5. A superconducting magnet system for esophageal atresia traction anastomosis according to claim 2, characterized in that, The gradient magnetic field winding includes: a pair of gradient magnetic field main windings.

6. A superconducting magnet system for esophageal atresia traction anastomosis according to claim 5, characterized in that, The gradient magnetic field winding further includes: at least one pair of gradient magnetic field auxiliary windings; The gradient magnetic field auxiliary winding is located on the axial inner side of the gradient magnetic field main winding.

7. A superconducting magnet system for esophageal atresia traction anastomosis according to claim 2, characterized in that, The uniform magnetic field winding is connected in series with a superconducting closed-loop switch. The superconducting closed-loop switch uses a superconducting coil wound on a heating body and is connected in parallel with the power supply of the uniform magnetic field winding.

8. A superconducting magnet system for esophageal atresia traction anastomosis according to claim 2, characterized in that, The superconducting magnet device also includes: a refrigerator; The refrigerator passes through the outer Dewar and the cold shield, and is connected to the uniform magnetic field winding and the gradient magnetic field winding for heat conduction.

9. A superconducting magnet system for esophageal atresia traction anastomosis according to claim 2, characterized in that, The outer cylinder and two end plates of the outer Dewar are all made of ferromagnetic material.

10. A method for operating a superconducting magnet system as described in any one of claims 1 to 9, characterized in that, include: The superconducting magnet device was evacuated and cooled. Ferromagnetic cores and permanent magnets are respectively placed at the proximal and distal ends of the esophagus of the esophageal atresia target. The target of esophageal occlusion is inserted into the central hole of the superconducting magnet device via a movable plate. When the uniform magnetic field winding of the superconducting magnet device is energized, a uniform magnetic field is generated inside the central hole, which magnetizes the ferromagnetic core to saturation. When the gradient magnetic field winding of the superconducting magnet device is energized, a gradient magnetic field is generated inside the central hole, so that the ferromagnetic core and the permanent magnetic core provide opposing traction forces for the esophageal atresia target. The magnitude of the traction force is controlled by adjusting the current flowing through the gradient magnetic field winding.

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