A superconducting magnet system and method for esophageal atresia traction anastomosis

Abstract

The present invention discloses a superconducting magnet system and method for esophageal atresia traction and anastomosis, wherein the system includes: a superconducting magnet device, a movable plate, a bracket, a ferromagnetic core and a permanent magnetic core; the movable plate is movably arranged inside the center hole of the superconducting magnet device, the bracket is fixedly connected to the superconducting magnet device, the ferromagnetic core and the permanent magnetic core are placed inside the center hole of the superconducting magnet device and are respectively located at the proximal end and the 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 center hole; the ferromagnetic core and the permanent magnetic core are used to provide traction forces in opposite directions for the esophageal atresia target under the uniform magnetic field and the gradient magnetic field. The present application combines the uniform magnetic field, the gradient magnetic field, the ferromagnetic core and the permanent magnetic core, so that the magnitude of the traction force in opposite directions provided to the esophageal atresia target is adjustable and there is no need to adjust the direction, thereby improving the traction strength, control flexibility and control accuracy.

Description

Technical Field

[0001] The present application relates to the technical field of superconducting magnets, and in particular to a superconducting magnet system and method for esophageal atresia traction and anastomosis. Background Art

[0002] The incidence of congenital esophageal atresia in newborns is about 1 / 2500 to 1 / 4000. Among them, long-segment esophageal atresia refers to the proximal and distal ends of the esophagus being more than 2 cm apart. Although there are many surgical methods, they seriously damage the physiological structure of newborns. At present, some scholars have proposed using magnets to pull each other to shorten the distance of esophageal atresia, but this method generates less traction when the distance of esophageal atresia is large, and the traction effect cannot be achieved. Therefore, it is necessary to study and improve the device used for traction and anastomosis of esophageal atresia.

[0003] In the prior art, Chinese patent CN108606930A discloses a medical device for congenital esophageal atresia and its preparation method, including an upper guide device, a lower guide device and a digital Gauss meter, wherein the upper guide device includes a first upper hose and an upper magnetic attraction device disposed at the lower end of the first upper hose, and the lower guide device includes a first lower hose and a lower magnetic attraction device disposed at the upper end of the first lower hose. This prior art can achieve synchronous growth and self-healing of the upper and lower blind ends of the esophagus, retain the integrity of the esophageal structure and function of the child, avoid surgical methods that replace the esophagus with other organs, and at the same time, the upper and lower blind ends of the esophagus are automatically anastomosed and connected through the magnetic effect, and the growth of the esophagus is observed with the assistance of a digital Gauss meter, thereby reducing the number of surgeries and greatly reducing the trauma caused by surgical treatment.

[0004] However, the above-mentioned prior art has poor traction strength when facing a situation where the esophageal atresia distance is large, and it is difficult to adjust the size and direction of the traction force, and the control flexibility and control accuracy of the traction force are poor. Summary of the invention

[0005] The present application provides a superconducting magnet system and method for traction and anastomosis of esophageal atresia, which is used to solve the problems of the prior art that the traction force strength is poor when the esophageal atresia distance is large, the size and direction of the traction force are difficult to adjust, and the control flexibility and control accuracy of the traction force are poor.

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

[0007] The movable plate is movably arranged 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 magnetic core are placed inside the central hole of the superconducting magnet device and are respectively located at the proximal end and the 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 atresia target into the central hole of the superconducting magnet device.

[0010] The bracket is used for supporting and fixing the superconducting magnet device.

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

[0012] In a 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 skeleton, and the gradient magnetic field winding is wound on the gradient magnetic field skeleton. Both the uniform magnetic field winding and the gradient magnetic field winding are made of superconducting materials.

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

[0015] The uniform magnetic field winding, the uniform magnetic field skeleton, the gradient magnetic field winding, the gradient magnetic field skeleton, and the connecting structural parts 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 shield.

[0018] The suspension rods are fixedly connected to the superconducting coil winding structure and the outer dewar from a radial direction.

[0019] The axial pull rod axially fixes and connects the superconducting coil winding structure and the outer dewar.

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

[0021] In a possible implementation manner, 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 a possible implementation, the gradient magnetic field winding includes: a pair of gradient magnetic field main windings.

[0024] In a possible implementation manner, 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 axially inside the gradient magnetic field main winding.

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

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

[0028] In a 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 in a cooling manner.

[0030] In a possible implementation, the outer cylinder and both side end plates of the outer dewar are made of ferromagnetic materials.

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

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

[0033] The ferromagnetic core and the permanent magnetic core are respectively arranged at the proximal end and the distal end of the esophagus of the esophageal atresia target.

[0034] The esophageal atresia target is introduced into the central hole of the superconducting magnet device through the movable plate.

[0035] The uniform magnetic field winding of the superconducting magnet device is energized to generate a uniform magnetic field inside the central hole, and the ferromagnetic core is magnetized to a saturation state.

[0036] The gradient magnetic field winding of the superconducting magnet device is energized to generate a gradient magnetic field inside the central hole, so that the ferromagnetic core and the permanent magnetic core provide traction forces towards each other for the esophageal atresia target.

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

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

[0039] By combining uniform magnetic field, gradient magnetic field, ferromagnetic core and permanent magnetic core, uniform magnetic field and gradient magnetic field are generated inside the central hole of the superconducting magnet device, and by adjusting the current of the magnetic field, the magnitude of the traction force provided to the target of esophageal atresia is adjustable without adjusting the direction, thereby improving the traction strength, control flexibility and control accuracy. And because the uniform magnetic field and gradient magnetic field exist inside the entire central hole, when the position of the ferromagnetic core and the permanent magnetic core changes, the traction force will not change due to the change of position, thereby improving the stability of the traction force.

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

[0041] The superconducting coil winding structure and the outer dewar are fixedly connected radially by suspension rods, and the superconducting coil winding structure and the outer dewar are fixedly connected axially by axial rods, so that the structure between the superconducting coil winding structure and the outer dewar is stable, thereby stabilizing the magnetic field and the traction force.

[0042] At least one pair of uniform magnetic field auxiliary windings is proposed, and the uniform magnetic field auxiliary windings are located axially inside the uniform magnetic field main windings. The uniform magnetic field generated by the uniform magnetic field main windings is adjusted by the uniform magnetic field auxiliary windings, thereby improving the magnetic field uniformity of the entire magnetic field space.

[0043] At least one pair of gradient magnetic field auxiliary windings is proposed, and the gradient magnetic field auxiliary windings are located axially inside the gradient magnetic field main windings. The gradient magnetic field generated by the gradient magnetic field main windings 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 adopts a superconducting coil wound on a heating body and is connected in parallel with a power supply of the uniform magnetic field winding. When the power supply of the uniform magnetic field winding energizes the uniform magnetic field winding and reaches the required magnetic field strength, the power supply of the uniform magnetic field winding can be short-circuited by the superconducting closed-loop switch. By utilizing the unimpeded current-carrying ability of the superconducting material, it is no longer necessary to energize the uniform magnetic field winding to maintain the magnetic field strength of the uniform magnetic field, and at the same time, the leakage heat load caused by the power supply of the uniform magnetic field winding is reduced.

[0045] The proposed refrigerator passes through the external dewar and the cold shield and is connected to the uniform magnetic field winding and the gradient magnetic field winding for cooling. Compared with the general liquid helium cooling, the refrigerator can be used only by powering on, which is more economical and convenient.

[0046] The outer cylinder and the end plates on both sides of the proposed external dewar are made of ferromagnetic materials, thus achieving magnetic shielding and improving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0048] Figure 1 A schematic diagram of the structure of a superconducting magnet system for esophageal atresia traction and anastomosis provided in an embodiment of the present application;

[0049] Figure 2 A schematic diagram of the esophageal atresia target provided in an embodiment of the present application;

[0050] Figure 3 Schematic diagram of uniform magnetic field winding and gradient magnetic field winding provided in the embodiment of the present application;

[0051] Figure 4 A schematic diagram of power supply for a uniform magnetic field winding and a gradient magnetic field winding provided in an embodiment of the present application;

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

[0053] Figure 6 A schematic diagram of a separate gradient magnetic field distribution provided in an embodiment of the present application;

[0054] Figure 7 A schematic diagram of the superposition distribution of a uniform magnetic field and a gradient magnetic field provided in an embodiment of the present application;

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

[0056] Description of reference numerals:

[0057] 1-esophageal atresia target, 2-superconducting magnet device, 3-movable plate, 4-bracket, 201-uniform magnetic field winding, 202-uniform magnetic field skeleton, 203-gradient magnetic field winding, 204-gradient magnetic field skeleton, 205-connecting structure, 206-cold shield, 207-external dewar, 208-refrigerator, 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 body. DETAILED DESCRIPTION

[0058] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0059] like Figure 1 and Figure 2 As shown, an embodiment of the present application provides a superconducting magnet system for esophageal atresia traction and anastomosis, including: a superconducting magnet device 2, a movable plate 3, a bracket 4, a ferromagnetic core 103 and a permanent magnetic core 104.

[0060] The movable plate 3 is movably arranged 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 magnetic core 104 are placed inside the central hole of the superconducting magnet device 2 and are respectively located at the proximal end 101 and the distal end 102 of the esophagus of the esophageal atresia 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 deliver the esophageal atresia 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 traction forces in opposite directions for the esophageal atresia target 1 under the uniform magnetic field and the gradient magnetic field generated by the superconducting magnet device 2 .

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

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

[0067] Exemplarily, the superconducting magnet device 2 includes: a uniform magnetic field winding 201 , a uniform magnetic field skeleton 202 , a gradient magnetic field winding 203 , a gradient magnetic field skeleton 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 skeleton 202 , and the gradient magnetic field winding 203 is wound on the gradient magnetic field skeleton 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 is fixedly connected to the uniform magnetic field skeleton 202 and the gradient magnetic field skeleton 204 , so that the uniform magnetic field skeleton 202 is located outside or inside the gradient magnetic field skeleton 204 , and the uniform magnetic field skeleton 202 and the gradient magnetic field skeleton 204 are both concentric with the central hole of the superconducting magnet device 2 .

[0070] The uniform magnetic field winding 201 , the uniform magnetic field skeleton 202 , the gradient magnetic field winding 203 , the gradient magnetic field skeleton 204 , and the connecting structural member 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 shield 206 .

[0073] The suspension rod 209 is used to fix the superconducting coil winding structure and the outer dewar 207 in a radial direction.

[0074] The axial pull rod 210 axially fixes and connects the superconducting coil winding structure and the outer dewar 207 .

[0075] Specifically, the connecting structure 205 is used to fix the positions of the uniform magnetic field skeleton 202 and the gradient magnetic field skeleton 204, and provide a cooling effect; the cold shield 206 is used to reduce the radiation 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, and the suspension rod 209 and the axial rod 210 are used to avoid movement between the superconducting coil winding structure and the external dewar 207 due to electromagnetic force, and to reduce conduction 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 skeleton 202 may be located outside or inside the gradient magnetic field skeleton 204. In this embodiment, the uniform magnetic field skeleton 202 may be located outside the gradient magnetic field skeleton 204. In other possible embodiments, the uniform magnetic field skeleton 202 may also be located inside the gradient magnetic field skeleton 204.

[0078] like Figure 3 As shown, 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, -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] like Figure 3 As shown, exemplarily, the uniform magnetic field winding 201 includes: a pair of uniform magnetic field main windings 2011.

[0080] Exemplarily, 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 axially inside the uniform magnetic field main winding 2011 .

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

[0083] Exemplarily, 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 axially inside the gradient magnetic field main winding 2031 .

[0085] Specifically, Figure 3 As shown, 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. Among them, the uniform magnetic field main winding 2011 is used to generate a uniform magnetic field inside the central hole of the superconducting magnet device 2, and the uniform magnetic field auxiliary winding 2012 is used to adjust the uniform magnetic field to improve the magnetic field uniformity of the entire magnetic field space; the gradient magnetic field main winding 2031 is used to generate a gradient magnetic field inside the central hole of the superconducting magnet device 2, and the gradient magnetic field auxiliary winding 2032 is used to adjust the gradient magnetic field so that the magnetic field gradient of the entire magnetic field space is more consistent. In other possible embodiments, other numbers of uniform magnetic field auxiliary windings 2012 and gradient magnetic field auxiliary windings 2032 can also be set according to actual conditions.

[0086] Exemplarily, 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 a heating body 214 and is connected in parallel with the power supply of the uniform magnetic field winding 201 .

[0088] Specifically, Figure 4 As shown, 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] In the cooling stage of the superconducting magnet device 2, the superconducting closed-loop switch 213 is cooled to a temperature lower than the superconducting critical temperature together with the uniform magnetic field winding 201 and the gradient magnetic field winding 203, and enters the superconducting state; before the uniform magnetic field winding 201 is energized, the superconducting closed-loop switch 213 is first heated by the heating body 214 to make its temperature higher than the superconducting critical temperature, and exits the superconducting state; at this time, the uniform magnetic field winding power supply 211 is used to energize the uniform magnetic field winding 201, and when the required magnetic field strength (in this embodiment, the uniform magnetic field strength of When the magnetic field strength does not exceed 1T), the 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, and the uniform magnetic field winding power supply 211 is short-circuited; at this time, the uniform magnetic field winding power supply 211 is evacuated, and the unimpeded current carrying capacity of the superconducting materials of the uniform magnetic field winding 201 and the superconducting closed-loop switch 213 is utilized, so that the uniform magnetic field winding 201 does not need to be energized, and the magnetic field strength of the uniform magnetic field can be maintained, while reducing the leakage heat load caused by the uniform magnetic field winding power supply 211. In the actual working process, the magnetic field gradient of the gradient magnetic field only needs to be controlled by controlling the current of the gradient magnetic field winding 203, thereby controlling the magnitude of the traction force.

[0090] Exemplarily, the superconducting magnet device 2 further includes: a refrigerator 208 .

[0091] The 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 in a cooling manner.

[0092] Specifically, compared with general liquid helium cooling, the refrigerator 208 can be used by just turning on the power, which is 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] Exemplarily, the outer cylinder and both side end plates of the outer dewar 207 are made of ferromagnetic materials.

[0094] Specifically, in this embodiment, the outer cylinder and both side end plates of the outer dewar 207 are made of ferromagnetic materials for magnetic shielding, so that the environmental magnetic leakage within one meter around the superconducting magnet device 2 is much less than 5Gs, thereby improving safety.

[0095] Specifically, when the uniform magnetic field winding 201 is powered on alone, the uniform magnetic field distribution is as follows: Figure 5As shown, 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 supplied to the uniform magnetic field winding 201 is the maximum. It can be seen that in a single uniform magnetic field, the magnetic field strength is constant in 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 supplied. At the same time, the magnitude of the magnetic field strength can also be changed by changing the magnitude of the current supplied. 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 powered on individually, the individual gradient magnetic field distribution is as follows: Figure 6 As shown, the Z axis is the axial direction of the superconducting magnet device 2, and the B axis is the magnetic field intensity. When the current supplied to the gradient magnetic field winding 203 is I1, the slope of the magnetic field intensity (i.e., the magnetic field gradient) is K1. It can be seen that in a single gradient magnetic field, the magnetic field gradient remains unchanged in 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 supplied, i.e., the slope of the magnetic field intensity changes from K1 to -K1. At the same time, the magnitude of the magnetic field gradient can be changed by changing the magnitude of the current supplied. When the current supplied to 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 energized at the same time, the uniform magnetic field and the gradient magnetic field are superimposed and distributed as follows: Figure 7 As shown, the Z axis is the axial direction of the superconducting magnet device 2, the B axis is the magnetic field intensity, and S1, S2, and S3 are the relationship lines of the magnetic field intensity and the axial direction of the superconducting magnet device 2 in three cases, respectively. Among them, with line S1 as a reference, the magnetic field gradient is K1, when the current of the uniform magnetic field winding 201 is changed, the magnitude of the magnetic field intensity changes while the magnetic field gradient remains unchanged, that is, line S1 will move up and down, thereby obtaining lines S2 and S3. In other words, the change in the magnitude of the magnetic field intensity will not change 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×μM×gradB

[0100] Wherein, V represents the volume of the magnetic core, μM represents the magnetization intensity of the magnetic core, and gradB represents the magnetic field gradient (i.e., the slope of the magnetic field intensity in this embodiment). It can be seen that the volume V of the ferromagnetic core 103 and the permanent magnetic core 104 are both constant values, and the magnetization intensity of the permanent magnetic core 104 is a constant value. When the ferromagnetic core 103 is magnetized to a saturated state, the magnetization intensity of the ferromagnetic core 103 is also a constant value, 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 passing through the gradient magnetic field winding 203, thereby controlling the magnitude and direction of the traction force of the ferromagnetic core 103. It can also be seen from the formula of the traction force F 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 will not be affected by the magnitude of the esophageal atresia distance L.

[0101] The present application also provides an operation method of a superconducting magnet system for esophageal atresia traction and anastomosis, comprising:

[0102] Superconducting magnet device 2 is evacuated and cooled.

[0103] The ferromagnetic core 103 and the permanent magnetic core 104 are respectively disposed at the esophageal proximal end 101 and the esophageal distal end 102 of the esophageal atresia target 1 .

[0104] The esophageal atresia target 1 is introduced into the central hole of the superconducting magnet device 2 through the movable plate 3 .

[0105] The uniform magnetic field winding 201 of the superconducting magnet device 2 is energized to generate a uniform magnetic field inside the central hole, and the ferromagnetic core 103 is magnetized to a saturation state.

[0106] The gradient magnetic field winding 203 of the superconducting magnet device 2 is energized to generate a gradient magnetic field inside the central hole, so that the ferromagnetic core 103 and the permanent magnetic core 104 provide traction forces in opposite directions for the esophageal atresia target 1 .

[0107] The magnitude of the pulling force is controlled by controlling the magnitude of the current flowing through the gradient magnetic field winding 203 .

[0108] Specifically, in the present embodiment, evacuating and cooling the superconducting magnet device 2 includes: evacuating the interior of the outer dewar 207, and when the vacuum degree 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 temperatures of the uniform magnetic field winding 201, the gradient magnetic field winding 203, and the superconducting closed-loop switch 213 are lower than the superconducting critical temperature, entering a superconducting state, and meeting the conditions for power-on.

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

[0110] In this embodiment, before the uniform magnetic field winding 201 is energized, the superconducting closed-loop switch 213 is first heated by the heating body 214 to make its temperature higher than the superconducting critical temperature and exit the superconducting state; at this time, the uniform magnetic field winding power supply 211 is used to energize the uniform magnetic field winding 201, and when the required magnetic field strength is reached (the magnetic field strength of the uniform magnetic field in this embodiment does not exceed 1T), the 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, and the uniform magnetic field winding power supply 211 is short-circuited; at this time, the uniform magnetic field winding power supply 211 is evacuated, and the unimpeded current carrying capacity of the superconducting materials of the uniform magnetic field winding 201 and the superconducting closed-loop switch 213 is utilized, so that the uniform magnetic field strength can be maintained without energizing the uniform magnetic field winding 201, and at the same time, the leakage heat load caused by the uniform magnetic field winding power supply 211 is reduced. Generally speaking, the ferromagnetic core 103 can be magnetized to a saturated state when the magnetic field strength does not exceed 1T.

[0111] like Figure 8 As shown, in this embodiment, after the ferromagnetic core 103 is magnetized to a saturated state, the gradient magnetic field winding power supply 212 is used to energize the gradient magnetic field winding 203 of the superconducting magnet device 2, so that the traction direction of the ferromagnetic core 103 is directed from the distal end 102 of the esophagus to the proximal end 101 of the esophagus (see Figure 8 The pulling force direction of the permanent magnetic core 104 is from the proximal end 101 of the esophagus to the distal end 102 of the esophagus (see F2 in FIG. Figure 8 F1 in the figure), and 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 force of the ferromagnetic core 103 and the permanent magnetic core 104. Since the ferromagnetic core 103 and the permanent magnetic core 104 provide traction forces in opposite directions for the esophageal atresia target 1, the esophageal proximal end 101 and the esophageal distal end 102 are simultaneously pulled toward each other, and therefore, 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 end 101 of the esophagus and the distal end 102 of the esophagus is close to zero, the superconducting magnet device 2 can be withdrawn, and the ferromagnetic core 103 is demagnetized without the external uniform magnetic field. Since the distance between the proximal end 101 of the esophagus and the distal end 102 of the esophagus is close to zero at this time, the permanent magnetic core 104 produces a new magnetization effect on the demagnetized ferromagnetic core 103 (equivalent to the effect of permanent magnets attracting iron in real life), and the ferromagnetic core 103 and the permanent magnetic core 104 continue to attract each other, causing ischemia and necrosis of the esophageal tissue between them, and the adjacent esophageal tissues are healed and connected, thereby achieving the anastomosis of the proximal end 101 of the esophagus and the distal end 102 of the esophagus, avoiding the surgical safety risks and slow postoperative recovery caused by the use of open chest surgery or thoracoscopic surgery to anastomose the proximal end 101 of the esophagus and the distal end 102 of the esophagus.

[0113] In a possible comparative embodiment, the permanent magnetic core 104 is replaced by a ferromagnetic core 103 (i.e., the ferromagnetic core 103 is provided at both the proximal end 101 and the distal end 102 of the esophagus). Since the two ferromagnetic cores 103 are magnetized in the same manner under a uniform magnetic field, after the gradient magnetic field winding 203 generates a gradient magnetic field, the traction directions of the two ferromagnetic cores 103 are consistent, and only the proximal end 101 of the esophagus or the distal end 102 of the esophagus can be pulled alone. In order to pull and bring both the proximal end 101 and the distal end 102 of the esophagus closer, the direction of the current of the gradient magnetic field winding 203 needs to be changed, thereby changing the direction of the traction force. Therefore, when the ferromagnetic core 103 is provided at both the proximal end 101 and the distal end 102 of the esophagus, the actual time for esophageal traction is twice that when the ferromagnetic core 103 and the permanent magnetic core 104 are provided, and the anastomosis of the proximal end 101 and the distal end 102 of the esophagus cannot be achieved when the ferromagnetic core 103 is provided at both the proximal end 101 and the distal end 102 of the esophagus. The present application provides traction forces in opposite directions for the esophageal atresia target 1 under uniform magnetic fields and gradient magnetic fields, thereby solving the problems of long traction time and failure to achieve esophageal anastomosis in the comparative embodiment.

[0114] In a possible comparative embodiment, the ferromagnetic core 103 is replaced by a permanent magnetic core 104 (ie, the permanent magnetic core 104 is disposed at both the proximal end 101 of the esophagus and the distal end 102 of the esophagus). In case one, if the magnetic poles of the two permanent magnetic cores 104 are in the same direction, that is, the S pole is opposite to the N pole, and the N pole is opposite to the S pole, then the two permanent magnetic cores 104 themselves generate attractive forces toward each other, but when the distance L between the proximal end 101 of the esophagus and the distal end 102 of the esophagus is relatively far, the attractive force generated by the two permanent magnetic cores 104 themselves is relatively small, and the traction effect cannot be achieved. Even if a gradient magnetic field is applied, since the magnetic poles of the two permanent magnetic cores 104 are in the same direction, the traction direction in the gradient magnetic field is consistent, that is, the proximal end 101 of the esophagus and the distal end 102 of the esophagus cannot be pulled toward each other; in case two, if the magnetic poles of the two permanent magnetic cores 104 are in opposite directions, that is, the S poles are opposite to the S poles, and the N poles are opposite to the N poles, then the two permanent magnetic cores 104 themselves generate repulsive forces toward each other. When the distance L between the proximal end 101 of the esophagus and the distal end 102 of the esophagus is relatively far, the repulsive force is negligible. At this time, a gradient magnetic field is applied. Since the magnetic poles of the two permanent magnetic cores 104 are in opposite directions, the traction forces in the gradient magnetic field are also in opposite directions, which can provide opposite traction forces. However, when the distance between the proximal end 101 of the esophagus and the distal end 102 of the esophagus is close to zero, the repulsive force generated by the two permanent magnetic cores 104 themselves gradually increases. It is necessary to always keep the superconducting magnet device 2 running, and the current of the gradient magnetic field winding 203 needs to be increased 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 withdrawn, the repulsive force of the two permanent magnetic cores 104 cannot make the proximal end 101 of the esophagus and the distal end 102 of the esophagus fit together. Therefore, when both the proximal esophagus end 101 and the distal esophagus end 102 are provided with permanent magnetic cores 104, there is a problem that the traction effect cannot be achieved when the magnetic poles are in the same direction, and the proximal esophagus end 101 and the distal esophagus end 102 cannot be matched when the magnetic poles are in opposite directions.

[0115] The embodiment of the present 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 of the magnetic field, the magnitude of the traction force provided to the esophageal atresia target 1 is adjustable and the direction does not need to be adjusted, thereby improving the traction strength, control flexibility and control accuracy. And because the uniform magnetic field and the gradient magnetic field exist inside the entire central hole, when the positions of the ferromagnetic core 103 and the permanent magnetic core 104 change, the traction force will not change due to the change in position, thereby improving the stability of the traction force.

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

[0117] The superconducting coil winding structure and the outer dewar 207 are fixedly connected radially by the suspension rod 209, and the superconducting coil winding structure and the outer dewar 207 are fixedly connected axially 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 is proposed, and the uniform magnetic field auxiliary windings 2012 are located axially inside 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 is proposed, and the gradient magnetic field auxiliary windings 2032 are located axially inside the gradient magnetic field main windings 2031. The gradient magnetic field generated by the gradient magnetic field main windings 2031 is adjusted by the gradient magnetic field auxiliary windings 2032 to make the magnetic field gradient of the entire magnetic field space 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 adopts a superconducting coil wound on a 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 energizes the uniform magnetic field winding 201 and reaches the required magnetic field strength, the power supply of the uniform magnetic field winding 201 can be short-circuited by the superconducting closed-loop switch 213. By utilizing the unimpeded current-carrying ability of the superconducting material, it is no longer necessary to energize the uniform magnetic field winding 201 to maintain the magnetic field strength of the uniform magnetic field, and at the same time, the leakage heat load caused by the power supply of the uniform magnetic field winding 201 is reduced.

[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 by cooling. Compared with the general liquid helium cooling, the refrigerator 208 can be used only by powering on, which is more economical and convenient.

[0122] The outer cylinder and the end plates on both sides of the proposed outer dewar 207 are made of ferromagnetic materials, thereby achieving magnetic shielding and improving safety.

[0123] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0124] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A superconducting magnet system for esophageal atresia traction and anastomosis, characterized in that: include: Superconducting magnet devices, movable plates, brackets, ferromagnetic cores and permanent magnetic cores; The movable plate is movably arranged 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 magnetic core are placed inside the central hole of the superconducting magnet device and are respectively located at the proximal end and the 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 atresia 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 traction forces towards each other for the esophageal atresia target under the uniform magnetic field and the gradient magnetic field generated by the superconducting magnet device; The superconducting magnet device comprises: 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; The uniform magnetic field winding is wound on the uniform magnetic field skeleton, and the gradient magnetic field winding is wound on the gradient magnetic field skeleton, and 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 frame and the gradient magnetic field frame, so that the uniform magnetic field frame is located outside or inside the gradient magnetic field frame, and the uniform magnetic field frame and the gradient magnetic field frame are both concentric with the central hole of the superconducting magnet device; The uniform magnetic field winding, the uniform magnetic field skeleton, the gradient magnetic field winding, the gradient magnetic field skeleton, and the connecting structural parts 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 fixedly connected to the superconducting coil winding structure and the outer dewar from a radial direction; The axial pull rod axially fixes and connects the superconducting coil winding structure and the outer dewar.

2. A superconducting magnet system for esophageal atresia traction and anastomosis according to claim 1, characterized in that: The uniform magnetic field winding comprises: a pair of uniform magnetic field main windings.

3. A superconducting magnet system for esophageal atresia traction and anastomosis according to claim 2, characterized in that: The uniform magnetic field winding further comprises: 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.

4. The superconducting magnet system for esophageal atresia traction and anastomosis according to claim 1, characterized in that: The gradient magnetic field winding includes: a pair of gradient magnetic field main windings.

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

6. The superconducting magnet system for esophageal atresia traction and anastomosis according to claim 1, characterized in that: The uniform magnetic field winding is connected in series with a superconducting closed-loop switch; The superconducting closed-loop switch adopts a superconducting coil wound on a heating body and is connected in parallel with a power supply of the uniform magnetic field winding.

7. The superconducting magnet system for esophageal atresia traction and anastomosis according to claim 1, characterized in that: The superconducting magnet device further comprises: 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 in a cooling manner.

8. The superconducting magnet system for esophageal atresia traction and anastomosis according to claim 1, characterized in that: The outer cylinder and the end plates on both sides of the outer dewar are made of ferromagnetic materials.

9. A method for operating a superconducting magnet system according to any one of claims 1 to 8, characterized in that: include: Evacuate and cool the superconducting magnet device; The ferromagnetic core and the permanent magnetic core are respectively arranged at the proximal end and the distal end of the esophagus of the esophageal atresia target; Delivering the esophageal atresia target into the central hole of the superconducting magnet device through a movable plate; Energizing the uniform magnetic field winding of the superconducting magnet device to generate a uniform magnetic field inside the central hole and magnetizing the ferromagnetic core to a saturation state; Energizing the gradient magnetic field winding of the superconducting magnet device to generate a gradient magnetic field inside the central hole, so that the ferromagnetic core and the permanent magnetic core provide traction forces towards the esophageal atresia target; The magnitude of the traction force is controlled by controlling the magnitude of the current flowing through the gradient magnetic field winding.

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