CN104188725A - Magnetic field generating device of cardiac magnetic navigation surgery system - Google Patents

Abstract

Disclosed is a magnetic field generating device of a cardiac magnetic navigation surgery system. Eight superconducting magnets (7) are symmetrically arranged on a four-axis oblique coordinate axis formed by four oblique diagonal lines of a regular hexahedron. The center of a navigation area (4) is located at the original point of a four-axis oblique coordinate system, and a uniform magnetic field generated by the superconducting magnets (7) is arranged in the navigation area (4). Permanent magnet rings (24) are arranged in the front end of a catheter (23), and the permanent magnet rings (24) in the navigation area (4) bear torque applied by the uniform magnetic field to be parallel to the direction of the magnetic field. An input control unit (19) inputs a direction instruction to a controller (20), the controller (20) transforms the instruction into control signals to superconducting magnet power sources (21), the direction of the magnetic field in the navigation area (4) is adjusted by changing currents in the eight superconducting magnets (7), and therefore the direction of the end of the catheter (23) is controlled, and navigation on the catheter (23) is achieved.

Description

A magnetic field generating device for cardiac magnetic navigation surgery system

technical field

The invention relates to a medical device, in particular to a magnetic field generating device for an interventional cardiac magnetic navigation system.

Background technique

Cardiac interventional surgery has been widely used clinically. At present, most hospitals that can implement cardiac interventional surgery use manual intubation technology. Its working principle is realized by the doctor standing beside the patient and manually operating the catheter under the guidance of X-ray machine imaging. During the intubation process, the head end of the catheter is turned or bent to enter the target by pulling back the guide wire. Most cardiovascular diseases can be diagnosed and treated by manual cannulation interventional cardiac surgery, but for some complicated cases, manual cannulation cardiac interventional surgery system needs to be improved in terms of guiding ability and positioning accuracy. Since the interventional doctor is located next to the catheter bed intermittently or works under X-ray irradiation, even though there are radiation-proof clothes, the body will inevitably be damaged by small doses of X-rays. discomfort. In addition, manual cardiac interventional surgery also has disadvantages such as slow control speed, long operation time, and low positioning accuracy. The literature [Sabine Ernst, et al., Initial Experience With Remote Catheter Ablation Using a Novel Magnetic Navigation System: Magnetic Remote Catheter Ablation, Circulation, March30, 2004] presents a permanent magnet magnetic navigation cardiac interventional surgery system. Its working principle is to use the magnetic field to guide the direction of travel of the catheter, and the catheter can automatically and quickly reach the required position through the automatic pusher. The permanent magnet magnetic navigation system is also combined with the cardiac mapping system, allowing interventional doctors to complete most of the cardiovascular interventional operations away from the operating table, avoiding X-ray exposure. Its core component is a hemispherical magnet formed by two rotatable permanent magnets, and the hemispherical magnet produces a spherical shimming area at the patient's heart. The end of the catheter is equipped with a permanent magnet block, and the forward direction of the end of the catheter can be adjusted by adjusting the direction of the magnetic field in the shimming area. Although the permanent magnet magnetic navigation cardiac interventional surgery system realizes the desire of interventional doctors to complete cardiovascular interventional procedures away from the operating table, the magnetic field of the permanent magnetic magnetic navigation cardiac interventional surgery system is generated by permanent magnets. , the change of the magnetic field direction is realized by rotating the hemispherical permanent magnet. Due to the limitation of the rotating space, the permanent magnet magnetic navigation cardiac interventional surgery system can only diagnose and treat most cardiovascular diseases, and some patients who are difficult to access or locate Cases are also difficult to treat. In addition, due to the limitation of mechanical inertia and magnetic field strength, the response speed of its navigation will not be too fast, and the navigation accuracy will also be limited to a certain extent. The use of conventional electromagnets to achieve cardiac magnetic navigation interventional surgery can improve the speed and operational accuracy of the surgical operating system, but its volume and power consumption are huge, which limits the wide-scale application of magnetic navigation cardiac interventional surgery systems based on conventional electromagnets .

Contents of the invention

The purpose of the present invention is to overcome the deficiency of the magnetic field generating device in the existing permanent magnet magnetic navigation interventional cardiac surgery system, and propose a magnetic field generator for the magnetic navigation cardiac interventional surgery system. The invention has the advantages of fast magnetic field orientation and high magnetic field intensity.

The device of the invention includes an upper support frame, a lower support frame, a column, a center column, a superconducting magnet, a superconducting magnet power supply, a magnetic field detection device, an input control unit, a controller, a display unit, a navigation area, and a catheter.

The upper support frame and the lower support frame are two coaxial annular mechanical structures, the upper support frame and the lower support frame are fixed together by four columns, and the four columns are evenly arranged along the ring direction and connected with the ring The axis of the mechanical structure is parallel. The eight joint points formed by the upper support frame, the lower support frame and the four columns are geometrically located on the eight vertices of the regular hexahedron. Eight central columns are respectively installed at the eight joint points of the upper support frame and the lower support frame and the column. The eight central columns are equal in length and have threads. The eight central columns are symmetrically arranged on the A axis, B axis, C axis On the four-axis oblique coordinate axis formed by the D-axis and the D-axis, the coordinate origin is located at the center point of the structure composed of the upper support frame, the lower support frame and the four columns, and the angle between two adjacent coordinate axes is 70.5° . There are eight superconducting magnets in total, which are installed on eight central columns respectively, and the two ends of the superconducting magnets are fixed with fastening nuts. Two superconducting magnets located on the same coordinate axis form a pair, and eight superconducting magnets are divided into four pairs. A pair of superconducting magnets are connected in series, so that the direction of the magnetic field generated by the pair of superconducting magnets is the same after electrification. The magnetic field detection device is installed at the center of the end of the central column, and the magnetic field detection device is used to detect whether the magnetic field strength generated by the superconducting magnet meets the set requirements. The navigation area is a spherical area inside the area surrounded by eight superconducting magnets. The eight superconducting magnets generate a direction-adjustable uniform magnetic field in the navigation area. The center of the navigation area is located at the origin of the four-axis oblique coordinate system. The diameter of the navigation area is smaller than the distance from the magnetic field detection device to the origin. The output of each superconducting magnet power supply is connected to a pair of superconducting magnets located on the same coordinate axis. The catheter is a movable part and has no mechanical contact with other parts of the device of the present invention. Three permanent magnetic rings are installed in the front end of the catheter. The working area of the catheter is inside the navigation area, and when the catheter moves into the navigation area, the magnetic field generated by the superconducting magnet starts to navigate the catheter.

The output of the input control unit is connected to the input of the controller, and the output of the controller is connected to the display unit; the output of the controller is connected to four superconducting magnet power supplies at the same time, and each superconducting magnet power supply supplies power to a pair of superconducting magnets . After the superconducting magnet is energized, an electromagnetic field is generated in the navigation area, and the magnetic field detection device feeds back the detected magnetic field information to the controller. The input control unit is an instruction input unit, and the interventional doctor inputs the designated three-dimensional magnetic field direction according to the operation needs, and the input control unit converts the analog control quantity input by the interventional doctor into a digital quantity that the controller can recognize, and sends it to the controller. The controller converts the three-dimensional magnetic field direction into the four-axis direction control quantity required for actual control, and applies a corresponding control strategy, and then transmits the control quantity to the four superconducting magnet power sources respectively. Each superconducting magnet power supply supplies power in series to a pair of superconducting magnets located on the same coordinate axis, and the direction of the central magnetic field generated by the pair of superconducting magnets is consistent. Eight superconducting magnets generate electromagnetic fields in the directions of four oblique axes. Since the magnetic field is a vector field, by adjusting the excitation currents on the four pairs of superconducting magnets, a steady magnetic field with a certain strength in any direction can be generated. The magnetic field generated by the superconducting magnet is detected by the magnetic field detection device, and the detected magnetic field information is fed back to the controller to realize closed-loop control, so that the direction of the magnetic field generated by the superconducting magnet is consistent with the direction of the magnetic field input by the interventional doctor. The controller processes the detected magnetic field information and sends it to the display unit. At the same time, the controller sends the input control unit input magnetic field direction to the display unit. The display unit displays the specified magnetic field direction and the measured magnetic field direction in the navigation area in real time.

The superconducting magnet includes a refrigerator, a cryogenic container, a cold shield and a superconducting coil. The cryogenic container is a closed container with a cylindrical structure, and a temperature hole runs through the cryogenic container along the central axis of the cryogenic container. The refrigerator is installed on the upper end of the cryogenic container, and the primary cold head of the refrigerator is located inside the cryogenic container. The cold shield is a cylindrical structure with a through hole along the axial direction, which is coaxial with the temperature hole of the cryogenic container. The cold screen is placed inside the cryogenic container and fixed on the lower part of the upper end cover of the cryogenic container through a tie rod, and the upper end face of the cold screen is fastened together with the lower end face of the primary cold head of the refrigerator by bolts. The superconducting coil is a cylindrical structure with a through hole along the central axis. The superconducting coil is placed inside the cold shield and fixed to the lower part of the upper end cover of the cryogenic container through a tie rod, and the upper end surface of the superconducting coil and the lower end surface of the secondary cold head of the refrigerator are fastened together by bolts.

The superconducting coil includes a central cylinder, end plates, insulating plates and double cakes. The central cylinder is a metal circular tube structure with threads processed at both ends. The double cakes, end plates and insulating plates are all circular cake-shaped structures, and the axis lines of the double cakes, end plates and insulating plates have circular through holes, and the diameter of the through holes is the same as the outer diameter of the central cylinder. The double cakes are coaxial with the insulation boards and arranged alternately. End plates are placed on the upper and lower ends of the double cake and the insulating plate; the central cylinder passes through the through holes of the double cake, the insulating plate and the end plate, and the two sides of the end plate are fastened with bolts.

The double cakes are wound with high-temperature superconducting tapes, and further, the high-temperature superconducting tapes wound with double cakes are YBCO tapes.

The front end of the catheter is equipped with three permanent magnetic rings, and the direction of the magnetic moment of the permanent magnetic rings is parallel to the central axis of the permanent magnetic rings and points to the end of the catheter. The torque applied by the uniform magnetic field to the permanent magnetic ring in the navigation area makes the magnetic moment of the permanent magnetic ring parallel to the uniform magnetic field, and the permanent magnetic ring is parallel to the external magnetic field. The torque received by the permanent magnet ring is T _m ＝M·B·A _m ·L _m ·sin(θ),

Among them: M is the magnetic moment amplitude of the permanent magnet ring, B is the magnetic field intensity amplitude at the position of the permanent magnet ring, A _m is the cross-sectional area of the permanent magnet ring, L _m is the axial length of the permanent magnet ring, and θ is the permanent magnetic ring The angle between the magnetic moment vector M of the magnetic ring and the magnetic field intensity B at the position of the permanent magnetic ring. In this way, the direction of the tip of the catheter can be controlled by adjusting the direction of the uniform magnetic field in the navigation area.

The beneficial effects of the present invention are: by changing the current in the eight superconducting magnets, the direction and strength of the magnetic field in the navigation area can be changed conveniently and quickly, and the mechanical bearing part used to change the direction of the magnetic field in the permanent magnet magnetic navigation equipment is omitted , which not only improves the response speed of the magnetic navigation system, but also reduces the noise of the equipment, so that the patient is in a relatively comfortable medical environment. In addition, since the magnetic navigation device of the present invention is not limited by the rotation space, a magnetic field in any three-dimensional direction can be generated by controlling the current of the superconducting magnet, so that there is no dead angle for the navigation direction of the catheter, and it is convenient for acute-angle branched blood vessels or blood vessels The navigation control of parts with large structural variations expands the scope of application of interventional cardiac surgery and improves the success rate of surgery.

Description of drawings

Fig. 1 is the overall schematic diagram of the device of the present invention. In the figure: 1 upper support frame, 2 lower support frame, 3 column, 4 navigation area, 5 fastening nut, 6 central column, 7 superconducting magnet;

Fig. 2 is a cross-sectional view of the superconducting magnet 7 of the device of the present invention on the plane where the axis is located. In the figure: 8 refrigerator, 9 cryogenic container, 10 cold screen, 11 superconducting coil, 12 primary cold head of refrigerator, 13 secondary cold head of refrigerator;

Fig. 3 is a cross-sectional view of the superconducting coil 11 of the device of the present invention on the plane where the axis is located. In the figure: 14 central tube, 15 double cake, 16 end plate, 17 insulating plate;

Fig. 4 is an electrical connection diagram of the device of the present invention. In the figure: 19 input control unit, 20 controller, 18 display unit, 21 superconducting magnet power supply, 22 magnetic field detection device, 4 navigation area, 7 superconducting magnet;

Fig. 5 is a schematic diagram of the catheter of the device of the present invention. Among the figure: 23 conduits, 24 permanent magnetic rings.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

The device of the present invention includes an upper support frame 1, a lower support frame 2, a column 3, a center column 6, a superconducting magnet 7, a superconducting magnet power supply 21, a magnetic field detection device 22, an input control unit 19, a controller 20, a display unit 18, Navigation area 4, and conduit 23.

As shown in FIG. 1 , the upper support frame 1 and the lower support frame 2 are two coaxial annular mechanical structures. The upper support frame 1 and the lower support frame 2 are fixed together by four columns 3 . The four columns 3 are evenly arranged along the ring direction and are parallel to the axis of the ring mechanical structure. The eight joint points formed by the upper support frame 1 , the lower support frame 2 and the four columns 3 are geometrically located on the eight vertices of the regular hexahedron. Eight central posts 6 are respectively housed on the eight joint points, and the lengths of the eight central posts 6 are equal and all have threads. The eight central columns 6 are symmetrically arranged on the four-axis oblique coordinate axis formed by the A axis, the B axis, the C axis and the D axis. The coordinate origin is located on the upper support frame 1, the lower support frame 2 and the four columns 3 The center point of the structure, the angle between two adjacent coordinate axes is 70.5°. There are eight superconducting magnets 7, which are installed on the eight central columns 6 respectively. The two ends of the superconducting magnet 7 are fixed with fastening nuts 5 . The eight superconducting magnets 7 are equidistant from the origin of the four-axis oblique coordinate system. Two superconducting magnets 7 located on the same coordinate axis are a pair, and a pair of superconducting magnets 7 are connected in series, so that the directions of the magnetic fields generated by a pair of superconducting magnets 7 are the same after being energized. The eight superconducting magnets 7 are divided into four pairs and distributed on the four axes of the four-axis oblique coordinate system. The navigation area 4 is a spherical area inside the area surrounded by eight superconducting magnets 7. The eight superconducting magnets 7 generate a uniform magnetic field with adjustable direction in the navigation area 4. The center of the navigation area 4 is located in the four-axis oblique coordinate system origin. The magnetic field detection device 22 is installed at the central position of the end of the central column 6 close to the navigation area 4, and the magnetic field detection device 22 is used to detect whether the magnetic field strength generated by the superconducting magnet 7 meets the set requirements. The diameter of the navigation area 4 is smaller than the distance from the magnetic field detection device 22 to the origin.

The upper support frame 1 and the lower support frame 2 can be rectangular, elliptical or other shapes, but to meet the mechanical strength required to support the superconducting magnet 7, and to satisfy the eight superconducting magnets 7 in space along the four-axis oblique Requirements for cross-coordinate axisymmetric distribution.

The column 3 may have a certain radian or other decorative appearance, but it must meet the mechanical strength required to support the superconducting magnet 7, and at the same time satisfy the requirement that the eight superconducting magnets 7 be symmetrically distributed along the four-axis oblique coordinate axis in space. Require.

As shown in FIG. 2 , the superconducting magnet 7 includes a refrigerator 8 , a cryogenic container 9 , a cold shield 10 and a superconducting coil 11 . The cryogenic container 9 is a closed container with a cylindrical structure, and a temperature hole runs through the cryogenic container 9 along the central axis of the cryogenic container 9 . The refrigerator 8 is installed on the upper end of the cryogenic container 9 , and the primary cold head 12 of the refrigerator 8 is located inside the cryogenic container 9 . The cold shield 10 is a cylindrical structure with a through hole along the axial direction, which is coaxial with the temperature hole of the cryogenic container 9 . The cold shield 10 is placed inside the cryogenic container 9 and fixed on the lower part of the upper end cover of the cryogenic container 9 by a tie rod, and the upper end surface of the cold shield 10 and the lower end surface of the primary cold head 12 of the refrigerator 8 are fastened together by bolts. The superconducting coil 11 is a cylindrical structure with a through hole along the central axis. The superconducting coil 11 is placed inside the cold shield 10, and is fixed on the lower part of the upper end cover of the cryogenic container 9 through a tie rod, and at the same time, the upper end surface of the superconducting coil 11 and the lower end surface of the secondary cold head 13 of the refrigerator 8 are fastened together by bolts .

As shown in FIG. 3 , the superconducting coil 11 includes a central cylinder 14 , end plates 16 , insulating plates 17 and double cakes 15 . The central cylinder 14 is a metal circular tube structure with threads processed at both ends. Described double cake 25, end plate 16 and insulating plate 17 are all round cake-shaped structures, and the axial center line of double cake 25, end plate 16 and insulating plate 17 has circular through hole, and the diameter of this through hole is the same as that of central cylinder. 14 have the same outer diameter. The double cakes 15 are coaxial with the insulating plates 17 and arranged alternately. The upper and lower ends of the double cakes 15 and the insulating plates 17 are placed with end plates 16, and the central cylinder 14 passes through the through holes of the double cakes 15, insulating plates 17 and end plates 16. , Both sides of the end plate 16 are fastened with bolts.

The double pie 15 is wound with a high temperature superconducting strip, and further, the high temperature superconducting strip around which the double pie 15 is wound is a YBCO strip.

Since the device of the present invention has the same structure on the four axes and the same electrical connection, only the A axis is used as an example for illustration. As shown in Figure 4, the output of the input control unit 19 is connected to the input of the controller 20, and the output of the controller 20 is connected to the display unit 18; The magnetic field information is fed back to the controller 20. The input control unit 19 is an instruction input unit, and the interventional doctor inputs the designated three-dimensional magnetic field direction according to the operation needs, and the input control unit 19 converts the analog control quantity input by the interventional doctor into a digital quantity that can be recognized by the controller 20, and sends it into controller 20. The controller 20 converts the three-dimensional magnetic field direction into the four-axis direction control quantity required for actual control, and applies a corresponding control strategy, and then transmits the control quantity to the four superconducting magnet power supplies 21 respectively. Each superconducting magnet power supply 21 supplies power in series to a pair of superconducting magnets 7 located on the same coordinate axis, and the direction of the central magnetic field generated by a pair of superconducting magnets 7 after electrification is consistent. Eight superconducting magnets 7 generate electromagnetic fields in four oblique axis directions. Since the magnetic field is a vector field, by adjusting the excitation current on the four pairs of superconducting magnets 7, a steady magnetic field with a certain intensity in any direction can be generated. The magnetic field generated by the superconducting magnet 7 is detected by the magnetic field detection device 22, and the detected magnetic field information is fed back to the controller 20 to realize closed-loop control, so that the direction of the magnetic field generated by the superconducting magnet 7 is consistent with the direction of the magnetic field input by the interventional doctor. The controller 20 sends the detected magnetic field information to the display unit 18 after processing, and the controller 20 transmits the input control unit 19 input magnetic field direction to the display unit 18 at the same time, and the display unit 18 displays the specified magnetic field direction and the location in the navigation area 4 in real time. The direction of the measured magnetic field.

The conduit 23 is a movable part and has no mechanical contact with other parts of the device of the invention. A permanent magnetic ring 24 is housed in the front end of the guide tube 23 . The working area of the catheter 23 is inside the navigation area 4 , and when the catheter 23 moves into the navigation area 4 , the magnetic field generated by the superconducting magnet 7 starts to navigate the catheter 23 . As shown in FIG. 5 , three permanent magnet rings 24 are installed in the front end of the catheter 23 , and the direction of the magnetic moment of the permanent magnet rings 24 is parallel to the central axis of the permanent magnet rings 24 and points to the end of the catheter 23 . The torque applied by the uniform magnetic field to the permanent magnetic ring 24 in the navigation area 4 makes the magnetic moment of the permanent magnetic ring 24 parallel to the uniform magnetic field, so that the permanent magnetic ring 24 is parallel to the external magnetic field. The torque received by the permanent magnet ring 24 is T _m =M·B·A _m ·L _m ·sin(θ),

Wherein: M is the magnetic moment amplitude of the permanent magnet ring 24, B is the magnetic field intensity amplitude of the permanent magnet ring 24 position, A _m is the cross-sectional area of the permanent magnet ring 24, and L _m is the axial length of the permanent magnet ring 24 , θ is the angle between the magnetic moment vector M of the permanent magnet ring 24 and the magnetic field intensity B at the position of the permanent magnet ring 24 . In this way, the direction of the end of the catheter 23 can be controlled by adjusting the direction of the uniform magnetic field in the navigation area 4 .

The manufacturing material of the permanent magnet ring 24 is NdFeB.

Claims (9)

1. a magnetic field generating device of cardiac magnetic navigation surgery system, is characterized in that, described magnetic field generating device comprises upper support frame (1), lower support frame (2), column (3), central column (6), Superconducting magnet (7), superconducting magnet power supply (21), magnetic field detection device (22), input control unit (19), controller (20), display unit (18), navigation area (4), and catheter ( 23); the upper support frame (1) and the lower support frame (2) are two ring-shaped mechanical structures coaxially placed, and the upper support frame (1) and the lower support frame (2) pass through four columns (3) fixed together, the four columns (3) are evenly arranged along the ring direction, and are parallel to the axis of the ring mechanical structure; The three joints are geometrically located on eight vertices of the regular hexahedron; the eight joints are respectively equipped with eight central columns (6), the eight central columns (6) are equal in length and have threads, and the eight central columns (6) Symmetrically arranged on the four-axis oblique coordinate axis formed by A-axis, B-axis, C-axis and D-axis, the coordinate origin is located on the upper support frame (1), the lower support frame (2) and the four columns ( 3) The center point of the formed structure, the angle between two adjacent coordinate axes is 70.5°; the eight superconducting magnets (7) are respectively installed on the eight central columns (6), and the superconducting magnets (7) The two ends of each are fixed with fastening nuts (5); the distances between the eight superconducting magnets (7) and the origin of the four-axis oblique coordinate system are equal; the two superconducting magnets (7) on the same coordinate axis are a pair, and one The superconducting magnets (7) are connected in series so that the direction of the magnetic field generated by a pair of superconducting magnets (7) is the same after being energized; the eight superconducting magnets (7) are divided into four pairs, which are respectively arranged on the four-axis oblique coordinate system On four axes; the navigation area (4) is a spherical area inside the area surrounded by eight superconducting magnets (7), and the eight superconducting magnets (7) produce a uniform direction adjustable in the navigation area (4). Magnetic field, the center of the navigation area (4) is located at the origin of the four-axis oblique coordinate system; the diameter of the navigation area is less than the distance from the magnetic field detection device to the origin; the magnetic field detection device (22) is installed at the end of the central column (6) Central position; the output of the input control unit (19) is connected to the input of the controller (20), and the output of the controller (20) is connected to the display unit (18); the controller (20) is also connected with four superconducting The magnet power supply (21) is connected, and the magnetic field information detected by the magnetic field detection device (22) is fed back to the controller (20); the output of each described superconducting magnet power supply (21) is connected to a pair of superconducting magnets located on the same coordinate axis. Magnet (7); Described catheter (23) is a movable part, without mechanical contact with other parts; Permanent magnetic ring (24) is housed in the front end of catheter (23), and the working area of catheter (23) is navigation area (4 ) inside, when the catheter (23) moves into the navigation area (4), the magnetic field generated by the superconducting magnet (7) starts to navigate the catheter (23). 2. according to the described magnetic field generating device of claim 1, it is characterized in that, described superconducting magnet (7) comprises refrigerator (8), cryogenic container (9), cold shield (10) and superconducting coil (11 ); the low-temperature container (9) is a closed container of a cylindrical structure, and a temperature hole runs through the low-temperature container (9) along the central axis direction of the low-temperature container (9); ), the primary cold head (12) of the refrigerator (8) is located inside the cryogenic container (9); The temperature holes of (9) are coaxial; the cold screen (10) is placed inside the low-temperature container (9), and is fixed on the lower part of the upper end cover of the low-temperature container (9) by a pull rod, and the upper end surface of the cold screen (10) is in contact with the refrigerator ( 8) The lower surface of the primary cold head (12) is fastened together by bolts; the superconducting coil (11) is a cylindrical structure with a through hole along the central axis; the superconducting coil (11) is placed in the cold The inside of the screen (10) is fixed on the lower part of the upper end cover of the cryogenic container (9) through a pull rod, and at the same time, the upper end surface of the superconducting coil (11) is tightly connected to the lower end surface of the secondary cold head (13) of the refrigerator (8) by bolts. solid together. 3. according to the described magnetic field generating device of claim 2, it is characterized in that, described superconducting coil (11) comprises central tube (14), end plate (16), insulating plate (17) and double cake (15) ; The center cylinder (14) is a metal circular tube structure, and the two ends are processed with threads; the double cake (15), end plate (16) and insulating plate (17) are all round cake-shaped structures, and the double cake (25) 1. There is a circular through hole on the axis of the end plate (16) and the insulating plate (17), and the diameter of the through hole is the same as the outer diameter of the central cylinder (14); the double cake (15) is coaxial with the insulating plate (17) , arranged alternately, the upper and lower ends of the double cake (15) and the insulating plate (17) are placed with the end plate (16); the central cylinder (14) passes through the double cake (15), the insulating plate (17) and the end plate (16) The through holes of the end plate (16) both sides are fastened with bolts. 4. The magnetic field generating device according to claim 3, characterized in that, said double cake (15) is made of high temperature superconducting tape. 5. The magnetic field generating device according to claim 3, characterized in that, said double cake (15) is wound from a YBCO strip. 6. according to the described magnetic field generating device of claim 1, it is characterized in that, the direction of the magnetic moment of the permanent magnet ring (24) in the described catheter (23) front end is parallel with the central axis of the permanent magnet ring (24), and Pointing to the end of the catheter (23); the permanent magnetic ring (24) is subjected to the torque applied by the uniform magnetic field in the navigation area (4), so that the magnetic moment of the permanent magnetic ring (24) is parallel to the uniform magnetic field, so that the permanent magnetic ring (24 ) is parallel to the external magnetic field; the torque received by the permanent magnet ring (24) is T _m =M·B·A _m ·L _m ·sin(θ), Wherein: M is the magnetic moment amplitude of permanent magnet ring (24), B is the magnetic field intensity amplitude of permanent magnet ring (24) position, A _m is the cross-sectional area of permanent magnet ring (24), L _m is permanent magnet The axial length of the ring (24), θ is the angle between the magnetic moment vector M of the permanent magnet ring (24) and the magnetic field intensity B at the position of the permanent magnet ring (24). 7. according to the described magnetic field generating device of claim 6, it is characterized in that, the making material of described permanent magnetic ring (24) is neodymium iron boron. 8. The magnetic field generating device according to claim 6, characterized in that three permanent magnetic rings (24) are installed in the front end of the catheter (23). 9. according to the described magnetic field generating device of claim 1, it is characterized in that, described input control unit (19) is instruction input unit; Interventional doctor inputs the specified three-dimensional magnetic field direction according to operation needs, and input control unit (19) will The input analog control quantity is converted into a digital quantity recognizable by the controller (20) and sent to the controller (20); the controller (20) converts the three-dimensional magnetic field direction into the four-axis direction control quantity required for actual control, and Apply a corresponding control strategy, and then pass the control amount to four superconducting magnet power supplies (21); each of the superconducting magnet power supplies (21) is connected in series to a pair of superconducting magnets (7) located on the same coordinate axis Power supply, a pair of superconducting magnets (7) produce the central magnetic field in the same direction after being energized; eight superconducting magnets (7) produce electromagnetic fields in four oblique axis directions, and the magnetic fields produced by the superconducting magnets (7) are detected by the magnetic field The device (22) detects, and the detected magnetic field information is fed back to the controller (20), so as to realize closed-loop control, so that the direction of the magnetic field generated by the superconducting magnet (7) is consistent with the direction of the magnetic field input by the interventional doctor; the controller (20) After the detected magnetic field information is processed, it is sent to the display unit (18), and the controller simultaneously transmits the input control unit (19) input magnetic field direction to the display unit (18), and the display unit (18) displays the specified magnetic field direction and navigation in real time. The measured magnetic field direction in region (4).