Magnetic nanoparticle imaging system based on permanent magnet and electromagnet composite driving

Abstract

The application relates to the field of magnetic particle imaging, in particular to a magnetic nanoparticle imaging system based on a permanent magnet and electromagnet composite driving mode, which comprises a magnet device, a first electric rotating table, a second electric rotating table, a third electric rotating table and a sample feeding device, the first electric rotating table and the second electric rotating table are located on the two sides of the magnet device, the third electric rotating table is located on one side of the second electric rotating table, the magnet device comprises a permanent magnet and an electromagnet, the permanent magnet comprises a focusing field permanent magnet and two selection field permanent magnets, the two selection field permanent magnets are driven to rotate through the first electric rotating table and the second electric rotating table, the focusing field permanent magnet is driven to rotate through the third electric rotating table, the electromagnet part is located outside the permanent magnet part and does not rotate, and the sample feeding device is located in the cavity of the permanent magnet part and does not rotate. The permanent magnet and the electromagnet composite driving mode can effectively reduce the power consumption of the magnetic nanoparticle imaging system.

Description

Technical Field

[0001] This invention belongs to the field of magnetic nanoparticle imaging technology, and particularly relates to a magnetic nanoparticle imaging system based on a composite drive of permanent magnets and electromagnets. Background Technology

[0002] Magnetic nanoparticle imaging (MPI) is an emerging imaging technique that uses an external magnetic field to manipulate the position and motion of magnetic nanoscale particles for imaging. Compared to traditional imaging techniques, MPI technology offers extremely high spatial resolution and sensitivity, enabling imaging at the cellular and tissue levels. It also boasts advantages such as being radiation-free, allowing for long-term dynamic monitoring, and exhibiting high biosafety. Imaging devices based on MPI technology can be widely applied in the diagnosis and treatment of cardiovascular and cerebrovascular diseases, neuroscience research, drug delivery, and cell tracking, holding significant scientific and socio-economic importance in the biomedical field.

[0003] Existing MPI systems use electromagnets to achieve the selection and focusing fields, but they consume a lot of power. Therefore, there is an urgent need for a low-power MPI system. Summary of the Invention

[0004] In view of this, the present invention aims to provide a magnetic nanoparticle imaging system based on a composite drive of permanent magnets and electromagnets, in order to solve the technical problem of high power consumption in existing MPI systems.

[0005] To achieve the above objectives, the technical solution created by this invention is implemented as follows:

[0006] A magnetic nanoparticle imaging system based on a composite drive of permanent magnets and electromagnets includes a magnet device, a first electrically driven rotating stage, a second electrically driven rotating stage, a third electrically driven rotating stage, and a sample introduction device; wherein,

[0007] The magnet device includes a first bearing sleeve, a second bearing sleeve, a first rolling bearing, a second rolling bearing, a third rolling bearing, a first connector, a second connector, a first selective field permanent magnet, a second selective field permanent magnet, a focusing field permanent magnet, a coil sleeve, and an electromagnet. The first bearing sleeve is connected to the second bearing sleeve. The inner ring of the first rolling bearing is connected to the first selective field permanent magnet through the first connector, and the outer ring of the first rolling bearing is connected to the first bearing sleeve. The inner ring of the second rolling bearing is connected to the second selective field permanent magnet through the second connector, and the outer ring of the second rolling bearing is connected to the second bearing sleeve. The electromagnet is connected to the first bearing sleeve, or the electromagnet is connected to the second bearing sleeve, or the electromagnet is simultaneously connected to both the first and second bearing sleeves.

[0008] The first electric rotary table and the second electric rotary table are located on both sides of the magnet device. The first electric rotary table is connected to the first cylindrical Halbach array permanent magnet through the first transition flange and is used to drive the first cylindrical Halbach array permanent magnet to rotate. The second electric rotary table is connected to the second cylindrical Halbach array permanent magnet through the second transition flange and is used to drive the second cylindrical Halbach array permanent magnet to rotate.

[0009] The focusing field permanent magnet is located in the inner cavity of the first selective field permanent magnet and the second selective field permanent magnet. The third electric rotary stage is located on one side of the second electric rotary stage. One end of the focusing field permanent magnet is connected to the inner ring of the third rolling bearing through the third connector. The outer ring of the third rolling bearing is connected to the first transition flange. The other end of the focusing field permanent magnet is connected to the third electric rotary stage through the third transition flange. The first selective field permanent magnet, the second selective field permanent magnet and the focusing field permanent magnet are all cylindrical Halbach array permanent magnets.

[0010] A first flange bearing is installed in the central through hole of the first electric rotary stage, and a second flange bearing is installed in the central through hole of the third electric rotary stage. The sample feeding device is located inside the permanent magnet of the focusing field and its two ends are respectively matched with the first flange bearing and the second flange bearing.

[0011] Furthermore, the electromagnet includes a coil sleeve and a fingerprint coil wound around the coil sleeve.

[0012] Furthermore, the magnetic nanoparticle imaging system based on the composite drive of permanent magnets and electromagnets also includes a magnet support frame, on which the coil sleeve is supported.

[0013] Furthermore, when there is one coil sleeve, the coil sleeve is connected to the first bearing sleeve or the second bearing sleeve; when there are two coil sleeves, the two coil sleeves are connected to the first bearing sleeve and the second bearing sleeve, respectively.

[0014] Furthermore, the magnetic nanoparticle imaging system based on the composite drive of permanent magnets and electromagnets also includes a first annular connecting frame and a second annular connecting frame. The first annular connecting frame is connected to the first bearing sleeve and the second annular connecting frame is connected to the second bearing sleeve by connecting rods. Both the first annular connecting frame and the second annular connecting frame are supported on the magnet support frame.

[0015] Furthermore, the magnetic nanoparticle imaging system based on the composite drive of permanent magnets and electromagnets also includes a first electric rotary stage support and a second electric rotary stage support. The first electric rotary stage is supported on the first electric rotary stage support, and the second electric rotary stage and the third electric rotary stage are jointly supported on the second electric rotary stage support.

[0016] Furthermore, the sample introduction device includes a shielding cylinder, an excitation coil, a receiving coil, a first sample introduction cylinder, a second sample introduction cylinder, and a support cylinder. The receiving coil is located inside the excitation coil, and the excitation coil and the receiving coil are combined to form an assembly. The assembly is located inside the support cylinder, and the support cylinder is located inside the shielding cylinder. The two ends of the shielding cylinder are connected to the first sample introduction cylinder and the second sample introduction cylinder, respectively.

[0017] Furthermore, grooves are provided axially on the wall of the shielding cylinder to reduce eddy currents.

[0018] Furthermore, the grooves are evenly distributed along the circumference of the shielding cylinder.

[0019] Furthermore, the support cylinder has a hollow structure.

[0020] Compared with the prior art, the present invention can achieve the following beneficial effects:

[0021] 1. The magnetic nanoparticle imaging system provided by the present invention adopts a composite driving method of permanent magnet and electromagnet. The selection field and focusing field are realized by the cylindrical arrangement of Halbach permanent magnets. Since the permanent magnet is a passive device, the power consumption of the magnetic nanoparticle imaging system can be effectively reduced.

[0022] 2. The electromagnet uses a fingerprint coil to improve the uniformity of the magnetic field.

[0023] 3. The grooves on the outer wall of the shielding tube can block the formation path of eddy currents, reducing eddy current loss without affecting the radio frequency shielding effect of the shielding tube, thereby reducing the heating temperature of the shielding tube. Attached Figure Description

[0024] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0025] Figure 1 This is a schematic diagram of the structure of a magnetic nanoparticle imaging system based on a composite drive of permanent magnets and electromagnets according to an embodiment of the present invention.

[0026] Figure 2 This is a schematic diagram of the main view structure of a magnetic nanoparticle imaging system based on a composite drive of permanent magnets and electromagnets according to an embodiment of the present invention.

[0027] Figure 3 This is a schematic cross-sectional view of the magnetic nanoparticle imaging system based on a composite drive of permanent magnets and electromagnets, according to an embodiment of the present invention.

[0028] Figure 4 yes Figure 3 A partially enlarged structural diagram.

[0029] Explanation of reference numerals in the attached figures:

[0030] Magnet device 1, first bearing sleeve 101, second bearing sleeve 102, first rolling bearing 103, second rolling bearing 104, first connector 105, second connector 106, first selective field permanent magnet 107, second selective field permanent magnet 108, electromagnet 110, first coil sleeve 111, first drive coil 112, second coil sleeve 113, second drive coil 114, focusing field permanent magnet 115, third rolling bearing 116, third connector 117, first electric rotary table 2, first transition flange 201, first flange bearing 202, second electric... Rotary stage 3, second transition flange 301, second flange bearing 302, sample injection device 4, shielding cylinder 401, excitation coil 402, receiving coil 403, first sample injection cylinder 404, second sample injection cylinder 405, support cylinder 406, magnet support frame 5, first magnet bracket 501, second magnet bracket 502, transverse support rod 503, first annular connecting frame 6, second annular connecting frame 7, connecting rod 8, first electric rotary stage support 9, rotary stage base 901, I-shaped support 902, second electric rotary stage support 10, third electric rotary stage 11, third transition flange 12. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not constitute a limitation thereof.

[0032] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0033] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0034] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0035] The invention will now be described in detail with reference to the figures and embodiments.

[0036] like Figures 1-4 As shown, the magnetic nanoparticle imaging system based on a composite drive of permanent magnets and electromagnets provided in this invention includes a magnet device 1, a first electric rotating stage 2, a second electric rotating stage 3, a third electric rotating stage 11, and a sample introduction device 4. The first electric rotating stage 2 and the second electric rotating stage 3 are located on both sides of the magnet device 1. The magnet device 1 includes a permanent magnet part and an electromagnet part. The permanent magnet part is driven to rotate by the first electric rotating stage 2 and the second electric rotating stage 3. The permanent magnet part provides a static gradient field. The electromagnet part is located outside the permanent magnet part and does not rotate. The electromagnet part provides a driving field to cause the zero magnetic field line to deflect. The deflection range of the zero magnetic field line is the scanning range. The sample introduction device 4 is located in the cavity of the permanent magnet part and does not rotate. The sample enters the interior of the magnet device 1 through the sample introduction device 4.

[0037] The magnet device 1 includes a first bearing sleeve 101, a second bearing sleeve 102, a first rolling bearing 103, a second rolling bearing 104, a first connecting member 105, a second connecting member 106, a first selective field permanent magnet 107, a second selective field permanent magnet 108, an electromagnet 110, a focusing field permanent magnet 115, a third rolling bearing 116, and a third connecting member 117. The first bearing sleeve 101 is connected to the second bearing sleeve 102. The inner ring of the first rolling bearing 103 is connected to the first selective field permanent magnet 107 via the first connecting member 105. The outer ring of the first rolling bearing 103 is connected to the first bearing sleeve 104. 01 Connection, the inner ring of the second rolling bearing 104 is connected to the second selective field permanent magnet 108 through the second connector 106, and the outer ring of the second rolling bearing 104 is connected to the second bearing sleeve 102; the electromagnet 110 includes a first coil sleeve 111, a first drive coil 112, a second coil sleeve 113, and a second drive coil 114. The first coil sleeve 111 is connected to the first bearing sleeve 101, the first drive coil 112 is wound around the first coil sleeve 111, the second coil sleeve 113 is connected to the second bearing sleeve 102, and the second drive coil 114 is wound around the second coil sleeve 113.

[0038] It should be noted that when the electromagnet 110 uses only one coil sleeve, it is either connected to the first bearing sleeve 101 or to the second bearing sleeve 102.

[0039] The driving coil of the electromagnet 110 uses a fingerprint coil, which can improve the uniformity of the magnetic field. The fingerprint coil can be an integrated solenoid coil, a saddle coil, or a Helmholtz coil. When the fingerprint coil is energized, it provides a driving field, causing the zero magnetic field line to deflect. The range of this deflection is the scanning range.

[0040] The first electric rotary table 2 is connected to the first selective field permanent magnet 107 via the first transition flange 201, and is used to drive the first selective field permanent magnet 107 to rotate.

[0041] The second electric rotary table 3 is connected to the second selective field permanent magnet 108 via the second transition flange 301, and is used to drive the second selective field permanent magnet 108 to rotate.

[0042] The present invention can drive the first selective field permanent magnet 107 and the second selective field permanent magnet 108 to rotate synchronously by the first electric rotary table 2 and the second electric rotary table 3, or drive the first selective field permanent magnet 107 and the second selective field permanent magnet 108 to rotate asynchronously, or drive one cylindrical Halbach array permanent magnet to rotate while the other cylindrical Halbach array permanent magnet does not rotate.

[0043] The focusing field permanent magnet 115 is located in the inner cavity of the first selective field permanent magnet 107 and the second selective field permanent magnet 108. The third electric rotary table 11 is located on one side of the second electric rotary table 3. One end of the focusing field permanent magnet 115 is connected to the inner ring of the third rolling bearing 116 through the third connector 117. The outer ring of the third rolling bearing 116 is connected to the first transition flange 201. The other end of the focusing field permanent magnet 115 is connected to the third electric rotary table 11 through the third transition flange 12. The third transition flange 12 passes through the central through hole of the second electric rotary table 3 and the inner cavity of the first transition flange 201 and then connects to the focusing field permanent magnet 115. The third electric rotary table 11 drives the focusing field permanent magnet 115 to rotate.

[0044] The first selective field permanent magnet 107 and the second selective field permanent magnet 108 are used to achieve the selective field, and the focusing field permanent magnet 115 is used to achieve the focusing field. All three are cylindrical Harbach array permanent magnets, resulting in a relatively uniform distribution of the magnetic field along the circular path. Using cylindrical Harbach array permanent magnets minimizes variations in magnetic field strength, which is beneficial for improving magnetic field stability.

[0045] The driving method of this invention is a composite focusing drive that combines an electromagnet and a permanent magnet array, while the traditional driving method is a simple electromagnet focusing drive. The use of passive permanent magnets can achieve low power consumption in the magnetic nanoparticle imaging system.

[0046] The sample introduction device 4 includes a shielding cylinder 401, an excitation coil 402, a receiving coil 403, a first sample introduction cylinder 404, a second sample introduction cylinder 405, and a support cylinder 406. The receiving coil 403 is located inside the cavity of the excitation coil 402. The excitation coil 402 is used to emit an excitation signal to excite the magnetization effect of magnetic nanoparticles in the sample. The receiving coil 403 is used to receive the magnetic nanoparticle signal. The excitation coil 402 and the receiving coil 403 are combined to form an assembly, which is located inside the cavity of the support cylinder 406. The support cylinder 406 is located inside the cavity of the focusing field permanent magnet 115. The two ends of the shielding cylinder 401 are connected to the first sample introduction cylinder 404 and the second sample introduction cylinder 405, respectively.

[0047] Grooves for reducing eddy currents are formed along the axial direction on the wall of the shielding cylinder 401. To avoid eddy current concentration, the grooves are evenly distributed along the circumference of the shielding cylinder.

[0048] To enhance the heat dissipation of the sample introduction device 4, the support cylinder 406 adopts a hollow structure.

[0049] A first flange bearing 202 is installed in the central through hole of the first electric rotary table 2. The first sample inlet cylinder 404 passes through the inner cavity of the third connecting piece 117 and the first transition flange 201 and then engages with the first flange bearing 202 to prevent the sample inlet device 4 from rotating with the first electric rotary table 2. Similarly, a second flange bearing 302 is installed in the central through hole of the third electric rotary table 11. The second sample inlet cylinder 405 passes through the inner cavity of the third transition flange 12 and then engages with the second flange bearing 302.

[0050] Considering rotational accuracy, this invention adopts a direct drive method that uses a motor rotary table connected to a transition flange to drive the permanent magnet to rotate. This method has the advantages of relatively simple manufacturing, high transmission accuracy, low noise, and convenient installation. At the same time, the transition flange can be made of aluminum alloy, which can significantly reduce weight and will not interfere with the magnetic field.

[0051] The magnetic nanoparticle imaging system also includes a magnet support frame 5, a first annular connecting frame 6, and a second annular connecting frame 7. The first annular connecting frame 6 is connected to the first bearing sleeve 101, and the second annular connecting frame 7 is connected to the second bearing sleeve 102, respectively, by connecting rods 8. The connecting rods 8 are evenly distributed around the circumference of the first annular connecting frame 6 and the second annular connecting frame 7, connecting the first annular connecting frame 6, the first bearing sleeve 101, the second annular connecting frame 7, and the second bearing sleeve 102 into a whole. The first annular connecting frame 6 and the first bearing sleeve 101 are distributed at both ends of the first coil sleeve 111, and the second annular connecting frame 7 and the second bearing sleeve 102 are distributed at both ends of the second coil sleeve 113. The first annular connecting frame 6 and the second annular connecting frame 7 are both supported on the magnet support frame 5 below.

[0052] The magnet support frame 5 includes a first magnet bracket 501, a second magnet bracket 502, and multiple transverse support rods 503, which are connected between the first magnet bracket 501 and the second magnet bracket 502 to provide transverse support for them. This ensures the stability of the magnet support frame 5 while also achieving weight reduction. The bottom surfaces of the first magnet bracket 501 and the second magnet bracket 502 are flat, while their top surfaces are arc-shaped, cooperating with the first annular connecting frame 6 and the second annular connecting frame 7. Weight-reducing holes are provided in the middle of the first magnet bracket 501 and the second magnet bracket 502.

[0053] The magnetic nanoparticle imaging system further includes a first electrically driven rotary stage support 9 and a second electrically driven rotary stage support 10 with identical structures. The first electrically driven rotary stage 9 includes a turntable base 901 and an I-shaped support 902. The turntable base 901 is fixed on the I-shaped support 902, and the first electrically driven rotary stage 2 is installed inside the turntable base 901. The second electrically driven rotary stage support 10 has two turntable bases fixed on the I-shaped support, and the second electrically driven rotary stage 3 and the third electrically driven rotary stage 11 are jointly supported within the two turntable bases.

[0054] This invention employs a double internal rolling bearing with a bearing sleeve to connect the Halbach array permanent magnets, ensuring that the two Halbach array permanent magnets are coaxial and generate magnetic fields for selection and focusing. The two ends of the Halbach array permanent magnets are connected to an electric rotary stage, and a support frame is used to support the Halbach array permanent magnets below, minimizing the weight of the entire magnetic nanoparticle imaging system. The electric rotary stage is used to directly drive the magnetic nanoparticle imaging system to achieve low-noise, high-precision rotational scanning motion.

[0055] It should be understood that the various forms of processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this invention disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this invention can be achieved, and this is not limited herein.

[0056] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A magnetic nanoparticle imaging system based on a composite drive of permanent magnets and electromagnets, characterized in that, It includes a magnet device, a first electrically driven rotary stage, a second electrically driven rotary stage, a third electrically driven rotary stage, and a sample introduction device; wherein, The magnet device includes a first bearing sleeve, a second bearing sleeve, a first rolling bearing, a second rolling bearing, a third rolling bearing, a first connector, a second connector, a first selective field permanent magnet, a second selective field permanent magnet, a focusing field permanent magnet, a coil sleeve, and an electromagnet. The first bearing sleeve is connected to the second bearing sleeve. The inner ring of the first rolling bearing is connected to the first selective field permanent magnet through the first connector, and the outer ring of the first rolling bearing is connected to the first bearing sleeve. The inner ring of the second rolling bearing is connected to the second selective field permanent magnet through the second connector, and the outer ring of the second rolling bearing is connected to the second bearing sleeve. The electromagnet is connected to the first bearing sleeve, or the electromagnet is connected to the second bearing sleeve, or the electromagnet is simultaneously connected to both the first and second bearing sleeves. The first electric rotary table and the second electric rotary table are located on both sides of the magnet device. The first electric rotary table is connected to the first cylindrical Halbach array permanent magnet through the first transition flange and is used to drive the first cylindrical Halbach array permanent magnet to rotate. The second electric rotary table is connected to the second cylindrical Halbach array permanent magnet through the second transition flange and is used to drive the second cylindrical Halbach array permanent magnet to rotate. The focusing field permanent magnet is located in the inner cavity of the first selective field permanent magnet and the second selective field permanent magnet. The third electric rotary stage is located on one side of the second electric rotary stage. One end of the focusing field permanent magnet is connected to the inner ring of the third rolling bearing through the third connector. The outer ring of the third rolling bearing is connected to the first transition flange. The other end of the focusing field permanent magnet is connected to the third electric rotary stage through the third transition flange. The first selective field permanent magnet, the second selective field permanent magnet and the focusing field permanent magnet are all cylindrical Halbach array permanent magnets. A first flange bearing is installed in the central through hole of the first electric rotary stage, and a second flange bearing is installed in the central through hole of the third electric rotary stage. The sample feeding device is located inside the permanent magnet of the focusing field and its two ends are respectively matched with the first flange bearing and the second flange bearing.

2. The magnetic nanoparticle imaging system based on a composite drive of permanent magnets and electromagnets according to claim 1, characterized in that, The electromagnet includes a coil sleeve and a fingerprint coil wound around the coil sleeve.

3. The magnetic nanoparticle imaging system based on a composite drive of permanent magnets and electromagnets according to claim 2, characterized in that, It also includes a magnet support frame, on which the coil sleeve is supported.

4. The magnetic nanoparticle imaging system based on a composite drive of permanent magnets and electromagnets according to claim 3, characterized in that, When there is one coil sleeve, the coil sleeve is connected to the first bearing sleeve or the second bearing sleeve. When there are two coil sleeves, the two coil sleeves are connected to the first bearing sleeve and the second bearing sleeve respectively.

5. The magnetic nanoparticle imaging system based on a composite drive of permanent magnets and electromagnets according to claim 4, characterized in that, It also includes a first annular connecting frame and a second annular connecting frame. The first annular connecting frame is connected to the first bearing sleeve and the second annular connecting frame is connected to the second bearing sleeve by connecting rods. Both the first annular connecting frame and the second annular connecting frame are supported on the magnet support frame.

6. The magnetic nanoparticle imaging system based on a composite drive of permanent magnets and electromagnets according to claim 1, characterized in that, It also includes a first electric rotary table support and a second electric rotary table support. The first electric rotary table is supported on the first electric rotary table support, and the second electric rotary table and the third electric rotary table are jointly supported on the second electric rotary table support.

7. The magnetic nanoparticle imaging system based on a composite drive of permanent magnets and electromagnets according to claim 1, characterized in that, The sample introduction device includes a shielding cylinder, an excitation coil, a receiving coil, a first sample introduction cylinder, a second sample introduction cylinder, and a support cylinder. The receiving coil is located inside the excitation coil. The excitation coil and the receiving coil are combined to form an assembly, which is located inside the support cylinder. The support cylinder is located inside the shielding cylinder. The two ends of the shielding cylinder are connected to the first sample introduction cylinder and the second sample introduction cylinder, respectively.

8. The magnetic nanoparticle imaging system based on a composite drive of permanent magnets and electromagnets according to claim 7, characterized in that, Grooves are formed along the axial direction on the wall of the shielding cylinder to reduce eddy currents.

9. The magnetic nanoparticle imaging system based on a composite drive of permanent magnets and electromagnets according to claim 8, characterized in that, The grooves are evenly distributed along the circumference of the shielding cylinder.

10. The magnetic nanoparticle imaging system based on a composite drive of permanent magnets and electromagnets according to claim 7, characterized in that, The support cylinder has a hollow structure.

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