An interventional surgical robot system and control method with electromagnetic and permanent magnet coordinated control

Abstract

This invention belongs to the fields of medical device technology and magnetically controlled soft robot technology, and more specifically, relates to an interventional surgical robot system and control method with electromagnetic-permanent magnet collaborative control. The interventional surgical robot system includes an electromagnetic-permanent magnet hybrid magnetic field generator, a magnetic guide wire, and a guide wire driving device. The electromagnetic-permanent magnet hybrid magnetic field generator includes a permanent magnet and an electromagnetic coil, with the permanent magnet embedded in the electromagnetic coil. Based on this hybrid magnetic field generator, an interventional surgical robot control system with electromagnetic-permanent magnet collaborative control is constructed. The permanent magnet is used to "coarsely adjust" the deflection direction of the magnetic guide wire, and the intermittent electromagnetic coil is used to "finely adjust" the deflection angle of the magnetic guide wire. This effectively reduces the system's energy consumption and size while ensuring control accuracy, fully utilizing the inherent advantages of permanent magnets and electromagnetic coils, and solving the problem of insufficient control accuracy for large robotic arms in existing permanent magnet driven methods.

Description

Technical Field

[0001] This invention belongs to the fields of medical device technology and magnetically controlled soft robot technology, and more specifically, relates to an interventional surgical robot system and control method with electromagnetic permanent magnet collaborative control. Background Technology

[0002] In recent years, cardiovascular and cerebrovascular diseases have become one of the diseases with high mortality and morbidity rates. Vascular embolism is the most important clinical manifestation of cardiovascular and cerebrovascular diseases, and interventional surgery is currently the most common and effective treatment for these diseases.

[0003] During interventional surgery, surgeons need to manually pull the guide wire to reach the lesion area. Given the complex environment of the cardiovascular system, even highly experienced surgeons require a considerable amount of time to complete the procedure. Furthermore, they are exposed to the dangers of X-ray radiation during the surgery. Wearing bulky protective suits for extended periods can cause fatigue for the surgeons, leading to more frequent tremors and impacting both the surgical outcome and safety.

[0004] Introducing robotic technology into cardiovascular and cerebrovascular surgery is an effective way to reduce radiation exposure for medical staff and patient suffering. Currently, research on interventional surgical robots focuses on the advancement, deflection, and rotation of guidewires during interventional procedures, mainly divided into passive and active methods. Traditional passive guidewires, for cases involving vascular branches or significant deflections, pre-shape the guidewire tip (e.g., "loach" guidewires), and then achieve deflection in a specified direction by rotating the guidewire tip. However, this movement is unpredictable and uncontrollable in practice, especially in narrow and winding environments, easily causing damage to blood vessels.

[0005] Currently, the most advanced active guidewires in research and application utilize magnetic field actuation. The team led by Zhao Xuanhe at MIT first printed ferromagnetic soft material ink into soft guidewires with diameters of only tens to hundreds of micrometers and radially magnetized them. Then, under remote control with an external magnetic field, the ferromagnetic soft guidewire robot can deflect and rotate in any direction, rapidly navigating complex vascular networks. During the actuation process, the position and orientation of a cylindrical permanent magnet fixed at its end are adjusted by a robotic arm, thereby changing the direction of the axial magnetic field of the permanent magnet on the guidewire and causing deflection. This means that the method is highly dependent on the precise movement of the robotic arm. Because the change in guidewire deflection angle is not linear with the distance between the permanent magnet and the guidewire, it is difficult to achieve precise deflection. On the other hand, using the axial magnetic field of the cylindrical permanent magnet, when the guidewire needs to be deflected upwards or downwards, the permanent magnet may enter the angiography area, thus affecting the procedure.

[0006] Patent CN114191098A discloses an electromagnetically controlled interventional surgical system and method. This system uses an embedded system module to dynamically and accurately control the current configuration of coils and generate an external magnetic field, enabling remote control of a guided wire to a designated position. Compared to permanent magnet drives, electromagnetic devices offer more accurate and rapid control; however, the energy density of electromagnetic devices is much lower than that of permanent magnets, resulting in a significant amplification of the magnetic source device. Furthermore, the heat generated by electromagnetic devices also presents a challenge due to the longer interventional surgical time. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides an interventional surgical robot system and control method with electromagnetic and permanent magnet coordinated control. By coordinating the control of electromagnets and permanent magnets to adjust the magnetic field distribution, it aims to solve the problem that existing interventional surgical robot systems cannot simultaneously achieve low energy consumption, small size, and high-precision magnetic field control.

[0008] To achieve the above objectives, the present invention provides an electromagnetic-permanent magnet hybrid magnetic field generator, which includes a permanent magnet and an electromagnetic coil. The permanent magnet is embedded in the electromagnetic coil, and there are one or more electromagnetic coils. In use, the permanent magnet is magnetized along the axial direction, and a current is passed through the electromagnetic coil. The magnetic field generated by the electromagnetic coil can be controlled by adjusting the amplitude and direction of the current, and the magnetic field generated by the electromagnetic coil can strengthen or weaken the magnetic field of the permanent magnet.

[0009] Preferably, the permanent magnet is a cylindrical permanent magnet, and there are two electromagnetic coils. The two electromagnetic coils are symmetrically and separately arranged on both sides of the cylindrical permanent magnet. The two ends of the permanent magnet are flush with the outer end face of the electromagnetic coil, or are protruding relative to the electromagnetic coil, and are symmetrically distributed along the xy plane.

[0010] Preferably, the optimized design method for the structure of the hybrid magnetic field generator includes the following steps:

[0011] (1) The optimization variables for this hybrid magnetic field generator are defined as follows: the radius of the cylindrical permanent magnet is R. m The height is 2H m The distance H between the outer end face of the electromagnetic coil on either side and the end face of the adjacent permanent magnet is... em1 The distance H between the inner end face of the electromagnetic coil and the end face of the same permanent magnet is em2 The width of the electromagnetic coil is R. em ;

[0012] (2) Define the distance between the surface of the hybrid magnetic field generator and the working area as z when the hybrid magnetic field generator is working; take the maximum amplitude magnetic field generated by the hybrid magnetic field generator at a distance of z as the optimization target;

[0013] (3) The mass m of the hybrid magnetic field generator total As a constraint, where, Where ρ1 is the density of the permanent magnet, ρ2 is the density of the electromagnetic coil conductor, and D CS The thickness of the coil frame reserved between the permanent magnet and the electromagnetic coil;

[0014] (4) Electromagnetic field B in the hybrid magnetic field generator EM For the magnetic field B of the permanent magnet PM It has adjustable capabilities, and its constraint is set to 1 / 2. EM / B PM <1; and the magnetic field along the axis of the cylindrical permanent magnet is represented as:

[0015]

[0016] The two electromagnetic coils symmetrically and separately arranged on the surface of the cylindrical permanent magnet are two hollow cylindrical coils with equal radius and thickness, and their heights are 2 (H) and 2 (H) respectively. m -H em1 ), 2(H m -H em2 The magnetic field on the circumference of the electromagnetic coil can be obtained by subtracting the magnetic fields generated by the two hollow cylindrical coils, i.e., B. EMz =B EMz1 -B EMz2 ;in,

[0017]

[0018]

[0019] Where M is the remanent magnetization of the permanent magnet, J is the coil current density, and μ0 is the free permeability; therefore, the total magnetic field along the axis of this hybrid magnetic field generator is expressed as:

[0020] B total =B PMz +B EMz

[0021] Among them, B total B represents the total magnetic field along the axis of the hybrid magnetic field generator. PMz B represents the magnetic field of the cylindrical permanent magnet located at a distance z from the working region. EMz This represents the magnetic field generated by the electromagnetic coil at a distance z from the working area;

[0022] (5) Based on the above design goals and constraints, the genetic algorithm is used to perform global optimization on the optimization variables to obtain the specific structural parameters of the hybrid magnetic field generator.

[0023] ​Preferably, it includes a permanent magnet, an electromagnetic coil, and a fixing component. The permanent magnet is embedded in the electromagnetic coil and fixed by the fixing component. The fixing component serves as the frame of the electromagnetic coil to prevent the electromagnetic coil from deforming and damaging the permanent magnet.

[0024] According to another aspect of the present invention, an interventional surgical robot system with electromagnetic permanent magnet coordinated control is provided, comprising a magnetic field control device, a magnetic guidewire, a guidewire driving device, and a remote control device, wherein:

[0025] The magnetic field control device includes a robotic arm and the hybrid magnetic field generator. The robotic arm is used to drive and rotate the hybrid magnetic field generator, thereby changing the direction and angle of the magnetic field.

[0026] The magnetic guide wire is an interventional guide wire with a magnetic head. The magnetic guide wire is used to deflect under the magnetic field generated by the hybrid magnetic field generator and to move forward or backward in a preset direction under the drive of the guide wire driving device.

[0027] The remote control device is used to adjust the position and angle of the end effector space of the robotic arm, adjust the distance by which the guide wire drive device drives the magnetic guide wire forward or backward, and adjust the magnitude and direction of the current in the electromagnetic coil.

[0028] According to another aspect of the present invention, a control method for the robot system is provided, comprising the following steps:

[0029] S1: By controlling the device remotely, the robotic arm moves and rotates the hybrid magnetic field generator, placing the magnetic field generator near the direction the magnetic guide wire head is to be deflected, so that the magnetic guide wire head is attracted or repelled to the preset direction under the combined action of magnetic torque and gradient force.

[0030] S2: By adjusting the distance between the surface of the hybrid magnetic field generator and the head of the magnetic guide wire, the direction and amplitude of the driving magnetic field strength are "coarsely adjusted", thereby controlling the head of the magnetic guide wire to deflect in the preset direction;

[0031] S3: Fix the position and angle of the mixed magnetic field generator, and fine-tune the driving magnetic field strength by controlling the input current of the electromagnetic coil, thereby adjusting the alignment of the magnetic guide wire head with the preset direction;

[0032] S4: The magnetic guide wire is moved forward in a preset direction by controlling the guide wire driving device.

[0033] In summary, compared with the prior art, the above-described technical solutions conceived by this invention have the following advantages:

[0034] Beneficial effects:

[0035] (1) The electromagnetic-permanent magnet hybrid magnetic field generating device provided by the present invention includes a permanent magnet and an electromagnetic coil. The permanent magnet is embedded in the electromagnetic coil, and there are one or more electromagnetic coils. In use, the permanent magnet is magnetized along the axial direction, and a current is passed through the electromagnetic coil. The magnetic field generated by the electromagnetic coil can be controlled by adjusting the amplitude and direction of the current, and the magnetic field generated by the electromagnetic coil can strengthen or weaken the magnetic field of the permanent magnet. Based on this hybrid magnetic field generating device, an interventional surgical robot control system with electromagnetic-permanent magnet collaborative control is constructed. The permanent magnet is used to "coarsely adjust" the deflection direction of the magnetic guide wire, and the intermittent electromagnetic coil is used to "finely adjust" the deflection angle of the magnetic guide wire. While ensuring control accuracy, the system's energy consumption and volume are effectively reduced. The inherent advantages of the permanent magnet and the electromagnetic coil are fully utilized, avoiding the problem of insufficient control accuracy of current large robotic arms.

[0036] (2) The present invention first makes the key structural parameters of the electromagnetic-permanent magnet hybrid magnetic field generator continuous. Then, with the total mass and adjustment capability of the device as constraints, the specific geometric dimensions of the hybrid magnetic field generator with the maximum magnetic field generation capability are optimized by genetic algorithm, so that the device can improve the magnetic field generation efficiency as much as possible.

[0037] (3) The TPU-type magnetic guide wire with optical fiber / nickel-titanium alloy core based on the heating extrusion method provided by the present invention has the advantages of simple operation, high preparation accuracy and fast preparation speed. It has significant advantages over the traditional mold injection method and provides a new way for the commercial mass production of magnetically controlled guide wire and catheter robot in the future.

[0038] (4) The guide wire drive device used in the interventional surgical robot system provided by the present invention utilizes the pre-tension of the spring and, when necessary, the further mechanical external force of the precision adjustment thread pair to achieve the clamping of the guide wire wheel on the wire feeding gear, and then, under the driving action of the stepper motor, realizes the transmission requirements of guide wires of different diameters and the control of different driving force magnitudes. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the electromagnetic permanent magnet collaborative control interventional surgical robot system of the present invention.

[0040] Figure 2 This is a schematic diagram of the electromagnetic-permanent magnet hybrid structure in the hybrid magnetic field generating device used in this embodiment of the invention.

[0041] Figure 3 This is a structural diagram of a hybrid magnetic field generator optimized in some embodiments of the present invention.

[0042] Figure 4This is a bar chart showing the geometric parameter variables and dependent variables of the hybrid magnetic field generator optimized in some embodiments of the present invention.

[0043] Figure 5 This is a graph showing the trend of magnetic flux variation along the axial direction on the surface of a permanent magnet in the case of a single permanent magnet, as provided in an embodiment of the present invention.

[0044] Figure 6 This is a schematic diagram illustrating the principle of the mold injection method provided in an embodiment of the present invention.

[0045] Figure 7 This is a schematic diagram illustrating the principle of the heated extrusion method provided in an embodiment of the present invention.

[0046] Figure 8 This is an equivalent circuit diagram of the pulse magnetization device provided in the embodiments of the present invention.

[0047] Figure 9 This is a back view of the guide wire driving device provided in an embodiment of the present invention.

[0048] Figure 10 This is a front side view of the guide wire driving device provided in an embodiment of the present invention.

[0049] Figure 11 This is a rear view of the guide wire driving device provided in an embodiment of the present invention.

[0050] Among them, 1 is the magnetic field control device; 1-1 is the permanent magnet; 1-2 is the electromagnetic coil; 1-3 is the fixed component; 1-4 is the robotic arm; 2 is the medical imaging device; 3 is the magnetic guide wire; 4 is the guide wire drive device; 4-1 is the stepper motor; 4-2 is the worm gear; 4-3 is the turbine; 4-4 is the turbine fixed shaft; 4-5 is the driving gear; 4-6 is the driven gear; 4-7 is the wire feeding gear; 4-8 is the guide wheel; 4-9 is the spring; 4-10 is the guide wheel fixed shaft; 4-11 is the guide slide rail; 4-12 is the side base plate; 4-13 is the catheter; 4-14 is the needle; 4-15 is the precision adjusting thread pair; 4-16 is the bearing; 4-17 is the base plate; and 5 is the remote control device. Detailed Implementation

[0051] 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 embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0052] The present invention provides an electromagnetic-permanent magnet hybrid magnetic field generating device, which includes a permanent magnet and an electromagnetic coil. The permanent magnet is embedded in the electromagnetic coil, and there are one or more electromagnetic coils. In use, the permanent magnet is magnetized along the axial direction, and a current is passed through the electromagnetic coil. The magnetic field generated by the electromagnetic coil can be controlled by adjusting the amplitude and direction of the current, and the magnetic field generated by the electromagnetic coil can strengthen or weaken the magnetic field of the permanent magnet.

[0053] In some embodiments, such as Figure 2 As shown, the permanent magnet in this hybrid magnetic field generator is defined as a cylindrical permanent magnet, and there are two electromagnetic coils. The two electromagnetic coils are symmetrically and separately arranged on both sides of the cylindrical permanent magnet. The two ends of the permanent magnet are flush with the outer end faces of the electromagnetic coils, or protrude relative to the outer end faces of the electromagnetic coils, and are symmetrically distributed along the xy plane. In the figure, "Magnet" represents the permanent magnet and "Coil" represents the electromagnetic coil. Based on this structure, and setting the two ends of the permanent magnet to protrude relative to the electromagnetic coils, an optimized design method for the structure of the hybrid magnetic field generator to obtain the maximum amplitude magnetic field when the distance between the hybrid magnetic field generator and the working area is z is proposed. The method includes the following steps:

[0054] (1) The optimization variables for this hybrid magnetic field generator are defined as follows: the radius of the cylindrical permanent magnet is R. m The height is 2H m The distance H between the outer end face of the electromagnetic coil on either side and the end face of the adjacent permanent magnet is... em1 The distance H between the inner end face of the electromagnetic coil and the end face of the same permanent magnet is em2 The width of the electromagnetic coil is R. em ;

[0055] (2) Define the distance between the surface of the hybrid magnetic field generator and the working area as z when the hybrid magnetic field generator is working; take the maximum amplitude magnetic field generated by the hybrid magnetic field generator at a distance of z as the optimization target;

[0056] (3) Typically, in such devices, the load-bearing capacity of the robotic arm is a limitation that must be considered; therefore, the mass m of the hybrid magnetic field generator should be... total As a constraint, where, Where ρ1 is the density of the permanent magnet, ρ2 is the density of the copper conductor in the electromagnetic coil, and D CS The thickness of the coil frame reserved between the permanent magnet and the electromagnetic coil;

[0057] (4) Electromagnetic field B in the hybrid magnetic field generator EM For the magnetic field B of the permanent magnet PM It has adjustable capabilities, and its constraint is set to 1 / 2. EM / B​PM <1; and the magnetic field along the axis of the cylindrical permanent magnet is represented as:

[0058]

[0059] The two electromagnetic coils symmetrically and separately arranged on the surface of the cylindrical permanent magnet are two hollow cylindrical coils with equal radius and thickness, and their heights are 2 (H) and 2 (H) respectively. m -H em1 ), 2(H m -H em2 The magnetic field on the circumference of the electromagnetic coil can be obtained by subtracting the magnetic fields generated by the two hollow cylindrical coils, i.e., B. EMz =B EMz1 -B EMz2 ;in,

[0060]

[0061]

[0062] Where M is the remanent magnetization of the permanent magnet, J is the coil current density, and μ0 is the free permeability; therefore, the total magnetic field along the axis of this hybrid magnetic field generator is expressed as:

[0063] B total =B PMz +B EMz

[0064] Among them, B total B represents the total magnetic field along the axis of the hybrid magnetic field generator. PMz B represents the magnetic field of the cylindrical permanent magnet located at a distance z from the working region. EMz This represents the magnetic field generated by the electromagnetic coil at a distance z from the working area.

[0065] (5) Based on the above design goals and constraints, the genetic algorithm is used to perform global optimization on the optimization variables to obtain the specific structural parameters of the hybrid magnetic field generator.

[0066] In some embodiments, when optimizing the structure of the hybrid magnetic field generator, corresponding parameters can be set according to the actual situation and needs. For example, the mass m of the hybrid magnetic field generator in step (3) can be defined. total <8Kg, the thickness D of the coil frame reserved between the permanent magnet and the electromagnetic coil CS =5mm; The corresponding remanent magnetization of the permanent magnet is set according to the permanent magnet material used. When the permanent magnet material used is N35, the remanent magnetization of the permanent magnet is set to M = 9.55 × 10. 6 A / m, coil current density is J = 5 × 10 6 A / m2 Vacuum permeability μ0 = 4π × 10 -7 N / A 2 .

[0067] In some embodiments, the optimized hybrid magnetic field generator is as follows: Figure 3 As shown, it includes: a permanent magnet 1-1 made of N35 cylindrical magnet; and an electromagnetic coil 1-2 made of 2mm*4mm copper wire (with glass fiber coating); the permanent magnet 1-1 is embedded in the electromagnetic coil and fixed by a fixing component 1-3; the fixing component 1-3 serves as the electromagnetic coil frame to prevent deformation of the electromagnetic coil from damaging the permanent magnet; the optimization variables and dependent variables are as follows. Figure 4 As shown, the specific geometric parameters are as follows: R m =30.6mm, H m =30.6mm, H em1 =1.8mm, H em2 =27.5mm, R em =43mm.

[0068] This embodiment establishes Figure 2 The finite element digital simulation model shown is for the electromagnetic-permanent magnet hybrid case, with the remanence of the permanent magnet set to 1.23T (along the axial direction of the cylinder). Figure 5 The graphs showing the axial trend of magnetic flux on the surface of the hybrid magnet under different current densities reveal that the magnetic flux distribution of the permanent magnet in space decays rapidly with distance. If magnetic field control is achieved solely by adjusting the distance between the permanent magnet and the magnetic wire, the requirements for robotic arms or other mechanical transmission devices would need to be at the millimeter level or even higher. However, simulations show that at a distance of 100 mm from the surface, with the electromagnetic-permanent magnet synergistic magnetic field generator remaining unchanged, the magnetic field can be infinitely adjusted from 7.5 mT to 22.5 mT. This structure has a significant advantage in precise control.

[0069] This invention also provides an interventional surgical robot system with electromagnetic permanent magnet coordinated control, such as... Figure 1 As shown, it includes a magnetic field control device 1, a magnetic guide wire 3, a guide wire drive device 4, and a remote control device 5, wherein:

[0070] The magnetic field control device 1 includes a robotic arm 1-4 and the hybrid magnetic field generator. The robotic arm 1-4 is used to drive and rotate the hybrid magnetic field generator, thereby changing the direction and angle of the magnetic field.

[0071] The magnetic guide wire 3 is an interventional guide wire with a magnetic head. The magnetic guide wire is used to deflect under the action of the magnetic field generated by the hybrid magnetic field generator and to move forward or backward in a preset direction under the drive of the guide wire driving device 4.

[0072] The remote control device 5 is used to adjust the position and angle of the end space of the robotic arm, adjust the distance by which the guide wire drive device drives the magnetic guide wire forward or backward, and adjust the magnitude and direction of the current in the electromagnetic coil.

[0073] In use, a robotic arm moves and rotates the hybrid magnetic field generator, placing its central axis directly in front of or behind the desired deflection direction of the magnetic guide wire head. This causes the magnetic guide wire head to be attracted or repelled to the preset direction under the combined action of magnetic torque and gradient force. The driving magnetic field strength is coarsely adjusted by changing the distance between the surface of the hybrid magnetic field generator and the magnetic guide wire head (the electromagnetic coil is not operating at this time), thereby controlling the magnetic guide wire head to deflect in the preset direction. The position and angle of the hybrid magnetic field generator are fixed, and the driving magnetic field strength is finely adjusted by controlling the input current of the electromagnetic coil, thereby regulating the alignment of the magnetic guide wire head with the preset direction. Finally, the guide wire driving device is controlled to advance the magnetic guide wire in the preset direction.

[0074] In some embodiments, the remote control device consists of a handle and an electronic screen. The handle can control the spatial position and angle of the robotic arm end effector, control the guide wire drive device to drive the magnetic guide wire forward and backward, and adjust the magnitude and direction of the current in the electromagnetic coil; the electronic screen can display the above parameters.

[0075] In some embodiments, the robotic system operates with the assistance of a medical imaging device 2. Specifically, for example, through an interventional X-ray imaging system, the spatial position of the magnetic guidewire can be clearly observed; after the contrast agent is injected through the catheter, the outline and direction of the blood vessels at the catheter port can also be observed, which is beneficial for the next step of the magnetic guidewire path planning.

[0076] In some embodiments, the magnetic wire is a radially magnetized magnetic wire, and the magnetization method is as follows: the prepared magnetic wire is vertically fixed at the center position of the magnetizing coil, and under the action of the pulsed magnetic field, the magnetic wire is radially magnetized.

[0077] In some embodiments, the magnetic head is made of a mixture of ferromagnetic powder and elastomer, and the interventional guidewire is a straight universal guidewire, etc.

[0078] In some embodiments of the present invention, the magnetic guidewire is connected to a conventional linear interventional guidewire via a heat shrink tubing by a magnetic head, and the heat shrink tubing is heated to 100 degrees Celsius by a hot air gun to cause it to neck.

[0079] In some embodiments, the magnetic head is prepared as follows: First, a certain mass of NdFeB powder (model MQFP-15-7-20065-089, manufactured by Magnequench, particle size 5μm) is weighed using a balance, and the powder's tap density (7.61 g / cm³) is measured. 3 The theoretical volume of the powder was calculated; then, a specific volume of PDMS liquid (model Sylgard-184, manufactured by Dow Corning) was drawn using a syringe, ensuring a volume ratio of NdFeB:PDMS = 1:4; the NdFeB powder was poured into the PDMS liquid and stirred in a planetary mixer at 2000 rpm for 2 minutes, followed by degassing at 2000 rpm for 1 minute, and cooled to room temperature for 1 minute. Then, a curing agent was added at a volume ratio of catalyst:PDMS = 1:9, and the mixture was stirred again at 2000 rpm for 1 minute to complete the preparation of the magnetic mixture; a polyimide tube with an inner diameter of 0.8 mm and a nickel-titanium alloy wire with a diameter of 0.08 mm were used as the mold tube and inner core, respectively. The inner core was placed in the mold tube, with the foremost end of the inner core positioned at... The inner end of the tube is placed close to the injection nozzle, with the last end extending out and secured to prevent the inner core from being squeezed out of the mold tube by the magnetic mixture during injection. The magnetic mixture is poured into the syringe, the bottom of which is inserted into the pressure booster. The injection nozzle is inserted into the mold tube and the connection is sealed. The pressure booster screw is slowly rotated to squeeze the magnetic mixture into the mold tube until it is completely filled. The mold tube filled with the magnetic mixture is then placed in an electric heating drying oven and heated at 170°C for 10 minutes. The magnetic mixture has now completely solidified. Finally, the mold tube is carefully cut along its length using a pen knife blade, and the guide wire is completely detached from the mold tube. Care should be taken to avoid scratching the guide wire during this process. A schematic diagram of the mold injection molding process is shown below. Figure 6 As shown.

[0080] In other embodiments, the magnetic head can also be prepared by the following steps: weighing a certain mass of NdFeB powder (model MQFP-15-7-20065-089, manufactured by Magnequench, particle size 5μm) and TPU powder (model MH-T70, manufactured by Jiecheng Plastics, particle size 25μm) using a balance, and determining their respective tap densities (7.61g / cm³). 3 and 1.2g / cm 3Calculate the theoretical volume of the powder to ensure the volume ratio NdFeB:TPU = 1:4; feed NdFeB and TPU powder into the extruder's feeding chamber, setting the internal temperature of the feeding chamber to 70℃, the middle section temperature to 125℃, and the die head extrusion outlet temperature to 130℃, with an extrusion outlet inner diameter of 0.8mm; after preheating, start the feed screw and coiler to extrude a certain length of hollow guide wire, and check the diameter with a laser diameter gauge; after confirming the wire diameter meets the standard, insert a 0.08mm diameter nickel-titanium alloy wire into the die head extrusion outlet; after the produced cored guide wire reaches the predetermined length, shut down the extruder. A schematic diagram of the heated extrusion method is shown below. Figure 7 As shown.

[0081] After the magnetic guide wire of this invention is prepared, it is vertically fixed at the center of the magnetizing coil. Under the action of a pulsed magnetic field, the head of the magnetic guide wire is radially magnetized. In some embodiments, as shown in the example... Figure 8 The pulse magnetization device shown is used to magnetize the magnetic wire. Specifically, the pulse magnetization device includes a discharge capacitor, a pulse electromagnetic coil, a discharge switch, line impedance (line resistance and inductance), and a freewheeling circuit (diode, freewheeling resistor, and freewheeling switch). Before discharging, the wire is first vertically fixed at the center of the magnetization coil, and the freewheeling circuit switch is closed to charge the capacitor. Then, the discharge switch is closed to discharge the pulse electromagnetic coil.

[0082] The magnetic guide wire driving device and driving method of the present invention can adopt existing guide wire driving devices and methods, or can be designed independently. For example, in some embodiments, such as... Figure 9 , Figure 10 and Figure 11As shown, the magnetic wire guide drive device includes a stepper motor 4-1, a worm gear 4-2, a turbine gear 4-3, a turbine fixed shaft 4-4, a driving gear 4-5, a driven gear 4-6, a wire feeding gear 4-7, a guide wheel 4-8, a spring 4-9, a guide wheel fixed shaft 4-10, a guide rail 4-11, a side base plate 4-12, a guide tube 4-13, a needle 4-14, a bearing 4-16, and a base plate 4-17. During operation, the stepper motor 4-1 drives the worm gear 4-2, transferring kinetic energy to the turbine gear 4-3. One end of the turbine fixed shaft 4-4 fixes the turbine gear 4-3, and the other end fixes the driving gear 4-5. The driving gear 4-5 drives the driven gear 4-6 to rotate. The driven gear 4-6 is coaxial with the wire feeding gear 4-7, causing the driven gear 4-6 to rotate... During operation, the wire feeding gear 4-7 and the driven gear 4-6 rotate simultaneously and in the same direction; the two wire feeding gears 4-7 are located on both sides of the bottom of the guide wheel 4-8, and the guide wheel 4-8 uses the tension of the spring 4-9 to press the magnetic guide wire and the wire feeding gear 4-7; the guide wheel 4-8 is fixed on the guide wheel fixing shaft 4-10, and the guide wheel fixing shaft 4-10 is fixed on the guide slide rail 4-11; one end of the spring 4-9 is fixedly connected to the guide slide rail 4-11, and the other end is fixed on the side base plate 4-12; the guide wire passes through the guide tube 4-13 and the needle 4-14, and under the electric drive of the stepper motor 4-1, it is transmitted forward by the friction generated by the wire feeding gear 4-7 and the guide wheel 4-8 pressing the guide wire. There are three bearings 4-16, which provide support for the driving gear 4-5, driven gear 4-6 and wire feeding gear 4-7 respectively; all the above components are fixedly mounted on the base plate 4-17 by structural components.

[0083] In a preferred embodiment, the top of the guide rail 4-11 is further provided with a precision adjusting threaded pair 4-15, which is used to adjust the force exerted by the threaded pair on the guide rail 4-11 and further on the guide wheel fixing shaft 4-10 and the guide wheel 4-8 to press down on the wire feeding gear 4-7 as needed, so as to adapt to the transmission requirements of guide wires of different diameters. The diameter of the guide wire in interventional surgery varies in different blood vessels. For example, the guide wire for large blood vessels can be 0.7-1.5 mm, but the guide wire for neurointervention is only 0.4 mm. This invention utilizes the preload of a spring, and, when necessary, the further mechanical force of the precision adjusting threaded pair, to achieve the pressing of the guide wheel on the wire feeding gear, and then, under the drive of a stepper motor, to meet the transmission requirements of guide wires of different diameters.

[0084] The present invention also provides a control method for the above-mentioned robot system, comprising the following steps:

[0085] S1: By controlling the device remotely, the robotic arm moves and rotates the hybrid magnetic field generator, placing the magnetic field generator near the direction the magnetic guide wire head is to be deflected, so that the magnetic guide wire head is attracted or repelled to the preset direction under the combined action of magnetic torque and gradient force.

[0086] S2: By adjusting the distance between the surface of the mixed magnetic field generator and the head of the magnetic guide wire, the direction and amplitude of the driving magnetic field strength are "coarsely adjusted" (at this time, the electromagnetic coil is not working), thereby controlling the head of the magnetic guide wire to deflect in the preset direction;

[0087] S3: Fix the position and angle of the mixed magnetic field generator, and fine-tune the driving magnetic field strength by controlling the input current of the electromagnetic coil, thereby adjusting the alignment of the magnetic guide wire head with the preset direction;

[0088] S4: The magnetic guide wire is moved forward in a preset direction by controlling the guide wire driving device.

[0089] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An electromagnetic-permanent magnet hybrid magnetic field generating device, characterized in that, It includes a permanent magnet and an electromagnetic coil, wherein the permanent magnet is embedded in the electromagnetic coil, and the electromagnetic coil may be one or more. In use, the permanent magnet is magnetized along the axial direction, and current is passed through the electromagnetic coil; the magnetic field generated by the electromagnetic coil can be controlled by adjusting the amplitude and direction of the current, and the magnetic field generated by the electromagnetic coil can strengthen or weaken the magnetic field of the permanent magnet. The permanent magnet is a cylindrical permanent magnet, and there are two electromagnetic coils. The two electromagnetic coils are symmetrically and separately arranged on both sides of the cylindrical permanent magnet. The two ends of the permanent magnet are flush with the outer end face of the electromagnetic coil, or are protruding relative to the electromagnetic coil, and are symmetrically distributed along the xy plane. The optimized design method for the structure of the hybrid magnetic field generator includes the following steps: (1) The optimization variables for this hybrid magnetic field generator include: the radius of the cylindrical permanent magnet is... The height is The distance between the outer end face of the electromagnetic coil on either side and the end face of the adjacent permanent magnet is... The distance between the inner end face of the electromagnetic coil and the end face of the same permanent magnet is The width of the electromagnetic coil is ; (2) Define the distance between the surface of the device and the working area when the hybrid magnetic field generator is working as . z The hybrid magnetic field generator is located at a distance of z The optimization objective is to generate the magnetic field with the largest amplitude at a given location. (3) The mass of the hybrid magnetic field generator As a constraint, where, ;in, Density of permanent magnets The conductor density of the electromagnetic coil, D CS The thickness of the coil frame reserved between the permanent magnet and the electromagnetic coil; (4) The electromagnetic magnetic field in the hybrid magnetic field generator B EM magnetic field of permanent magnet B PM It has the ability to adjust, and constrains it to Furthermore, the magnetic field along the axis of the cylindrical permanent magnet is represented as: The two electromagnetic coils symmetrically and separately arranged on the surface of the cylindrical permanent magnet are two hollow cylindrical coils with equal radius and thickness, and their heights are 2 ( H m -H em1 ), 2 ( H m -H em2 The magnetic field on the circumference of the electromagnetic coil can be obtained by subtracting the magnetic fields generated by the two hollow cylindrical coils, i.e. ;in, in, M The remanent magnetization of the permanent magnet. J For coil current density, μ 0 represents the free permeability; therefore, the total magnetic field along the axis of this hybrid magnetic field generator is expressed as: in, B total This represents the total magnetic field along the axis of the hybrid magnetic field generator. B PMz Indicates the distance from the work area as z The magnetic field of the cylindrical permanent magnet at that location. B EMz Indicates the distance from the work area as z The magnetic field generated by the electromagnetic coil at that location; (5) Based on the above design goals and constraints, the genetic algorithm is used to perform global optimization on the optimization variables to obtain the specific structural parameters of the hybrid magnetic field generator.

2. The hybrid magnetic field generating device as described in claim 1, characterized in that, It includes a permanent magnet (1-1), an electromagnetic coil (1-2), and a fixing component (1-3). The permanent magnet is embedded in the electromagnetic coil and fixed by the fixing component. The fixing component serves as the frame of the electromagnetic coil and is used to prevent the electromagnetic coil from deforming and damaging the permanent magnet.

3. An interventional surgical robot system with electromagnetic permanent magnet coordinated control, characterized in that, It includes a magnetic field control device (1), a magnetic guide wire (3), a guide wire drive device (4), and a remote control device (5), wherein: The magnetic field control device (1) includes a robotic arm (1-4) and a hybrid magnetic field generating device as described in claim 1 or 2. The robotic arm (1-4) is used to drive and rotate the hybrid magnetic field generating device, thereby changing the direction and angle of the magnetic field. The magnetic guide wire (3) is an interventional guide wire with a magnetic head. The magnetic guide wire is used to deflect under the action of the magnetic field generated by the hybrid magnetic field generator and to move forward or backward in a preset direction under the drive of the guide wire driving device (4). The remote control device (5) is used to adjust the position and angle of the end space of the robotic arm, adjust the distance by which the guide wire drive device drives the magnetic guide wire forward or backward, and adjust the magnitude and direction of the current of the electromagnetic coil.

4. The robot system as described in claim 3, characterized in that, The magnetic wire is a radially magnetized magnetic wire. The magnetization method is as follows: the prepared magnetic wire is vertically fixed at the center of the magnetizing coil, and under the action of the pulsed magnetic field, the magnetic wire is radially magnetized.

5. The robot system as described in claim 3, characterized in that, The magnetic head is made of a mixture of ferromagnetic powder and elastomer, and the interventional guidewire is a straight guidewire.

6. The robot system as described in claim 3, characterized in that, The magnetic wire guide drive device includes a stepper motor (4-1), a worm gear (4-2), a turbine (4-3), a turbine fixed shaft (4-4), a driving gear (4-5), a driven gear (4-6), a wire feeding gear (4-7), a guide wheel (4-8), a spring (4-9), a guide wheel fixed shaft (4-10), a guide rail (4-11), a side base plate (4-12), a guide tube (4-13), and a needle (4-14). During operation, the stepper motor (4-1) drives the worm gear (4-2), transferring kinetic energy to the turbine (4-3); one end of the turbine fixed shaft (4-4) fixes the turbine (4-3), and the other end fixes the driving gear (4-5); the driving gear (4-5) drives the driven gear (4-6) to rotate; the driven gear (4-6) is coaxial with the wire feeding gear (4-7), so that when the driven gear (4-6) rotates, the wire feeding gear (4-7) and the driven gear (4-6) rotate simultaneously and in the same direction; the two wire feeding gears (4-7) are located on both sides of the bottom of the guide wheel (4-8), and the guide wheel (4-8) is supported by a spring. The tension of (4-9) presses down on the magnetic guide wire and the wire feeding gear (4-7); the guide wheel (4-8) is fixed on the guide wheel fixing shaft (4-10), and the guide wheel fixing shaft (4-10) is fixed on the guide slide rail (4-11); one end of the spring (4-9) is fixedly connected to the guide slide rail (4-11), and the other end is fixed on the side base plate (4-12); the magnetic guide wire passes through the guide tube (4-13) and the needle (4-14), and under the electric drive of the stepper motor (4-1), it is transmitted forward by the friction force generated by the wire feeding gear (4-7) and the guide wheel (4-8) pressing the magnetic guide wire.

7. The robot system as described in claim 6, characterized in that, The top of the guide slide rail (4-11) is also provided with a precision adjusting thread pair (4-15), which is used to adjust the force of the guide slide rail (4-11) and further press the wire feeding gear (4-7) downward on the guide wheel fixing shaft (4-10) and the guide wheel (4-8) as needed, so as to adapt to the transmission requirements of guide wires of different diameters.

8. The control method for the robot system according to any one of claims 3 to 7, characterized in that, Includes the following steps: S1: By controlling the device remotely, the robotic arm moves and rotates the hybrid magnetic field generator, placing the magnetic field generator near the direction the magnetic guide wire head is to be deflected, so that the magnetic guide wire head is attracted or repelled to the preset direction under the combined action of magnetic torque and gradient force. S2: By adjusting the distance between the surface of the hybrid magnetic field generator and the head of the magnetic guide wire, the direction and amplitude of the driving magnetic field strength are "coarsely adjusted", thereby controlling the head of the magnetic guide wire to deflect in the preset direction; S3: Fix the position and angle of the mixed magnetic field generator, and fine-tune the driving magnetic field strength by controlling the input current of the electromagnetic coil, thereby adjusting the alignment of the magnetic guide wire head with the preset direction; S4: The magnetic guide wire is advanced in a preset direction by controlling the guide wire driving device.

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