Magnetic-controlled microrobot system and its application

Abstract

This invention provides a magnetically controlled microrobot system and its usage method, relating to the interdisciplinary field of ophthalmic medical devices and magnetically controlled robots. The magnetically controlled microrobot system includes an electromagnetic drive device, a magnetic microrobot, and a control device. The electromagnetic drive device includes a first electromagnetic array and a second electromagnetic array whose magnetic field directions are at an angle. The first and second electromagnetic arrays together form a driving magnetic field that can be controlled in multiple dimensions. The magnetic microrobot includes a magnetic body for responding to the driving magnetic field to perform multi-degree-of-freedom motion and / or posture adjustment. The control device is communicatively connected to the magnetic electromagnetic drive device and is used to control the electromagnetic drive device to generate a target magnetic field to drive the magnetic microrobot to perform the target operation. When used to treat rhegmatogenous retinal detachment, this magnetically controlled microrobot system enables controllable, multi-degree-of-freedom, and precise control of the magnetic microrobot within the limited space inside the eye.

Description

Technical Field

[0001] This invention relates to the field of interdisciplinary technology of ophthalmic medical devices and magnetically controlled robots, and in particular to a magnetically controlled microrobot system and its usage method. Background Technology

[0002] Rhegmatogenous retinal detachment (RRD) refers to the separation of the retinal neuroepithelium from the underlying retinal pigment epithelium (RPE) in the presence of a full-thickness retinal tear. The pathogenesis of RRD is complex, primarily involving the structure of the vitreous humor, the state of the vitreous-retinal interface, and age-related changes. Persistent vitreoretinal adhesions can lead to traction on the retina, further resulting in a retinal tear. Fluid seeps in through these tears, causing the retinal neuroepithelium to separate from the retinal pigment epithelium. The incidence of RRD varies across countries. For example, a Swedish study showed an average annual incidence of 10.6 cases per 100,000 population between 1971 and 1981; while in the Netherlands, the incidence in 2009 was 18.2 cases per 100,000 population. Further research indicates that the incidence of RRD in the Netherlands increased by 44% between 2009 and 2016, reaching 26.2 cases per 100,000 population. Risk factors for recurrent cataracts (RD) include age, male sex, history of cataract surgery, and myopia.

[0003] Scleral buckling (SB), pars plana vitrectomy (PPV), and pneumatic retinopexy (PR) are the main existing treatments for rhegmatogenous retinal detachment (RRD). Regardless of the treatment method used, the key to success lies in effectively closing the retinal tear and relieving vitreous traction.

[0004] Scleral buckling (SB) surgery primarily involves placing implants such as scleral buckles or scleral bands on the outer surface of the eyeball to compress or band the sclera, thereby indirectly altering the shape of the eyeball and causing the eye wall to concave inward to counteract the traction of the vitreous humor on the retina. Its success depends on the different materials and sizes of scleral buckle / scleral band elements, sutures and matching suturing instruments for fixing the buckles, and surgical tools for positioning and tension adjustment. Common complications include refractive changes, movement disorders, vitreous or retinal incarceration, suprachoroidal or subretinal hemorrhage, and migration of the buckling element. Among these, refractive changes are the most significant complication, usually caused by changes in axial length resulting from the banding procedure. A large retrospective study of 1477 patients with retinal detachment who underwent SB surgery showed that the average refractive error shift in phakic eyes was 1.7 D, while the average refractive error shift in aphakic eyes was 0.91 D.

[0005] PPV (Procedure for Vitreous Vulning) involves inserting a vitrectomy probe, fiber optic illumination, and infusion tubing into the eye through a small incision in the sclera. High-frequency cutting and negative pressure suction are used to remove the vitreous humor, relieving traction. This can be combined with intraocular laser and cryotherapy to treat related areas. The procedure relies on a vitrectomy machine, a cutting probe (with a negative pressure suction system), an intraocular irrigation and pressure control system, and intraocular illumination and imaging aids. Vitreous traction is relieved by directly cutting the vitreous humor, and postoperative intraocular packing is necessary. The main complication of PPV is cataract development; more than one-third of patients may experience retinal damage during surgery, and the incidence of postoperative nuclear cataracts is increased.

[0006] Pneumatic retinostomy (PR) typically involves injecting a small amount of inert gas into the eye, causing the gas bubble to press against the retina from above, thus adhering it to the underlying tissues. This is then reinforced with photocoagulation or cryotherapy. While it causes relatively little intraocular disturbance, its indications are narrower, applicable only to fresh, concentrated retinal tears and detachments located superiorly. Therefore, the initial retinal reattachment rate of PR is lower than that of septal retinostomy (SB) and prophylactic retinal detachment (PPV).

[0007] Regardless of the surgical procedure used, the use of intraocular gas packs carries the risk of postoperative intraocular pressure elevation. 100% SF6 gas expands approximately twice its original size within 1-2 days, while 100% C3F8 gas expands approximately four times its original size within 3-4 days. The absorption time for 20% SF6 gas is approximately 2 weeks, while the absorption time for 14% C3F8 gas is approximately 8 weeks.

[0008] In summary, the existing main methods for treating rhegmatogenous retinal detachment (RRD) have the following shortcomings in terms of equipment and devices: Implants such as scleral buckles or scleral buckles placed on the outer surface of the eyeball indirectly affect the retina by altering the overall shape of the eyeball, but lack finely adjustable mechanical control, easily causing axial elongation, refractive changes, and limited eye movement; vitrectomy systems mostly rely on extensive vitrectomy and passive packing materials such as silicone oil / gas for support and repositioning, making it difficult to perform high-precision, minimally invasive operations in localized areas, and increasing risks such as cataract progression, increased intraocular pressure, and dependence on patient positioning; gas retinal fixation devices have relatively crude control over the morphology and range of action of intraocular bubbles, resulting in limited initial repositioning rates and the risk of new retinal tears.

[0009] Therefore, how to design a device for treating rhegmatogenous retinal detachment that can achieve effective treatment without prolonging the patient's axial length, reducing interference with the inside of the eyeball, and preserving the patient's healthy vitreous fluid to the greatest extent has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0010] To address the technical problems of existing devices for treating rhegmatogenous retinal detachment, which prolong the axial length of the patient's eye, cause significant interference with the internal structure of the eye, and require extensive removal of healthy vitreous fluid, this invention provides a magnetically controlled microrobot system and its method of use.

[0011] A magnetically controlled microrobot system, comprising: An electromagnetic drive device includes a first electromagnetic array and a second electromagnetic array, wherein the magnetic field directions of the first electromagnetic array and the second electromagnetic array are at an angle; the first electromagnetic array and the second electromagnetic array together form a drive magnetic field that can be controlled in multiple dimensions. A magnetic microrobot, comprising a magnetic body, is used to perform multi-degree-of-freedom motion and / or attitude adjustment in response to the driving magnetic field; A control device, which is communicatively connected to the electromagnetic drive device, is used to control the electromagnetic drive device to generate a target magnetic field so as to drive the magnetic microrobot to perform the target operation.

[0012] Furthermore, the magnetic body has a spherical structure and its surface is covered with a biocompatible coating.

[0013] Furthermore, the magnetic body is made of neodymium iron boron permanent magnet material; And / or, the diameter of the magnetic body is 1±0.2 mm, and the surface roughness Ra<0.2 μm; And / or, the biocompatible coating is made of medical-grade parylene with a thickness of 5-10 μm.

[0014] Furthermore, the driving magnetic field includes: A rotating magnetic field is used to drive the magnetic microrobot to perform rolling motion; A gradient magnetic field is used to drive the magnetic microrobot to perform translational motion.

[0015] Furthermore, the first electromagnetic array and the second electromagnetic array are arranged in layers, and each includes multiple coils arranged at intervals; The electromagnetic drive device also includes a multi-channel current control module, which is connected to each of the coils respectively, for independently adjusting the magnitude and direction of the current in each coil, so as to form the target magnetic field with arbitrary direction and magnitude through the combination of the currents of multiple coils.

[0016] Furthermore, the first electromagnetic array includes two first coils and two second coils; the two first coils are arranged opposite each other along a first direction, and the two second coils are arranged opposite each other along a second direction, with the first direction being perpendicular to the second direction; The second electromagnetic array includes four third coils, which are located between adjacent first and second coils, and the axis of each third coil forms a 45° angle with the axes of the first and second coils.

[0017] Furthermore, each of the coils is provided with an iron core inside; And / or, each of the coils is wound on a coil frame, the coil frame comprising an inner coil and an outer coil; And / or, each of the coils is made of copper wire with a diameter of 0.6 mm, and a layer of thermally conductive silicone grease is applied to its outer surface every 60-70 turns during the winding process.

[0018] Furthermore, the electromagnetic drive device also includes; Base; Four horizontal coil support bases are arranged at circumferential intervals along the base, and each horizontal coil support base is provided with a first mounting hole for mounting the first coil or the second coil; Four inclined coil support bases are respectively disposed between two adjacent horizontal coil support bases, and each inclined coil support base is provided with a second mounting hole for mounting the third coil.

[0019] Furthermore, the number of the magnetic microrobots is at least two; At least two of the magnetic microrobots are interconnected under the control of the electromagnetic drive device to form a chain-like structure or a ring-like structure.

[0020] On the other hand, the present invention also provides a method of using a magnetically controlled microrobot system, comprising the following steps: Place the magnetic microrobot into the work area; The electromagnetic drive device generates a controlled magnetic field according to control commands to drive the magnetic microrobot to perform target operations; After all the target operations are completed, the magnetic microrobot is removed from the work area.

[0021] Compared with the prior art, the magnetically controlled microrobot system provided in this embodiment of the invention has at least the following technical effects: The magnetically controlled microrobot system includes an electromagnetic drive device, a magnetic microrobot, and a control device. The electromagnetic drive device comprises a first electromagnetic array and a second electromagnetic array, wherein the magnetic field directions of the first and second electromagnetic arrays are at an angle. The first and second electromagnetic arrays together form a driving magnetic field that can be controlled in multiple dimensions. The magnetic microrobot includes a magnetic body for responding to the driving magnetic field to perform multi-degree-of-freedom motion and / or posture adjustment. The control device is communicatively connected to the magnetic electromagnetic drive device and is used to control the electromagnetic drive device to generate a target magnetic field to drive the magnetic microrobot to perform the target operation. When used to treat rhegmatogenous retinal detachment, this magnetically controlled microrobot system enables controllable, multi-degree-of-freedom, and precise manipulation of the magnetic microrobot within the limited space inside the eye, effectively avoiding the risks of axial elongation and refractive changes associated with traditional procedures such as placing scleral buckles or scleral braces on the outer surface of the eyeball. Meanwhile, when the magnetic microrobot moves and performs target operations within the vitreous cavity of the eye, it does not require the use of a vitrectomy system to remove large areas of vitreous tissue, nor does it require the implantation of silicone oil or gas to pack the eye. This reduces adverse effects such as glaucoma, corneal degeneration, and increased intraocular pressure caused by packing materials, minimizes interference with the internal environment of the eye, and preserves as much healthy vitreous fluid as possible for the patient. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a three-dimensional structural diagram of an electromagnetic drive device according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a magnetic microrobot in one embodiment of the present invention; Figure 3 This is a top view of the electromagnetic drive device in one embodiment of the present invention; Figure 4This is a schematic diagram of the assembly structure of the electromagnetic drive device in one embodiment of the present invention; Figure 5 This is a schematic diagram of the control flow of a magnetically controlled microrobot system in one embodiment of the present invention; Figure 6 This is a schematic diagram of the coil frame structure in one embodiment of the present invention; Figure 7 This is a schematic diagram of the base structure in one embodiment of the present invention; Figure 8 This is a schematic diagram of the usage method of a magnetically controlled microrobot system in one embodiment of the present invention; Figure 9 This is a schematic diagram of multiple magnetic microrobots assembled into a chain-like structure in one embodiment of the present invention; Figure 10 This is a schematic diagram of multiple magnetic microrobots assembled into a ring structure in one embodiment of the present invention.

[0024] Possession Mark: 10. Electromagnetic drive device; 11. First electromagnetic array; 111. First coil; 112. Second coil; 12. Second electromagnetic array; 121. Third coil; 13. Iron core; 14. Coil frame; 15. Base; 16. Horizontal coil support; 161. First mounting hole; 17. Inclined coil support; 171. Second mounting hole; 20. Magnetic microrobot; 21. Magnetic body; 22. Biocompatible coating. Detailed Implementation

[0025] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly set on the other component; when a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to the other component.

[0027] Please refer to the attached document. Figures 1 to 4As shown, an embodiment of the present invention provides a magnetically controlled microrobot system, including an electromagnetic drive device 10, a magnetic microrobot 20, and a control device. The electromagnetic drive device 10 includes a first electromagnetic array 11 and a second electromagnetic array 12; wherein the magnetic field directions of the first electromagnetic array 11 and the second electromagnetic array 12 are at an angle; the first electromagnetic array 11 and the second electromagnetic array 12 together form a driving magnetic field that can be controlled in multiple dimensions; the magnetic microrobot 20 includes a magnetic body 21, used to respond to the driving magnetic field to perform multi-degree-of-freedom motion and / or posture adjustment; the control device is communicatively connected to the magnetic electromagnetic drive device 10, used to control the electromagnetic drive device 10 to generate a target magnetic field to drive the magnetic microrobot 20 to perform target operations. It should be further noted that the magnetically controlled microrobot system can be used to treat rhegmatogenous retinal detachment. Specifically, the electromagnetic drive device 10 is located above the eye, and the magnetic microrobot 20 is placed inside the vitreous cavity of the eyeball. Under the action of the driving magnetic field, the magnetic microrobot 20 can perform multi-degree-of-freedom motion and / or posture adjustment within the vitreous cavity of the eyeball to perform intraocular target operations.

[0028] In this embodiment, the magnetically controlled microrobot system includes an electromagnetic drive device 10, a magnetic microrobot 20, and a control device. The electromagnetic drive device 10 includes a first electromagnetic array 11 and a second electromagnetic array 12, wherein the magnetic field directions of the first electromagnetic array 11 and the second electromagnetic array 12 are at an angle. The first electromagnetic array 11 and the second electromagnetic array 12 together form a driving magnetic field that can be controlled in multiple dimensions. The magnetic microrobot 20 includes a magnetic body 21, which is used to respond to the driving magnetic field to perform multi-degree-of-freedom motion and / or posture adjustment. The control device is communicatively connected to the magnetic electromagnetic drive device 10 and is used to control the electromagnetic drive device 10 to generate a target magnetic field to drive the magnetic microrobot 20 to perform the target operation. When this magnetically controlled microrobot system is used to treat rhegmatogenous retinal detachment, it can achieve controllable, multi-degree-of-freedom, and precise manipulation of the magnetic microrobot 20 in the limited space inside the eye, effectively avoiding the risks of axial elongation and refractive changes caused by traditional operations such as placing scleral buckles or scleral buckles on the outer surface of the eyeball. Meanwhile, when the magnetic microrobot 20 moves and performs target operations within the vitreous cavity of the eye, it does not require the use of a vitrectomy system to remove large areas of vitreous tissue, nor does it require the implantation of silicone oil or gas into the eye for packing. This reduces adverse effects such as glaucoma, corneal degeneration, and increased intraocular pressure caused by packing materials, reduces interference with the internal environment of the eye, and preserves as much healthy vitreous fluid as possible for the patient.

[0029] In some optional embodiments, the magnetic body 21 has a spherical structure and its surface is coated with a biocompatible coating 22. The biocompatible coating 22 enables the magnetic microrobot 20 to have good biocompatibility, meeting the safety requirements for intraocular implantation. The spherical structure makes the magnetic microrobot 20 experience more uniform force in the driving magnetic field, avoiding motion instability caused by posture changes.

[0030] In some optional embodiments, the magnetic body 21 is made of neodymium iron boron permanent magnet material, specifically N35H grade neodymium iron boron permanent magnet alloy. This material has a high remanent magnetic induction intensity (approximately 1.21–1.25 T) at room temperature, a coercivity greater than 900 kA / m, and a maximum magnetic energy product of 263–279 kJ / m³. The high remanent magnetic induction intensity allows the magnetic microrobot 20 to generate sufficient magnetic torque response even in a relatively weak driving magnetic field.

[0031] It should be further noted that, after precision machining and surface treatment, the diameter of the magnetic body 21 can be controlled within 1 ± 0.2 mm, and the surface roughness is controlled within Ra < 0.2 μm. The diameter of the magnetic body 21, set at 1 ± 0.2 mm, ensures sufficient magnetic field response sensitivity while allowing free movement within the vitreous cavity without causing tissue damage. The surface roughness Ra < 0.2 μm of the magnetic body 21 makes its surface structure more uniform, reducing the risk of local dissolution and cracking of the magnetic microrobot 20 after a period of use, thus improving the structural integrity and service life of the magnetic microrobot 20.

[0032] Furthermore, the biocompatible coating 22 is made of medical-grade parylene C with a thickness of 5-10 μm. Parylene possesses excellent biocompatibility, chemical stability, and mechanical strength, and has been widely used in the surface modification treatment of various implantable medical devices. In a specific embodiment, the magnetic dipole moment direction of the magnetic body 21 is set along the north and south pole axes. In the driving magnetic field, the magnetic dipoles are subjected to magnetic torque and tend to align parallel to the driving magnetic field direction. By controlling the direction of the driving magnetic field, the posture of the magnetic microrobot 20 can be precisely controlled. The symmetry of the spherical structure ensures that the magnetic dipole moment direction of the magnetic microrobot 20 remains relatively stable during rolling, without posture jitter, thus guaranteeing the accuracy and stability of motion control.

[0033] In some optional embodiments, the first electromagnetic array 11 and the second electromagnetic array 12 are arranged in layers and each includes multiple coils spaced apart, with the multiple coils arranged in a three-dimensional, intersecting spatial distribution. The electromagnetic drive device 10 also includes a multi-channel current control module. The multi-channel current control module is connected to each coil and is used to independently control the magnitude and direction of the current in each coil, so as to form a target magnetic field with arbitrary direction and magnitude through the combination of currents from multiple coils, enabling the magnetic microrobot 20 to achieve precise and multi-degree-of-freedom motion control within the vitreous cavity of the eye.

[0034] It should be further explained that the driving magnetic fields generated by the first electromagnetic array 11 and the second electromagnetic array 12 include a rotating magnetic field and a gradient magnetic field. The rotating magnetic field is used to drive the magnetic microrobot 20 to roll. The rolling speed of the magnetic microrobot 20 can be controlled by changing the frequency and intensity of the rotating magnetic field, and the forward or reverse rolling of the magnetic microrobot 20 can be controlled by changing the rotation direction of the rotating magnetic field. The gradient magnetic field is used to drive the magnetic microrobot 20 to translate. The direction and magnitude of the gradient magnetic field determine the net displacement direction and speed of the magnetic microrobot 20. By coordinating the control of the rotating magnetic field and the gradient magnetic field, arbitrary path planning and micron-level precise positioning of the magnetic microrobot 20 can be achieved. When the magnetic microrobot 20 moves to the retinal tear region, maintaining a static magnetic field of appropriate intensity allows the magnetic microrobot 20 to stably adhere to the edge of the tear. At this time, the surface of the magnetic microrobot 20 can be loaded with biological adhesives or retinal pigment epithelial cells, achieving a dual effect of physical sealing and biological repair at the local tear site.

[0035] In some optional embodiments, the control device includes an embedded controller (such as a National Instruments embedded controller) for generating control signals and providing feedback. The electromagnetic drive device 10 also includes a multi-channel current control module. This module consists of multiple programmable independent current sources (e.g., eight programmable independent current sources), each corresponding to a coil. Each programmable independent current source has an output current range of -5A to +5A, a current resolution of 10mA, and a response time of less than 100μs. By precisely controlling the current combinations of multiple coils through these multiple programmable independent current sources, continuously adjustable rotating magnetic fields and gradient magnetic fields can be generated.

[0036] Furthermore, the magnetically controlled microrobot system also includes a host computer, such as a human-machine interface (HMI) module. The HMI module is a laptop computer with LabVIEW installed, used for generating and issuing HMI commands and visualizing data. An embedded controller communicates with the HMI module to receive motion commands and generate corresponding control signals. The output of the embedded controller is connected to a power amplifier, and the output of the power amplifier is connected to the electromagnetic drive device 10. In addition, the electromagnetic drive device 10 uses a top camera to collect the position and attitude information of the magnetic microrobot 20 in real time and feeds it back to the host computer, forming a closed-loop control system.

[0037] Please see the appendix Figure 5 As shown, the control flow of the magnetically controlled microrobot system is as follows: First, the system is initialized, and the magnetic microrobot 20 to be controlled is prepared. Then, multiple coils in the electromagnetic drive device 10 are electrically connected to the output of the multi-channel current control module, and the embedded controller is connected to the input of the multi-channel current control module via a power amplifier. Next, the top camera is turned on and the imaging field of view is adjusted to initially position the magnetic microrobot 20. Then, the operator selects or sets the target point position in the human-machine interface module and moves the electromagnetic drive device 10 using a handheld device or motion mechanism (such as a robotic arm) to position the magnetic microrobot 20 in a suitable initial position. After the position is adjusted, the operator issues control commands to the embedded controller through the human-machine interface module and starts the control program. The embedded controller generates corresponding control signals based on preset parameters and commands from the human-machine interface module and outputs them to the multi-channel current control module. To prevent the coils from burning out due to excessive current, the embedded controller monitors the output current of each programmable independent current source during the control process. Simultaneously, based on the magnetic response characteristics of the magnetic microrobot 20, the frequency range of the background magnetic field is constrained to prevent the background magnetic field frequency from exceeding the response cutoff frequency of the magnetic microrobot 20. Depending on the specific application requirements, the operator can select to generate a rotating magnetic field or a gradient magnetic field in the human-machine interface module. The embedded controller calculates the direction, magnitude, and time-varying pattern of the target magnetic field based on the control commands and the position of the magnetic microrobot 20, and decomposes it into current combinations corresponding to multiple coils, generating multiple specific control signals. These signals are amplified by a power amplifier and then input to multiple coils in the electromagnetic drive device 10. The multiple coils work together to generate a dynamic background magnetic field along a specific spatial direction, thereby driving the magnetic microrobot 20 to move.

[0038] In some embodiments, the operator can also adjust the target magnetic field in real time via a handle input device connected to the human-machine interface module. As the handle commands change, the current combinations output by the embedded controller change, enabling the magnetic microrobot 20 to achieve precise, micrometer-level controllable motion. If necessary, the operator can again adjust the position of the electromagnetic drive device 10 via a handheld device or a robotic arm, and adjust the control signal with the handle to change the magnetic field direction, thereby achieving precise control over the rolling direction, trajectory, and path tracking of the magnetic microrobot 20.

[0039] It should be further explained that the first electromagnetic array 11 includes two first coils 111 and two second coils 112. The two first coils 111 are arranged opposite each other along a first direction, and the two second coils 112 are arranged opposite each other along a second direction perpendicular to the first direction. The second electromagnetic array 12 includes four third coils 121, which are respectively located between adjacent first coils 111 and second coils 112, and the axis of each third coil 121 forms a 45° angle with the axes of the first coil 111 and the second coil 112. In this embodiment, the first direction is defined as the X-axis direction, and the second direction is defined as the Y-axis direction. Both the first coils 111 and the second coils 112 can be Helmholtz coils, wherein the two first coils 111 are coaxial and center-aligned, and the two second coils 112 are also coaxial and center-aligned. The two first coils 111, the two second coils 112, and the four third coils 121 together constitute an eight-coil electromagnetic array configuration. By adjusting the magnitude and direction of the current in each coil, the magnetic field vectors generated by the eight coils in the workspace are superimposed, thereby synthesizing a target magnetic field of arbitrary direction and magnitude.

[0040] In some alternative embodiments, each coil has an iron core 13 inside. The iron core 13 can be a silicon steel core 13 with a diameter of 10 mm. By providing an iron core 13 inside the coil, the magnetic field strength and inductance of the coil can be increased, resulting in a stronger magnetic field output under the same current, thereby enhancing the driving force on the magnetic microrobot 20.

[0041] It is worth noting that each coil (via a winder) is wound on coil bobbin 14, and thermal grease can be filled between each layer of the coil. Please refer to the appendix. Figure 6As shown, the coil frame 14 includes an inner coil and an outer coil, which is used to concentrate the electromagnetic field and increase the magnetic field strength in the working space. A limiting hole is formed in the center of the coil frame 14, the diameter of which can be, but is not limited to, 13 mm, for fixing the iron core 13. Exemplarily, each coil is wound with copper wire of 0.6 mm diameter, and a layer of thermally conductive silicone grease is applied to its outer surface every 60-70 turns during the winding process. The thermal conductivity of the silicone grease is 5.0. Applying thermally conductive silicone grease increases the thermal conductivity of the coil, allowing the heat generated by the inner copper wire to be quickly conducted to the outer layer through the silicone grease, and then cooled by air cooling, preventing the coil from overheating and causing performance degradation or damage.

[0042] In some alternative embodiments, please refer to the appendix. Figure 7 As shown, the electromagnetic drive device 10 also includes a base 15, four horizontal coil support seats 16, and four inclined coil support seats 17. The base 15 is used to support the first electromagnetic array 11 and the second electromagnetic array 12. The four horizontal coil support seats 16 are arranged circumferentially around the base 15, and each horizontal coil support seat 16 is provided with a first mounting hole 161 for mounting the first coil 111 or the second coil 112; the four inclined coil support seats 17 are respectively arranged between two adjacent horizontal coil support seats 16, and each inclined coil support seat 17 is provided with a second mounting hole 171 for mounting the third coil 121. During the coil installation process, the corresponding iron core 13 is first inserted into the limiting hole in the center of the coil frame 14 for positioning, and then the iron core 13 together with the coil frame 14 is fixed to the horizontal coil support seat 16 or the inclined coil support seat 17. Preferably, the iron core 13 is fixed to the corresponding horizontal coil support seat 16 or the inclined coil support seat 17 by a two-component epoxy resin adhesive.

[0043] In some optional embodiments, the number of magnetic microrobots 20 is at least two. The at least two magnetic microrobots 20 are interconnected to form a chain-like structure or a ring-like structure. The chain-like structure can effectively expel subretinal fluid through a tapping motion, creating conditions for closure of the retinal tear. The ring-like structure can precisely adhere to the edge of the retinal tear, achieving closure of the retinal tear.

[0044] Based on the above magnetically controlled microrobot system, please refer to the appendix. Figure 8 As shown, the present invention also provides a method for using a magnetically controlled microrobot system, comprising the following steps: S1: Place the magnetic microrobot into the working area; for example, place the magnetic microrobot into the vitreous cavity of the eyeball, specifically by injecting the pre-prepared magnetic microrobot into the vitreous cavity of the eyeball through an injection needle, and the magnetic microrobot is stably suspended in the vitreous fluid.

[0045] S2: The electromagnetic drive device generates a controlled magnetic field according to control commands to drive the magnetic microrobot to perform a target operation; for example, the electromagnetic drive device generates a controlled magnetic field according to control commands to drive the magnetic microrobot to move to the retinal tear region. The target operation includes assembling multiple magnetic microrobots into a chain structure to drain subretinal fluid; or assembling multiple magnetic microrobots into a ring structure to close the tear.

[0046] S3: After completing all target operations, remove the magnetic microrobot from the work area. For example, remove the magnetic microrobot from the vitreous cavity of the eye. Specifically, guide the magnetic microrobot to a safe location via control commands, and then remove it from the eye through the irrigation port of the vitrectomy procedure or a specialized suction device.

[0047] To demonstrate the feasibility of implanting the magnetically controlled microrobot system of this invention in the intraocular environment and its motion control performance, the magnetically controlled microrobot system and its usage method of this invention are applied to intraocular implantation and motion control experiments for verification, as detailed below: First, an incision was made through the pars plana of the ciliary body, and a 1 mm diameter magnetic microrobot was implanted into the vitreous cavity of a pig's eye. Observation using a lighting device (such as a chandelier) revealed that the magnetic microrobot could not move within the eye. Subsequently, after partially removing the vitreous body using a vitrectomy device, the magnetically controlled microrobot system was activated, generating a controllable driving magnetic field within the vitreous cavity via an electromagnetic drive device. Observations showed that after partial vitreous removal, the 1 mm diameter magnetic microrobot could move flexibly within the eye under the influence of the driving magnetic field.

[0048] In in vitro experiments, a viscoelastic agent was used to simulate a vitreous environment, and a magnetic microrobot with a diameter of 1 mm was placed in the viscoelastic agent. The experiment showed that, under the action of a driving magnetic field, the magnetic microrobot could achieve uniform movement in multiple directions, including left, right, forward, backward, as well as upward and downward movements, at a relatively slow but stable speed.

[0049] In in vivo experiments, after removing part of the vitreous body from the vitreous cavity of a pig's eye, it was observed that a magnetic microrobot with a diameter of 1 mm exhibited flexible and rapid movement in the intraocular environment under the influence of a driving magnetic field.

[0050] To verify the application potential of magnetically controlled microrobot systems in the treatment of rhegmatogenous retinal detachment, a retinal tear was fabricated in a pig eye model, and saline solution was injected under the tear to construct a rhegmatogenous retinal detachment model. Based on this model, seven magnetic microrobots with a diameter of 1 mm were linked end-to-end to form a chain-like robot structure (see appendix). Figure 9As shown in the diagram, after removing part of the vitreous humor using the aforementioned method, the chain-like robot is placed inside the vitreous cavity. Under the influence of a controllable driving magnetic field, the chain-like robot can perform a tapping motion in the vitreous tear region, effectively draining some of the subretinal fluid.

[0051] In further experiments, seven magnetic microrobots with a diameter of 1 mm were used to construct a ring-shaped robot (see appendix). Figure 10 As shown in the image, the ring-shaped robot was placed inside the vitreous cavity of a pig eye containing a retinal tear. Under the influence of a controllable driving magnetic field, the ring-shaped robot was able to close the retinal tear.

[0052] The magnetically controlled microrobot system and its usage method provided by the invention have at least the following technical effects: (1) Reduce surgical invasiveness and risk of complications: There is no need to place scleral buckles or scleral bands on the outer surface of the eyeball, thus avoiding the risks of axial elongation and refractive changes caused by traditional scleral buckling surgery.

[0053] (2) Maximizing the preservation of healthy vitreous structure: Traditional vitrectomy usually requires the removal of a large area or even the entire vitreous, which leads to the destruction of the intraocular mechanical support structure and a decrease in intraocular stability. This invention only cuts part or a minimal area of ​​the vitreous according to the surgical requirements, preserving as much healthy vitreous tissue as possible while meeting the movement space requirements of the magnetic microrobot, maintaining the natural support and buffering environment within the eye, thereby reducing the risk of decreased intraocular stability and long-term complications caused by a large amount of vitreous loss.

[0054] (3) Avoid complications related to intraocular packing: There is no need to implant silicone oil, SF6, C3F8 or other packing materials into the eye, which fundamentally eliminates complications such as glaucoma, corneal degeneration, silicone oil emulsification and acute high intraocular pressure caused by gas expansion caused by silicone oil; at the same time, patients do not need to maintain a strict prone position or other specific body position after surgery, which greatly reduces the burden of postoperative care for patients and improves their postoperative comfort.

[0055] (4) Achieving minimally invasive mechanical retinal repair: This invention uses a driving magnetic field to control multiple magnetic microrobots to assemble into a chain-like or ring-like structure. The chain-like structure can effectively expel subretinal fluid through a tapping motion, while the ring-like structure can precisely adhere to the edge of the retinal tear to achieve tear closure, providing a novel non-packing, non-traction-based retinal repair mechanism. This repair method has been verified to be effective in a pig eye RRD model, with stable repair results and minimal damage to retinal tissue.

[0056] (5) Achieving precise and controllable multi-degree-of-freedom intraocular manipulation: The magnetic microrobot of the present invention is a spherical structure with a diameter of about 1 mm. Combined with the controllable driving magnetic field generated by the eight-coil electromagnetic array, it can achieve flexible, fast, and micron-level precision translation, flipping, path tracking and other multi-degree-of-freedom movements in the vitreous cavity. It can accurately reach the location of retinal tears in any area of ​​the fundus, without being limited by the number, size and location of the tears. It has unique therapeutic advantages for posterior pole tears that are difficult to reach with traditional laser or cryotherapy.

[0057] (6) High biosafety: The magnetic body of the magnetic microrobot is made of medical-grade N35H neodymium iron boron permanent magnet material and coated with a biocompatible parylene coating. It has no sharp edges and will not cause mechanical damage to the fragile retina, vitreous body and other tissues in the eye. Moreover, the magnetic microrobot adopts a wireless magnetic field drive method, which eliminates the need to implant wires or power sources in the eye, avoiding the risks of wire breakage and power leakage, and reducing the probability of intraocular infection. It meets the biosafety requirements of intraocular implantable medical devices.

[0058] (7) High precision and strong stability of magnetic field control: There is an angle between the magnetic field directions of the first electromagnetic array and the second electromagnetic array. With the precise control of the independent programmable current source, a composite magnetic field vector of any direction and size can be generated in the vitreous cavity, realizing multi-degree-of-freedom motion control of the microrobot. The high resolution and fast response characteristics of the current source ensure the precision and real-time performance of magnetic field control, which can effectively counteract the small autonomous movements of the eyeball, enabling the robot to maintain a stable motion state and positioning accuracy in the dynamic intraocular fluid environment.

[0059] (8) Wide range of applications: This invention is not only applicable to minimally invasive treatment of rhegmatogenous retinal detachment, but can also achieve targeted drug delivery and local tissue repair for various fundus diseases such as age-related macular degeneration, glaucoma, and diabetic retinopathy by loading different drugs or biomaterials on the surface of the robot. At the same time, the design concept of this magnetically controlled microrobot system can be extended to the design of medical robots for other small cavities, and has broad clinical application prospects.

[0060] (9) Simple and quick operation: The magnetic field drive module of the present invention is equipped with a graphical human-computer interaction interface based on LabVIEW. The operation interface is intuitive and simple, and ophthalmologists with professional training can master the operation skills in a short time. The intraocular movement and operation of the robot can be observed in real time through a microscope combined with a wide-angle lens. The degree of visualization of the surgical operation is high, which greatly reduces the difficulty of the surgical operation and shortens the operation time.

[0061] The above description is merely an embodiment of the present invention. It should be noted that those skilled in the art can make improvements without departing from the inventive concept of the present invention, but these improvements all fall within the protection scope of the present invention.

Claims

1. A magnetically controlled microrobot system, characterized in that, include: An electromagnetic drive device includes a first electromagnetic array and a second electromagnetic array, wherein the magnetic field directions of the first electromagnetic array and the second electromagnetic array are at an angle; the first electromagnetic array and the second electromagnetic array together form a drive magnetic field that can be controlled in multiple dimensions. A magnetic microrobot, comprising a magnetic body, is used to perform multi-degree-of-freedom motion and / or attitude adjustment in response to the driving magnetic field; A control device, which is communicatively connected to the electromagnetic drive device, is used to control the electromagnetic drive device to generate a target magnetic field so as to drive the magnetic microrobot to perform the target operation.

2. The magnetically controlled microrobot system according to claim 1, characterized in that, The magnetic body has a spherical structure and its surface is covered with a biocompatible coating.

3. The magnetically controlled microrobot system according to claim 2, characterized in that, The magnetic body is made of neodymium iron boron permanent magnet material; And / or, the diameter of the magnetic body is 1±0.2 mm, and the surface roughness Ra<0.2 μm; And / or, the biocompatible coating is made of medical-grade parylene with a thickness of 5-10 μm.

4. The magnetically controlled microrobot system according to claim 1, characterized in that, The driving magnetic field includes: A rotating magnetic field is used to drive the magnetic microrobot to perform rolling motion; A gradient magnetic field is used to drive the magnetic microrobot to perform translational motion.

5. The magnetically controlled microrobot system according to claim 1, characterized in that, The first electromagnetic array and the second electromagnetic array are arranged in layers, and each includes multiple coils arranged at intervals. The electromagnetic drive device also includes a multi-channel current control module, which is connected to each of the coils respectively, for independently adjusting the magnitude and direction of the current in each coil, so as to form the target magnetic field with arbitrary direction and magnitude through the combination of the currents of multiple coils.

6. The magnetically controlled microrobot system according to claim 5, characterized in that, The first electromagnetic array includes two first coils and two second coils; the two first coils are arranged opposite each other along a first direction, and the two second coils are arranged opposite each other along a second direction, with the first direction being perpendicular to the second direction; The second electromagnetic array includes four third coils, which are located between adjacent first and second coils, and the axis of each third coil forms a 45° angle with the axes of the first and second coils.

7. The magnetically controlled microrobot system according to claim 6, characterized in that, Each of the coils has an iron core inside; And / or, each of the coils is wound on a coil frame, the coil frame comprising an inner coil and an outer coil; And / or, each of the coils is made of copper wire with a diameter of 0.6 mm, and a layer of thermally conductive silicone grease is applied to its outer surface every 60-70 turns during the winding process.

8. The magnetically controlled microrobot system according to claim 6, characterized in that, The electromagnetic drive device also includes; Base; Four horizontal coil support bases are arranged at circumferential intervals along the base, and each horizontal coil support base is provided with a first mounting hole for mounting the first coil or the second coil; Four inclined coil support bases are respectively disposed between two adjacent horizontal coil support bases, and each inclined coil support base is provided with a second mounting hole for mounting the third coil.

9. The magnetically controlled microrobot system according to claim 1, characterized in that, The number of the magnetic microrobots is at least two; At least two of the magnetic microrobots are interconnected under the control of the electromagnetic drive device to form a chain-like structure or a ring-like structure.

10. A method of using a magnetically controlled microrobot system, characterized in that, Including the following steps: Place the magnetic microrobot into the work area; The electromagnetic drive device generates a controlled magnetic field according to control commands to drive the magnetic microrobot to perform target operations; After all the target operations are completed, the magnetic microrobot is removed from the work area.

Images