A magnetic micro-nanorobot system for ophthalmic treatment and a control method thereof

Abstract

The application discloses a magnetic control micro-nano robot system for ophthalmic treatment and a control method thereof, comprising a micro robot body, a magnetic field generating device and a control module. The micro robot body comprises a central body and at least one spiral structure containing magnetic material. The central body is provided with a drug storage cavity, and the spiral structure is arranged around the outer peripheral side of the central body, with the first side edge connected to the central body and the second side edge spaced from the central body to form a gap. The gap is in fluid communication with the drug storage cavity. When the micro robot body rotates forward in a first direction, the gap is closed to lock the drug; when the micro robot body rotates backward in a second direction, the gap is opened to expose the drug storage cavity to release the drug. The magnetic field generating device is used for generating a driving magnetic field, and the control module is electrically connected to the magnetic field generating device and controls the magnetic field parameters. The application controls the drug locking and releasing by switching the movement direction. The application solves the technical problem that the existing micro-nano robot cannot release the drug on demand during the intraocular movement.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a magnetically controlled micro / nano robot system and its control method for ophthalmic treatment. Background Technology

[0002] Existing ophthalmic micro- and nanorobots typically only possess motion control capabilities, enabling them to perform basic operations such as movement, turning, and positioning within the vitreous cavity, retinal surface, or other cavities of the eye under the influence of an external magnetic field. These robots have relatively simple structural designs, primarily consisting of a helical or flagellated body made of magnetic material, propelled forward by hydrodynamic forces generated by a rotating magnetic field.

[0003] However, the functions of these traditional robots are limited to physical movement. Their structure lacks a dedicated drug-carrying chamber and a controllable drug release mechanism. Therefore, they cannot carry sufficient therapeutic drugs during movement, nor can they actively release drugs into the target tissue area after reaching the lesion site. Clinically, drug treatment for eye diseases still relies on auxiliary methods such as eye drops and intravitreal injections. The role of micro-nano robots is limited to "movement" rather than "treatment," resulting in insufficient functional completeness. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the present invention aims to provide a magnetically controlled micro-nano robot system and its control method for ophthalmic treatment, so as to solve the technical problem that existing micro-nano robots cannot complete the on-demand drug release during intraocular movement.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A magnetically controlled micro / nanorobotic system for ophthalmic treatment, comprising:

[0007] A microrobot body includes a central body and at least one helical structure, wherein the central body and / or the helical structure contains a magnetic material; the central body has a drug storage cavity; the helical structure is arranged around the outer periphery of the central body, and the helical structure has a first side edge and a second side edge; the first side edge is flexibly connected to the central body so that the helical structure can elastically deform relative to the central body; a gap is formed between the second side edge of the helical structure and the central body, and the gap is in fluid communication with the drug storage cavity; wherein, when the microrobot body rotates forward in a first direction, the helical structure moves towards the central body under the action of fluid resistance, causing the gap to close or narrow; when rotating backward in a second direction, the helical structure unfolds away from the central body under the action of fluid resistance, causing the gap to open to expose the drug storage cavity;

[0008] A magnetic field generating device, which is used to generate a magnetic field to drive the movement of the microrobot body;

[0009] A control module is electrically connected to the magnetic field generator and is used to control the parameters of the magnetic field.

[0010] Furthermore, the outer surface of the spiral structure is provided with a recessed structure and / or a raised structure to reduce the resistance of the microrobot body moving in the fluid.

[0011] Furthermore, there are two spiral structures, which are coiled around the outer periphery of the central body in a centrally symmetrical manner.

[0012] Furthermore, the two ends of the central body are respectively provided with tapered guide structures, and the central axis of the tapered guide structures coincides with the central axis of the central body.

[0013] Furthermore, a temporary sealing layer is provided at the gap; the temporary sealing layer is configured such that: when the microrobot body rotates forward in a first direction, the temporary sealing layer remains intact to assist in sealing the gap; when the microrobot body rotates backward in a second direction, the temporary sealing layer partially or completely dissolves to expose the gap.

[0014] Furthermore, the temporary sealing layer is at least one of gelatin, polylactic acid, chitosan, or poloxamer.

[0015] Furthermore, the magnetic field generating device includes at least one of a triaxial Helmholtz coil or an octagonal electromagnetic coil array.

[0016] Furthermore, the magnetically controlled micro / nanorobot system for ophthalmic treatment includes an imaging module, which is used to acquire the position information of the microrobot body in the eye in real time and feed the position information back to the control module; the imaging module is selected from at least one of optical coherence tomography, ultrasound imaging, or fluorescence imaging.

[0017] A control method for a magnetically controlled micro / nanorobotic system for ophthalmic treatment includes the following steps:

[0018] Step S1: Introduce the drug-loaded microrobot into the target cavity of the eye;

[0019] Step S2: The control module controls the magnetic field generator to generate a magnetic field in the first direction, driving the microrobot body to rotate and move forward in the first direction. At this time, the spiral structure moves towards the central body under the action of fluid resistance, so that the gap is closed or narrowed, and the drug is locked in the drug storage cavity.

[0020] Step S3: The imaging module acquires the position information of the micro-robot body in real time and feeds the position information back to the control module to form a closed-loop control until the micro-robot body reaches the target position;

[0021] Step S4: The control module controls the magnetic field generator to switch to a second-direction rotating magnetic field, driving the microrobot body to rotate backward along the second direction. At this time, the spiral structure unfolds away from the central body under the action of fluid resistance, causing the slit opening to open and expose the drug storage chamber. The drug is released from the slit opening to the target position.

[0022] Step S5: After treatment, the microrobot body is withdrawn by means of a reverse magnetic field or attraction.

[0023] Furthermore, before step S1, a pretreatment step is included: immersing the microrobot body in a temporary sealing material solution, so that the temporary sealing material forms a temporary sealing layer at the gap; in step S2, the temporary sealing layer remains intact to assist in sealing the gap; in step S4, the temporary sealing layer is partially or completely dissolved due to the reverse rotation and backward movement of the microrobot body and / or at least one of the environmental factors of pH value, temperature or enzyme concentration at the target location, to assist in opening the gap.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1. The microrobot body includes a central body and at least one helical structure. The central body is provided with a drug storage cavity. The first side edge of the helical structure is connected to the central body. A gap is formed between the second side edge of the helical structure and the central body. The gap is in fluid communication with the drug storage cavity. The connection between the helical structure and the central body is made of a flexible material to allow the helical structure to undergo reversible deformation under the action of fluid resistance. This realizes the structural integration of the drug storage cavity and the gap, and the basic principle of controllable deformation for drug storage.

[0026] 2. Based on the fact that when the microrobot body rotates forward in the first direction, the spiral structure moves towards the central body under the action of fluid resistance, causing the gap to close or narrow; when rotating backward in the second direction, the spiral structure unfolds away from the central body under the action of fluid resistance, causing the gap to open to expose the drug storage cavity, and a temporary sealing layer is provided at the gap. When moving forward, the temporary sealing layer remains intact to assist in sealing the gap; when moving backward, the temporary sealing layer is partially or completely dissolved under the action of tearing and / or self-degradation to assist in opening the gap. This achieves dual control of the drug release timing by the direction of movement, namely mechanical deformation control and sealing layer material dissolution control.

[0027] 3. Based on the magnetic field generator used to generate a magnetic field that drives the movement of the microrobot body, the control module is electrically connected to the magnetic field generator and used to control the parameters of the magnetic field. By adjusting the direction and intensity of the magnetic field through the control module, the microrobot body is driven to rotate along a first or second direction, achieving wireless and precise control over the robot's motion state, the direction of deformation of the helical structure, the opening and closing of gaps and notches, and the timing of the temporary sealing layer's dissolution. This structural design, through the coordinated operation of the microrobot body, the magnetic field generator, and the control module, achieves controllable movement of the microrobot and on-demand drug release in ophthalmic treatment. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of the microrobot body of a magnetically controlled micro / nanorobot system for ophthalmic treatment according to the present invention.

[0029] Figure 2 for Figure 1 A structural schematic diagram from another perspective is shown;

[0030] Figure 3 for Figure 1 A cross-sectional view of the structural schematic diagram shown;

[0031] Figure 4 This is a schematic diagram of the magnetic field generating device and imaging module.

[0032] In the figure: 1. Microrobot body; 101. Central body; 102. Spiral structure; 103. First side edge; 104. Second side edge; 105. Gap; 107. Drug storage cavity; 108. Recessed structure; 109. Conical guide structure; 2. Magnetic field generating device; 6. Imaging module; 7. Operating position. Detailed Implementation

[0033] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0034] It should be noted that when an element is described as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is described as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementations.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0036] See Figures 1-4 A preferred embodiment of the present invention is described below:

[0037] A magnetically controlled micro / nanorobotic system for ophthalmic treatment includes a microrobot body 1, a magnetic field generating device 2, and a control module. The microrobot body 1 includes a central body 101 and at least one helical structure 102, wherein the central body 101 and / or the helical structure 102 contain magnetic material. The central body 101 has a drug storage cavity 107. The helical structure 102 is disposed around the outer periphery of the central body 101, and the helical structure 102 has a first side edge 103 and a second side edge 104. The first side edge 103 is connected to the central body 101, and a gap is formed between the second side edge 104 of the helical structure 102 and the central body 101. The slit notch 105 is fluidly connected to the drug storage chamber 107. When the microrobot body 1 rotates forward in the first direction, the spiral structure 102 moves towards the central body 101 under the action of fluid resistance, causing the slit notch 105 to close or narrow. When rotating backward in the second direction, the spiral structure 102 unfolds away from the central body 101 under the action of fluid resistance, causing the slit notch 105 to open and expose the drug storage chamber 107. The magnetic field generating device 2 is used to generate a magnetic field that drives the movement of the microrobot body 1. The control module is electrically connected to the magnetic field generating device 2 and is used to control the parameters of the magnetic field.

[0038] This invention controls the deformation direction of the spiral structure 102 by switching the movement direction of the microrobot body 1, so that the gap 105 closes to lock the drug when moving forward and opens to release the drug when moving backward, thus achieving a precise correlation between the drug delivery timing and the robot's movement state.

[0039] In practice, the drug is first injected into the drug storage cavity 107 of the microrobot body 1 using an injection tool. Then, the drug-loaded microrobot body 1 is introduced into the target cavity of the eye (after ocular surface anesthesia, a puncture of less than 1 mm is made through the limbus or pars plana of the ciliary body, and the robot loaded with intraocular pressure-lowering drugs such as travoprost or bimatoprost is introduced into the anterior chamber through the puncture). Then, the control module controls the magnetic field generator 2 to generate a rotating magnetic field in the first direction, driving the microrobot body 1 to rotate forward in the first direction. At this time, the spiral structure 102 moves towards the central body 101 under the action of fluid resistance, the gap 105 closes or narrows, and the drug is locked in the drug storage cavity 107. The imaging module 6 is selected from at least one of optical coherence tomography, ultrasound imaging, or fluorescence imaging. The imaging module 6 acquires the position information of the microrobot body 1 in real time and feeds the position information back to the control module to form a closed-loop control until the microrobot body 1 reaches the target position. Subsequently, the control module switches the magnetic field generator 2 to a second-direction rotating magnetic field, driving the microrobot body 1 to rotate and retreat along the second direction. At this time, the spiral structure 102 unfolds away from the central body 101 under the action of fluid resistance, the slit opening 105 opens, exposing the drug storage cavity 107, and the drug is released from the slit opening 105 to the target location. After treatment, the microrobot body 1 is withdrawn by a reverse magnetic field or suction. Alternatively, before introducing the microrobot body 1 into the target cavity, it can be immersed in a temporary sealing material solution, so that the temporary sealing material forms a temporary sealing layer at the slit opening 105. This helps to seal the slit opening 105 during the forward movement and partially or completely dissolves during the backward movement due to at least one of the following environmental factors: reverse rotation and backward movement, pH value, temperature, or enzyme concentration at the target location, thus helping the slit opening 105 to open.

[0040] The microrobot body 1 includes a central body 101 and at least one helical structure 102, wherein the central body 101 and / or the helical structure 102 contain magnetic materials. The central body 101 has a drug storage cavity 107 for containing a drug to be delivered. The helical structure 102 is arranged around the outer periphery of the central body 101, and has a first side edge 103 and a second side edge 104. The first side edge 103 is connected to the central body 101, and a gap 105 is formed between the second side edge 104 of the helical structure 102 and the central body 101, the gap 105 being in fluid communication with the drug storage cavity 107. The connection between the helical structure 102 and the central body 101 may also be made of a flexible material, allowing the helical structure 102 to undergo reversible deformation under stress. A temporary sealing layer may also be provided at the gap 105, which may be made of at least one material selected from gelatin, polylactic acid, chitosan, or poloxamer, to assist in sealing the gap 105 before the robot reaches the target position. The magnetic field generator 2 is used to generate a magnetic field that drives the movement of the microrobot body 1. The control module is electrically connected to the magnetic field generator 2 and is used to control the parameters of the magnetic field.

[0041] It is understood that the microrobot body 1 includes a central body 101 and at least one helical structure 102. The central body 101 is provided with a drug storage cavity 107. The first side edge 103 of the helical structure 102 is connected to the central body 101. A gap 105 is formed between the second side edge 104 of the helical structure 102 and the central body 101. The gap 105 is in fluid communication with the drug storage cavity 107. The connection between the helical structure 102 and the central body 101 is made of a flexible material to allow the helical structure 102 to undergo reversible deformation under the action of fluid resistance. This realizes the structural integration of the drug storage cavity 107 and the gap 105 and the basic basis for controllable deformation of drug storage. When the microrobot body 1 rotates forward in the first direction, the spiral structure 102 moves towards the central body 101 under the action of fluid resistance, causing the gap 105 to close or narrow; when rotating backward in the second direction, the spiral structure 102 unfolds away from the central body 101 under the action of fluid resistance, causing the gap 105 to open to expose the drug storage cavity 107, and a temporary sealing layer is provided at the gap 105. When moving forward, the temporary sealing layer remains intact to help seal the gap 105; when moving backward, the temporary sealing layer is partially or completely dissolved under the action of tearing and / or self-degradation to help the gap 105 open, thus realizing dual control of the drug release timing by the direction of movement, namely mechanical deformation control and sealing layer material dissolution control. The magnetic field generator 2 generates a magnetic field to drive the movement of the microrobot body 1. The control module is electrically connected to the magnetic field generator 2 and controls the parameters of the magnetic field. By adjusting the direction and intensity of the magnetic field, the control module drives the microrobot body 1 to rotate along a first or second direction, achieving wireless and precise control over the robot's motion state, the deformation direction of the helical structure 102, the opening and closing of the gap 105, and the timing of the temporary sealing layer's dissolution. This structural design, through the coordinated operation of the microrobot body 1, the magnetic field generator 2, and the control module, enables controllable movement of the microrobot and on-demand drug release in ophthalmic treatment.

[0042] This invention also features a multimodal motion switching mechanism. The microrobot body 1 can autonomously or controllably switch between rolling, tumbling, and spiral propulsion modes according to the environmental characteristics of different ocular cavities such as the lacrimal duct, vitreous cavity, and anterior chamber, adapting to the motion requirements under different duct diameters and fluid viscosities, demonstrating strong environmental adaptability. This invention can integrate multiple therapeutic functions, including a physical unblocking module that mechanically breaks up obstructions through rotary drilling, a drug delivery module that loads anti-inflammatory or intraocular pressure-lowering drugs and precisely releases them at the lesion site, and a thermal ablation module that generates local heat through high-frequency magnetic field oscillation to ablate abnormal tissue. These three functions can be used independently or in combination according to clinical needs, achieving a multifunctional integrated system-level innovation.

[0043] Preferably, the outer surface of the spiral structure 102 is provided with a recessed structure 108 and / or a raised structure to reduce the resistance of the microrobot body 1 in the fluid. The recessed structure 108 and / or the raised structure on the outer surface of the spiral structure 102 further reduce the resistance of the microrobot body 1 in the high-viscosity fluid inside the eye.

[0044] When the microrobot body 1 moves within the intraocular fluid, the fluid flows over the surface area containing the recessed structure 108 and / or the raised structure. The recessed structure 108 traps microbubbles, forming a solid-gas-liquid three-phase interface between the solid surface and the fluid, reducing the direct contact area between the fluid and the surface of the microrobot body 1. The raised structure induces localized eddies or slip effects as the fluid flows, further reducing viscous resistance. The combined effect of the recessed structure 108 and / or the raised structure gives the surface of the microrobot body 1 hydrophobic or superhydrophobic properties, significantly reducing fluid resistance and enabling the microrobot body 1 to maintain a high speed of movement in high-viscosity tears, vitreous humor, or aqueous humor.

[0045] The recessed structure 108 can also be configured as at least one of the following forms: pit, groove, or spiral recess; the raised structure can also be configured as at least one of the following forms: protrusion, ridge, or spiral protrusion. The recessed structure 108 and / or the raised structure can also be simultaneously provided on the outer surface of the central body 101. The depth of the recessed structure 108 can also be less than its opening width, and the height of the raised structure can also be less than its bottom width. The recessed structure 108 and the raised structure can also be arranged alternately to form regular or irregular surface textures.

[0046] Preferably, there are two spiral structures 102, which are coiled around the outer periphery of the central body 101 in a centrally symmetrical manner.

[0047] When the microrobot body 1 rotates under the drive of an external rotating magnetic field, the two helical structures 102 simultaneously interact with the surrounding intraocular fluid. The rotational motion of the two helical structures 102 converts the viscous drag of the fluid into axial propulsion, propelling the microrobot body 1 forward or backward. Because the two helical structures 102 are centrally symmetrically distributed, the propulsion forces generated by them are balanced circumferentially, maintaining axial stability of the microrobot body 1 during movement and reducing lateral drift and rotational jitter. Compared to the single helical structure 102, the double helix structure 102 has a larger fluid contact area, generating greater rotational torque and axial propulsion, enabling the microrobot body 1 to maintain high speed and stability even in high-viscosity tear fluid, vitreous humor, or aqueous humor.

[0048] The two helical structures 102 can also be evenly distributed on the outer periphery of the central body 101, and the pitches of the two helical structures 102 can be the same or different. The helix angles of the two helical structures 102 can also be equal or complementary. The blade width of the two helical structures 102 can also gradually narrow or gradually widen from the end closer to the central body 101 to the end farther away from the central body 101. The outer edges of the two helical structures 102 can also be provided with rounded chamfers or beveled transition structures. The two helical structures 102 can also be processed with the central body 101 using an integrated molding process.

[0049] Preferably, the central body 101 has tapered guide structures 109 at both ends, and the central axis of the tapered guide structures 109 coincides with the central axis of the central body 101. The design of the tapered guide structures 109 reduces the fluid resistance of the microrobot body 1 when it enters in the forward direction and exits in the reverse direction, and guides the microrobot body 1 to move along the axial direction.

[0050] When the microrobot body 1 rotates forward in the first direction, the conical guide structure 109 at the front end of the forward direction first contacts the fluid or tissue. Its conical surface disperses the fluid or tissue in all directions, reducing the pressure area at the front end of the microrobot body 1 and thus reducing forward resistance. When the microrobot body 1 rotates backward in the second direction, the conical guide structure 109 at the other end plays the same guiding role, reducing backward resistance. The central axis of the conical guide structures 109 at both ends coincides with the central axis of the central body 101, ensuring that the microrobot body 1 maintains the straightness of axial movement when entering forward and exiting backward, avoiding yaw or sideslip due to uneven force. The conical guide structure 109 can also play a role in preliminary puncture or positioning when the microrobot body 1 drills into the lesion tissue, providing guidance for the subsequent rotational advancement of the helical structure 102.

[0051] The cone angle of the tapered guide structure 109 can also be set as an acute angle, an obtuse angle, or a rounded transition shape. The surface of the tapered guide structure 109 can also be coated with a smooth coating or a hydrophobic coating. The cone angles of the two ends of the tapered guide structure 109 can also be equal or different, with one end having a larger cone angle than the other. The top of the tapered guide structure 109 can also be set as a spherical or flat-top structure. A rounded transition surface can also be provided at the connection between the tapered guide structure 109 and the central body 101.

[0052] Preferably, a temporary sealing layer is provided at the gap 105; the temporary sealing layer is configured such that: when the microrobot body 1 rotates forward in a first direction, the temporary sealing layer remains intact to assist in sealing the gap 105; when the microrobot body 1 rotates backward in a second direction, the temporary sealing layer partially or completely dissolves to expose the gap 105. The gap 105 is sealed before the microrobot body 1 reaches the target position to prevent premature drug leakage, and the sealing is released after reaching the target position to allow drug release.

[0053] The temporary sealing layer can also be a single-layer structure or a multi-layer composite structure. The temporary sealing layer can also cover only a localized area of ​​the slit notch 105 instead of the entire area. The thickness of the temporary sealing layer can also be a uniform thickness or a gradually varying thickness, with the thickness near the opening of the slit notch 105 being less than the thickness further away from the opening. The temporary sealing layer can also be formed at the slit notch 105 by at least one of the following methods: spraying, impregnation, vapor deposition, or in-situ polymerization. The temporary sealing layer can also be a material layer that gradually softens at body temperature, or a structural layer that gradually swells and detaches in the intraocular fluid environment.

[0054] When the microrobot body 1 rotates forward in the first direction, the temporary sealing layer remains intact. Its physical barrier function, combined with the mechanical sealing effect of the spiral structure 102 approaching the central body 101, seals the gap 105, preventing the drug in the storage cavity 107 from leaking out. When the microrobot body 1 reaches the target position and switches to rotating backward in the second direction, the spiral structure 102 unfolds away from the central body 101 under fluid resistance, stretching or tearing the temporary sealing layer. Simultaneously, the fluid shear force from the backward movement also applies a peeling force to the temporary sealing layer. Under the aforementioned mechanical forces, the temporary sealing layer partially or completely detaches, breaks, or dissolves from the gap 105, exposing the gap 105. The drug in the storage cavity 107 is then released from the open gap 105 into the target tissue. The disappearance of the temporary sealing layer is synchronized with the backward movement of the microrobot body 1, ensuring that drug release only begins after reaching the target position.

[0055] Preferably, the temporary sealing layer is at least one of gelatin, polylactic acid, chitosan, or poloxamer. The temporary sealing layer is made of a material that is biocompatible and can degrade and disappear within the intraocular environment.

[0056] Once the microrobot 1 enters the eye, the temporary sealing layer comes into direct contact with the tear fluid, aqueous humor, or vitreous humor. Gelatin gradually dissolves at body temperature, and the dissolution time can be adjusted by the degree of cross-linking. Polylactic acid degrades slowly through hydrolysis, with degradation times ranging from several hours to several weeks, which can be controlled by molecular weight and crystallinity. Chitosan is degraded by lysozyme in the eye, and the degradation rate is related to the enzyme concentration. Poloxamer has reverse thermosensitive properties, being liquid at low temperatures and forming a gel at body temperature, and can gradually dissolve at body temperature. The above materials do not produce toxic byproducts during degradation or dissolution and have good biocompatibility. The disappearance time of the temporary sealing layer can be preset through material selection, molecular weight adjustment, cross-linking degree control, or composite ratio optimization to match the transportation time required for the microrobot 1 to reach the target location, ensuring that the temporary sealing layer remains intact during transportation and dissolves promptly upon arrival at the target location.

[0057] Gelatin can be replaced by at least one of collagen or silk fibroin. Polylactic acid can be replaced by at least one of polycaprolactone or polyhydroxyalkanoates. Chitosan can be replaced by at least one of sodium alginate or hyaluronic acid. Poloxamer can be replaced by at least one of polyvinyl alcohol or polyethylene glycol. The temporary sealing layer can also be a blend or copolymer of two or more of the above materials. The temporary sealing layer can also be configured as a multilayer structure, wherein the inner layer is gelatin and the outer layer is polylactic acid, or the inner layer is chitosan and the outer layer is poloxamer. Plasticizers or stabilizers can also be added to the above materials to adjust their mechanical properties and degradation rate.

[0058] Preferably, the magnetic field generating device 2 includes at least one of a triaxial Helmholtz coil or an octagonal electromagnetic coil array. This magnetic field generating device 2 generates a three-dimensional rotating magnetic field and a gradient magnetic field required to drive the movement of the microrobot body 1.

[0059] When the control module applies current to the magnetic field generator 2, a triaxial Helmholtz coil or an octagonal electromagnetic coil array generates a uniform magnetic field in the internal space. By adjusting the current ratio in the three axes, magnetic field vectors in any direction can be synthesized. When it is necessary to drive the microrobot body 1 to rotate forward in the first direction, the control module controls the magnetic field generator 2 to generate a magnetic field that rotates uniformly around a certain axis in space. The magnetic particles inside the microrobot body 1 rotate in the direction of the magnetic field under the action of the magnetic field torque, driving the entire microrobot body 1 to rotate synchronously. The helical structure 102 converts the rotational motion into axial propulsion, propelling the microrobot body 1 forward. By changing the rotation axis direction of the rotating magnetic field, the forward direction of the microrobot body 1 can be changed. By applying a gradient magnetic field, a translational force can be generated on the microrobot body 1 for assisting in positioning or attitude adjustment. When it is necessary to switch to rotating backward in the second direction, the control module reverses the rotation direction of the rotating magnetic field, and the rotation direction of the microrobot body 1 is reversed accordingly. The axial thrust generated by the helical structure 102 is reversed, and the microrobot body 1 moves backward. The triaxial Helmholtz coil is suitable for generating a large-scale uniform magnetic field, while the octagonal electromagnetic coil array is suitable for generating a high-intensity gradient magnetic field. The two can be used individually or in combination, depending on the application scenario. The operating position 7 is located in the central area of ​​the magnetic field generating device 2 and is used to accommodate the patient's eyes or head, ensuring that the microrobot body 1 remains within the uniform magnetic field area during movement.

[0060] The triaxial Helmholtz coil can also be replaced by a spherical coil array or a cylindrical coil array. The octagonal electromagnetic coil array can also be replaced by a hexagonal electromagnetic coil array or a dodecagonal electromagnetic coil array. The magnetic field generating device 2 can also include a combination structure of permanent magnets and electromagnetic coils. The magnetic field generating device 2 can also be configured as an open coil structure, i.e., a partial coil covering only the eye area rather than a full-head coil. The magnetic field generating device 2 can also integrate a cooling system for heat dissipation during coil operation. The three axial coils of the triaxial Helmholtz coil can also be arranged orthogonally and concentrically. The eight coils of the octagonal electromagnetic coil array can also be distributed in a circular or square pattern on the same plane.

[0061] Preferably, a magnetically controlled micro / nanorobot system for ophthalmic treatment includes an imaging module 6. The imaging module 6 is used to acquire the position information of the microrobot body 1 within the eye in real time and feed the position information back to the control module. The imaging module 6 is selected from at least one of an optical coherence tomography scanner, an ultrasound imager, or a fluorescence imager. The imaging module 6 acquires the position information of the microrobot body 1 within the eye in real time and feeds it back to the control module, forming a closed-loop control.

[0062] As the microrobot 1 moves within the eye, the imaging module 6 continuously acquires image data of the ocular region. An optical coherence tomography (OCT) scanner emits a near-infrared beam and receives backscattered light from intraocular tissues, reconstructing the three-dimensional position of the microrobot 1 relative to intraocular structures such as the retina, lens, or cornea through interference principles. An ultrasound imager emits ultrasound waves and receives echoes, suitable for robot localization in deep tissues or opaque refractive media with poor optical signal penetration. A fluorescence imager captures fluorescent signals marked on the microrobot 1 under excitation light, suitable for simultaneous tracking of multiple robots or detection of low-concentration robots. The imaging module 6 transmits the acquired position information to the control module in real time at a frequency of tens to hundreds of frames per second. The control module compares the received actual position with the preset target position, calculates the position deviation, and adjusts the output parameters of the magnetic field generator 2 accordingly, correcting the trajectory of the microrobot 1 in real time until it reaches the target position. This closed-loop control mechanism ensures that the microrobot 1 maintains high positioning accuracy even in the complex intraocular environment. This magnetically controlled closed-loop navigation system achieves precise five-degree-of-freedom control with a magnetic field control error of less than 2%.

[0063] The imaging module 6 can also be selected from a combination of an optical coherence tomography (OCT) scanner and an ultrasound imager, or a combination of an OCT scanner and a fluorescence imager. The scanning beam of the OCT scanner can also be configured to be coaxial with or at an angle to the direction of movement of the microrobot body 1. The ultrasound probe of the ultrasound imager can also be configured as a handheld or adhesive structure, attached to the surface of the eyelid or sclera. The excitation source of the fluorescence imager can also be configured to be synchronously triggered with the magnetic field generator 2, only briefly activated during imaging to reduce phototoxicity. The imaging module 6 can also be integrated into the optical path of a surgical microscope, sharing the objective lens with the microscope. The sampling frequency of the imaging module 6 can also be set to match the rotation frequency of the magnetic field, enabling dynamic tracking during movement. The imaging module 6 can also include an image processing unit for automatically identifying and extracting the position coordinates of the microrobot body 1 from the acquired images.

[0064] A control method for a magnetically controlled micro / nanorobotic system for ophthalmic treatment includes the following steps:

[0065] Step S1: Introduce the drug-loaded microrobot body 1 into the target cavity of the eye;

[0066] Step S2: The magnetic field generator 2 is controlled by the control module to generate a magnetic field in the first direction, which drives the micro-robot body 1 to rotate and move forward in the first direction. At this time, the spiral structure 102 moves towards the central body 101 under the action of fluid resistance, so that the gap 105 is closed or narrowed, and the drug is locked in the drug storage cavity 107.

[0067] Step S3: The imaging module 6 acquires the position information of the micro-robot body 1 in real time and feeds the position information back to the control module to form a closed-loop control until the micro-robot body 1 reaches the target position.

[0068] Step S4: The magnetic field generator 2 is switched to the second direction rotation magnetic field by the control module, and the micro-robot body 1 is driven to rotate and move backward along the second direction. At this time, the spiral structure 102 unfolds away from the central body 101 under the action of fluid resistance, so that the gap 105 opens and exposes the drug storage chamber 107. The drug is released from the gap 105 to the target position.

[0069] Step S5: After treatment, the microrobot body 1 is withdrawn by means of a reverse magnetic field or attraction.

[0070] In summary, the movement direction of the microrobot body 1 is controlled by switching the magnetic field direction, and the deformation of the spiral structure 102 is driven by fluid resistance to achieve drug latch-up and on-demand release.

[0071] In practice, the drug is first injected into the drug storage cavity 107 of the microrobot body 1 using an injection tool. Then, the drug-loaded microrobot body 1 is introduced into the target cavity of the eye, which can be the nasolacrimal duct, anterior chamber, vitreous cavity, or subconjunctival space. The control module controls the magnetic field generator 2 to generate a first-direction rotating magnetic field, driving the microrobot body 1 to rotate forward in that direction. At this time, the spiral structure 102 moves towards the central body 101 under the action of fluid resistance, the gap 105 closes or narrows, and the drug in the drug storage cavity 107 is locked in, preventing leakage. Simultaneously, the imaging module 6 acquires the position information of the microrobot body 1 in real time and feeds it back to the control module. The control module dynamically adjusts the magnetic field parameters according to the deviation between the actual position and the target position, forming a closed-loop navigation until the microrobot body 1 reaches the target position. After reaching the target position, the control module controls the magnetic field generator 2 to switch to a second-direction rotating magnetic field, driving the microrobot body 1 to rotate backward in the second direction. At this point, the spiral structure 102 unfolds away from the central body 101 under the action of fluid resistance, the slit notch 105 opens, the drug storage chamber 107 is exposed, and the drug is released from the slit notch 105 to the target location. After release, the microrobot body 1 is attracted back to the vicinity of the puncture site by a reverse magnetic field, or it is extracted from the eye by a negative pressure suction device. Throughout the entire control process, the forward movement, navigation, release, and withdrawal of the microrobot body 1 are all wirelessly driven by an external magnetic field, without the need for a power supply or control circuit on the robot body.

[0072] In step S1, the microrobot body 1 can be introduced into the target cavity via at least one of a syringe, microcatheter, or implantable drug delivery device. The first directional magnetic field in step S2 can also be set to a clockwise or counterclockwise rotating magnetic field. In step S3, the imaging module 6 can continuously acquire images and feed back position information at a frequency of 50 to 100 frames per second. The second directional rotating magnetic field in step S4 can also be set to a rotation direction opposite to the first direction. The reverse magnetic field in step S5 can also be set to a gradient magnetic field to pull the microrobot body 1 back to the vicinity of the puncture site; the suction method can also be set to a negative pressure suction device or a magnetic suction probe. In steps S2 to S4, the control module can also use a PID control algorithm or a model predictive control algorithm to adjust the magnetic field parameters in real time.

[0073] Preferably, a pretreatment step is included before step S1: immersing the microrobot body 1 in a temporary sealing material solution to form a temporary sealing layer at the gap 105; in step S2, the temporary sealing layer remains intact to assist in sealing the gap 105; in step S4, the temporary sealing layer is partially or completely dissolved due to the reverse rotation and retraction of the microrobot body 1 and / or at least one of the environmental factors of pH, temperature, or enzyme concentration at the target location, to assist in opening the gap 105. A temporary sealing layer is pre-formed at the gap 105 before the microrobot body 1 enters the body to assist in blocking the drug during transportation and in assisting in the release of the drug at the target location.

[0074] Before introducing the microrobot body 1 into the body after processing, it is first immersed in a solution containing temporary sealing material. The molecules of the temporary sealing material in the solution diffuse into the tiny gaps of the slit notch 105 and adhere to the inner surface of the slit notch 105. After removing the microrobot body 1 from the solution, the solvent is removed by natural drying, low-temperature drying, or vacuum drying. The temporary sealing material solidifies at the slit notch 105 to form a continuous or semi-continuous thin film, i.e., a temporary sealing layer. This temporary sealing layer physically blocks the gap 105 from the drug storage cavity 107. During the rotational advance in step S2, the temporary sealing layer maintains its structural integrity and works in conjunction with the mechanical sealing effect generated by the spiral structure 102 approaching the central body 101 to double-seal the gap 105, preventing premature leakage of the drug during transportation. During the rotational retraction process in step S4, the spiral structure 102 unfolds away from the central body 101, generating tensile force. Simultaneously, the fluid shear force generated by the retraction action acts on the temporary sealing layer. Combined with the possible acidic pH, body temperature, or specific enzyme activity at the target location, the temporary sealing layer undergoes mechanical rupture, interfacial peeling, or material dissolution, partially or completely disappearing from the gap 105, thus exposing the gap 105 and allowing the drug in the drug storage cavity 107 to be smoothly released into the target tissue. This pretreatment step is simple to operate, requires no complex equipment, and can be completed on-site before clinical use.

[0075] In the pretreatment step, the microrobot body 1 can be immersed in a temporary sealing material solution multiple times, and then removed and dried after each immersion to form a multi-layered composite temporary sealing layer. The temporary sealing material solution can also be set as a gradient concentration solution, immersing the robot in a low-concentration solution first and then a high-concentration solution to adjust the density of the sealing layer. The immersion time can also be set to any duration within the range of 1 minute to 60 minutes, determined according to the required sealing layer thickness. After immersion, low-temperature drying or vacuum drying can be performed. After the temporary sealing layer is formed, selective removal can be performed in areas other than the gap 105, retaining only the sealing layer at the gap 105. Spraying, dripping, or microneedle dispensing methods can also be used instead of immersion in the pretreatment step.

[0076] In summary, this invention discloses a magnetically controlled micro / nanorobot system and its control method for ophthalmic treatment. The system includes a microrobot body 1, a magnetic field generating device 2, a control module, and an imaging module 6. The microrobot body 1 is composed of a central body 101 and at least one helical structure 102. The central body 101 and / or the helical structure 102 contain magnetic materials. The central body 101 is provided with a drug storage cavity 107. The helical structure 102 is arranged around the outer periphery of the central body 101. The first side edge 103 of the helical structure 102 is connected to the central body 101, and a gap 105 is formed between the second side edge 104 and the central body 101. The gap 105 is in fluid communication with the drug storage cavity 107. When the microrobot body 1 rotates forward in the first direction, the spiral structure 102 moves towards the central body 101 under the action of fluid resistance, the slit notch 105 closes or narrows, and the drug is locked in the drug storage cavity 107; when rotating backward in the second direction, the spiral structure 102 unfolds away from the central body 101, the slit notch 105 opens, exposing the drug storage cavity 107, and the drug is released to the target position. The magnetic field generating device 2 includes a triaxial Helmholtz coil or an octagonal electromagnetic coil array, used to generate a magnetic field to drive the movement of the microrobot body 1. The control module is electrically connected to the magnetic field generating device 2 and controls the magnetic field parameters. The imaging module 6 is selected from at least one of an optical coherence tomography scanner, an ultrasound imager, or a fluorescence imager, used to acquire the position information of the microrobot body 1 in real time and feed it back to the control module to form a closed-loop control. The outer surface of the spiral structure 102 is provided with a concave structure 108 and / or a convex structure to reduce fluid movement resistance, and the two ends of the central body 101 are provided with tapered guide structures 109 to reduce ingress and egress resistance. A temporary sealing layer can be installed at the gap 105. This sealing layer can be made of biocompatible materials such as gelatin, polylactic acid, chitosan, or poloxamer. It remains intact to help seal the gap during forward movement and dissolves due to mechanical action and environmental factors (pH, temperature, enzyme concentration) during backward movement to help the gap open. This invention achieves precise control of drug latch-up and on-demand release by controlling the deformation of the spiral structure 102 and the dissolution of the temporary sealing layer through switching of movement direction. It is suitable for minimally invasive ophthalmic surgeries such as nasolacrimal duct recanalization, glaucoma targeted drug delivery, and retinal lesion ablation.

[0077] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.

[0078] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0079] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in this application, and these should all be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A magnetically controlled micro / nanorobotic system for ophthalmic treatment, characterized in that, include: A microrobot body (1) includes a central body (101) and at least one helical structure (102), wherein the central body (101) and / or the helical structure (102) contain magnetic material; the central body (101) is provided with a drug storage cavity (107); the helical structure (102) is disposed around the outer periphery of the central body (101), and the helical structure (102) has a first side edge (103) and a second side edge (104); the first side edge (103) is flexibly connected to the central body (101) so that the helical structure (102) can elastically deform relative to the central body (101); A gap (105) is formed between the second side edge (104) of the spiral structure (102) and the central body (101), and the gap (105) is in fluid communication with the drug storage cavity (107); wherein, when the microrobot body (1) rotates forward in the first direction, the spiral structure (102) moves toward the central body (101) under the action of fluid resistance, so that the gap (105) closes or narrows; when rotating backward in the second direction, the spiral structure (102) unfolds away from the central body (101) under the action of fluid resistance, so that the gap (105) opens to expose the drug storage cavity (107). Magnetic field generating device (2), the magnetic field generating device (2) is used to generate a magnetic field to drive the movement of the microrobot body (1); The control module is electrically connected to the magnetic field generator (2) and is used to control the parameters of the magnetic field.

2. The magnetically controlled micro / nanorobotic system for ophthalmic treatment according to claim 1, characterized in that, The outer surface of the spiral structure (102) is provided with a recessed structure (108) and / or a raised structure to reduce the resistance of the microrobot body (1) moving in the fluid.

3. The magnetically controlled micro / nanorobotic system for ophthalmic treatment according to claim 1, characterized in that, There are two spiral structures (102), and the two spiral structures (102) are coiled around the outer periphery of the central body (101) in a centrally symmetrical manner.

4. The magnetically controlled micro / nanorobotic system for ophthalmic treatment according to claim 1, characterized in that, The central body (101) has tapered guide structures (109) at both ends, and the central axis of the tapered guide structure (109) coincides with the central axis of the central body (101).

5. A magnetically controlled micro / nanorobotic system for ophthalmic treatment according to claim 1, characterized in that, A temporary sealing layer is provided at the gap (105); the temporary sealing layer is configured such that when the microrobot body (1) rotates forward in a first direction, the temporary sealing layer remains intact to assist in sealing the gap (105); when the microrobot body (1) rotates backward in a second direction, the temporary sealing layer is partially or completely dissolved to expose the gap (105).

6. A magnetically controlled micro / nanorobotic system for ophthalmic treatment according to claim 5, characterized in that, The temporary sealing layer is at least one of gelatin, polylactic acid, chitosan, or poloxamer.

7. A magnetically controlled micro / nanorobotic system for ophthalmic treatment according to claim 1, characterized in that, The magnetic field generating device (2) includes at least one of a triaxial Helmholtz coil or an octagonal electromagnetic coil array.

8. A magnetically controlled micro / nanorobotic system for ophthalmic treatment according to claim 1, characterized in that, The magnetically controlled micro-nano robot system for ophthalmic treatment includes an imaging module (6), which is used to acquire the position information of the microrobot body (1) in the eye in real time and feed the position information back to the control module; the imaging module (6) is selected from at least one of optical coherence tomography, ultrasound imaging or fluorescence imaging.

9. A control method for a magnetically controlled micro / nanorobotic system for ophthalmic treatment, characterized in that, Includes the following steps: Step S1: Introduce the drug-loaded microrobot body (1) into the target cavity of the eye; Step S2: The magnetic field generator (2) is controlled by the control module to generate a magnetic field in the first direction, which drives the microrobot body (1) to rotate and move forward in the first direction. At this time, the spiral structure (102) moves towards the central body (101) under the action of fluid resistance, so that the gap (105) is closed or narrowed, and the drug is locked in the drug storage cavity (107). Step S3: The position information of the micro-robot body (1) is acquired in real time through the imaging module (6), and the position information is fed back to the control module to form a closed-loop control until the micro-robot body (1) reaches the target position; Step S4: The control module controls the magnetic field generator (2) to switch to a second direction rotating magnetic field, driving the microrobot body (1) to rotate backward along the second direction. At this time, the spiral structure (102) unfolds away from the central body (101) under the action of fluid resistance, causing the gap (105) to open and exposing the drug storage chamber (107). The drug is released from the gap (105) to the target position. Step S5: After treatment, the microrobot body (1) is removed by means of a reverse magnetic field or attraction.

10. The control method for a magnetically controlled micro / nanorobotic system for ophthalmic treatment according to claim 9, characterized in that, Before step S1, a pretreatment step is also included: immersing the microrobot body (1) in a temporary sealing material solution, so that the temporary sealing material forms a temporary sealing layer at the gap (105); in step S2, the temporary sealing layer remains intact to assist in sealing the gap (105); in step S4, the temporary sealing layer is partially or completely dissolved due to the reverse rotation and backward movement of the microrobot body (1) and / or at least one of the environmental factors of pH value, temperature or enzyme concentration at the target position, to assist the gap (105) to open.

Images