36 results about "Micro coil" patented technology

Tracking a pose of a portion of an anatomical structure using an inverted-direction electromagnetic navigation system may comprise generating a signal comprising a plurality of frequencies. The signal comprising the plurality of frequencies may be received at a transmitter coil array. The transmitter coil array comprises a plurality of transmitting micro coils. Each of the plurality of transmitting micro coils is coupled to a portion of an anatomical structure of a patient. In response to receiving the signal comprising the plurality of frequencies, an electromagnetic field may be generated at each of the plurality of transmitting micro coils based on the received signal. Each of the generated electromagnetic fields may be detected at a receiver coil array comprising at least one receiving coil. A pose of at least one of the plurality of transmitting micro coils may then be determined.

The present application relates to a kind of micro nuclear magnetic resonance probe and nucleic acid, antibody nuclear magnetic resonance detection method.Micro nuclear magnetic resonance probe includes the parallel arrangement of first plane shimming coil, nuclear magnetic resonance micro coil chip, digital microfluidic chip and second plane shimming coil in sequence, digital microfluidic chip is single pole plate form, the microstrip of medium substrate on nuclear magnetic resonance micro coil chip is annular microstrip coil, nuclear magnetic resonance micro coil chip and digital microfluidic chip are spaced apart.There is beneficial effect: through digital microfluidic chip control droplet, with simple structure, easy integration advantage;Annular microstrip coil can generate a uniform B1 field that matches the shape of droplet, can improve the filling factor of trace sample droplet;Nucleic acid, antibody modified magnetic particle probe can enhance nuclear magnetic resonance detection sensitivity, by quantitative analysis the change amount of relaxation time and the concentration of target detection substance, nucleic acid, antibody quantitative detection can be realized.

The invention discloses an electric micro-electro-mechanical system (MEMS) loudspeaker, which is provided with a pair of stators and a diaphragm arranged between the stators, and is used for generating an acoustic output according to an input electro-acoustic signal. The moving part is related to the performance of the electric MEMS loudspeaker due to the symmetrical structure of the thin conductor connecting part and the rigid polyimide membrane suspended on the diagonal spring structure, and the structure is uniformly distributed on the elastic membrane. In addition, by means of the structure, the frequency bandwidth is improved, and the broadband is large. The multi-circle planar micro-coil structure is manufactured at the top and / or the bottom of the diaphragm, and a single layer or double layers can be used, so that the efficiency of the MEMS loudspeaker is improved.

This invention discloses a high-precision dual-mass silicon micro-gyroscope device based on the tunneling magnetoresistive effect. The device comprises two layers: an upper layer is a silicon sensing structure, and a lower layer is a glass substrate structure with metal electrodes and a tunneling magnetoresistive detection module. The upper structure is bonded to the lower structure via anchor points. The upper structure consists of two identical gyroscope substructures, a pair of support beams, and a pair of anchor points. The lower structure consists of a tunneling magnetoresistive detection module, a glass substrate, driving electrodes, driving and detection electrodes, quadrature electrodes, a coil input interface, a coil input electrode, a coil output interface, a coil output electrode, a common electrode, and signal leads. This invention proposes a silicon micro-gyroscope using a miniature coil as the excitation mechanism, resulting in a stable magnetic field, controllable field strength, and high integration. Simultaneously, the use of a differential tunneling magnetoresistive detection structure provides advantages such as strong anti-common-mode error capability, high sensitivity, and high measurement accuracy.

The invention relates to the technical field of microelectronic packaging, in particular to a micro coil external welding process which comprises the following steps: S1, arranging a metal alloy bonding pad on the surface of a welding area; s2, performing laser etching on the surface of the metal alloy bonding pad to form a lead positioning groove array; s3, embedding the depainted coil lead end into the lead positioning groove to form a contact interface; s4, the contact interface is coated with low-temperature soldering paste to form a solder layer; s5, selective heating is conducted on the welding flux layer through pulse laser, and a welding combination layer is formed; s6, forced cooling is conducted on the welding bonding layer; and S7, a target micro welding spot is obtained. According to the method, through the collaborative design of multi-layer bonding pad construction, precise lead positioning, selective laser welding and thermal control cooling, the welding effects of high reliability, low heat influence and high consistency between the lead and the bonding pad of the micro coil are achieved.

The utility model relates to a miniature loudspeaker, comprising an induction chip which is manufactured through a semiconductor manufacturing process and is connected with a vibrating diaphragm; the control chip is manufactured through a semiconductor manufacturing process and is electrically connected with the sensing chip; a gap for the sensing chip to bear the vibration diaphragm to move is formed between the magnetic element and the sensing chip; wherein the control chip is used for receiving an electrical signal, the polarity of the electrical signal is changed and input to the sensing chip so as to form a variable magnetic field on the sensing chip, a force for driving the vibrating diaphragm to move is formed between the magnetic element and the sensing chip, and the moving vibrating diaphragm generates sound waves output by the miniature loudspeaker. An induction chip formed by a micro coil element is manufactured through a semiconductor manufacturing process, and the purpose of microminiaturization of the loudspeaker is achieved.

The invention belongs to the technical field of radioactive element detection, and discloses a radioactive element content detection method and system and application, and the detection method comprises the following steps: carrying out quantum state initialization on a diamond nitrogen vacancy color center; converting gamma ray radiation of the to-be-detected sample into an optical signal; converting and amplifying the optical signal and driving a micro coil to obtain an electromagnetic signal; receiving the electric signal through the diamond nitrogen vacancy color center, and outputting a response light signal; converting the response optical signal into a response electric signal; and calculating to obtain the radioactive element content of the to-be-detected sample. According to the method, the detection lower limit of a traditional method is broken through by utilizing the high sensitivity characteristic of quantum sensing, and the content detection of trace radioactive elements is realized; gamma ray radiation is converted and amplified into electric signals which can be received by a diamond nitrogen vacancy color center, so that the coupling difficulty of quantum sensing and radioactive element signals is solved; and a novel high-sensitivity detection means is provided for the fields of environmental safety, food safety and nuclear emergency.

The application belongs to the technical field of magnetic suspension motor, and discloses a magnetic suspension fan motor winding temperature monitoring device and a warning method; the method comprises the following steps: laminating a preset temperature-sensitive ferromagnetic material and a magnetic suspension fan motor stator core according to a preset process to obtain a composite core; deploying a high-frequency excitation system on the composite core, adjusting the number of turns of the micro coil of the high-frequency excitation system according to a target magnetic field intensity, collecting real-time excitation current, and analyzing to obtain magnetic induction intensity; analyzing the magnetic induction intensity through multi-physical field coupling iteration to obtain a winding three-dimensional temperature field; performing temperature gradient analysis on the three-dimensional temperature field, performing temperature warning according to the analysis result, and dynamically adjusting motor operating parameters; the application effectively improves the comprehensiveness of magnetic suspension fan motor winding temperature monitoring, the timeliness of warning and the accuracy of cooling control, and guarantees the safe and stable operation of the motor under complex working conditions.

The invention provides a method and a device for improving the sensitivity and the signal-to-noise ratio of in-situ electrochemical nuclear magnetic resonance, and relates to the field of in-situ electrochemical-nuclear magnetic resonance. The method comprises the following steps: designing an electrochemical nuclear magnetic resonance in-situ pool according to a coil of an in-situ electrochemical nuclear magnetic resonance probe; a micro coil and a micro capacitor are attached to the outer part of the electrochemical nuclear magnetic resonance in-situ pool; the sensitivity and the spectrogram signal-to-noise ratio of the in-situ electrochemical nuclear magnetic resonance probe are improved through inductive coupling between the miniature coil and the coil of the in-situ electrochemical nuclear magnetic resonance probe as well as between the miniature capacitor and the coil of the in-situ electrochemical nuclear magnetic resonance probe. The device comprises an electrochemical nuclear magnetic resonance in-situ pool assembly, a micro coil and a micro capacitor, the micro coil and the micro capacitor are bonded and fixed on the outer wall of the shell, and the micro coil and the micro capacitor are connected through a welded copper wire. The in-situ spectrogram signal-to-noise ratio and the probe sensitivity are improved through the integrated scheme that the micro coil is coupled with the nuclear magnetic resonance in-situ pool.

The application belongs to the technical field of planar motor and provides a magnetic field adjusting method for magnetic suspension planar motor. The magnetic suspension planar motor comprises a mover assembly and a stator assembly. The mover assembly comprises a mover top plate, a controller cabin, an adjustable magnetic array layer and a mover bottom plate connected from top to bottom. The adjustable magnetic array layer comprises a permanent magnet array and a magnetic field reconstruction unit. The permanent magnet array is composed of multiple permanent magnet subarray units. The magnetic field reconstruction unit is arranged in the magnetic pole gap of the permanent magnet array. Each magnetic field reconstruction unit comprises a micro soft magnetic core and a micro coil wound on the micro soft magnetic core. The controller cabin is provided with a mover controller for receiving instructions and controlling the current of the micro coil. The method is adjusted by controlling the magnetic field reconstruction unit. The application solves the problem of poor utilization of magnetic leakage field caused by the physical gap between the mover permanent magnets in the planar motor.

Tracking a pose of a portion of an anatomical structure using a bi-directional electromagnetic navigation system may include generating a signal comprising a plurality of frequencies. The signal may be received at a bi-directional coil array that comprises a plurality of bi-directional micro coils configured to both generate electromagnetic fields and detect electromagnetic fields generated by neighboring bi-directional micro coils. Each of the plurality of bi-directional micro coils may be coupled to a portion of a structure. In response to receiving the signal, an electromagnetic field may be generated at each of the plurality of bi-directional micro coils. At least one of the generated electromagnetic fields may be detected at a neighboring bi-directional micro coil of a bi-directional micro coil that is generating the at least one detected electromagnetic field. A pose of the bi-directional micro coil that is generating the at least one detected electromagnetic field may be determined.

Disclosed in the present application is a device for treating cerebral apoplexy. The device comprises a controller, a driver assembly, and a stimulation electrode assembly. The controller comprises an upper computer, a signal generation circuit, a power supply management circuit, and a filtering and amplifying circuit, and is configured for setting treatment parameters. The controller is electrically connected to the driver assembly. The driver assembly comprises a first resonant matching circuit and a transmitting coil, and supplies power to the stimulation electrode assembly in a wireless energy supply manner. The stimulation electrode assembly comprises a stimulation electrode and a micro coil receiving circuit connected to the stimulation electrode. The stimulation electrode is surgically implanted into the palatal canal of the oral cavity of a human body, and the micro coil receiving circuit is attached to a side of a tooth. As the electrical stimulation waveform and energy are wirelessly transmitted by means of the coil in a resonant coupling manner, the transmission is stable and efficient. A receiving end circuit realizes a bipolar electric stimulation function, thereby ensuring charge balance during stimulation.

The application discloses a multi-coil differential driving variable stiffness magnetic guide wire, which comprises an interventional guide wire body and an external control system, wherein the interventional guide wire body is composed of a super-elastic nickel-titanium alloy inner core, a polyimide insulating flexible isolation layer, a micro coil array and a common ground line topology flexible wire; the external control system is composed of an external magnetic field generating system, a main control console, an electrical control system and a medical image system DSA; the electrical control system comprises an MCU microcontroller, a high-frequency PWM signal generator, an H-bridge driving circuit and a programmable constant current source; the external magnetic field generating system comprises a six-degree-of-freedom mechanical arm and an end cylindrical neodymium iron boron permanent magnet, the six-degree-of-freedom mechanical arm is freely movable in the three-dimensional space of the operating bed area, so as to adjust the position and posture of the end cylindrical neodymium iron boron permanent magnet; the end cylindrical neodymium iron boron permanent magnet is used for generating a global space magnetic field with adjustable direction and gradient in the target blood vessel area, and provides a magnetic coupling external field for the guide wire coil; and a corresponding control method is also disclosed.

The embodiment of the utility model provides a miniature coil framework convenient for automatic winding, which comprises an insulating bottom plate, a through hole is formed in the center of the insulating bottom plate, copper columns are respectively arranged at the front end and the rear end of the insulating bottom plate, and folding parts are respectively arranged on the left side and the right side of the insulating bottom plate; insulating wrapping posts are arranged on the two folding parts, and copper needles are coaxially embedded in the insulating wrapping posts; the folding part is flexibly connected with the insulating bottom plate, so that the folding part can be folded back and forth relative to the insulating bottom plate so as to be switched back and forth between a folding position and an unfolding position; during winding, the folding part can be folded to the folding position, so that the two insulating winding posts deviate from each other, and the winding machine can automatically wind and arrange wires.

The application provides a method and device for improving the sensitivity and signal-to-noise ratio of in-situ electrochemical nuclear magnetic resonance, and relates to the field of in-situ electrochemical nuclear magnetic resonance. The method comprises the following steps: designing an electrochemical nuclear magnetic resonance in-situ cell according to the coil of an in-situ electrochemical nuclear magnetic resonance probe; the electrochemical nuclear magnetic resonance in-situ cell is externally attached with a micro coil and a micro capacitor; the sensitivity and spectral signal-to-noise ratio of the in-situ electrochemical nuclear magnetic resonance probe are improved through inductive coupling between the micro coil and the micro capacitor and the coil of the in-situ electrochemical nuclear magnetic resonance probe. The device comprises: an electrochemical nuclear magnetic resonance in-situ cell assembly, a micro coil and a micro capacitor; the micro coil and the micro capacitor are fixedly bonded to the outer wall of a shell, and the micro coil and the micro capacitor are connected through a welded copper wire. The in-situ spectral signal-to-noise ratio and the sensitivity of the probe are improved through the micro coil coupling nuclear magnetic resonance in-situ cell integration scheme.

The invention discloses titanium dioxide as well as a preparation method and application thereof. The preparation method of the titanium dioxide comprises the following steps: reacting a mixed solution in a micro coil pipe to obtain the titanium dioxide, the mixed solution comprises titanium tetrachloride and ammonia water, and the mass ratio of the titanium tetrachloride to the ammonia water is 1: (0.5-3); the reaction temperature is 140 to 200 DEG C; the titanium dioxide has the advantages of large specific surface area and small secondary particle size, and the lithium iron phosphate material doped with the titanium dioxide is applied to the lithium ion battery, so that the cycle performance of the lithium ion battery can be improved.

The present application relates to a kind of in-situ calibration method of coil constant of micro three-dimensional magnetic compensation coil.The coil constant of micro coil is equivalently characterized based on the idea of volume average magnetic field, and the coil constant of micro coil is calibrated reversely using large coil whose coil constant has been calibrated, which effectively improves the precision of coil constant calibration of micro coil, thereby solving the problem that coil constant cannot be calibrated using traditional fluxgate magnetometer due to the micro volume (≤1cm 3 ) of micro coil and its easy bending deformation. The method is reasonable, and the experimental operation is simple. The coil constant of micro coil can be calibrated after its assembly, which effectively improves the accuracy of magnetic field measurement of single atomic magnetometer and the consistency of magnetic field measurement among multiple probes of array atomic magnetometer, and plays a great role in promoting the development of atomic magnetometer.

The invention belongs to the technical field of winding machines, and particularly relates to a semi-automatic winding machine for a micro coil, which comprises a machine table, and an electronic screen is mounted at the top of the machine table; the moving mechanism is mounted at the top of the machine table; the inner wall of the feeding mechanism is in threaded connection with the outer wall of the moving mechanism; the winding mechanism is installed at the top of the machine table, and the inner wall of the winding mechanism is connected with the outer wall of the moving mechanism in a clamped mode. By arranging the feeding mechanism, a sliding block moves up and down on a fixing frame in the winding process of a metal wire, the tightness degree of the metal wire can be preliminarily adjusted, then surface cleaning is conducted through a wiping assembly, and the metal wire can be conveniently cleaned; the bent part of the metal wire is straightened, the metal wire is wound in a straightened state, knotting or loosening of the metal wire in the winding process can be reduced, the limiting assembly assists in adjustment of the tension of the metal wire, and the situation that the metal wire is too tight to be broken, and the winding efficiency is affected is avoided.

A mini-coil magnetic neural stimulator (MCMS) includes a coil that generates magnetic stimulation and a coil driver circuit that controls the magnetic stimulation. The coil driver circuit may include an H-bridge gate driver that includes a plurality of switches that are arranged in the shape of an “H;” a storage capacitor that stores energy that is used to power the coil during the magnetic stimulation. The coil driver circuit may further include a gate driver that controls switching of the plurality of switches. The coil driver circuit may further include a timing signal generation module that generates a first pulse generator a deadtime controller, a second pulse generator, and a zero-current switching controller.

An optical device and a terminal apparatus. The optical device comprises an array substrate (1) and a micromirror structure (2), wherein the array substrate (1) comprises a TFT device (5) and a micro-coil (70); the micromirror structure (2) comprises a binding ball (100) and a mirror body (110); a circle of magnetic particles (120) are provided in an edge area (4) on the mirror body (110); in the direction of the film thickness, one micro-coil (70) is aligned with at least one magnetic particle (120); and the TFT device (5) independently drives the micro-coil (70) to generate a magnetic field, such that the magnetic particles (120) drive the micromirror structure (2) to deflect.

The invention is suitable for the technical field of planar motors, and provides a magnetic field adjusting method of a magnetic suspension planar motor. The magnetic suspension planar motor comprises a rotor assembly and a stator assembly. The rotor assembly comprises a rotor top plate, a controller cabin, an adjustable magnetic array layer and a rotor bottom plate which are connected from top to bottom. The adjustable magnetic array layer comprises a permanent magnet array and a magnetic field reconstruction unit, and the permanent magnet array is formed by arranging a plurality of permanent magnet sub-array units; the magnetic field reconstruction units are arranged in magnetic pole gaps of the permanent magnet array, and each magnetic field reconstruction unit comprises a miniature soft magnetic core and a miniature coil wound on the miniature soft magnetic core; a rotor controller used for receiving an instruction and controlling the current of the micro coil is arranged in the controller cabin; the method is adjusted by controlling the magnetic field reconstruction unit. According to the invention, the problem of poor magnetic flux leakage magnetic field utilization rate caused by physical gaps between rotor permanent magnets in a planar motor is solved.

The invention discloses a server data synchronization method and system, and relates to the technical field of data processing. A sliding piece is fixedly arranged on the side wall in the server cabinet body; the sliding piece is specifically composed of a sliding groove and a sliding block sliding on the sliding groove, the sliding block is fixedly installed at the bottom of the server, data are summarized in a wired and wireless mode, the data modification frequency is dynamically evaluated through an intelligent algorithm, and therefore the synchronization interval is adjusted in a self-adaptive mode, and the resource utilization rate is optimized while the data timeliness is guaranteed; afterwards, data is converted and transmitted through a high-reliability optical waveguide, and an electromagnetic array and a micro coil are innovatively adopted to carry out macroscopic displacement and micron-order precision focusing on an optical path, so that a highly stable dynamic optical signal channel is realized, and the whole process from intelligent data processing to stable and high-speed synchronous transmission is realized.

The invention relates to the technical field of eddy current detection, and discloses a small-gap rotating part surface defect in-situ eddy current detection method which is used for aero-engine blade detection. According to the eddy current detection sensor, the micro coil is embedded on the ultrathin metal sheet with the gradually-changed thickness, namely, the ultrathin metal sheet with the gradually-changed thickness is used as a supporting framework of the micro coil, so that the fine structural design of the eddy current detection sensor is realized; the device has certain rigidity and can extend into a narrow gap between a blade tip and the surface of the inner wall of a casing to implement in-situ detection, and the engineering technical problem that a conventional eddy current detection means cannot be effectively implemented is solved. The method has the advantages of being reliable in detection result, free of missing detection and high in detection efficiency.

The application discloses a single-drive electromagnetic micro-gripper, which comprises a fixed side plate, an FPC coil arranged in the fixed side plate, the FPC coil comprising a plurality of planar coils, and a first clamping arm arranged at one end of the fixed side plate; a movable side plate connected to the fixed side plate and arranged opposite to the fixed side plate, a permanent magnet arranged in the movable side plate, and a second clamping arm arranged at one end of the movable side plate; when the FPC coil is electrified, the FPC coil generates a magnetic field and exerts a force on the permanent magnet, the permanent magnet and the movable side plate move together, and the second clamping arm is driven to move towards or away from the first clamping arm. The FPC coil is made by FPC technology, is a planar micro coil, has small size and good reliability, is convenient to assemble in the fixed side plate to control the overall volume of the gripper, can effectively reduce the size of the micro gripper while providing sufficient driving force, realizes miniaturization of the electromagnetic micro gripper, has high displacement precision, can achieve fast response, and improves the accuracy, stability and rapidity of clamping.

The utility model discloses a non-contact UART (Universal Asynchronous Receiver / Transmitter) communication device, which relates to the field of shared charging and comprises a transmitting end and a receiving end. The transmitting terminal comprises a first microprocessor used for generating a UART signal and outputting the UART signal to a coil driving unit; the coil driving unit is used for driving current change based on the UART signal after receiving the UART signal and outputting the current change to the micro coil; compared with the prior art, the utility model has the beneficial effects that non-contact UART (Universal Asynchronous Receiver / Transmitter) communication is realized by utilizing the micro coil (transmitting end) and the switch-type Hall device (receiving end), and transmission data is modulated and demodulated through a magnetic field, so that physical contact abrasion is avoided, and the service life of equipment is prolonged; compared with wireless communication schemes such as Bluetooth, WiFi and the like, the cost of the micro coil and the Hall device is far lower than that of a Bluetooth module and a WiFi module; the method is directly compatible with a standard UART protocol, and the existing charge pal main control logic does not need to be modified

The invention discloses a multi-node coordinated regulation passive micro-magnetic stimulation system of a distributed structure, and belongs to the field of biomedical engineering. Firstly, a multi-node coordinated control passive micro magnetic stimulator of a distributed structure is designed, and the passive micro magnetic stimulator is composed of a transmitting coil, an identification coil, a micro coil (a stimulating coil and addressing coil assembly unit), a rectifying circuit and a crystal oscillator; secondly, based on the structure and characteristics of the micro-coil, designing a rectifying circuit for supplying power to a crystal oscillator so as to excite the addressing coil; then, a signal acquisition and frequency analysis module is established and is used for performing acquisition and frequency analysis on a frequency response signal of the micro-coil; and finally, each node micro-coil is identified, so that the positioning of the micro-coils and the monitoring of the cooperative working state are realized, multi-node cooperative magnetic stimulation is carried out, the long-term enhancement effect of the brain hippocampus CA1 region is enhanced, and the system has the potential ability of improving learning and memory.

The invention provides a multifunctional tool for winding a miniature coil. The multifunctional tool comprises a mandrel, the core shaft is sleeved with a starting end fixing mechanism and a tail end fixing mechanism, and a coil frame connected to the core shaft in a sleeving mode is arranged between the starting end fixing mechanism and the tail end fixing mechanism. The starting end fixing mechanism is provided with an enameled wire protective film fixing reed and a protective film, and the enameled wire protective film fixing reed, the protective film and the coil rack are matched with one another to work; one end of the mandrel is a threaded section, and a flat gasket and a nut are sequentially arranged on the threaded section; one end of the initial end fixing mechanism is provided with a pressure spring sleeved on the mandrel, and the pressure spring is adjacent to the flat gasket; the head and tail end fixing mechanism comprises a wire pressing block and a wire positioning block, and the wire positioning block of the head and tail end fixing mechanism is connected with the coil rack. According to the invention, the leading-out wire and the coil rack are combined together, multiple functions of micro coil winding, pin winding and varnished wire starting end protection on a winding machine are realized, and convenient conditions are provided for realizing automation of subsequent processes.

This invention discloses a back EMF detection circuit for a brushless motor controller used in automotive cooling fans, relating to the field of motor technology. Key technical features include a stator with a rotor rotatably connected to its center. A circuit board is mounted on the top of the stator, and a miniature coil is mounted on the circuit board. A lubrication device is rotatably connected to the center of the rotor. The circuit board also integrates a back EMF detection circuit, which includes a signal sampling unit, a filtering and shaping unit, and a comparison and judgment unit connected in sequence. The miniature coil is electrically connected to the output of the back EMF detection circuit. When the comparison and judgment unit detects a back EMF signal indicating that the rotor is in an inertial rotation or driven by airflow, it triggers the miniature coil to operate. This invention accurately identifies recoverable kinetic energy states through the back EMF detection circuit, converting the mechanical energy of wind-driven or inertial rotation into control signals to drive the lubrication, heat dissipation, and dust removal systems in synergy.

The present invention discloses a magnetic compensation system structure for a miniature atomic inertial device, comprising: a Y-axis microcoil pair, a Z-axis microcoil pair, an X-axis microcoil pair, a support and limit base, and a printed circuit board. The X-axis and Z-axis microcoil pairs are perpendicular to the printed circuit board, while the Y-axis microcoil pair is parallel to the printed circuit board. The microcoil pairs for the X, Y, and Z axes are nested and orthogonal to each other and placed on the support and limit base to generate a magnetic field to compensate for static residual magnetism and magnetic field disturbances. The support and limit base is located on the printed circuit board, accommodating an air chamber and providing positional support for the three-axis microcoil pairs. The printed circuit board is located at the bottom layer of the structure and provides peripheral electrical connections and current transmission for the three-axis coil pairs. Compared to the traditional miniaturization method of proportionally reducing PCB coils, the present invention provides an effective structural solution with the advantages of higher processing accuracy, lower cost, and higher positioning and alignment accuracy.

The invention discloses a multi-time controllable tMCAO model construction method for simulating recurrent cerebral infarction. The method is suitable for research on focal cerebral ischemia of rats. According to the method, a shape memory silk thread is implanted under the skull skin of a rat along a preset path, and the two ends of the shape memory silk thread are guided to symmetrical positions to be fixed, so that the silk thread forms a closed structure capable of surrounding the middle cerebral artery. The silk thread is connected to the stretching end outside the scalp, tension is applied through a micro tension control device composed of a spiral knob, a tension pulley or a micro coil, the silk thread is tightened in the body to form a blood vessel blocking state, and ischemia is induced. After tension is relaxed, the silk thread rebounds, and compression is relieved to recover blood flow. By means of repeated tensioning and releasing operation, multiple ischemia-reperfusion cycles are achieved under the condition that the implantation device is not replaced, the recurrent cerebral infarction pathological process is simulated, an experimental model is built in combination with control parameters and blood flow change data, and good controllability, repeatability and applicability are achieved.