99 results about "Low frequency magnetic field" patented technology

The invention provides an adipose-derived stem cell composition for wound repair as well as a preparation method and application thereof, and belongs to the technical field of stem cells. The method comprises the following steps: adding fetal calf serum, dexamethasone, penicillin, streptomycin, collagen, magnetic particles and a P substance into a DMEM culture medium to prepare a culture medium, performing low-frequency magnetic field culture and separation on adipose-derived stem cells to obtain a stem cell solution, performing embedding to obtain stem cell microspheres, freeze-drying supernate to obtain a paracrine culture substance, and performing freeze-drying on the paracrine culture substance to obtain the adipose-derived stem cells. The adipose-derived stem cell composition for wound repair is prepared by mixing the adipose-derived stem cell with stem cell microspheres, hydroxypropyl methyl cellulose, carboxymethyl chitosan, hyaluronic acid, glycerol and stem cell microspheres, has better effects of implanting into damaged tissues, releasing nutrient substances, promoting neovascularization, regulating oxidative stress and inducing anti-inflammatory response, is beneficial to wound repair, and has a good application prospect. The gel can be converted into a gel phase at the skin epidermis temperature of 35-37 DEG C, components are stabilized, and sustained and controlled release is realized.

According to the displacement modulation and optical assistance-based SERF atom magnetometer magnetic imaging method, an SERF atom magnetometer integrated with a magnetic flux guider is used as a magnetic sensor, and low-frequency magnetic field modulation is introduced to the magnetic sensor by controlling a to-be-tested sample to perform periodic infinitesimal displacement in the sensitive direction of the magnetic sensor; the modulation signal is demodulated by combining a phase-locked amplification technology, and a magnetic response signal subjected to phase-locked demodulation at each spatial position is extracted; constructing a magnetic response matrix through two-dimensional track scanning of micron-order step pitch; an image acquisition module and a reflection optical assembly are introduced for spatial registration so as to monitor the relative position in real time, and the visibility and controllability of the magnetic imaging process are guaranteed; the point-by-point detection of fT-level weak magnetic signals can be realized on the premise that an array structure is not needed; the low-frequency noise interference can be effectively inhibited, the stability and definition of direct-current and low-frequency magnetic field imaging are improved, and the method is suitable for high-resolution space imaging application of weak magnetic sources such as magnetic domain structures, nervous tissue slices and ancient rock samples.

According to the cable multi-parameter fusion sensor and method, in the cable multi-parameter fusion sensor, a shielding shell is of an open-close type metal annular structure; the zero-flux sensor module is arranged on the inner layer of the shielding shell so as to detect a cable sheath ring current signal; the pulse current sensor module is arranged on the outer side of the zero-flux sensor module so as to detect a cable partial discharge pulse current signal and an overvoltage impact current signal; the magnetic shielding layer is arranged between the zero-flux sensor module and the pulse current sensor module to shield low-frequency magnetic field interference; the zero magnetic flux sensor module and the pulse current sensor module share the shielding shell to form an electromagnetic shielding structure.

The invention discloses a magnetic positioning system, which relates to the technical field of magnetic field measurement and positioning and is used for realizing six-degree-of-freedom real-time tracking of a tracking target in a space range. A magnet is carried on a rotating bearing, a controller is adopted to drive a motor, a low-frequency magnetic field signal is generated, a magnetic sensor measures the generated magnetic signal, real-time rotating information output by an angle encoder for fixing a rotating shaft of the motor is combined, and space pose information of the sensor is solved through a calculation program. The system can realize instantaneous positioning of low-frequency periodic magnetic signals, solves the problems that a low-frequency magnetic field positioning technology is slow in speed and a high-frequency magnetic field positioning technology is easily interfered by metal, improves the convenience and stability of a magnetic positioning method, and reduces the cost of the magnetic positioning method.

The invention provides a stem cell extract composition for promoting hair growth and a preparation method thereof, and belongs to the technical field of cosmetics. Fetal calf serum, dexamethasone, penicillin, streptomycin, interleukin-2 and magnetic composite particles are added into a DMEM culture medium to prepare the culture medium, the culture medium is used for in-vitro culture of stem cells, during culture, a stem cell solution is prepared by combining a low-frequency magnetic field with low-energy laser culture, exosomes are extracted from an extracting solution, the exosomes and the stem cells are mixed and embedded to prepare embedded microspheres, and the embedded microspheres are used for in-vitro culture of the stem cells. The stem cell extract composition for promoting hair growth is prepared by uniformly mixing the stem cell extract with extracts extracted from fresh ginger, ginseng and polygonum multiflorum, the storage stability of stem cells and exosomes is obviously improved, hair growth is promoted, hair follicle development is promoted, mouse hair is induced and maintained in a growth period, and the stem cell extract composition is free of hormone addition, safe and non-irritant, and has a good application prospect. Wide application prospects are realized.

Inductor component (100) in SMD package for low-frequency magnetic fields, comprising a housing (102) with a housing base (104) for mounting on a printed circuit board, three windings arranged within the housing (102), in particular essentially orthogonal to each other, along an X, Y and Z winding axis, a plurality of connection contacts (110) arranged on the housing base (104), and a pin configuration with at least two electrical interconnections (130, 132) permanently manufactured within the housing (102), wherein each of the electrical interconnections (130, 132) electrically connects two specific terminal contacts (110) and the terminal contacts (110) are assigned to the winding ends of the X, Y and Z windings, so that each winding can be electrically connected via the terminal contacts (110).

The invention discloses an optical coupler isolation-based inertial measurement device temperature control noise suppression method, which is characterized in that electrical isolation is added between a temperature control module and a power amplification circuit, and electromagnetic noise reflection of a power element is suppressed, so that low-frequency magnetic field noise in an SERF inertial measurement device alkali metal air chamber temperature control process is suppressed. Comprising the steps that a high-frequency heating signal isolation circuit is arranged in a temperature control system of the inertial measurement device, the high-frequency heating signal isolation circuit is an optocoupler isolation circuit, and an optocoupler input side containing a light-emitting diode in the optocoupler isolation circuit is connected with an input signal from a temperature control circuit through an input signal modulation circuit; the optocoupler output side, comprising a photodiode, in the optocoupler isolation circuit transmits an output signal to a power amplification circuit which drives a heating film through a high-frequency heating signal through an output signal demodulation circuit, and the optocoupler output side and the output signal demodulation circuit are both connected with a second power supply. The optocoupler input side and the input signal modulation circuit are connected with a first power supply.

The invention relates to an optical fiber ring module with high magnetic shielding performance and a manufacturing method thereof, and solves the technical problem of limited magnetic shielding performance in the prior art. The shielding device comprises a base, a shielding framework sleeving the base and a shielding bottom cover, an optical fiber ring is arranged in the shielding framework; a Y waveguide, a coupler and a temperature sensor are mounted on the base; a first-layer upper shielding cover and a first-layer lower shielding cover are respectively arranged on the outer layer to realize first-layer full magnetic shielding; a second-layer upper shielding cover, a second-layer shielding cylinder and a second-layer lower shielding cover are correspondingly connected to realize second-layer full magnetic shielding; and a third-layer shielding cover is arranged, and the third-layer shielding cover and the third-layer shielding sleeve are correspondingly connected to realize third-layer full-magnetic shielding. Wherein the first magnetic shielding layer and the third magnetic shielding layer are made of magnetic conductive materials so as to shield interference of a low-frequency magnetic field, the middle second magnetic shielding layer is made of conductive materials so as to shield interference of a high-frequency magnetic field, and the magnetic shielding performance is improved through three-layer full magnetic shielding coating.

The EPDM conductive shielding composite material comprises the following raw materials in parts by weight: 100 parts of EPDM rubber, 55-60 parts of a softening agent, 8-10 parts of an inorganic filler, 25-30 parts of carbon nanotubes, 85-98 parts of carbon black, and 7-11 parts of an accelerant and a vulcanizing agent. The ethylene propylene diene monomer is adopted as a main material, the weather aging resistance is excellent, the strength is high, the extrusion process is good, and the long service life and the high strength of the material are guaranteed; the carbon nanotubes and the carbon black are selected as conductive materials, the conductivity and the surface smoothness of the product can be improved by utilizing the excellent conductivity and self-lubricating effect of the carbon nanotubes, and the surface of the product has the self-lubricating effect and is not easy to damage; the carbon black can effectively improve the conductivity of the product and the strength of the material, the stiffness is good in the extrusion process of the coreless support, and the structure of the product is not easy to deform; the material has the advantages of high tensile strength, high elongation and small resistance, can be used for shielding low-frequency magnetic fields and high-frequency magnetic fields, and has good shielding performance.

A method of data transmission includes transmitting a magnetic signal that is modulated with the bit stream, the magnetic signal having a nominal frequency and being formed of a high frequency and a low frequency, the nominal frequency being the average frequency of the magnetic signal. The bit stream is modulated onto the magnetic signal by encoding the bit stream into the magnetic signal, where each bit in the bit stream is represented by a transition between adjoining data symbols formed of K repetitions of a first state or a second state. The first state of the pair of states includes M / 2 cycles of the nominal frequency with a signal at the high frequency and M / 2 cycles of the nominal frequency with a signal at the low frequency. The second state is complementary to the first state.

A fully integrated micro search coil magnetometer (μSCM) with a low-noise instrumentation amplifier is provided for low-frequency magnetic field measurements in the range of 1Hz to 1kHz. A micro search coil formed by stacking planar spiral inductors and serially connecting them with an in-phase configuration is used for magnetic field measurements. The critical line width and inner diameter of a planar spiral inductor are theoretically calculated and experimentally verified, enabling the development of a unique CMOS layout. This layout incorporates the calculated critical inner diameter, significantly optimizing the area utilization on the CMOS die. Additionally, the CMOS die includes a polysilicon-layer inductor for on-chip calibration, a Hall effect sensor for DC magnetic field measurement, and a temperature sensor for enhanced functionality. The μSCM delivers a compact, energy-efficient, and highly sensitive solution for low-frequency magnetic field measurements, surpassing the performance of most commercially available Hall effect sensors.

The invention discloses a multi-frequency point calibration test method and system for 0-10 Hz ultralow frequency magnetic field immunity. The method comprises the steps of system building, single frequency point reference calibration, test execution and exception handling. When the system is built, the hardware modules are connected according to a specific mode; in the calibration stage, references are established for frequency points of 2Hz, 4Hz, 6Hz and 8Hz; during testing, precise field intensity control and data recording are realized through combination of coarse adjustment and fine adjustment; and verifying the probe position when abnormity occurs. The system comprises an arbitrary function generator, a power amplifier, a radiation ring and a gauss meter, and parameters of each module are adaptive to a frequency band of 0-10Hz. The field intensity larger than or equal to 1000 A / m can be stably generated, the testing precision is improved, the 0-10 Hz frequency band standard testing blank is filled, and the device is suitable for electronic equipment testing in the fields of industrial automation, new energy automobiles and the like.

The utility model provides a human body model-based low-frequency magnetic field test system, which comprises a human body model, a plurality of organ models and a data acquisition instrument are arranged in the human body model, each organ model is provided with a plurality of magnetic field probes, and the data acquisition instrument is arranged below the organ models and connected with the magnetic field probes. The human body model is filled with an electrolyte solution, and the organ model and the data acquisition instrument are both placed in the electrolyte solution. The magnetic field probe solves the problems that in the prior art, a used magnetic field probe with a fixed shape and a fixed size is greatly different from an actual human organ, and the magnetic field environment neglects the influence of human skin and in-vivo tissue fluid, so that measured magnetic field data is inaccurate.

Mobile response device (MRD) and methods and systems of using the same. Sets of MRDs are configured and deployed in a given facility, mounted to moving objects such as robots or autonomous vehicles, and / or worn by personnel. The MRD is compact and relatively low in cost to manufacture, incentivizing its wider use for increased overall safety at facilities, such as fulfillment facilities or warehouses configured with very narrow aisles (VNA) and open pedestrian zones shared with vehicles. The MRD is equipped with two tuned circuits to detect low frequency magnetic field pulses along perpendicular horizontal axes and a radio transmitter that transmits radio frequency signals when a low frequency magnetic field pulse has been detected, notifying the vehicle that generated the low frequency magnetic field pulse of the nearby presence of the MRD such that anti-collision measures can be initiated.

Tumor glycocalyx may be regarded as a glycan “canopy” above the tumor plasma membrane. Disclosed are methods of treating a neoplastic malignant cell cancer wherein the neoplastic malignant cancer cell has a malignant glycocalyx B. Also disclosed are methods of inducing apoptosis of one or more neoplastic malignant cells and methods of increasing a subject's responsiveness to an immunotherapy wherein the neoplastic malignant cancer cell has a malignant glycocalyx B.

1. The name of the product of this design: Control device for low-frequency magnetic field generating device. 2. Purpose of this design product: used to control the power supply to the low-frequency magnetic field generating device. 3. The design key point of this appearance design product lies in the shape. 4. The picture or photo that best illustrates the design points: three-dimensional picture.

A dock area control system includes a vehicle proximity detection system (PDSC). The PDSC includes a vehicle low frequency magnetic field generator (MFG) that generates a vehicle pulsed magnetic field that is sensed by a dock area controller electronics module (DEM).

A method of data transmission includes transmitting a magnetic signal that is modulated with the bit stream, the magnetic signal having a nominal frequency and being formed of a high frequency and a low frequency, the nominal frequency being the average frequency of the magnetic signal. The bit stream is modulated onto the magnetic signal by encoding the bit stream into the magnetic signal, where each bit in the bit stream is represented by a transition between adjoining data symbols formed of K repetitions of of a first state or a second state. The first state of the pair of states includes M / 2 cycles of the nominal frequency with a signal at the high frequency and M / 2 cycles of the nominal frequency with a signal at the low frequency. The second state is complementary to the first state.

This suppresses the decrease in current measurement accuracy caused by the skin effect. [Solution] The current sensor comprises a shield having an opening for taking in a magnetic field generated by a current flowing through a conductor, a magnetic field sensor disposed inside the shield and outputting a sensor voltage corresponding to the magnetic field at that location, and a detection circuit disposed outside the shield and detecting a current based on the sensor voltage of the magnetic field sensor, wherein the magnetic field sensor includes a first magnetic field sensor for detecting low-frequency magnetic fields and a second magnetic field sensor for detecting high-frequency magnetic fields, the first magnetic field sensor being disposed closer to the opening than the second magnetic field sensor, and the second magnetic field sensor being disposed further from the opening than the first magnetic field sensor.

The present application relates to a kind of low-frequency magnetic field generator for rat electromagnetic experiment and its uniform area measuring method, the method includes the following steps: S1, analysis display terminal calculates the magnetic induction intensity distribution of Helmholtz coil under given condition, and according to the change of magnetic induction intensity relative error determines the uniform area of magnetic field distribution, is recorded as reference area, corresponding boundary is reference boundary;S2, using magnetic field probe coil measures the magnetic induction intensity on reference boundary;S3, least square method is applied to obtain the measured boundary of magnetic field distribution uniform area;S4, according to the average absolute percentage error of magnetic induction intensity at measured boundary and reference boundary determines its actual uniform boundary;S5, analysis display terminal displays the actual uniform area of Helmholtz coil magnetic field distribution under given current amplitude and frequency, for rat electromagnetic experiment.Compared with prior art, the present application has the advantages of obtaining accurate magnetic field uniform area, reducing test workload and the like.

A system and method for applying a low strength, low frequency magnetic field therapy to biological tissues. A coil is excited with a low frequency oscillating current, e.g., 10-1000 Hz. The coil is, e.g., 5-200 turns, having a diameter of 2-20 mm, and produces a magnetic field strength of about 0.01-5 mTelsa at a distance of 1 cm from the coil, or a cover over the coil, into the tissue. The current is preferably controlled by a smartphone or other programmable device controlled by a downloadable app in accordance with a PEMF program which may be separately downloaded or updated, and provided through an audio jack. Alternately, a digital interface and / or wireless interface may control the current. An app on the smartphone may be used to control the frequency, amplitude / envelope modulation, waveform, duration, etc. of the oscillation. The coil may be in mineral housing with a simple filter, and TRRS-type audio jack.

The utility model discloses a protection mechanism for a low frequency magnetic field receiving device, which relates to the field of electronic engineering and comprises a low frequency magnetic field receiver and a shell arranged on the outer side of the low frequency magnetic field receiver, a clamping assembly is fixedly connected in the shell and comprises two electric push rods slidably connected to the inner side wall of the shell, and the two electric push rods are arranged on the inner side wall of the shell. One end of the electric push rod is fixedly connected with a connecting plate, one side of the connecting plate is fixedly connected with a telescopic rod, the outer side of the telescopic rod is fixedly sleeved with a spring, one end of the spring is fixedly connected with a protection plate, the protection plate abuts against the low-frequency magnetic field receiver, and the protection plate is fixedly connected with a trigger button. The connecting plate abuts against the trigger button in a matched mode, and the trigger button is electrically connected with the electric push rod. According to the low-frequency magnetic field receiver clamping device, the trigger button and the connecting plate are matched and abut against each other through the thrust of the electric push rod, so that the low-frequency magnetic field receiver is stably clamped, and meanwhile the clamping force can be prevented from being too large.

This application discloses a personnel rescue method based on low-frequency magnetic field communication, comprising: real-time acquisition of vital sign information of the person to be rescued to construct personnel status information; encoding the personnel status information to generate personnel status data; real-time modulation of a low-frequency magnetic field signal using the personnel status data to generate a corresponding real-time personnel status signal and radiating it outward; real-time reception of the personnel status signal using multiple magnetic field receiving units not on a straight line; and determination of the location, identity information, and vital status of the person to be rescued based on the personnel status signal. This application utilizes the physical characteristic of low-frequency magnetic field signals having minimal attenuation when penetrating obstacles such as rock layers and soil, combined with improved pulse coding technology, to achieve simultaneous detection of vital sign data, location, and identity information of trapped personnel, providing accurate and powerful reference information for optimizing rescue plans and significantly improving the efficiency of personnel rescue.

Example positioning system based on a low frequency magnetic field and apparatus are described. One example positioning system includes a low frequency magnetic field transmit apparatus and a low frequency magnetic field receive apparatus. The transmit apparatus includes a transmit coil, a conflict detect coil, and a magnetic field generation detection control module. The receive apparatus includes a receive coil and a magnetic field detection control module. When the conflict detect coil does not sense a low frequency magnetic field signal, the magnetic field generation detection control module controls the transmit coil to transmit a first low frequency magnetic field signal. When the received low frequency magnetic field signal is the first low frequency magnetic field signal, the magnetic field detection control module determines relative positions of the transmit coil and the receive coil based on signal strength of the first low frequency magnetic field signal.

The invention relates to the technical field of tracking and positioning, and provides a position detection method, device and system and a storage medium. The method is used for detecting the position of a to-be-detected object, and the to-be-detected object is provided with a receiver. The method comprises the following steps: controlling at least two magnets in an emitter matched with the receiver to rotate to generate a low-frequency magnetic field; receiving a magnetic field change induction electric signal obtained by a coil in a receiver in the low-frequency magnetic field; and determining the position of the to-be-detected object based on the magnetic field change induction electric signal. According to the scheme, position detection is achieved through the magnetic field change induction electric signal generated by the low-frequency magnetic field in the coil, interference of a metal conductor on the position detection device can be reduced, the size of the coil can be flexibly customized, the application scene of the position detection method is expanded, and the detection precision is improved.

The invention discloses a low-frequency weak magnetic field calibration device and method. The device comprises a magnetic shielding chamber, a multi-layer permalloy shielding cylinder, an integrated ferrite shielding cylinder, a torque-free coil, a shunt, a low-frequency magnetic field excitation source, a data collector and an automatic magnetic eraser. The multi-layer permalloy shielding cylinder, the integrated ferrite shielding cylinder, the torque-free coil, the shunt, the low-frequency magnetic field excitation source and the data collector are all located in the magnetic shielding chamber; the integrated ferrite shielding cylinder is nested in the multi-layer permalloy shielding cylinder, and the torque-free coil is placed in the integrated ferrite shielding cylinder and used for reproducing a weak magnetic field; a calibrated magnetic sensor is placed in a working area of the torque-free coil, and magnetic axes of the two are parallel; the low-frequency magnetic field excitation source supplies power to the torque-free coil through the shunt, and the data collector collects output signals of the calibrated magnetic sensor. The automatic demagnetizer is used for demagnetizing the multi-layer permalloy shielding cylinder and the integrated ferrite shielding cylinder. The magnetic field noise is low, the lower limit of the reproduction magnetic field is low, and the external interference resistance is high.

This invention discloses a mobile terminal-based contactless anti-theft method and device based on the frequency domain characteristics of low-frequency magnetic fields. The method involves activating a magnetic field transmitting module to emit a set low-frequency magnetic field. Based on this magnetic field, a dual-mode sensing receiver collects raw three-axis magnetic field data. After high-pass filtering to remove the DC component of the Earth's magnetic field, three-dimensional AC magnetic field data is obtained. The Euclidean norm of the three-dimensional AC magnetic field data is calculated, converting it into a one-dimensional scalar signal. Based on this one-dimensional scalar signal, the Gosser algorithm is used to extract the magnetic field energy value corresponding to the target frequency in the magnetic field. The data is then demodulated and the area identification code is verified to obtain the verification result. Combining the magnetic field energy value and the verification result, a hysteresis comparison and multi-level decision logic are used to determine the security status of the protected object. When the alarm triggering conditions are met, the corresponding alarm operation is executed. This invention solves the problems of poor physical connection experience, susceptibility to false alarms due to wireless radio frequency obstruction, and high hardware tag costs in existing technologies.

The invention provides a weight-losing composition containing mesenchymal stem cells as well as a preparation method and application of the weight-losing composition, and belongs to the technical field of medicines. Eurotium cristatum and lactobacillus plantarum are used for fermenting white tea and dark green tea, probiotics are collected and embedded to prepare embedded probiotics, tea residues are subjected to supercritical fluid extraction, oxidation and extraction to prepare a tea brown composition, fetal calf serum, dexamethasone, penicillin, streptomycin, magnetic particles and interleukin-2 are added into a DMEM culture medium, a culture medium is prepared, and the white tea and dark green tea are prepared. The preparation method comprises the following steps: carrying out low-frequency magnetic field culture and separation on adipose-derived stem cells to obtain a stem cell solution, embedding to obtain stem cell microspheres, freeze-drying supernate to obtain a paracrine culture substance, and uniformly mixing the paracrine culture substance with a fermentation product, a brown composition and embedded probiotics to obtain the weight-losing composition containing the adipose-derived stem cells. The health-care food not only has good anti-oxidation, anti-inflammatory, antibacterial and blood sugar and blood fat regulating effects, but also has a good weight-losing effect, and has a wide application prospect.

Inductor component (100) in SMD package for low-frequency magnetic fields, comprising a housing (102) with a housing base (104) for mounting on a printed circuit board, three windings arranged within the housing (102), in particular essentially orthogonal to each other, along an X, Y and Z winding axis, and Connection contacts (110) arranged on the base surface (104) in a pad layout (108), wherein the dimensions of the housing base (104) and the dimensions of the connection contacts (110) provide a flat design profile with a predetermined coplanarity of the connection contacts (110), preferably with a coplanarity of at most 0.10 mm for an AOI-optimized design and at most 0.15 mm for a standard design.

The application provides a train low-frequency magnetic field interference detection method and device, the method comprises the following steps: acquiring the magnetic field intensity of the area where the train is located and the induced voltage generated by the first coil in the area when rotating; matching the corresponding relationship curve of the magnetic field intensity of the area and the induced voltage of the first coil from the relationship curve of the magnetic field intensity and the induced voltage; wherein the relationship curve is the relationship curve under different frequencies in the preset low-frequency frequency band; determining whether the train is interfered by the low-frequency magnetic field according to whether the relationship curve is matched or not. The application improves the accuracy of train low-frequency magnetic field interference detection, reduces the detection cost and is simple to operate.