10229 results about "Nuclear physics" patented technology

A system for administering transcranial magnetic stimulation in which two or more coils are applied to the patient's body. The coils each may emit a magnetic field which when positioned in one or more configurations result in field overlapping. Magnetic field overlap achieves therapeutic effects otherwise difficult, or impossible, to achieve from traditional single coil TMS devices.

A driving method of a transcranial magnetic stimulation 3D coil device is disclosed, which includes: determining first and second signal peaks corresponding to a specified rotating magnetic field direction, in which the first and second signal peaks respectively correspond to first and second coils in multiple coils; providing a first pulse current having the first signal peak to the first coil, in which the first pulse current signal stimulates the first coil to provide a first magnetic field; providing a second pulse current signal having a second signal peak to the second coil, in which the second pulse current signal stimulates the second coil to provide a second magnetic field, in which the first magnetic field and the second magnetic field form a rotating magnetic field having the specified rotating magnetic field direction.

A nuclear fusion reaction device, system and method. The outer wall of a vacuum chamber (301) in the nuclear fusion reaction device (30) comprises an inner ring surface (M1) and an outer ring surface (M2) which are connected to each other; the outer ring surface (M2) surrounds the inner ring surface (M1); the inner ring surface (M1) protrudes toward the central axis of the vacuum chamber (301); the vacuum chamber (301) surrounds a plurality of first coils (302); at least some of the plurality of first coils (302) extend in the circumferential direction of the inner ring surface (M1) and are sequentially arranged in the axial direction of the vacuum chamber (301); a plurality of second coils (303) surround the vacuum chamber (301), extend in the circumferential direction of the outer ring surface (M2), and are sequentially arranged in the axial direction of the vacuum chamber (301); a plurality of third coils (304) all surround the vacuum chamber (301) and are sequentially arranged in the circumferential direction of the vacuum chamber (301); and the plurality of first coils (302), the plurality of second coils (303), and the plurality of third coils (304) are used for generating a magnetic field, such that plasma rings with negative triangular deformation are generated in the vacuum chamber (301), and a fusion reaction occurs.

MRI interference with a co-existing ultrasound system may be reduced or avoided by carrying out RF-sensitive operations of the treatment system only when gradient field activity of the MRI system is suppressed.

The present invention discloses an electrophysiological catheter having a distal microelectrode assembly, the distal microelectrode assembly having a covered ridge carrying a plurality of microelectrodes. The microelectrode assembly includes a first ridge radiating away from the longitudinal axis and a second ridge adjacent to the first ridge and radiating away from the longitudinal axis, the first ridge having a plurality of first microelectrodes disposed thereon. The second ridge has a plurality of second microelectrodes disposed thereon such that a first virtual circle intersecting one of the plurality of first microelectrodes does not intersect any of the second microelectrodes.

The invention relates to the field of medical equipment, and provides a compact multi-chamber proton treatment system based on a shared beam line, and the system comprises a fixed beam transmission line which is used for guiding the movement direction of a proton beam into a vertical direction; the rotating beam transmission line is used for guiding the movement direction of the proton beam into the horizontal direction; one end of the fixed beam transmission line is connected with the proton cyclotron, the other end of the fixed beam transmission line is connected with one end of the rotary beam transmission line, and the other end of the rotary beam transmission line is in butt joint with a plurality of treatment rooms; the rotating beam transmission line rotates around a central axis extending in the vertical direction. According to the invention, the proton beam can be safely, efficiently and accurately transmitted to each treatment room, and a fixed beam transmission system and a rotating rack do not need to be independently arranged for each treatment room, so that the beam control assembly and the system occupied area of the multi-room particle treatment device are minimized, and the number of treated patients can be remarkably increased.

The invention relates to the technical field of medical cyclotrons, in particular to a medical cyclotron magnetic field intensity adjusting method based on temperature compensation, and the method comprises the following steps: in the process of adjusting the magnetic field intensity of a main magnet based on temperature information, obtaining a temperature variation threshold: collecting the temperature on the surface of the main magnet in real time; determining a temperature difference coefficient, a temperature anomalous coefficient, a temperature abnormal coefficient and a trend approximate value of each acquisition moment; comprehensively analyzing the temperature values acquired by all the sensors, and determining the temperature difference degree and difference factor of each sensor at each acquisition moment; determining the avoiding adjustment value of each sensor at each acquisition moment; and acquiring a temperature variation threshold value at each acquisition moment. The invention aims to solve the problem that the magnetic field intensity of the cyclotron cannot be adjusted according to the actual environment temperature, so that the beam stability and the beam extraction efficiency in the operation process of the medical cyclotron are improved.

The invention discloses an MRI (Magnetic Resonance Imaging) image segmentation method based on WKA-Unet. The MRI image segmentation method comprises the following steps: 1) data preprocessing; 2) constructing a WKA-Unet network; and 3) testing. According to the technical scheme, on the basis of a U-Net network structure, an MRI image segmentation model is improved; a traditional Unet network is combined with a self-designed WKA module, multi-scale features are fully captured by using wavelet transform convolution and KAN convolution, and the loss of traditional Unet global information is relieved; an attention mechanism is introduced to pay attention to key parts, and redundant information is removed; according to the technical scheme, the network is trained more flexibly and accurately, a more accurate segmentation result is obtained, the segmentation precision is high, and the model structure is efficient and stable.

The utility model relates to the technical field of electron beam transmission, in particular to a magnet system. Comprising a first shaping unit and a second shaping unit, and the first shaping unit comprises first quadrupole iron tightly attached to an outlet of the accelerating tube and first octupole iron arranged at the focus position of the first quadrupole iron; the second shaping unit comprises second quadrupole iron and second octupole iron, the second quadrupole iron and the first octupole iron meet a first preset distance, the second octupole iron is arranged at the focus position of the second quadrupole iron, and the second shaping unit and the radiation field area meet a second preset distance; the inner diameter of the first octupole iron and the inner diameter of the second octupole iron are both larger than or equal to the maximum size of an electron beam group. Therefore, the quadrupole iron and the octupole iron are utilized to form the shaping unit which is homogenized in one direction, so that the problems that in the prior art, in the electron beam transmission process, a large amount of dose is lost, the size of a radiation field is limited, and the radiation field cannot be adjusted at will are solved; therefore, the electron beam bunch generated by the linear accelerator can be expanded and homogenized in a short distance.

A positron emission tomography (PET) scanner includes a plurality of gamma radiation detector modules arranged to form a detector ring. Each detector module includes an array of scintillator detectors. Each scintillator detector comprises a monolithic scintillation crystal and a plurality of photodetector arrays, such as silicon photomultipliers (SiPMs). A photodetector array is positioned on at least two nonparallel faces of each scintillation crystal. In some examples, a photodetector array is positioned on each of three orthogonal faces of each scintillation crystal.

The invention relates to the technical field of analysis and detection, in particular to a method for identifying free nucleic acid and nucleic acid wrapped by a carrier based on nuclear magnetic resonance phosphorus spectrums.The method comprises the following steps that 1, the free nucleic acid serves as a contrast, nuclear magnetic resonance phosphorus spectrum detection is conducted, and a nuclear magnetic phosphorus spectrogram of the free nucleic acid is obtained; (2) taking the nucleic acid combined with the carrier as an experimental group, and performing nuclear magnetic resonance phosphorus spectrum detection under the same condition to obtain a phosphorus spectrogram of the experimental group; and (3) comparing the characteristic changes of peak positions, peak shapes, peak heights, peak areas and the like of the experimental group and the control group to identify the free nucleic acid and the nucleic acid wrapped by the carrier. The method has good accuracy, repeatability and stability, can be used for nondestructive testing, and is suitable for analyzing sensitive samples. The method can be used for detecting the binding condition of a carrier and nucleic acid in a nucleic acid drug, predicting the encapsulation efficiency and release rate of the nucleic acid drug, and providing an important analysis tool for opening, production and quality control of the nucleic acid drug.

The invention provides a microdosimetry-based evaluation method for a targeted alpha radionuclide treatment biological effective dose, and the method comprises the steps: carrying out the integration of a time activity curve of alpha radionuclide in an organ, obtaining the cumulative activity, and calculating the physical absorbed dose and dose rate of the organ through Monte Carlo simulation; based on micro-dose Monte Carlo simulation, constructing a micro-dose spectrum of the alpha radionuclide to obtain saturation correction dose average linear energy for representing radiation quality; obtaining biological effect parameters of the alpha radionuclide by fitting saturation correction dose average line energy and cell experiment data by using a micro-dose kinetic model; and evaluating the biological effective dose of the target organ in combination with the physical absorbed dose, the dose rate and the biological effect parameter. According to the method, the problem that a biological effective dose evaluation method is lacked in dose evaluation of targeted alpha radionuclide treatment is solved.

The invention provides a fluorescence-magnetic particle image fusion method which can be applied to the technical field of medical image processing. The method comprises the following steps: performing two-dimensional convolution processing on a registered two-dimensional near-infrared fluorescence image to obtain a multi-channel near-infrared fluorescence extended feature map, and performing initial fusion on the multi-channel near-infrared fluorescence extended feature map and a registered three-dimensional magnetic particle cross-sectional image to obtain a three-dimensional near-infrared fluorescence extended feature map; performing multi-round three-dimensional convolution processing on the three-dimensional near-infrared fluorescence extended feature map to obtain a multi-scale near-infrared fluorescence feature map, and performing multi-round three-dimensional convolution processing on the registered three-dimensional magnetic particle cross-sectional image to obtain a multi-scale magnetic particle feature map; and based on an adaptive cross attention mechanism, performing multi-round feature map fusion on the multi-scale near-infrared fluorescence feature map and the multi-scale magnetic particle feature map on the same scale, and performing filtering convolution processing on a multi-round feature map fusion result to obtain a three-dimensional fluorescence-magnetic particle fusion image.

The invention belongs to the technical field of evaluation, development and research of oil and gas reservoirs, and discloses a T2 cutoff value calculation method based on a saturated nuclear magnetic resonance experiment. The method comprises the following steps: acquiring a saturated / bound water nuclear magnetic resonance T2 spectrum curve of a compact sandstone sample; determining a T2 cut-off value based on a saturated / bound water nuclear magnetic resonance accumulative porosity curve, and recording the T2 cut-off value as T2-Cuff; acquiring a logT2-logphi intersection curve of the saturated nuclear magnetic resonance T2 spectrum, and recording a T2 value corresponding to an inflection point of the curve as T2-Log; and determining a mathematical relationship between the T2-Log and the T2-Cuff, and establishing a T2 cut-off value calculation model based on the saturated nuclear magnetic resonance experiment. According to the method, the T2 cutoff value can be calculated only by performing the nuclear magnetic resonance experiment on the saturated water sample and performing mathematical treatment on the T2 spectrum, and the method has the advantages of being economical, simple, efficient and high in practicability.

The invention discloses a method and tool for manufacturing a cold shield of a nuclear fusion device, and relates to the technical field of metal plate machining. The manufacturing method of the cold shield of the nuclear fusion device comprises the following steps: providing a sub-panel, a flange and a pipe fitting; the multiple sub-panels are welded, and a first middleware is obtained; welding the edge of the first middleware and the turnup to obtain a second middleware; after the pipe fitting is welded to the surface of the second middleware, a third middleware is obtained; and the third middleware is shaped. According to the method, the third middleware is shaped, that is, the third middleware is shaped after all welding procedures are completed, so that the third middleware has relatively small profile tolerance, the profile tolerance of the cold shield meets the design requirement, the assembly difficulty of the cold shield is reduced, and the risk of failure of the cold shield is reduced.

The invention proposes a myocardial magnetic resonance image fibrosis classification method based on a convolutional neural network, and relates to the technical field of image processing, and the method comprises the steps: obtaining an original magnetic resonance image of a to-be-detected target from a magnetic resonance imaging device, and carrying out the preprocessing of the original magnetic resonance image; segmenting the preprocessed magnetic resonance image into a plurality of sub-regions based on the connected features, each sub-region representing an independent connected part in the image; constructing a gray scale measurement function for each sub-region, quantifying the gray scale distribution characteristics of each sub-region, and identifying the sub-region with the minimum gray scale measurement function value as a fibrosis tissue sub-region by comparing the gray scale measurement function values of the sub-regions; features are extracted from the identified fibrosis tissue sub-regions to serve as input of the convolutional neural network model, the fibrosis tissue sub-regions are classified, the fibrosis stages to which the fibrosis tissue sub-regions belong are output, and the accuracy of classification of the fibrosis tissue is improved.

A magnetic-based tracking system for tracking an ultrasound probe. The tracking system can create a three-dimensional visualization. The tracking system can include a reference device including a reference magnet and an ultrasound probe including an ultrasound acoustic transducer or acoustic array that acquires ultrasound images. The reference device can include a magnetometer that detects a magnetic field generated by the reference magnet. The ultrasound probe can couple a first ultrasound image with a first magnetic field strength, wherein both of the first ultrasound image is received and the first magnetic field strength is detected at a first time. The system can include a console including a processor and non-transitory computer-readable medium having stored thereon a plurality of processor executed logic modules that perform operations including receiving and recording a plurality of coupling of ultrasound images and detected magnetic field strengths to generate a 3D visualization from the ultrasound images.

The invention discloses a compressed sensing MRI (Magnetic Resonance Imaging) reconstruction method and system based on a double-domain fusion expansion model. The method comprises the following steps: acquiring an MRI image, preprocessing the MRI image to obtain a preprocessed image and a corresponding compressed sensing measurement value, and constructing a data set; training, testing and verifying the double-domain fusion expansion model by using the data set; and outputting a reconstructed image from the MRI image after mask sampling by using a double-domain fusion expansion model. According to the double-domain fusion expansion model, a complex convolutional neural network and a K-space attention mechanism are introduced for complex value data processing and double-domain information fusion in compressed sensing MRI reconstruction. The complex value data is processed through the complex network, the amplitude and phase information of the complex field is fully utilized, the detail recovery capability and the noise suppression effect of the model are enhanced, and particularly, excellent robustness is shown at a low sampling rate. The method is excellent in performance in complex MRI data reconstruction, and has high reconstruction precision and generalization ability.

The invention relates to the field of nuclear fusion, and discloses a fixing device for a nuclear fusion preassembled assembly, and the fixing device comprises a magnet connecting assembly which comprises a first beam body and a magnet connecting part, the first beam body extends in a first direction, and the magnet connecting part is arranged on the first beam body; the vacuum chamber connecting assembly and the magnet connecting assembly are spaced in the second direction, the vacuum chamber connecting assembly comprises a second beam body and a vacuum chamber connecting part, the second beam body extends in the first direction, and the vacuum chamber connecting part is arranged on the second beam body; the beam body connecting assembly is arranged at the two ends of the second beam body in the first direction, is connected with the first beam body and comprises a first connecting piece, a second connecting piece and an elastic energy storage piece, the first connecting piece is movably connected with the second connecting piece and is detachably connected with the first beam body, and the second connecting piece is detachably connected with the second beam body; one end of the elastic energy storage piece is movably connected with the first connecting piece, and the other end is movably connected with the second connecting piece. The gap between the magnet and the vacuum chamber can be restrained, and the position precision between the magnet and the vacuum chamber is guaranteed.

Dual-energy imaging of a recording region is provided by a recording arrangement with an X-ray tube assembly and an X-ray detector for receiving X-rays of an X-ray field emitted by the X-ray tube assembly in cone beam geometry. The field has a central beam, and the recording arrangement is rotated around the recording region for recording projection data of different directions of projection for two different X-ray spectra. For each X-ray spectrum, a three-dimensional image dataset of the recording region is reconstructed from the respective projection data. The projection data of the two X-ray spectra is recorded during the rotation that covers at least 360°. For each X-ray spectrum, an associated portion of the X-ray field is fixed over the rotation, and a corresponding, associated, fixed portion of the X-ray detector is used.

A magnetic resonance image reconstruction device according to an embodiment is a magnetic resonance image reconstruction device that reconstructs magnetic resonance image data in which an artifact due to undersampling is removed or reduced based on undersampled k-space data, and includes a reconstruction unit reconstructing the magnetic resonance image data using a reconstruction network having a correction module. The correction module includes a regularization block generating second image data by performing a regularization process on first image data using a first neural network, and a data consistency block generating third image data by performing a data consistency process so that k-space data corresponding to the second image data approaches the undersampled k-space data. The correction module further includes at least one of a data consistency adjustment block adjusting the data consistency process and a regularization adjustment block adjusting the regularization process.

The embodiment of the invention provides a magnetic resonance eddy current prediction method, system and device. The method comprises the following steps: acquiring a gradient parameter of a gradient signal of a magnetic resonance system; the gradient parameters are processed through an eddy current prediction model, eddy current field components corresponding to gradient signals are determined, and the gradient signals comprise single gradient signals or gradient signal combinations.

The invention provides a multi-component charged particle detection system, which comprises a low-energy ion analyzer and a low-energy electronic analyzer, and the two analyzers respectively adopt the same FPGA control program; component grouping measurement is added in the FPGA design and is used for realizing multi-component detection in unit measurement time; an instrument number interface is added in the interfaces and is used for reading the level of the instrument number interface; a number identification and control module is added and used for identifying the current instrument type and generating instrument identification parameters; the parameter acquisition module is used for acquiring engineering parameters of different paths when an instrument is a low-energy ion analyzer or a low-energy electronic analyzer; the control module is used for controlling and receiving an instruction conforming to equipment where a current FPGA configuration item is located; and the control module is also used for controlling to output a data packet conforming to the equipment where the current FPGA configuration item is located. According to the system provided by the invention, the same FPGA executable code is programmed on two different devices, namely the low-energy ion analyzer and the low-energy electronic analyzer, so that FPGA configuration item self-adaption 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.

The invention discloses a cosmic ray muon scattering imaging method, system and device, and relates to the field of ray imaging, and the method comprises the steps: obtaining the direction information of muons in a to-be-imaged region; calculating the most probable three-dimensional scattering track of the muons in the to-be-imaged region based on Bayesian inference and a particle multiple coulomb scattering distribution function according to the direction information of the muons in the to-be-imaged region; and reconstructing a scattering density image in the to-be-imaged region according to the direction information of the muon in the to-be-imaged region and the most probable three-dimensional scattering track. By calculating the most probable three-dimensional scattering track, the scattering points can be effectively reconstructed, the utilization efficiency of muon events is improved, the scattering points are prevented from being separated from the to-be-imaged area, the most probable three-dimensional scattering track better fits the real scattering track, and then the quality of the scattering density image is improved.

The invention belongs to the technical field of magnetic particle imaging, relates to a magnetic particle imaging reconstruction method based on a calibration magnetic field generation system matrix, and aims to solve the problems that a traditional magnetic particle imaging reconstruction method is poor in applicability in asymmetric bilateral structure magnetic particle imaging equipment (A-MPI) and cannot perform imaging in any region. The method comprises the following steps: performing grid division on an imaging area, calibrating magnetic field intensity, and obtaining magnetic field gradient distribution of each point; obtaining a theoretical system matrix according to a mathematical calculation mode; randomly moving the positions of the non-magnetic field points for scanning to obtain actually measured magnetic field gradient distribution and a system matrix, and constructing a data set; expanding the data set based on the simulation system; constructing a deep learning model, and inputting the extended data set and the measured data into the training deep learning model; and inputting a theoretical system matrix at any position, and obtaining an accurate system matrix by using the trained model. According to the invention, the system matrix at any position can be obtained under the A-MPI equipment, so that imaging at any position is realized.

The invention relates to the technical field of magnetic resonance imaging, in particular to an intelligent sparse low-rank non-Cartesian magnetic resonance dynamic imaging method, which comprises the following steps of: acquiring magnetic resonance k-space data which is subjected to non-Cartesian continuous sampling by adopting multiple coils, continuously sampling data, rearranging the continuously sampled data along a time dimension by using a framing operator to obtain under-sampled k-space data, and then inputting the framed non-Cartesian under-sampled k-space data to be reconstructed into a trained network for image reconstruction. And reconstructing a final dynamic image through depth space-time sparsity, time low-rank learning, data consistency verification and loss function constraint. Compared with the prior art, the non-Cartesian magnetic resonance dynamic image reconstruction method has the advantages that the image is reconstructed through multiple times of network feedback iteration, the reconstruction speed of the non-Cartesian magnetic resonance dynamic image is greatly increased, and the temporal-spatial resolution is improved.

The invention provides a magnetic particle imaging resolution improving method and system based on frequency domain information filtering, and relates to the technical field of magnetic particle imaging. Comprising the following steps: inputting original magnetic particle imaging data into a Transform model, and selectively filtering frequency domain information in the magnetic particle imaging data through a fusion frequency domain discrimination feedforward network module in an encoder to obtain the output of the encoder; inputting the output of the encoder into a bottleneck layer, aggregating global and local information through a multi-scale attention mechanism module, and then selectively filtering frequency domain information in the magnetic particle imaging data again to obtain the output of the bottleneck layer; inputting the output of the bottleneck layer into a decoder with the same structure as the bottleneck layer to obtain deep features; inputting the deep features into a convolutional layer to obtain a residual image; and calculating the sum of the original magnetic particle imaging data and the residual image to obtain a reconstructed image. According to the invention, the overall imaging resolution of the MPI image under the low-gradient field acquisition condition is improved.

The present disclosure provides various systems and methods for magnetic resonance imaging. In one aspect, a method for magnetic resonance imaging can include receiving k-space data sets acquired by radiofrequency (RF) coils. Each of the k-space data sets can correspond to a different one of the RF coils. Each of the k-space data sets can be truncated and / or under sampled. The method can further include generating partial images of a field of view based on the k-space data sets and generating an initial image based on the partial images. The initial image can be full image of the field of view. The method can further include applying an iterative image reconstruction technique to generate an updated image based on the initial image.

The invention belongs to but is not limited to the technical field of three-dimensional space dose visualization, and discloses a three-dimensional nuclear emergency radiation field calculation and visualization method and system, based on a point nuclear method, a cumulative factor, mass attenuation factor and flux rate-dose rate conversion factor database is established, a mean free path solving algorithm is optimized, and a three-dimensional nuclear emergency radiation field is obtained. The geometric types of radioactive sources are expanded, and the dose calculation efficiency is improved through parallel calculation; plane dose rate drawing at a certain height is realized based on a two-dimensional texture mapping method; three-dimensional space dose rate contour surface drawing is realized based on a moving cube algorithm; and three-dimensional space dose rate volume rendering is realized based on a three-dimensional texture volume rendering technology. Radiation field dose calculation, three-dimensional radiation field dose visualization and GIS are integrated, and the system is used as a subsystem of a nuclear emergency aid decision simulation platform. The dose distribution diagram in the area can be judged more visually, and the method has a good help effect on nuclear emergency command.