9188 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 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 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.

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.

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 discloses a brain nuclear magnetic imaging focus reasoning method based on a multi-hop memory network. The method comprises the following steps: S1, acquiring brain nuclear magnetic resonance imaging data and corresponding clinical annotation data; s2, generating preprocessed brain nuclear magnetic resonance image data; s3, constructing a medical priori knowledge graph; s4, constructing a multi-hop memory network model; s5, generating an image feature vector; s6, generating an image feature vector fused with the prior knowledge; s7, storing the updated features in a memory unit; s8, performing hop-by-hop calibration on the judgment of the focus position, the focus range and the focus property, and outputting a focus reasoning result; and S9, performing fusion display with the original brain nuclear magnetic resonance image data. According to the method, remarkable innovation is achieved on the algorithm level, and meanwhile the accuracy and clinical applicability of the focus reasoning result are remarkably improved.

The invention relates to a multi-contrast magnetic resonance image super-resolution reconstruction method and system. The method comprises the following steps: collecting an image data set, preprocessing the image data set, and dividing the image data set into a training set and a test data set; combining a Hilbert curve, a state space model and a frequency domain enhancement mechanism to construct a multi-contrast magnetic resonance super-resolution reconstruction model based on Hilbert double-domain fusion Mamba; and training a multi-contrast magnetic resonance super-resolution reconstruction model based on Hilbert double-domain fusion Mamba by using the training data set, and then completing the test of the test data set to obtain a super-resolution reconstruction image of the target contrast magnetic resonance image. Frequency domain features are scanned through a Hilbert curve, a cross-modal global frequency dependency relationship is captured, and high-frequency texture details are effectively recovered. And multi-modal local texture information is dynamically fused through a channel attention mechanism, so that neglect of local details by linear scanning is avoided, and the texture reconstruction precision is improved.

The invention relates to the technical field of image processing, in particular to a clinical focus auxiliary segmentation system based on a nuclear magnetic resonance image. The system comprises an MRI image processing module, a lesion auxiliary segmentation module, a probability segmentation correction module and a lesion boundary smoothing module, a corresponding clinical nuclear magnetic resonance image set of a patient can be obtained, image position alignment and gray level adjustment processing can be carried out, and meanwhile a corresponding clinical image lesion segmentation model is constructed to carry out multi-scale fusion auxiliary segmentation. Generating a clinical focus region segmentation fusion image; obtaining a focus confidence probability corresponding to each pixel point in the segmentation image through the clinical focus region segmentation fusion image, and carrying out probability segmentation boundary correction on the clinical focus region segmentation fusion image to obtain a clinical focus region segmentation correction result image; and performing focus edge shape smoothing processing on the clinical focus region segmentation correction result map to generate a clinical focus edge shape segmentation optimization result. According to the invention, high-precision segmentation of the focus in the MRI image can be realized.

A system and method for reducing scan time of periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) imaging include acquiring a plurality of blades of k-space data of a region of interest in a rotational manner around a center of k-space via a magnetic resonance imaging (MRI) scanner during a PROPELLER sequence, wherein each blade of the plurality of blades of k-space data includes a plurality of parallel phase encoding lines sampled in a phase encoding order. Each blade of the plurality of blades of k-space data is undersampled. The system and method include utilizing a deep learning-based Cartesian-like reconstruction network to individually and separately reconstruct each blade of the plurality of blades of k-space data to generate a plurality of fully sampled blades. The system and method include utilizing a PROPELLER reconstruction algorithm to generate a complex image from the plurality of fully sampled blades.

The invention belongs to the field of magnetic particle imaging, particularly relates to a magnetic particle high-resolution reconstruction method based on fast feature fusion, and aims to solve the problems that an existing magnetic particle reconstruction method is slow in system matrix calibration, low in reconstructed magnetic particle image resolution, limited in signal-to-noise ratio and the like. The method comprises the following steps: collecting a system matrix generated by using a standard particle sample as a low-resolution system matrix; acquiring a voltage signal of the to-be-imaged phantom; inputting the low-resolution system matrix into the trained fast feature fusion Transform model to obtain a high-resolution system matrix; and based on the voltage signal, reconstructing the high-resolution system matrix to obtain a high-resolution MPI image. According to the method, the resolution of the MPI image is improved by carrying out rapid super-division on the system matrix, tedious and time-consuming calibration in system matrix reconstruction is avoided, in addition, resolution and signal-to-noise ratio improvement can be carried out on any system matrix, and a scanning mode related to the system matrix is not needed.

A sensor unit for detecting brain current-induced magnetic fields in an unshielded environment has a plurality of gradiometer units configured for arrangement around a head of a user. Each gradiometer unit has two magnetometers which are arranged at a fixed distance from each other. Each magnetometer has a sensor medium and is configured to detect a magnetic field strength at a measurement location by reading a spin resonance in the sensor medium depending on the magnetic field strength. The sensor unit further includes at least one excitation light source for radiating light into the sensor media of the magnetometer. The sensor unit further incudes at least one signal processing unit for determining a magnetic field gradient at a gradiometer unit as a difference of the output signals of the two magnetometers of the gradiometer unit and for detecting a time course of the magnetic field gradient.

The invention discloses a nuclear magnetic T2 spectrum correction method for a shale reservoir, and relates to the field of object detection, and the nuclear magnetic T2 spectrum correction method for the shale reservoir comprises the following steps: 1, determining the gas logging porosity, saturated water porosity and main mineral components of the shale reservoir; compared with the prior art, the method disclosed by the invention has the beneficial effects that a drying-saturated water-centrifugal two-dimensional nuclear magnetic resonance experiment is carried out, and signals of crystal water, clay bound water and hydroxyl in a sample are preliminarily identified; through inversion of organic matter signals in the dry sample, signals of movable water are further determined; the relation between the difference value among the gas logging porosity, the saturated water porosity and the nuclear magnetic porosity and different mineral contents is discussed, and particularly the remarkable influence of iron-containing minerals on the porosity difference value is discussed; by eliminating the influence of diffusion relaxation caused by the magnetic susceptibility difference, the T2 spectrum correction method based on the mineral magnetic susceptibility is established, and the T2 spectrum accuracy obtained through nuclear magnetic resonance measurement is improved.

The invention relates to a double-color magnetic nanoparticle imaging method based on a single-harmonic system matrix, which comprises the following steps: respectively moving two different types of magnetic nanoparticle samples to a central zero magnetic field point, applying a scanning magnetic field to enable the zero magnetic field point to scan the whole imaging field of view, applying an excitation magnetic field to magnetize magnetic nanoparticles, and applying an excitation magnetic field to magnetize the magnetic nanoparticles; acquiring magnetization frequency spectrum signals of the two magnetic nanoparticle samples; the method comprises the following steps: constructing single harmonic system matrixes A1 and A2 based on single harmonic of magnetization spectrum signals of two kinds of magnetic nanoparticle samples; measuring a to-be-measured object formed by the two kinds of magnetic nanoparticles to obtain a measurement magnetization signal U; transversely splicing the single harmonic system matrixes A1 and A2 of the two different types of magnetic nanoparticles to obtain a new single harmonic system matrix A; the concentration distributions c1 and c2 of two different types of magnetic nanoparticles are obtained by combining a new single-harmonic system matrix A with a measurement magnetization signal U, and the concentration distributions of the two different types of magnetic nanoparticles are respectively sent into different color channels to be displayed in different colors. The method has important significance in promoting the application of the magnetic nanoparticle imaging technology in clinical medicine.

The invention discloses a method for one-step electrifying extraction and separation of uranium elements from sandstone uranium ores, which comprises the following steps: adjusting the pH value of an activation environment to be less than or equal to 3 by using an activation leaching agent, and converting the uranium elements in the sandstone uranium ores into uranyl with positive charges and complexes thereof; and a direct-current electric field with the voltage gradient of 0.1-2 V / cm is applied between the cathode and the anode, so that the uranium element moves towards the cathode chamber under the action of the electric field and is selectively reduced on the cathode, and the uranium element is reduced into a low-valence insoluble uranium-containing substance through electrons to be precipitated on the surface of the cathode. According to the method, uranium ions only forming positive charges and complexes of the uranium ions are activated and leached, and the uranium element directionally moves towards the cathode under the electrophysical actions of electromigration, electroosmosis and the like, so that the extraction of the uranium element in the sandstone uranium ore is realized; and meanwhile, soluble uranium is reduced and fixed on the surface of the cathode conductive plastic electrode through electrochemical actions such as reduction generated by electrons on the surface of the cathode conductive plastic electrode, so that one-step separation and purification of the uranium element are realized.

The invention discloses an SERF atom magnetometer double-axis magnetic field detection method and device based on pulsed magnetic field modulation, relates to the technical field of magnetic field precision measurement, and compresses the action time of a modulation magnetic field additionally applied in the same unit period on a hot atom ensemble by replacing conventional continuous sinusoidal magnetic field modulation with pulsed magnetic field modulation. The pulse magnetic field with the duty ratio of d can reduce the spin exchange relaxation rate to 2d times of that of a conventional method under the same modulation amplitude and frequency, due to the fact that the spin exchange relaxation rate is effectively restrained, the collected polarizability response signal is obviously improved, and the polarizability response signal can be obtained through the pulse magnetic field with the duty ratio of d and the pulse magnetic field with the duty ratio of d. Low-relaxation-rate sensitivity-enhanced double-axis magnetic field measurement under a pulse modulation scheme is realized, the double-axis measurement sensitivity of a miniaturized SERF atom magnetometer is further improved, and the method has great significance in supporting leap-type development of a future array type extremely-weak magnetic imaging system and medical application thereof.

The invention provides a free breathing heart fat fraction and multi-relaxation parameter simultaneous quantitative magnetic resonance imaging method, a free breathing heart fat fraction and multi-relaxation parameter simultaneous quantitative magnetic resonance imaging device, a terminal and a medium. The method comprises the following steps: scanning a plurality of imaging layers on heart tissues of a detected object in a free breathing state to obtain a double-echo image of each cardiac cycle corresponding to each imaging layer and an electrocardio trigger signal; simulating an evolution process of a magnetization vector based on a Bloch equation and an electrocardio trigger signal, and establishing a dictionary; on the basis of the double-echo image after image processing, water-fat separation operation based on mixed multi-echo is executed, and a water signal image and a fat fraction graph are obtained; and obtaining a relaxation parameter group diagram of the detected object in a mode of matching the water signal image with the dictionary. Collection is carried out when the detected object freely breathes, the burden of the detected object is relieved, and the fat fraction quantification precision and the water-fat separation accuracy are guaranteed.