16 results about "Nuclear physics" patented technology

The invention discloses a nuclear magnetic resonance image automatic classification method and device based on an MDCLSTM-LdenseNet network, and belongs to the field of medical image processing. The method comprises the following steps: obtaining nuclear magnetic resonance images of different types of subjects; preprocessing the nuclear magnetic resonance image to obtain a training data set, a verification data set and a test data set; training is carried out on the constructed MDCLSTM-LDenseNet network model, so that the MDCLSTM-LDenseNet network model can be obtained; inputting the test dataset into the trained MDCLSTM-LDenseNet network model to carry out a test; obtaining classification results of the nuclear magnetic resonance images of the three types of subjects with normal cognition, mild cognitive impairment and Alzheimer's disease and classification accuracy of the MDCLSTM-LdenseNet network model; according to the method and the device, used data sets are strictly divided; data leakage is avoided; the method is advantaged in that the training data set, the verification data set and the test data set are not intersected, reliability of classification results of normal cognition, mild cognitive impairment and Alzheimer's disease is guaranteed, classification accuracy is higher, the missed diagnosis rate and the misdiagnosis rate are lower, and doctors can be more effectively and reliably assisted to diagnose Alzheimer's disease.

The invention discloses a magnetic resonance fixing device. The magnetic resonance fixing device comprises a mounting plate and is characterized in that a supporting frame is arranged on the mountingplate; a U-shaped connecting seat is arranged at the top of the supporting frame; a screw rod is rotatably connected inside the U-shaped connecting seat; a screw rod sleeve sleeves the screw rod; thescrew rod sleeve is in threaded connection with the screw rod; one end of the screw rod penetrates through the top of the supporting frame and is fixedly connected with a hand ring; two side walls ofthe screw rod sleeve are symmetrically hinged with connecting rods; and the other ends of the connecting rods are respectively hinged with a left arc-shaped block and a right arc-shaped block. The magnetic resonance fixing device has a simple structure and is convenient to operate. The hand ring is rotated to drive the screw rod to rotate, and the screw rod drives the screw rod sleeve to move up and down, so as to drive the connecting rod to open or close the left arc-shaped block and the right arc-shaped block, so that the problem of unstable head fixation in a nuclear magnetic resonance process is solved, ghosting of nuclear magnetic resonance imaging due to head movement is prevented, and accuracy of judgment on patients by doctors is improved.

The invention relates to a magnetic resonance spectrometer system for realizing clock synchronization of a magnetic resonance spectrometer. The system comprises a clock source module and one or more function modules connected with the clock source module; the clock source module is used for supplying a synchronous clock signal to each function module; and each function module comprises a work clock synchronization sub-module which is used for receiving a synchronous clock signal corresponding to the function module and acquiring one or more work clock signals which are synchronous with the clock source module and have low clock jitter based on the synchronous clock signal. The invention provides a package of solutions for the whole clock synchronization for the spectrometer system, the clock synchronization among the constituent units of the spectrometer system is realized, and the requirement that the constituent units of the spectrometer acquire the clock which is synchronous with the clock signal of the spectrometer clock source unit and has low jitter is met, so that a solid foundation is laid for a spectrometer system to serve magnetic resonance high-quality scanning imaging.

The invention relates to the technical field of measuring instruments, and discloses a neutron measuring instrument for protection detection. The neutron measuring instrument comprises a device body,a chassis is fixedly connected with the bottom of the device body, a cross frame is fixedly connected with the bottom of the chassis, square boxes are movably inserted into the two ends of the outer surface of the cross frame, and threaded parts are fixedly connected into the square boxes; a threaded rod is in threaded connection with the interior of each threaded part in a sleeving mode, a rotating block is fixedly connected with the top of each threaded rod, a base is fixedly connected with the bottom of each threaded rod, and a second rotating column is fixedly connected with the outer surface of one side of each square box. Through the designed rotating blocks, the threaded parts, the base, the threaded rods and square blocks, the two ends of each square block can be conveniently inclined, and the two square boxes are driven to relatively move in the cross frame, so that the two bases can be in contact with the uneven ground more conveniently, and operation is convenient.

This invention discloses method for preparing a non-radioactive standard β-CFT. Using cocaine hydrochloride as the starting material, and after a series of hydrolysis, dehydration, esterification and bonding reactions, a non-radioactive standard (2β-Carbomethoxy-3β-(4-fluoropenyl) tropane) is prepared. Furthermore, this preparation method has fewer steps, is easy to operate, and the purity of the product is as high as 97.97%. Therefore, the method for preparing a non-radioactive standard β-CFT can promote the development of positron imaging in the diagnosis of Parkinson's disease.

The invention provides a control method and a control device of a magnetic resonance system. The control method comprises the following steps: measuring and recording radio frequency field data; obtaining an amplitude estimation value of the radio frequency field based on the radio frequency field data and a particle swarm algorithm; setting an amplitude control parameter of the radio frequency pulse based on the amplitude estimation value; acquiring a setting instruction of the sequence mode of the radio frequency pulse; and outputting a control signal based on the amplitude control parameter and the setting instruction. According to the configuration, on one hand, actual data of the radio frequency field can be found through measurement, on the other hand, the amplitude estimation value of the radio frequency field can be obtained based on the particle swarm optimization, the influence of noise errors is reduced, and the radio frequency amplitude calibration precision and speed are improved. Therefore, the problem that in the prior art, due to the fact that the field intensity of the radio frequency field is affected by various factors, the expected field intensity is changed, and the imaging effect is affected is solved.

The invention discloses a medical nuclear magnetic resonance examination device capable of stretching out and drawing back automatically. The device comprises a base and a bed body installed on the base, wherein a rectangular assembly cavity matched with the bed body is formed in the base; the two sides of the bed body are connected to the base through driving assemblies; the bed body is provided with a positioning assembly used for fixing the head of a patient; and the driving assemblies drive the bed body to move in the length direction of the base to change the position of the positioning assembly. According to the invention, the device for fixing the head of the human body and the bed body are arranged together, and the position of the head fixing and positioning device on the examination bed is dynamically changed, so that the adaptation to patients with different heights is achieved; and when other parts of the patient are examined, the telescopic amount of the bed body relative to an examination area of a nuclear magnetic resonance main body is kept in a relatively fixed state, so that the steps of human body positioning and calibration in the examination process are reduced, and the efficiency of automatic examination is improved.

The invention discloses a respiratory movement control device and method for a magnetic resonance accelerator, the respiratory movement control device comprises an abdominal pressure belt body, the abdominal pressure belt body comprises a back side belt and an abdominal side belt, the two ends of the back side belt in the length direction are connected with the corresponding ends of the abdominal side belt in a matched mode, and the back side belt is connected with the abdominal side belt in a matched mode. The connection position of the adaptive connection is adjustable and can be recorded; a mark in the length direction is arranged on the ventral side belt; an inflation bag is arranged in the middle area of the ventral side belt and connected with an inflation balloon and an air pressure detection mechanism. According to the invention, the binding position and the tightness during each treatment can be ensured to be consistent with those of the previous treatment, and accurate control and evaluation on the external boundary of the target region are ensured.

The invention discloses a positioning method for quickly and accurately positioning a radioactive source in a three-dimensional space environment, which belongs to the technical field of radioactive source positioning. Four positions which are not in the same plane are randomly selected in an area where a suspected lost radioactive source is located, and the four positions are marked as a point A, a point B, a point C and a point O respectively; the coordinates of the radioactive source are calculated according to the relation of the dose rates of the four points, the accurate position of the radioactive source can be obtained by using the least measurement point positions, and the time generated by measurement at different point positions is reduced to the maximum extent.