603 results about "Radio frequency coil" patented technology

A method for multi-slice magnetic resonance imaging, in which image data is acquired simultaneously from multiple slice locations using a radio frequency coil array, is provided. By way of example, a modified EPI pulse sequence is provided, and includes a series of magnetic gradient field “blips” that are applied along a slice-encoding direction contemporaneously with phase-encoding blips common to EPI sequences. The slice-encoding blips are designed such that phase accruals along the phase-encoding direction are substantially mitigated, while providing that signal information for each sequentially adjacent slice location is cumulatively shifted by a percentage of the imaging FOV. This percentage FOV shift in the image domain provides for more reliable separation of the aliased signal information using parallel image reconstruction methods such as SENSE. In addition, the mitigation of phase accruals in the phase-encoding direction provides for the substantial suppression of pixel tilt and blurring in the reconstructed images.

A tunable radio frequency birdcage coil (26, 34) has an improved tuning range for use with a magnetic resonance apparatus. The coil includes a pair of end ring conductors (60, 62) which are connected by a plurality of spaced leg conductors (L2, L4, . . ., L26) to form a generally cylindrical volume. Both the end rings and the leg conductors contain reactive elements, preferably capacitors (C2, C4, . . ., C124). The radio frequency coil also includes a pair of tuning rings (100, 120) for tuning the reactive elements (C2, C4, . . ., C124), which each include a non-conductive support cylinder (110, 130) and a plurality of tuning bands (120, 122, . . ., 142 and 150, 152, . . ., 172) which extend axially along the outer surface of the support cylinder (110, 130). The tuning rings (100, 120) are rotated or translated with respect to the leg conductors (L2, L4, . . ., L26) in order to vary capacitance and inductance of the coil (26, 34) to tune the (26, 34) coil to the desired resonant frequency.

Techniques for removing artefacts, such as RF interference and / or noise, from magnetic resonance data. The techniques include: obtaining input magnetic resonance (MR) data using at least one radio-frequency (RF) coil of a magnetic resonance imaging (MRI) system; and generating an MR image from input MR data at least in part by using a neural network model to suppress at least one artefact in the input MR data.

The present invention is a portable in-bore shim coil insert suitable for correcting high-degree and high-order magnetic field inhomogeneities over a limited examination zone in a magnetic resonance assembly operating above 3 T magnetic field strengths, wherein the magnetic resonance assembly includes at least a MRI magnet having an internal bore of known configuration and volume, at least one set of gradient coils, and an arrangement of radio frequency coils. The in-bore shim coil insert and corresponding method of use is able to produce higher degree and order shimming effects on-demand (i.e., the correction of at least some 3rd to 6th degree field terms or inhomogeneities) and will markedly improve the quality of in-vivo magnetic resonance spectroscopy and / or imaging of any desired anatomic site, i.e., any or all of the various organs, tissues, and systems present in the body of a living subject.

An infant transporter includes a transporter base, a support member secured to the base, and a housing supported by the support member. The housing includes a radio frequency coil adapted to emit a radio frequency configured to enable magnetic resonance imaging. The infant transporter exclusively comprises components that are magnetic resonance imaging compatible.

A wireless remote control unit (60) that operates in the radio frequency bandwidth is used for interfacing with a sequence control system (B) and an image processing system (C) from within a magnetic resonance suite (A) in the presence of a magnetic field produced by a main magnet assembly (10). The sequence control system and the image processing system are connected with a first wireless transceiver (30) whose antenna (28) is located within a magnetic resonance suite. The first transceiver (30) communicates with the remote control unit (60) and a second transceiver (32) connected with a transmitter (40) and gradient coil amplifiers (34). Resonance signals received by a radio frequency coil (46) are communicated to the first transceiver (30) by the second transceiver (32) or by a transceiver (46′) mounted on the receiving coil. The receiver coil transceiver also engages in a handshake protocol to identify itself.

An apparatus and method for NMR analysis of a plurality of core samples includes a core holder (11) that holds a core sample under pressurized conditions. A radio frequency coil (51) disposed about the core holder (11) generates a pulsed-mode magnetic field component over a sample volume occupied by the core sample. A support structure is removably secured to the respective core holder. A permanent magnet (65A, 65B) has an open configuration such that it is removably disposed into a position within the support structure about the radio frequency coil and the core holder. The open configuration allows the same permanent magnet to be used for NMR analysis of a plurality of core samples without the need for depressurizing the respective core holder and disassembling the core holder and corresponding load frame for each core sample. It also allows multiple core samples to be prepared for NMR analysis while separated from the NMR measurement apparatus.

The invention relates to a rock core holder compatible with nuclear magnetic resonance, which can simulate pressures and temperatures of deep reservoirs, perform oil water displacement of a rock core under simulated formation conditions, and simultaneously perform nuclear magnetic resonance on-line measurement. According to the invention, a radio frequency coil is embedded in the rock core holder, and the signal to noise ratio is greatly increased when the rock core holder is compared with a conventional rock core holder. The rock core holder is made of nonmagnetic nonmetal materials, which avoids the damage of the magnetic field uniformity caused by magnetic materials, and also avoids the generation of eddy current in the holder by a pulse gradient. Compared with a conventional rock core holder, the invention not only greatly increases the signal to noise ratio, but also fully ensures the accuracy of nuclear magnetic resonance measurement results at a high temperature and a high pressure. The holder is applicable to on-line measurement of nuclear magnetic resonance relaxation spectra, diffusion-relaxation two-dimensional spectra, and imaging methods during rock core oil water displacement at a high temperature and a high pressure. In addition, the invention performs real-time tracking compensation of temperatures and pressures of ring-crush fluid, and thus ensures the reliability of rock core simulated formation conditions.

A nuclear magnetic resonance (NMR) spectroscopy probe has a sample cell into and out of which a room temperature liquid sample may be directed. The cell is surrounded by a radio frequency coil that is used to perform NMR measurements of the liquid sample, and which is maintained at cryogenic temperatures. The coil is separated from the sample cell by a thermally insulative boundary, such as a vacuum. The sample may enter the cell through an input path, and may exit through an output path. The input path, output path and sample cell may be surrounded by a sheath through which flows room temperature gas. The ends of the sample cell may be tapered to promote thorough flow through the cell, and flow diverters may be included in the sample cell adjacent to the input and output paths to force flow to the outer wall of the sample cell.

A sputter deposition system comprises a vacuum chamber including a vacuum pump for maintaining a vacuum in the vacuum chamber, a gas inlet for supplying process gases to the vacuum chamber, a sputter target and a substrate holder within the vacuum chamber, and a plasma source attached to the vacuum chamber and positioned remotely from the sputter target, the plasma source being configured to form a high density plasma beam extending into the vacuum chamber. The plasma source may include a rectangular cross-section source chamber, an electromagnet, and a radio frequency coil, wherein the rectangular cross-section source chamber and the radio frequency coil are configured to give the high density plasma beam an elongated ovate cross-section. Furthermore, the surface of the sputter target may be configured in a non-planar form to provide uniform plasma energy deposition into the target and / or uniform sputter deposition at the surface of a substrate on the substrate holder. The sputter deposition system may include a plasma spreading system for reshaping the high density plasma beam for complete and uniform coverage of the sputter target.

The invention discloses a nuclear magnetic resonance sensor used for the nondestructive aging resonance of an umbrella skirt of a composite insulator. The sensor comprises a permanent magnet structure and a plane radio-frequency coil, wherein the permanent magnet structure mainly consists of two cylindrical permanent magnet sheets of same specification, the two cylindrical permanent magnet sheets are oppositely and coaxially arranged, and the permanent magnet structure is used for producing a static state main field B0; and the permanent magnet structure is provided with a slide mechanism, so that the distance between the permanent magnet sheets can be adjusted so as to adapt to umbrella skirts of different thickness. The plane radio-frequency coil is formed by two spiral coils which are connected in series on a plane according to the reverse direction of the magnetic field, and the plane radio-frequency coil is used for generating radio-frequency magnetic field B1 orthometric with the main magnetic field in a target region, and detecting return signals produced by a sample to be tested. During the aging detection of the umbrella skirt of the composite insulator, the slide mechanism is adjusted to enable the sensor to clamp the umbrella skirt to be tested, so that the transverse relaxation time T2 of the umbrella skirt can be measured, and further, the aging degree of the umbrella skirt can be judged according to the transverse relaxation time T2. The open-type nuclear magnetic resonance sensor has the advantages of small volume, light weight, and convenience in engineering field detection.

The invention relates to the technical field of medical experimental facilities, and discloses a small animal brain three-dimensional positioning system for magnetic resonance imaging scanning equipment. The system comprises a magnetic compatibility small animal brain three-dimensional positioning device used for conducting brain three-dimensional positioning on the head of a small animal and a magnetic resonance small animal radio frequency coil device which is used for receiving a magnetic resonance radio frequency signal in the X axis direction and transmitting the signal to a magnetic resonance imaging system. According to the system, in the piercing implementation process, magnetic resonance scanning can be carried out on an experimental animal, the magnetic resonance radio frequency signal is received through the small animal radio frequency coil, the signal is transmitted to the magnetic resonance imaging system, a magnetic resonance scanning image can be utilized for guiding and monitoring the piercing process, the magnetic resonance imaging scanning equipment can be utilized for guiding a small animal three-dimensional positioning operation or conducting positioning experiments such as piercing and stimulation exertion.

The invention relates to a measurement method and device of a Bell-Bloom self-modulation three-axis magnetic field. A conventional Bell-Bloom magnetometer utilizes a single beam to measure a scalar magnetic field, is simple in structure, is high in measurement accuracy and is widely applied to measurement of various scalar magnetic fields. The single-beam Bell-Bloom magnetometer can only measure the scalar magnetic fields, but three-axis magnetic field information is needed in many places in scientific researches and production life, and then a vector magnetometer is needed. Based on the single-beam Bell-Bloom magnetometer, the measurement method and device of the Bell-Bloom self-modulation three-axis magnetic field realize measurement of the three-axis magnetic field by utilizing the self-modulating action on detection light of atomic procession. Compared with the common vector magnetometer, the measurement device of the Bell-Bloom self-modulation three-axis magnetic field is not provided with a radio frequency coil or a magnetic shielding barrel, thereby having a simple light path, being compact in structure and achieving miniaturization and integration easily; the measurement device is low in heating temperature and needs fewer electric elements, so that systematic power consumption is lowered and operation conditions are met more easily; the measurement device utilizes the self-modulating action on detection light of the atomic procession, is lower in noise and is high in detection accuracy.

The invention discloses an MEMS atom cavity chip and a preparation method thereof. The chip comprises two glass substrates and a silicon substrate, heater strips and radio-frequency coils are integrated on the glass substrates, metal leads connecting front faces and reverse faces are processed by laser perforation and plating technology. Atom cavity spaces and thermal insolating rings are integrated on the silicon substrate. The injection of alkalis is finished in an anaerobic box, the injection and bonding of air is finished then, and the injection of high concentration supplementary air is realized. The invention has high integrated level, and realizes on-chip integration of the heater strip, the radio-frequency coil and thermal isolating ring structures. The invention can be used for MEMS atomic gyroscopes besides MEMS atomic clocks and MEMS atom magnetometers.

The invention discloses an intracranial and cervical joint radio frequency coil device for a magnetic resonance imaging system. The device comprises a base, an intracranial upper coil and a cervical upper coil in detachable combination, wherein the intracranial upper coil and the cervical upper coil are formed by packaging a coil circuit by deformable flexible polyethylene foams; a cavity of which the upper end and the cervical side are provided with openings is formed on the base; and the coil circuit is arranged around the cavity. The device has the advantages of weight far lighter than that of a conventional united coil made of hard polycarbonate plastic, convenient movement, smaller distance to a human body through the deformable coil, better imaging quality, respectively independent use or combined use of three parts of coils, and capacities of replacing a common coil, meeting detection requirements on common parts of all MRI and saving economic input.

A plasma system includes a plasma arc torch, a cylindrical tube and an eductor. The plasma arc torch includes a cylindrical vessel having a first end and a second end, a first tangential inlet / outlet connected to or proximate to the first end, a second tangential inlet / outlet connected to or proximate to the second end, an electrode housing connected to the first end such that a first electrode is (a) aligned with a longitudinal axis of the cylindrical vessel, and (b) extends into the cylindrical vessel, and a hollow electrode nozzle connected to the second end of the cylindrical vessel. The cylindrical tube is attached to the hollow electrode nozzle and aligned with the longitudinal axis, the cylindrical tube having a side inlet and a radio frequency coil disposed around or embedded within the cylindrical tube. The eductor is attached to the cylindrical tube and aligned with the longitudinal axis.

A Class-E amplifier has bee adapted for use in the radio frequency section of a magnetic resonance imaging (MRI) system. A drive signal is produces by modulating the envelope of a radio frequency carrier signal and then applied to a switch in the Class-E amplifier. The switch is connected in series with a choke between a supply voltage terminal and circuit ground with an output node formed between the choke and the switch. The output node is coupled to circuit ground by a shunt capacitor. In a preferred embodiment, a pair of such amplifiers, that are Π radians out of phase, are connected to each rung of a transverse electromagnetic transmit array type radio frequency coil of the MRI system.

A plasma system includes a plasma arc torch, a cylindrical tube and an eductor. The plasma arc torch includes a cylindrical vessel having a first end and a second end, a first tangential inlet / outlet connected to or proximate to the first end, a second tangential inlet / outlet connected to or proximate to the second end, an electrode housing connected to the first end such that a first electrode is (a) aligned with a longitudinal axis of the cylindrical vessel, and (b) extends into the cylindrical vessel, and a hollow electrode nozzle connected to the second end of the cylindrical vessel. The cylindrical tube is attached to the hollow electrode nozzle and aligned with the longitudinal axis, the cylindrical tube having a side inlet and a radio frequency coil disposed around or embedded within the cylindrical tube. The eductor is attached to the cylindrical tube and aligned with the longitudinal axis.

The invention discloses a magnetic resonance imaging method. The method comprises the following steps: applying a strong polarizing magnetic field to an imaging object, closing the polarizing magnetic field, applying a low-polar encoding magnetic field to the sample, applying a gradient magnetic field to the sample for space coding in this magnetic field, closing the encoding magnetic field, reading magnetic resonance signals by an optomagnetic resonance method in an nT-level magnetic field environment, and rebuilding images. The device comprises a polarizing magnet (101) for generating the polarizing magnetic field with controllable magnetic field, an encoding magnet (102) for generating the encoding magnetic field with the controllable magnetic field, a 3D gradient system (103) for generating the gradient magnetic field, an nT coil (104) for generating the nT-level magnetic field, a magnetic shielding system (105), a radio frequency coil (106), an optomagnetic probe (107), a pulse sequence control system (108) and an image processing computer (109). The imaging object and the optomagnetic probe (107) are arranged in the encoding magnet (102) and the polarizing magnet (101).

An electromagnetic acoustic transducer (EMAT) for inspecting an object is provided. The EMAT includes a magnet configured to generate a magnetic field in an object and a radio frequency coil configured to induce eddy currents on a surface of the object. The EMAT further includes a laminated wear plate disposed over the magnet and the radio frequency coil and configured to shield the magnet and the radio frequency coil from damage.

Various methods and systems are provided for a flexible, lightweight, and low-cost radio frequency (RF) coil of a magnetic resonance imaging (MRI) system. In one example, a RF coil assembly for an MRI system includes a distributed capacitance loop portion comprising two parallel conductor wires encapsulated and separated by a dielectric material, the two parallel conductor wires maintained separate by the dielectric material along an entire length of the loop portion between terminating ends thereof, a coupling electronics portion including a pre-amplifier, and a coil-interfacing cable extending between the coupling electronics portion and an interfacing connector of the RF coil assembly.

A magnetic resonance multi-core array radio frequency device and a magnetic resonance signal receiving method are provided. The device comprises a radio frequency receiver which includes a radio frequency coil (11), a low noise preamplifier (13), a multiplexer (15), a radio frequency band-pass filter (17), a program control amplifier (19), a frequency synthesizer (21), a mixer (23), an analog to digital converter (29) and a controller (31). The controller (31) is used for controlling the multiplexer (15) to select a corresponding radio frequency coil channel, a corresponding filtering channel, gain of the radio frequency band-pass filter (17), and receiving a magnetic resonance digital signal transmitted by the analog to digital converter (29). Due to the multiplexer (15), there is no need to configure different circuits respectively for different nuclear magnetic resonance, redundancy of the circuits is reduced, and cost is reduced.

Properties of a porous solid sample 19, which may be a core of rock taken from below ground are carried out using apparatus which performs both nuclear magnetic resonance (NMR) and porosimetry measurements. The apparatus has a magnet 11,12 providing a magnetic field and a radio frequency coil 20 for transmitting and / or receiving electromagnetic radiation so as to bring about NMR in the magnetic field, a pressure vessel 14, 15 to hold a sample 19 within the magnetic field, a supply of a non-wetting liquid connected to the vessel, means to apply pressure to the non-wetting liquid to force liquid into pores of the sample 19 means to measure applied pressure of the non-wetting liquid and means to measure volume thereof taken up by the sample. The pressure of non-wetting liquid may be increased in steps, using intruded liquid volume at each step to give a measurement of pore throat size using NMR at each step to give a measure of pore size such as diameter of equivalent sphere. The non-wetting liquid may be mercury and NMR may observe the Knight shift of 99 Hg.

An MRI apparatus excellent in magnetic field generation efficiency is provided. According to this invention, a main coil (52) of a gradient magnetic field coil (13) is partially recessed to reduce the total thickness of a radio-frequency coil (11) and a gradient magnetic field coil (13). That is, the main coil (52) is designed in a tubular shape, and the diameter r1 at the center portion of the imaging space is larger than the diameter r2 of the main coil end portion. Accordingly, the RF coil (11) can be disposed to be near to the gradient magnetic field coil (13) side without lowering the magnetic field generation efficiency.

A radio frequency coil includes a non-cylindrical conformal surface (62, 76) that substantially conforms with a magnetic resonance subject. A plurality of conductor loops (60, 71, 72, 73, 74) are disposed in or on the non-cylindrical conformal surface. The plurality of conductor loops are configured to produce a substantially uniform Bi field in the magnetic resonance subject responsive to energizing at a Bi frequency. Optionally, a plurality of load-compensating conductor loops (90) are disposed in or on a compensatory non-cylindrical conformal surface (62) that substantially conforms with a magnetic resonance subject. The plurality of load-compensating conductor loops are configured to produce a non-uniform Bi field that compensates for a loading Bi non-uniformity caused by the magnetic resonance subject. Moreover, the coil may comprise switching means for switching the coil between a first mode of operation (e.g. a volume transmit mode) and a second mode of operation (e.g. a phased array reception mode).

The invention relates to an intelligent vehicle control system and method based on an intelligent transportation platform. The system comprises an intelligent vehicle controller, a closed electromagnetic guide rail, an electromagnetic sensor, a steering engine, a motor driving module, a speed measuring module, an infrared distance measuring module, a radio frequency identification module, a radio frequency coil and a signal generator. The control method includes the steps that intelligent vehicles autonomously run along a set road of the intelligent transportation platform, the speeds of the vehicles are controlled, the vehicles run according to a formation, and the vehicles run at an intersection according to traffic rules. The function of tracking the intelligent vehicles is completed through the electromagnetic sensor, and the problem that when a photoelectric or camera sensor is adopted, the sensor can be easily disturbed by visible light is solved. Formation driving control is achieved based on infrared distance measurement, and the problems that when an ultrasonic wave distance measuring technology is adopted, influences caused by the temperature of the environment are serious, and the accuracy rate of detection is low are solved. The problem that because a control signal and a signal lamp can not be synchronous when the intelligent vehicles pass through an intersection, the vehicles jump the red light is solved based on the radio frequency identification technology.

A radio frequency coil assembly for use in a magnetic resonance system comprises a set of conductors for detecting magnetic resonance signals in three orthogonal planes and capacitors for resonating the set of conductors at a predetermined frequency. A conductor of the set of conductors is placed on each edge of a cube-shaped volume and the capacitors are placed on each conductor of the set of conductors such that each conductor has substantially equal effective capacitance.A four element band pass birdcage coil comprises two square end ring segments, each end ring segment comprising four sides of equal length, and four rungs of length equal to a side of the end ring segment, and wherein four rungs join in respective corners of the end ring segments.

The invention discloses a double-frequency radio-frequency coil which comprises at least one coil unit, wherein each coil unit comprises a closed loop circuit and a pre-amplifier, each closed loop circuit is composed of a double-frequency tuned circuit, a double-frequency detuned circuit, a double-frequency coil matching circuit and a capacitor C1, one end of the double-frequency coil matching circuit is connected with an input terminal (In) of the pre-amplifier through a capacitor C5, the other end of the double-frequency coil matching circuit is connected with a ground terminal (GND) of the pre-amplifier, and an output terminal (Out) of the pre-amplifier is connected with a double-frequency radio-frequency Balun circuit. According to the double-frequency radio-frequency coil, due to the fact that the double-frequency detuned circuit and the double-frequency radio-frequency Balun circuit can work under two frequencies and the double-frequency tuned circuit is also double-frequency, then the double-frequency radio-frequency coil can work under two frequency points, accordingly the double-frequency radio-frequency coil can be suitable for two nuclear magnetic resonance systems with different field intensity, and coil purchasing cost of hospitals is reduced.