Abstract: A magnetic resonance imaging device is described that includes multiple magnetic coils to generate a magnetic field. Additionally, the magnetic resonance imaging device may include one or more radial gaps within some or all of the magnetic coils (e.g., primary magnetic coils, bucking coils, and so forth) in which radial spacers may be located to help preserve the homogeneity of the magnetic isocenter of the primary magnetic coils during operation.
Type:
Grant
Filed:
October 9, 2019
Date of Patent:
April 19, 2022
Assignee:
General Electric Company
Inventors:
Anbo Wu, Ye Bai, Minfeng Xu, Paul St. Mark Shadforth Thompson, Mark Ernest Vermilyea, Michael Parizh
Abstract: A device for generating wideband signals in a local coil and a magnetic resonance tomography system with the device are provided. The device has a first analog-digital converter for digitizing a magnetic resonance signal, a signal conditioner, a pulse filter, and a transmit antenna. The signal conditioner is configured to increase a harmonic component in an output signal of the first analog-digital converter, and the pulse filter is configured to restrict an output signal of the signal conditioner to a predetermined frequency band before the output signal of the signal conditioner is emitted via the transmit antenna. The receiver is configured to receive and digitize the signal via a receive antenna, and regain a digital representation of the magnetic resonance signal by a signal processor.
Abstract: There is disclosed a layered article that can be used in indirect printing, in analog or digital processes. The layered article, when configured as a transfer member, may serve to receive an ink in any form, allow the ink to be treated so as to form an ink image, and permit the application of the ink image on a substrate. The transfer member comprises a support layer and an imaging layer, which may be formed of a silicon matrix including dispersed carbon black particles. Methods for preparing the same are also disclosed.
Type:
Grant
Filed:
October 1, 2020
Date of Patent:
April 12, 2022
Assignee:
LANDA LABS (2012) LTD.
Inventors:
Benzion Landa, Sagi Abramovich, Amit Haviv
Abstract: According to some aspects, a magnetic resonance imaging system capable of imaging a patient is provided. The magnetic resonance imaging system comprising at least one B0 magnet to produce a magnetic field to contribute to a B0 magnetic field for the magnetic resonance imaging system and a member configured to engage with a releasable securing mechanism of a radio frequency coil apparatus, the member attached to the magnetic resonance imaging system at a location so that, when the member is engaged with the releasable securing mechanism of the radio frequency coil apparatus, the radio frequency coil apparatus is secured to the magnetic resonance imaging system substantially within an imaging region of the magnetic resonance imaging system.
Type:
Grant
Filed:
August 28, 2019
Date of Patent:
April 12, 2022
Assignee:
Hyperfine Operations, Inc.
Inventors:
Anne Michele Nelson, Christopher Thomas McNulty, Jeremy Christopher Jordan, Michael Stephen Poole
Abstract: In a method for readout segmented magnetic resonance imaging (MRI) of an examination object, k-space is acquired in a plurality of segments along a readout direction using a parallel imaging (PI) technique. K-space in a first segment is acquired with a first acceleration factor, and k-space in a second segment is acquired with a second acceleration factor different from the first acceleration factor.
Abstract: A fixing unit includes a casing, a heating unit, a second rotary member, a first guide portion, a separation unit, and a separation unit movement mechanism. The separation unit has a separation member and movable relative to the casing between a first position at which the separation unit is positioned when the heating unit is positioned at a position to form a fixing nip portion, and a second position at which the separation unit is positioned when the heating unit is retracted from the position to form the fixing nip portion. The separation unit movement mechanism is configured to move the separation unit from the second position to the first position with the heating unit mounting to the position to form the fixing nip portion.
Abstract: A fixing unit or device that can be used in an image forming apparatus includes a first heater element that is formed of a material that increases in electrical resistance with increases in temperature. A controller of the fixing unit is configured to vary a duty ratio of electric power applied to the first heater element during a start-up operation in which the temperature of the first heater element is raised to a target operating temperature. By varying the duty ratio during the start-up operation, changes in the resistance of the first heater element with the heating can be compensated. For example, the duty ratio can be increased during the course of the start-up to achieve the target operating temperature faster.
Abstract: Disclosed is an MRI control signal providing method including obtaining an initial control variable array including time-series values of a control variable for controlling a spatial profile of an induced magnetic field induced by an MRI scanner, obtaining information about a desired spatial profile of the induced magnetic field in the MRI scanner, calculating a differentiation array obtainable by partially differentiating a predetermined function with respect to the control variable, and calculating a scaled array obtained by scaling the differentiation array with a predetermined scaling factor, and generating an updated control variable array from the initial control variable array by subtracting values of the scaled array from values of the initial control variable array.
Type:
Grant
Filed:
February 5, 2021
Date of Patent:
March 22, 2022
Assignee:
SEOUL NATIONAL UNIVERSITY R&DB FOUNDATION
Abstract: Systems and methods for measuring eddy current fields occurring as a result of gradient pulses in a magnetic resonance sequence at a point in time during the magnetic resonance sequence in relation to at least one direction of pulse effect. At least the parts of the magnetic resonance sequence comprising the gradient pulses relating to the at least one direction of pulse effect are performed as a preparation sequence up until the point in time followed directly by a measurement sequence in which first measurement data is recorded. The preparation sequence is played out again with the same, directly consecutive measurement sequence without the gradient pulses relating to the at least one direction of pulse effect or with gradient pulses having an inverted sign relating to the at least one direction of pulse effect. Second measurement data is recorded.
Abstract: In a device and method for monitoring an RF transmission circuit of an MRI device: a first power measurement signal is acquired that indicates a voltage of a first RF signal provided by an RF power amplifier of the RF transmission circuit; two second power measurement signals are received that each indicate a voltage of one second RF signal, the two second RF signals being generated based on the first RF signal by a bridge of the circuit and transmitted via an RF transmit coil; an inverse matrix calculation is performed based on the two second power measurement signals to obtain a voltage calculation value; the voltage calculation value is compared with the first power measurement signal; an operational status of the RF transmission circuit is determined based on a difference between the voltage calculation value and a voltage value of the first power measurement signal.
Abstract: A composite gear includes: a first member comprising a rotation shaft portion and a disk-shaped web extending in radial directions from the rotation shaft portion; and a second member comprising at least one engaging tooth on an outer periphery thereof and provided being supported by the web so as to surround an outer periphery of the first member. A space is provided between the second member and an outermost peripheral surface of the first member in a radial direction, a space is provided between the first member and an innermost peripheral surface of the second member in a radial direction, and at least one of the first member and the second member is formed to nip another of the first member and the second member from both sides thereof in an axial direction of the rotation shaft portion.
Type:
Grant
Filed:
June 18, 2020
Date of Patent:
March 8, 2022
Assignee:
Canon Kabushiki Kaisha
Inventors:
Gaku Iijima, Tatsurou Fujii, Yuta Itahashi
Abstract: A method of designing a pulse sequence for parallel-transmission MRI includes a) for each one of a plurality of subjects, estimating a linear adjustment transformation (L), converting amplitude maps of RF fields generated by respective transmit channels of a MRI apparatus into respective standardized maps; and b) determining RF waveforms (P) minimizing a discrepancy between subject-specific distributions of flip-angles of nuclear spin and a target distribution, averaged over said subjects, the subject-specific distributions corresponding to the flip-angle distributions achieved by applying a superposition of RF fields, each having a temporal profile described by one of said RF waveforms and a spatial amplitude distribution described by a respective standardized map determined for the subject. A method and an apparatus for performing parallel-transmission MRI using such a pulse sequence are provided.
Type:
Grant
Filed:
December 3, 2020
Date of Patent:
March 1, 2022
Assignee:
COMMISSARIAT A L'ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
Inventors:
Vincent Gras, Nicolas Boulant, Michel Luong, Alexis Amadon
Abstract: The invention relates to a gradient shield coil (5) for a MRI apparatus (1). The gradient shield coil (5) according to the invention comprises windings (6, 7) around its longitudinal axis (A), wherein at least one winding (7) is arranged as a meandering winding (7). This meandering winding (7) comprises multiple contiguous sections (8) along its circumference, wherein in each of these sections (8) a pair of conductor loops (9, 10) is provided in such a way that a current in the meandering winding (7) would run in opposite directions in the two conductor loops (9, 10). In this way, dissipation in the superconductive coils of a superconductive magnet (2) of a respective MRI apparatus (1) may be further reduced.
Abstract: The disclosure relates to a method for ascertaining a deviation of at least one gradient field of a magnetic resonance system from a reference. The method includes providing at least one first image data set and one second image data set of a phantom with isotropic diffusion properties, recorded with a diffusion-weighted imaging sequence, wherein the first image data set and the second image data set are recorded with different diffusion-weightings along a gradient direction to be tested of the gradient field using the magnetic resonance system. The method further includes ascertaining a map of apparent diffusion coefficients from the image data sets for at least a portion of the image points of the image data sets. The method further includes comparing the apparent diffusion coefficients with the reference.
Abstract: A pilot tone device for acquiring physiological data of a patient and a magnetic resonance tomography system with a corresponding pilot tone device are provided. The pilot tone device has a pilot tone transmitter that is designed to transmit a pilot tone in an ISM band.
Abstract: The present invention relates to an RF transmit system and method, MRI system and a pre-scan method and medium thereof. The RF transmit system comprises: an RF output unit, for generating and outputting an RF pulse signal; an RF amplifier, for amplifying the RF pulse signal; and a signal processing unit, for communicating the amplified RF pulse signal to an RF transmit coil of the MRI system and outputting a feedback signal to the RF output unit, wherein the RF output unit generates a linearity compensation control signal based on the feedback signal and a predetermined feedback signal-linearity compensation value-relationship, so as to carry out linearity compensation for the RF pulse signal outputted by the RF output unit. The RF transmit method corresponds to the above noted system and the MRI system comprises the above noted RF transmit system. The pre-scan method comprises the RF transmit method. Instructions recorded by the medium may execute the above noted RF transmit method and pre-scan method.
Abstract: A method includes the steps of: introducing a medium with a first temperature into a measuring volume; carrying out nuclear magnetic measurements on the medium with the first temperature; determining a property of the medium at the first temperature; determining a viscosity of the medium at the first temperature using the property; and determining a derived property of the medium at a second temperature using the property of the medium at the first temperature, the viscosity of the medium at the first temperature, the first temperature, and the second temperature. The property is at least one of a first spin-lattice relaxation time constant, a first spin-spin relaxation time constant, and a first diffusion time constant. The derived property is at least one of a second spin-lattice relaxation time constant, a second spin-spin relaxation time constant, and a second diffusion time constant.
Abstract: According to some aspects, a magnetic resonance imaging system capable of imaging a patient is provided. The magnetic resonance imaging system comprising at least one B0 magnet to produce a magnetic field to contribute to a B0 magnetic field for the magnetic resonance imaging system and a member configured to engage with a releasable securing mechanism of a radio frequency coil apparatus, the member attached to the magnetic resonance imaging system at a location so that, when the member is engaged with the releasable securing mechanism of the radio frequency coil apparatus, the radio frequency coil apparatus is secured to the magnetic resonance imaging system substantially within an imaging region of the magnetic resonance imaging system.
Type:
Grant
Filed:
July 19, 2019
Date of Patent:
February 1, 2022
Assignee:
Hyperfine, Inc.
Inventors:
Anne Michele Nelson, Christopher Thomas McNulty, Jeremy Christopher Jordan, Michael Stephen Poole, Gang Chen
Abstract: A technique facilitates tracking and assessing a fatigue life of a tubing string utilizing, for example, estimation of cycles to failure when used in a wellbore operation. The technique may comprise initially determining a fatigue life of a tubing string. Additionally, the technique comprises utilizing a sensing device, e.g. a magnetic flux leakage (MFL) device, to monitor the tubing string. When an anomaly, e.g. a new defect, is detected by the sensing device, a new fatigue life of the tubing string is determined based on the change. The new fatigue life may be used to estimate a fatigue life in terms of cycles to failure.
Abstract: According to some aspects, an apparatus is provided comprising a deployable guard device, configured to be coupled to a portable medical imaging device, the deployable guard device further configured to, when deployed, inhibit encroachment within a physical boundary with respect to the portable medical imaging device. According to some aspects, an apparatus is provided comprising a deployable guard device, configured to be coupled to a portable magnetic resonance imaging system, the deployable guard device further configured to, when deployed, demarcate a boundary within which a magnetic field strength of a magnetic field generated by the portable magnetic resonance imaging system equals or exceeds a given threshold.
Type:
Grant
Filed:
July 24, 2020
Date of Patent:
January 25, 2022
Assignee:
Hyperfine, Inc.
Inventors:
Christopher Thomas McNulty, Michael Stephen Poole