Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Other

Canon Medical Systems Corporation

Hitachi Medical Corporation

Synaptics Japan Gk

Hajime Tanabe

Shigenori Kuroda

Hirotaka Takeshima

Naoji Yoshida

Hiroshi Tazaki

Hajime Kawano

Takeshi Yatsuo

Takao Hommei

Satoshi Saito

Hajime Tamura

Tatsuya Inoue

Yasuyuki Tahara

Kazuki Moritsu

Takao Honmei

Kota Kitamura

Masayoshi Oya

A method includes: calculating a first optimum quantity of ferromagnetic arranged at each position so that each error component of a magnetic field distribution in a specific space satisfies a first restriction condition (S, S); discretizing, for each position, the first optimum quantity (S); calculating the error components that are obtained when ferromagnetic having a quantity of the first combination is arranged at each position (S); when the error component is less than the first lower limit, setting a condition including a lower limit greater than the first lower limit and an upper limit greater than the first upper limit as a second restriction condition, and when the error component is greater than the first upper limit, setting a condition including a lower limit less than the first lower limit and an upper limit less than the first upper limit as a second restriction condition (S).

Method and apparatus for homogenizing magnetostatic field generated from superconducting magnet

A spool has a cylindrical outer shape extending in an axial direction intersecting an upward/downward direction, the spool having an outer circumferential surface in which a plurality of annular groove portions extending in a circumferential direction are formed with a space being interposed between the plurality of annular groove portions in the axial direction, a superconducting coil being wound and accommodated inside each of the plurality of annular groove portions. A cover portion is attached to the spool so as to cover each of the plurality of annular groove portions, the cover portion and the plurality of annular groove portions forming a plurality of annular flow paths for refrigerant to cool the superconducting coil. One or more communication paths extend in parallel with the axial direction to communicate adjacent annular flow paths of the plurality of annular flow paths with each other.

Superconducting electromagnet device

A superconducting magnet includes: a superconducting coil; a coolant container; a radiation shield; a vacuum container; a refrigerator; a current lead; a first pipe including a mounting opening in which the refrigerator is inserted and fixed; a second pipe including a lead-out opening through which the current lead passes to be led out; and a flow rate ratio maintaining mechanism connected to at least one of the downstream side of the mounting opening of the first pipe and the downstream side of the lead-out opening of the second pipe, the flow rate ratio maintaining mechanism allowing the vaporized coolant to flow through the first pipe and the second pipe at a constant flow rate ratio.

Superconducting magnet

A liquid crystal display apparatus includes a liquid crystal display panel having gate lines and source lines, a GIP circuit which drives the gate lines and a source driver ICwhich drives the source lines. The source driver ICincludes a gate control signal generator which generates gate control signals SOUT-SOUTn which control the GIP circuit. The gate control signal generator is configured so that it is possible to control the waveforms of the gate control signals SOUT-SOUTn in software.

Display apparatus and display panel driver including software-controlled gate waveforms

There are provided the steps of: measuring a magnetic field in a predetermined space; and performing shimming by arranging a plurality of ferromagnetic shims in a superconducting magnet. The step of shimming includes arranging the plurality of shims at positions that make the magnetic field homogeneous, based on a result of measurement in the step of measuring the magnetic field and that provide a predetermined value of an electromagnetic force caused by the magnetic field to act on the plurality of shims.

Superconducting-magnet adjustment method

A method of the present invention includes: a step of shimming an MRI superconducting magnet in consideration of the magnetic field atmosphere of a use place; a step of generating a rated magnetic field in the MRI superconducting magnet thus shimmed, under an environment in which the magnetic field atmosphere of the use place is realized; and a step of installing the MRI superconducting magnet in the use place after the step of generating the rated magnetic field. This reduces possibility of occurrence of quench and improves stability in the MRI superconducting magnet.

Method for adjusting MRI superconducting magnet

A superconducting magnet device includes a main coil that generates a static magnetic field in an imaging space and a disturbance magnetic field compensation coil that suppresses influences of a variable magnetic field flowing inside from outside in the imaging space. The main coil is divided to at least two diode circuits. The disturbance magnetic field compensation coil has at least one coil formed of minus turns so that mutual inductances with the respective diode circuits in the main coil are made minimum.

Superconducting magnet device

A shim support guide jig includes a shim support guide pipe in which a guide passage for guiding the movement of a shim support is formed. In a state where a superconducting magnet has generated a static magnetic field, the designated shim support can be drawn out from the internal space of the superconducting magnet through the guide passage, and the designated shim support for which magnetic material shims have been arranged and adjusted can be inserted into the internal space through the guide passage. A magnetic field generation apparatus has the magnetic material shims arranged and adjusted using the shim support guide jig, and a magnetic resonance imaging equipment employs the magnetic field generation apparatus. Magnetic field adjustment methods for the magnetic field generation apparatus and for the magnetic resonance imaging equipment are performed using the shim support guide jig.

Shim support guide jig for magnetic field generation apparatus, magnetic field generation apparatus and magnetic resonance imaging equipment each including shim support in which magnetic material shims are arranged and adjusted by employing shim support guide jig, and magnetic field adjustment method for magnetic field generation apparatus, as well as magnetic field adjustment method for magnetic resonance imaging equipment

A superconducting magnet of the present invention includes a switching element that closes its output side (operation side) when the voltage on its input side is smaller than a predetermined value and opens the output side when the voltage on the input side is larger than the predetermined value, wherein the input side is connected in parallel to a main coil circuit, and the output side of is connected in series to external magnetic-field disturbance compensation coils, for releasing the circuit of the disturbance compensation coil by closing the output side if the voltage on the input side is smaller than the predetermined value.

Superconducting magnet and MRI apparatus using the same

A magnetic resonance imaging system is provided in which the two contradictory requirements, i.e., enhancing the feeling of being not confined by enlarging the subject-insertion space and decreasing magnetomotive force of the superconductive coils by bringing the superconductive coils as close as possible to a subject, can be met in a good balance. In a magnetic resonance imaging system that includes a superconductive electromagnetic device for generating a static magnetic field to be applied to a subject, a gradient-magnetic-field coil for forming a gradient magnetic field by tilting the magnetic-field strength of the static magnetic field, and a radio-frequency coil for transmitting a radio-frequency magnetic field to the subject and then receiving nuclear magnetic-resonance signals from the subject, a vacuum container for the superconductive electromagnetic device thereof has a recess; the gradient-magnetic-field coil and the radio-frequency coil thereof are accommodated in the recess; and a cosmetic cover that is fit into the recess and is supported by the wall surfaces of the recess is included therein.

Magnetic resonance imaging system

A superconductive magnet device comprises a pair of oppositely disposed superconductive bodies in which annular superconductive coils are accommodated, and fine chip-shaped ferromagnetic shims disposed on a surface of the pair of superconductive magnet bodies so as to improve uniformity of magnetic field in a uniform magnetic field in a uniform magnetic field space generated in the proximity of the center between the superconductive magnet bodies, wherein ring-shaped ferromagnetic shims are disposed concentrically with the center of annular superconductive coils on the surface of the superconductive magnet bodies.

Superconductive magnet device

An open-type magnet device for MRI includes a pair of upper and lower magnet assemblies, and shims are provided on opposite sides of their cooling containers and/or in holes passing through central portions of the cooling containers so as to facilitate providing a highly homogeneous static magnetic field.

Open-type magnet device for MRI

A superconductive magnet device comprises a pair of oppositely disposed superconductive bodies in which annular superconductive coils are accommodated, and fine chip-shaped ferromagnetic shims disposed on a surface of the pair of superconductive magnet bodies so as to improve uniformity of magnetic field in a uniform magnetic field space generated in the proximity of the center between the superconductive magnet bodies, wherein ring-shaped ferromagnetic shims are disposed concentrically with the center of annular superconductive coils on the surface of the superconductive magnet bodies.

A superconducting magnet apparatus. By forming one or more holes in each of platelike ferromagnetic substances forming a magnetic shield for focusing the magnetic flux generated by superconducting coils, the flow of lines of magnetic flux is adjusted. Thereby, a static magnetic field in a measurement space is corrected. By disposing coupling tubes for supporting two cooling vessels housing superconducting coils on the rear side with respect to a central axis (Z axis) of the measurement space of the vertical direction, access to the subject is facilitated. In addition, the magnetic shield has an opening portion wider than the superconducting magnet on its side face. After the magnetic shield has been assembled, the superconducting magnet can be inserted from the opening portion.

Growing community of inventors

Tokyo, Japan

Hajime Tanabe