Patent application number | Description | Published |
20090040664 | ACTIVE SHIELD SUPERCONDUCTING ELECTROMAGNET APPARATUS AND MAGNETIC RESONANCE IMAGING SYSTEM - The active shield superconducting electromagnet apparatus includes: a main switching circuit in which first and second main coils, first and second shield coils, and a first superconducting persistent current switch are connected in series; a sub switching circuit in which a bypass circuit, in which a superconducting fault current limiter and a second superconducting persistent current switch are connected in series, are connected to a series circuit of the first main coil and the second main coil in parallel; a first closed circuit in which at least one of the first main coil and the first shield coil, and a first quench protection circuit are connected in series; and a second closed circuit in which one of the second main coil and the second shield coil, and a second quench protection circuit are connected in series. | 02-12-2009 |
20090189721 | SUPERCONDUCTING MAGNET AND MAGNETIC RESONANCE IMAGING APPARATUS - In a superconducting magnet, including a vacuum vessel, a coil vessel inside the vacuum vessel, and a superconducting coil inside the coil vessel for generating a magnetic field, has a magnetic member, disposed inside the vacuum vessel, supported with thermal insulation, for compensating the magnetic field; a heat exchange device disposed outside the vacuum vessel for supplying to or absorbing heat from the vacuum vessel; and thermal conducting members thermally connecting the heat exchange device via the vacuum vessel to the magnetic member. An MRI including the superconducting magnet is also disclosed. | 07-30-2009 |
20100194393 | GRADIENT COIL DEVICE, MAGNETIC RESONANCE IMAGING DEVICE, AND METHOD OF DESIGNING COIL PATTERN - There is provided a gradient coil device which can suppress any generation of an error magnetic field and thus an eddy current, and which can improve the image quality of a cross-sectional image. An MRI device includes a first coil generating a linear magnetic field distribution at an imaging region of the MRI device, and a second coil which suppresses any leakage of a magnetic field from the first coil to a static-magnetic-field coil device that generates a uniform magnetic field distribution at the imaging region. | 08-05-2010 |
20100321019 | GRADIENT MAGNETIC FIELD COIL DEVICE AND MAGNETIC RESONANCE IMAGING APPARATUS - When the gradient magnetic field | 12-23-2010 |
20110037469 | Electromagnet Device and Magnetic Resonance Imaging Device - An electromagnet device which generates magnetic field in the direction perpendicular to the inserting direction of an inspection subject is reduced in size and weight by removing unnecessary arrangement as much as possible. A magnetic resonance imaging device is also provided. The electromagnet device comprises a first coil ( | 02-17-2011 |
20110057655 | SOFTWARE FOR ADJUSTING MAGNETIC HOMOGENEITY, METHOD FOR ADJUSTING MAGNETIC HOMOGENEITY, MAGNET DEVICE, AND MAGNETIC RESONANCE IMAGING APPARATUS - On the basis of the magnetic field intensity distribution of a magnetic field space ( | 03-10-2011 |
20110089943 | MAGNETIC FIELD ADJUSTMENT FOR MRI APPARATUS - A measured error magnetic field distribution is divided into eigen-mode components obtained by a singular decomposition and iron piece arrangements corresponding to respective modes are combined and arranged on a shim-tray. An eigen-mode to be corrected is selected in accordance with an attainable magnetic field accuracy (homogeneity) and appropriateness of arranged volume of the iron pieces. Because the adjustment can be made with the attainable magnetic field accuracy (homogeneity) being known, an erroneous adjustment can also be known, and the adjustment is automatically done during repeated adjustments. As a result, an apparatus with a high accuracy can be provided. In addition, there is an advantageous effect of being able to detect a poor magnet earlier by checking the attainable homogeneity. | 04-21-2011 |
20120176137 | GRADIENT MAGNETIC FIELD COIL AND MAGNETIC RESONANCE IMAGING DEVICE - In the magnetic resonance imaging device, the distance between the first and second coils is different in the circumferential direction and has a first region (A | 07-12-2012 |
20120235685 | GRADIENT COIL, MAGNETIC RESONANCE IMAGING DEVICE, AND METHOD FOR DESIGNING COIL PATTERN - A method for designing a coil pattern, whereby the production of an error magnetic field and further an eddy current can be suppressed to improve the quality of a cross-sectional image irrespective of cylindrical cross-sectional shape of the main coil and the shield coil. The difference between the initial values of the target magnetic field and the magnetic field vector is set as a difference target magnetic field. An approximate value of the current potential vector that produces the difference target magnetic field is represented by a polynomial of an eigenvector group of the current potential. The coefficient of each of the terms of the polynomial is determined on the basis of the singular value and the eigenvector group of the magnetic field distribution. | 09-20-2012 |
20120268119 | MAGNETIC FIELD ADJUSTMENT METHOD FOR MRI DEVICE - An eigen-mode to be corrected is selected in accordance with an attainable magnetic field accuracy (homogeneity) and appropriateness of arranged volume of the iron pieces. Because the adjustment can be made with the attainable magnetic field accuracy (homogeneity) being grasped, an erroneous adjustment can be grasped, and the adjustment is automatically done during repeated adjustment. When the magnetic field adjustment is carried out with support by the method of the present invention according to the first and second embodiments or an apparatus including this method therein, the magnetic field adjustment can be surely completed. As a result, the apparatus with a high accuracy can be provided. In addition, there is an advantageous effect of earlier detection of a poor magnet by checking the attainable homogeneity. They are applicable to magnet devices for the horizontal magnetic field type, being an open type MRI, and vertical magnetic field type MRI. | 10-25-2012 |
20130335088 | GRADIENT COIL DEVICE AND MAGNETIC RESONANCE IMAGING DEVICE - A gradient coil device includes a major axis gradient coil, having an ellipse in a cross section generating a gradient magnetic field inclined in a major axis direction of the ellipse at a magnetic field space; and a minor axis gradient coil, having an ellipse in a cross section generating a gradient magnetic field inclined in a minor axis direction of the ellipse at the magnetic field space. A length of the minor axis field coil in the center axis direction is shorter than a length of the major axis gradient coil in the center axis direction. A maximum value of a residual magnetic field generated by the minor axis gradient coil at a space outside the magnetic field space is equal to or smaller than a maximum value of a residual magnetic field generated by the major axis gradient coil at a space outside the magnetic field space. | 12-19-2013 |
Patent application number | Description | Published |
20110018540 | METHOD OF CALCULATING COIL PATTERN, AND GRADIENT MAGNETIC FIELD COIL. - The present invention eliminate the limitation of coil pattern design, facilitates the fabrication, and improves the accuracy of magnetic field. A coil pattern calculation method is characterized by comprising the steps of: calculating a current potential at each contact between finite surface elements forming each of the coil surfaces based on an initial value of an input current potential distribution, and, for each of the coil surfaces, repeatedly calculating the current potential alternately and, under each magnetic field condition, determining a current potential distribution that generates a magnetic field falling within the range of allowable error for each target magnetic field so that a surface current represented by the current potential will become close to a target magnetic field distribution set for each of the finite surface elements; and determining a coil pattern from the contour lines of the determined current potential distribution. | 01-27-2011 |
20140176138 | GRADIENT MAGNETIC FIELD COIL DEVICE, ADJUSTMENT METHOD THEREFOR, AND MAGNETIC RESONANCE IMAGING APPARATUS - In a gradient magnetic field coil device including: a plurality of main coils generating in an imaging region of a magnetic field resonance imaging device a magnetic field distribution in which an intensity linearly inclines; and a plurality of shield coils, arranged on an opposite side of the imaging region across the main coils, suppressing residual magnetic field generated by the main coils on the opposite side. The plurality of main coils and the plurality of shield coils are connected in series. The device further includes a plurality of current adjusting devices, connected to the shield coils in parallel, independently adjusting currents flowing through the shield coils, respectively, to enhance symmetry of the residual magnetic field. The gradient magnetic field coil device is provided which can suppress generation of eddy current magnetic field even if there is a relative position deviation between the main coils and shield coils. | 06-26-2014 |
20140210476 | MAGNETIC RESONANCE IMAGING DEVICE - A device includes: a static magnetic field generating device including static magnetic field generating sources generating a homogeneous magnetic field in a space; gradient magnetic field generating sources superimposing a gradient magnetic field on the homogeneous magnetic field, and conductor rings arranged between the static magnetic field generating sources and the gradient magnetic field generating sources in a pair of arranging regions on both sides in a direction of the homogeneous magnetic field in a region where the homogeneous magnetic field is generated (imaging region), respectively, the conductor rings being separated from each other and making a pair. The conductor rings are mechanically connected to the gradient magnetic field generating device or the static magnetic field generating device. This provides an MRI device 1 capable of reduction in vibration with suppression of the image quality deterioration of the tomographic images. | 07-31-2014 |