Polarizing Field Magnet Patents (Class 324/319)
  • Patent number: 8134433
    Abstract: Main coils, counteracting coils and correction coils, each forming superconducting coil, are enclosed in two cooling medium chamber facing to each other and an imaging region is formed between the two cooling medium chamber positioned in each vacuum chamber, the main coils being divided into two pieces to reduce the current density and the maximum experience magnetic filed and compression stress.
    Type: Grant
    Filed: September 28, 2004
    Date of Patent: March 13, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Mitsushi Abe, Takeshi Nakayama, Masanori Takahashi
  • Patent number: 8134368
    Abstract: The present invention relates to a magnetic resonance examination system (10) and to a method of operating such a magnetic resonance examination system (10). In particular the present invention relates to a magnetic resonance examination system (10) comprising a superconducting main magnet (20) surrounding an examination region (18) and generating a main magnetic field in the examination region (18), and further comprising a magnetic field gradient system (30) selectively causing alternating gradient magnetic fields in the examination region (18), said magnetic field gradient system (30) being coupled to the main magnet (20).
    Type: Grant
    Filed: November 5, 2007
    Date of Patent: March 13, 2012
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Holger Timinger, Johannes Adrianus Overweg
  • Patent number: 8058873
    Abstract: A magnetic resonance examination system (10) includes a superconducting main magnet (20) surrounding an examination region (18) and generating a main magnetic field in the examination region (18) A magnetic field gradient system (30) selectively causes alternating gradient magnetic fields in the examination region (18). The magnetic field gradient system (30) is disposed outside of the main magnet (20). In order to provide stable operation of the superconducting main magnet (20) of a magnetic resonance examination system (10) with such a magnetic field gradient system (30), the magnetic resonance examination system (10) is provided with a predicting device (91) and a preventing device (92) The predicting device (91) predicts the behavior of the main magnet (20) due to the gradient magnetic fields (e.g.
    Type: Grant
    Filed: November 5, 2007
    Date of Patent: November 15, 2011
    Assignee: Koninklijke Philips Electronics N.V.
    Inventor: Holger Timinger
  • Patent number: 8049503
    Abstract: A system includes a body-insertable apparatus disposed while introduced in a subject in a detection space, and an external apparatus disposed on the outside of the subject. The body-insertable apparatus includes a first switch for connecting/interrupting a resonance circuit and an oscillation circuit or a ground line. The external apparatus includes a drive coil driving unit for outputting a drive signal having the resonance frequency; a drive coil for generating the drive magnetic field in the detection space in accordance with the drive signal; and a second switch for connecting/interrupting the drive coil driving unit and the drive coil. The second switch connects the drive coil driving unit and the drive coil when the first switch is off, and disconnects them when the first switch is on. The resonance circuit generates the resonance magnetic field in accordance with the induction signal or the drive magnetic field.
    Type: Grant
    Filed: June 29, 2010
    Date of Patent: November 1, 2011
    Assignee: Olympus Medical Systems Corp.
    Inventors: Atsushi Kimura, Atsushi Chiba, Ryoji Sato, Hironao Kawano
  • Publication number: 20110248715
    Abstract: A magnet assembly primarily for use in MRI applications is disclosed. The magnet assembly is composed of a single disk and ring permanent magnet set connected to a C-type magnet yoke and return fixture with asymmetrically arranged poles. Together, the permanent magnets create a strong magnetic field that has a large static gradient in the central enclosure. The magnet assembly is primarily designed for diffusion based MRI scanning but can perform routine MRI scanning as well.
    Type: Application
    Filed: December 12, 2009
    Publication date: October 13, 2011
    Inventors: Grum Telemariam, Jianyu Lian, David Cory
  • Patent number: 8035379
    Abstract: A coil energizing apparatus has a superconducting energization power supply having an output port. The power supply is arranged to generate, when in use, a pulsed output current signal at the output port.
    Type: Grant
    Filed: February 20, 2009
    Date of Patent: October 11, 2011
    Assignee: Siemens PLC
    Inventor: Kevin Jonathan Hickman
  • Patent number: 8013697
    Abstract: A method of manufacturing a solenoidal magnet structure, includes the step of providing a collapsible accurate mold in which to wind the coils winding wire into defined positions in the mold, placing a mechanical support structure over the coils so wound, impregnating the coils and the mechanical support structure with a thermosetting resin, allowing the thermosetting resin to harden, and collapsing the mold and removing the resultant solenoidal magnet structure formed by the resin impregnated coils and the mechanical support structure from the mold as a single solid piece.
    Type: Grant
    Filed: January 22, 2009
    Date of Patent: September 6, 2011
    Assignee: Siemens PLC
    Inventors: Simon James Calvert, Jonathan Noys, Adrian Mark Thomas
  • Patent number: 8008916
    Abstract: A magnetic resonance apparatus has a cylindrical gradient coil with an x-gradient coil and a y-gradient coil that are asymmetrical relative to the z-direction of a coordinate system, the z-direction extending along a longitudinal direction of a patient receptacle. Shim coils are provided that generate magnetic fields to homogenize the basic magnetic field, produced by a cylindrical basic field magnet, in an examination volume in the patient receptacle. At least some of the shim coils are asymmetrical relative to the z-direction to minimize coupling induction between the asymmetrical x-gradient coil and y-gradient coil and the asymmetrical shim coils.
    Type: Grant
    Filed: July 14, 2006
    Date of Patent: August 30, 2011
    Assignee: Siemens Aktiengesellschaft
    Inventors: Jörg Riegler, Axel vom Endt
  • Patent number: 7999547
    Abstract: A system and method for magnetic resonance imaging assisted surgery. The system includes an antenna support assembly and an antenna that are used to acquire real time images of the surgical site that may be used by a surgeon to more accurately perform the surgical procedure. The method comprises acquiring real time images of the surgical site and feeding back the images to a surgeon performing the surgical procedure.
    Type: Grant
    Filed: March 16, 2009
    Date of Patent: August 16, 2011
    Assignee: Fonar Corporation
    Inventors: Charles A. Green, Arto Cinoglu, William H. Wahl
  • Patent number: 7990143
    Abstract: The nuclear magnetic resonance machine comprises a device (101) for creating an intense main magnetic field B0 in a useable interior space (109) in the form of a tunnel with axis Z, a device for radio-frequency excitation and processing of radio-frequency signals emitted in response by a body (150) placed in the useable interior space (109), and a set (110) of solenoidal gradient coils for superimposing on the intense magnetic field B0 components of an additional magnetic field, the gradient coils (111-122) being incorporated into tubes that are disposed in a annular cylindrical space (130).
    Type: Grant
    Filed: October 26, 2006
    Date of Patent: August 2, 2011
    Assignee: Commissariat a l'Energie Atomique et Aux Energies Alternatives
    Inventor: Guy Aubert
  • Patent number: 7986205
    Abstract: There is provided a magnetic field generator 10 which is capable of varying an orientation of a magnetic field at a target position P easily in all directions. The magnetic field generator 10 includes a pair of magnetic field generating units 16a, 16b which are disposed coaxially so that their respective first main surfaces 28a, 28b oppose in parallel to each other, with a gap G in between. The magnetic field generating units 16a, 16b are rotated by rotation drive units 20a, 20b respectively in Arrow A directions. By rotating each of the magnetic field generating units 16a, 16b in the same one direction of the Arrow A directions by the same angle, the orientation of the magnetic field at the target position P is varied on an X-Z plane.
    Type: Grant
    Filed: September 29, 2006
    Date of Patent: July 26, 2011
    Assignee: Hitachi Metals. Ltd
    Inventors: Kentarou Horisaka, Hisato Amano
  • Patent number: 7982566
    Abstract: A cryostat (1) with a magnet coil system including superconductors for the production of a magnet field B0 in a measuring volume (3) within a room temperature bore (2) of the cryostat has a plurality of radially nested solenoid-shaped coil sections (4, 5, 6) which surround the room temperature bore and which are electrically connected in series, at least one of which being an LTS section (5, 6) with a conventional low temperature superconductor (LTS) and at least one of which being an HTS section (4) including a high temperature superconductor (HTS), wherein the LTS section (5, 6) is located in a helium tank (9) of the cryostat (1) along with liquid helium at a helium temperature TL. The apparatus is characterized in that the HTS section (4) is disposed radially within the LTS section (5, 6) in a vacuum portion of the cryostat and is separated from the LTS section (5, 6) by the helium tank (9) wall (9a) facing the room temperature bore.
    Type: Grant
    Filed: March 7, 2007
    Date of Patent: July 19, 2011
    Assignee: Bruker BioSpin GmbH
    Inventor: Arne Kasten
  • Patent number: 7977946
    Abstract: A magnet assembly primarily for use in MRI Interventional applications having an array of four mam permanent magnets that are spaced-apart and arranged into a ring-like geometry with six easy-access openings The magnetization direction in each permanent magnet is anti-parallel to any other adjacent permanent magnet in the ?ng assembly while it is parallel to any other permanent magnet in the array that is oppositely located just as in a quadrupolar system Such an arrangement has the advantage of concentrating the magnetic field inside the nng enclosure while minimizing magnetic field generated outside Together, these four spatially spaced-apart permanent magnets create a very homogeneous and strong magnetic field in the central enclosure with two orthogonal access paths and one parallel access path to the enclosure Through one access pathway a patient can be inserted while through the other pathways a doctor can fully access the patient.
    Type: Grant
    Filed: June 25, 2007
    Date of Patent: July 12, 2011
    Inventors: Grum Teklemariam, Jianyu Lian
  • Patent number: 7944208
    Abstract: A Magnetic Resonance Imaging System consisting of a magnet (10) with a U-shaped frame (15), whose pole faces define an open magnetic imaging area [R] for a patient, and a magnetic field generator (17) that is controlled to generate magnetic fields inside the magnetic imaging area; a transport system (30) associated with the magnet has a support structure (20) that defines a movement path through the magnetic imaging area. The transport system (30) also includes a bench (40) to support the patient. The transport system (30) can slide the bench (40) along the support structure so that the patient can be introduced into and extracted from the magnetic imaging area. The bench (40) may further include a non-reclinable support part (41) coupled to reclinable support parts (42 and 43) at opposing ends to allow the position of patient to be rotatably changed on the bench (40).
    Type: Grant
    Filed: November 24, 2008
    Date of Patent: May 17, 2011
    Assignee: Paramed Medical Systems, Inc.
    Inventors: Roberto Dutto, Marco Monaldi
  • Patent number: 7936169
    Abstract: An apparatus in one example comprises a polarization filter and a polarization analyzer. The polarization filter comprises a first polarization axis. The polarization analyzer comprises a second polarization axis. The polarization filter is configured to polarize detection light for a nuclear magnetic resonance (NMR) cell along the first polarization axis. The polarization analyzer is configured to receive the detection light from the NMR cell and pass a portion of the detection light to a processor for determination of angular rate information. The portion of the detection light passed to the processor is based on an orientation of the second polarization axis relative to the first polarization axis. The orientation is selected to maximize a signal-to-noise ratio of the detection light.
    Type: Grant
    Filed: July 14, 2008
    Date of Patent: May 3, 2011
    Assignee: Northrop Grumman Guidance and Electronics Company, Inc.
    Inventor: Edward Kanegsberg
  • Patent number: 7928731
    Abstract: An arrangement for the adjustment of the homogeneity of a basic magnetic field in a magnetic resonance apparatus includes gradient coil support fashioned to support a gradient coil system. The gradient coil support has at least one channel that is fashioned to accommodate an associated shim tray. The shim tray is designed to accommodate ferromagnetic shim elements at predetermined positions in order to adjust the homogeneity of the basic magnetic field of the magnetic resonance apparatus. The shim tray has a first locking element coupled with it. The channel has a second locking element, and the first and second locking element are shaped such that both are positively connected with one another by a force produced by the basic magnetic field of the magnetic resonance apparatus upon activation thereof.
    Type: Grant
    Filed: April 23, 2009
    Date of Patent: April 19, 2011
    Assignee: Siemens Aktiengesellschaft
    Inventors: Michael Eberler, Andreas Krug, Johann Schuster, Stefan Stocker
  • Patent number: 7928359
    Abstract: A polarizing apparatus has a thermally conductive partitioning system in a polarizing cell. In the polarizing region, this thermally conductive partitioning system serves to prevent the elevation of the temperature of the polarizing cell where laser light is maximally absorbed to perform the polarizing process. By employing this partitioning system, increases in laser power of factors of ten or more can be beneficially utilized to polarize xenon. Accordingly, the polarizing apparatus and the method of polarizing 129Xe achieves higher rates of production.
    Type: Grant
    Filed: September 20, 2007
    Date of Patent: April 19, 2011
    Assignee: University of New Hampshire
    Inventor: F. William Hersman
  • Patent number: 7928730
    Abstract: The electromagnet apparatuses generate a homogeneous magnetic field in a homogeneous magnetic field region by a pair of superconductive main coils for facing to each other; a pair of superconductive shielding coils for facing to each other and passing a current in a direction reverse to that of the main coils; and a pair of first ferromagnetic members for facing to each other, and the apparatuses further include a pair of second ferromagnetic members for facing to each other and be disposed in contact with or adjacent to an opposite side of the region side of the first ferromagnetic members, wherein the region is interposed between the main coils, between the shielding coils, between the first members whose outer periphery is a circle, and between the second members whose outer periphery is a circle whose diameter is larger than that of the circle of the first members.
    Type: Grant
    Filed: January 18, 2007
    Date of Patent: April 19, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Manabu Aoki, Mitsushi Abe, Takeshi Nakayama, Masanori Takahashi
  • Publication number: 20110084695
    Abstract: Method for making magnets particularly for the use in MRI scanners, which magnets are three-dimensional and have a tubular wall made of magnetized material, with a closed or open annular shaped cross-section, the tubular wall being composed of individual elements made of magnetized material, the magnetization of each element made of magnetized material having a predetermined direction in the transverse section plane and said directions being determined such to generate a uniform static magnetic field in the cavity of the tubular wall.
    Type: Application
    Filed: October 6, 2010
    Publication date: April 14, 2011
    Applicant: ESAOTE S.p.A
    Inventors: Stefano BESIO, Stefano Pittaluga, Vincenzo Punzo, Alessandro Trequattrini
  • Patent number: 7924011
    Abstract: A cryocooler assembly includes a ferromagnetic shield and a moveable rare-earth regenerator for recondensing of a cooling liquid for cooling of a superconductive magnet of a magnetic resonance imaging apparatus. The ferromagnetic shield effectively provides depletion of a magnet field in the vicinity of the rare-earth regenerator and therefore on the one hand reduces the noise impact of the moving regenerator on the homogeneous magnetic field in the imaging volume of the MRI apparatus and on the other hand reduces the mechanical force exerted by the magnetic field on the rare-earth regenerator.
    Type: Grant
    Filed: June 21, 2006
    Date of Patent: April 12, 2011
    Assignee: Koninklijke Philips Electronics N.V.
    Inventor: Benjamin Hendricus Aarts
  • Patent number: 7906968
    Abstract: A nuclear magnetic resonance (NMR) imaging method in which, with the aid of a gradient system, a spatially and temporally variable magnetic field Bgrad is generated, for the at least two-dimensional spatial encoding of NMR measurement signals in a measurement sample region to be imaged, where the magnetic field Bgrad is employed in at least two forms Bgrad1 and Bgrad2 in the measurement sample region to be imaged during a single measurement cycle from excitation to reading of the NMR measurement signals, where the first form Bgrad1 has essentially ns poles, where ns is an even number > 2, and has ns essentially sectorial sub-regions, in each of which the magnetic field Bgrad is locally monotonic in one direction, where the measurement signals from the measurement sample are recorded by means of at least ns receiver coils which have different sensitivity over the ns sub-regions of the region to be imaged, is characterized in that the second form Bgrad2 is essentially identical to the first form Bgrad1 % wit
    Type: Grant
    Filed: November 12, 2008
    Date of Patent: March 15, 2011
    Assignee: Universitaetsklinikum Freiburg
    Inventors: Juergen Hennig, Maxim Zaitsev, Anna Welz, Gerrit Schultz
  • Patent number: 7898257
    Abstract: An open yoke MRI apparatus has a set of permanent magnets arranged at the inner surfaces of the yoke and spaced apart from one another. A set of annular permanent magnets is included in each magnet arrangement, including a set with trapezoidal cross-sections to provide a more uniform field and to allow greater access to a patient placed within the magnetic field.
    Type: Grant
    Filed: August 2, 2007
    Date of Patent: March 1, 2011
    Assignee: Aspect Magnet Technologies, Ltd.
    Inventor: Ehud Katznelson
  • Patent number: 7898258
    Abstract: A superconducting magnet configuration (4; 14) for generating a homogeneous magnetic field B0 in an examination volume (4b), has an interior radial superconducting main field coil (1) which is disposed rotationally symmetrically about an axis (z-axis) and an oppositely driven coaxial radially exterior superconducting shielding coil (2) is characterized in that the magnet configuration (4; 14) consists of the main field coil (1), the shielding coil (2), and a ferromagnetic field formation device (3; 18), wherein the ferromagnetic field formation device (3; 18) is located at the radially inside of the main field coil (1), the main field coil (1) consisting of an unstructured solenoid coil or of several radially nested unstructured solenoid coils (15, 16) which are driven in the same direction, the axial extent Labs of the shielding coil (2) being smaller than the axial extent Lhaupt of the main field coil (1), wherein the axial magnetic field profile (5) generated by the main field coil (1) and the shielding co
    Type: Grant
    Filed: April 16, 2009
    Date of Patent: March 1, 2011
    Assignee: Bruker BioSpin GmbH
    Inventors: Gerald Neuberth, Michael Westphal
  • Patent number: 7889034
    Abstract: Disclosed is a method for designing a superconducting magnet for generating high magnetic fields with high uniformity for controlling a stray field to be within an allowable range and acquiring structural and magnetic stability by optimizing the arrangement of positions and shapes of coils configuring the superconducting magnet. Volumes of a main coil and a shielding coil are set to be variables, and the critical value of a wires related on the current and magnetic field, the heat transfer depth, and the quench strain are defined to be restriction conditions so that linear programming is applied to determine an initial shape of the shielding coil and division of the main coil based on the sum of total volumes, that is, an objective function. The initial shapes of the main coil and the shielding coil determined through the linear programming are revised and the shape of a shimming coil is determined by using non-linear programming based on the objective function.
    Type: Grant
    Filed: November 29, 2005
    Date of Patent: February 15, 2011
    Assignee: Korea Basic Science Institute
    Inventors: Byoung-Seob Lee, Dong-Lak Kim, Hyun-Sik Kim, Jong-Shin Yoo
  • Patent number: 7876100
    Abstract: A method and apparatus for actively controlling quench protection of a superconducting magnet includes a magnetic resonance imaging (MRI) system and a computer readable storage medium having stored thereon a computer program comprising instructions which when executed by a computer cause the computer to detect a quench condition of the superconducting magnet. The instructions also cause the computer to actively control a quench protection system of the superconducting magnet in response to the detected quench condition.
    Type: Grant
    Filed: September 28, 2009
    Date of Patent: January 25, 2011
    Assignee: General Electric Company
    Inventors: Xianrui Huang, Minfeng Xu
  • Patent number: 7872473
    Abstract: An atomic magnetometer that simultaneously achieves high sensitivity, simple fabrication and small size. This design is based on a diverging (or converging) beam of light that passes through an alkali atom vapor cell and that contains a distribution of beam propagation vectors. The existence of more than one propagation direction permits longitudinal optical pumping of atomic system and simultaneous detection of the transverse atomic polarization. The design could be implemented with a micro machined alkali vapor cell and light from a single semiconductor laser. A small modification to the cell contents and excitation geometry allows for use as a gyroscope.
    Type: Grant
    Filed: August 6, 2008
    Date of Patent: January 18, 2011
    Assignee: The United States of America as represented by the Secretary of Commerce, the National Institute of Standards and Technology
    Inventors: John Kitching, Elizabeth A. Donley, Eleanor Hodby, Andrei Shkel, Erik Jesper Eklund
  • Patent number: 7868617
    Abstract: An apparatus for controlling a temperature of a warm bore of a superconducting magnet in a magnetic resonance imaging (MRI) system includes a cooling tube that is mounted on a surface of the warm bore and is configured to transport a coolant. A chiller is coupled to the cooling tube and is configured to provide the coolant to the cooling tube. A controller is coupled to the chiller and is configured to provide a control signal to the chiller to control a temperature of the coolant.
    Type: Grant
    Filed: November 15, 2007
    Date of Patent: January 11, 2011
    Assignee: General Electric Co.
    Inventors: Derek A. Seeber, Tomas Duby
  • Patent number: 7863899
    Abstract: A magnet structure for an MRI apparatus utilizing a permanent magnet, which apparatus has an inverted U shape with two essentially parallel opposed pole pieces, which are supported at a predetermined distance from each other by an inverted U-shaped magnetic yoke, which pole pieces and/or at least a portion of which yoke delimit a cavity for receiving at least a part of the patient's body, whereas a partial volume is generated in the volume of said cavity, which has such magnetic field values as to provide MRI images of a sufficient quality to enable the use thereof as diagnostic images, i.e. a so-called imaging volume. According to the invention, the distance (D1) between the pole pieces (1, 2) of the magnet structure is of 36 to 42 cm, and the pole pieces (1, 2) have a surface area of 4500 to 5500 cm2. The invention also relates to an MRI imaging apparatus, particularly designed for the spine region, or a part thereof, and which has a magnet structure as described above.
    Type: Grant
    Filed: May 2, 2005
    Date of Patent: January 4, 2011
    Assignee: Esaote S.p.A.
    Inventors: Luigi Satragno, Alessandro Quattrini, Stefano Pittaluga, Eugenio Biglieri
  • Patent number: 7847555
    Abstract: A magnet which includes ferromagnetic powder to be mainly a mother phase containing iron or cobalt. The ferromagnetic powder is provided with a high-resistance layer which has a resistance higher than or equal to ten times as high as a resistance of the mother phase and a Vickers hardness lower than a Vickers hardness of the mother phase. The high-resistance layer is being formed partially or entirely on the surface of the ferromagnetic powder.
    Type: Grant
    Filed: March 18, 2008
    Date of Patent: December 7, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Matahiro Komuro, Yuichi Satsu, Takao Imagawa, Katsumi Ishikawa, Takeyuki Itabashi
  • Patent number: 7843196
    Abstract: A compact whole-body open circular magnet system for MRI purposes includes a protrusion overhanging the central homogeneous field region. The overhanging protrusion permits a reduction of the total magnet homogeneity requirements of the MRI system. Further reducing the radius of this protrusion increases access to a patient under examination but diminishes the homogeneity. Active shimming means incorporated in a gradient coil can regain the original homogeneity while maintaining increased patient access.
    Type: Grant
    Filed: September 17, 2004
    Date of Patent: November 30, 2010
    Assignee: XBO Medical Systems Co., Ltd.
    Inventors: Grum Teklemariam, Jianyu Lian
  • Patent number: 7834629
    Abstract: An MRI includes a cylindrical housing having a long axis in which a patient is positioned essentially in parallel with the long axis of the cylindrical housing. The MRI includes an electromagnetic receiver coil system positioned about a cylindrical housing and aligned with the long axis of the cylindrical housing. The MRI includes an electromagnetic imaging gradients coil system positioned about the cylindrical housing and aligned with the long axis of the cylindrical housing. The MRI includes a main magnet having its north pole and south pole positioned about the housing, which produces a magnetic field through the housing perpendicular to the long axis of the cylindrical housing. A method for examining a patient.
    Type: Grant
    Filed: September 11, 2008
    Date of Patent: November 16, 2010
    Assignee: Allegheny-Singer Research Institute
    Inventor: Mark Doyle
  • Patent number: 7816917
    Abstract: A permeability measurement apparatus includes a magnetic field generation means applying an alternating magnetic field having a predetermined frequency to a magnetic substance to be measured; a probe needle placed in proximity or in contact to a microscopic area of the magnetic substance to be measured to which the alternating magnetic field is applied; a resonator including a coil wound on the probe needle, and generating a magnetic field having a resonant frequency higher than the frequency of the alternating magnetic field applied on the microscopic area having the probe needle in proximity or in contact thereto, and having an inductance of the coil varied as permeability in the microscopic area varies; and a measurement means measuring the permeability of the microscopic area of the magnetic substance to be measured based on the variation of the resonant frequency of the resonator according to the variation of the coil inductance.
    Type: Grant
    Filed: February 28, 2008
    Date of Patent: October 19, 2010
    Assignee: Tohoku University
    Inventor: Yasuo Cho
  • Patent number: 7812607
    Abstract: In one aspect, a magnet comprising a pair of pole supports spaced apart from one another and extending in a generally horizontal direction. The magnet includes a pair of flux return members extending between the pole supports so as to define a frame, each of the flux return members including a first columnar section that extends parallel to the polar axis and a second columnar section that extends perpendicular to the polar axis and projects towards the pole. In another aspect, a magnetic resonance imaging system comprises a ferromagnetic frame that is operative to support an upper pole member and a lower pole member along a vertical polar axis such that a gap is defined between the upper and lower pole members and an access floor that is isolated from the ferromagnetic frame and pole members for providing access to the gap.
    Type: Grant
    Filed: June 15, 2009
    Date of Patent: October 12, 2010
    Assignee: Fonar Corporation
    Inventors: Raymond V. Damadian, William H. Wahl, Hank Hsieh, Gordon T. Danby, John W. Jackson, Jevan Damadian, Luciano B. Bonanni, Mark Gelbien, Keith Saboe
  • Publication number: 20100231219
    Abstract: A magnet arrangement for generating an NMR-compatible homogeneous permanent magnetic field is described. The invention has two permanent magnets, referred to hereafter as main magnets, which each have a magnet pole surface area. The magnet pole surface areas are situated parallel and at a distance to one another, so that the main magnets define an interspace on both sides through their magnet surface areas. The magnet pole surfaces of the main magnets each have a magnetic polarization opposite to one another. At least two annular permanent magnets are used, which are referred to hereafter as ring magnets, are situated coaxially to one another and jointly radially bound a ring inner chamber. The ring magnets are situated relative to the two main magnets in so that the ring inner chamber at least regionally encloses the interspace, and the magnetic fields of the main and ring magnets are constructively superimposed.
    Type: Application
    Filed: May 31, 2007
    Publication date: September 16, 2010
    Inventors: Bertram Manz, Frank Volke, Martin Benecke
  • Patent number: 7786730
    Abstract: The nuclear magnetic resonance machine comprises a device (101) for creating an intense main magnetic field B0 in a usable interior space (109) in the form of a tunnel with axis Z, a radio-frequency excitation device that also processes radio-frequency signals emitted in response by a body (150) placed in the usable interior space (109), and a set (110) of solenoidal gradient coils for superimposing on the intense magnetic field B0 components of a additional magnetic field, the gradient coils (111-122) being incorporated into tubes disposed in an annular cylindrical space (130).
    Type: Grant
    Filed: October 26, 2006
    Date of Patent: August 31, 2010
    Assignee: Commissariat A l'Energie Atomique Et Aux Energies Alternatives
    Inventor: Guy Aubert
  • Patent number: 7759938
    Abstract: Apparatus and method for varying field strength in a magnetic resonance system while keeping a relatively uniform magnetic field distribution. In an embodiment, a two-pole, generally u-shaped magnet assembly generates a static and uniform magnetic field. The magnet assembly includes two facing magnet poles separated by an air gap. Holes may be formed with the magnet poles. The field control rods may be placed at a pre-determined distance into these holes and symmetrically or asymmetrically moved across each magnet poles in a controlled manner to change the magnetic field strength while keeping the uniform magnetic field distribution. Maximum magnetic field strength may occur when the rods are removed. Minimum magnetic field strength may occur when the rods are fully inserted.
    Type: Grant
    Filed: December 28, 2007
    Date of Patent: July 20, 2010
    Assignee: Morpho Detection, Inc.
    Inventors: Pablo J. Prado, Sankaran Kumar, Erik Edmund Magnuson
  • Patent number: 7755358
    Abstract: The method for determination of the design of the basic magnet of a magnetic resonance apparatus with at least one gradient coil system, the design of the basic magnet is determined by taking into consideration forces acting on the at least one gradient coil system that may lead to vibrations of the gradient coil system due to switching processes of the gradient coil system in the field of the basic magnet.
    Type: Grant
    Filed: May 28, 2008
    Date of Patent: July 13, 2010
    Assignee: Siemens Aktiengesellschaft
    Inventors: Peter Dietz, Graham Hutton, Andreas Krug, Axel Vom Endt
  • Patent number: 7746073
    Abstract: A magnetic resonance imaging system is provided, which can provide the homogeneous magnetic field to obtain a head anatomic image with a high resolution and high SNR by coaxially disposing a receive-only phased array antenna inside a transmit-only antenna with a predetermined gap, and thereby a detailed and accurate image of a man's head can be obtained.
    Type: Grant
    Filed: March 11, 2008
    Date of Patent: June 29, 2010
    Assignee: Gachon University of Medicine & Science Industry-Academic Cooperation Foundation
    Inventors: Zang Hee Cho, Young Bo Kim, Kyoung Nam Kim, Suk Min Hong
  • Patent number: 7746075
    Abstract: A circuit for determining a polarization of a gas. The circuit includes a polarimetry circuit having an NMR coil that is configured to excite a polarized gas and that is responsive to an electromagnetic signal generated by the excited, polarized gas. The polarimetry circuit has a reproducible polarization measurement variability of less than about 2% when the NMR coil is exposed to a temperature in a range of about 0° C. to about 200° C.
    Type: Grant
    Filed: September 18, 2007
    Date of Patent: June 29, 2010
    Assignee: Medi-Physics, Inc.
    Inventors: Zivko Djukic, Steve Kadlecek, John Nouls, Ian Nelson, Bastiaan Driehuys
  • Patent number: 7737696
    Abstract: In a magnetic resonance scanner, a main magnet system (10) is wound to generate a longitudinally directed main magnetic field (B0) at least in a scanning region (20). The main magnet system includes a central magnet winding region (30) wound layer-by-layer disposed between outer magnet winding regions (32, 34). A longitudinal magnetic field gradient system (12, 12?) includes a central gradient winding region (40, 40?, 42, 42?) wound to generate a main longitudinally directed magnetic field gradient disposed between outer gradient winding regions (44, 46) wound to generate a compensatory longitudinally directed magnetic field gradient having opposite polarity from the main longitudinally directed magnetic field gradient. The outer gradient winding regions are arranged to substantially null mutual inductance between the outer magnet winding regions (32, 34) and the longitudinal magnetic field gradient system (12, 12?).
    Type: Grant
    Filed: December 12, 2006
    Date of Patent: June 15, 2010
    Assignee: Koninklijke Philips Electronics N.V.
    Inventor: Johannes Overweg
  • Patent number: 7733090
    Abstract: There is provided a magnetic field generator which is capable of generating a uniform magnetic field of a desired intensity easily and stably without increasing running cost. The magnetic field generator includes a pair of plate yokes. The plate yokes have opposed surfaces provided with magnetic pole respectively. The magnetic pole includes a permanent magnet group whereas the magnetic pole includes a permanent magnet group. Each of the permanent magnet groups is formed substantially in a disc like shape, as an integral body made of a plurality of permanent magnets and a plurality of heat conducting members. Tubular heaters, buried in the plate yokes, generate heat, which is conducted via the plate yokes to each permanent magnet and each heat conducting member which constitute the permanent magnet groups.
    Type: Grant
    Filed: June 28, 2005
    Date of Patent: June 8, 2010
    Assignee: Hitachi Metals, Ltd.
    Inventor: Masaaki Aoki
  • Patent number: 7733089
    Abstract: A portable MRI or NMR imaging system comprising a cryogen vessel housing cooled equipment, said system being housed within a transportable container, said container being divided into at least three sections. A first section provides accommodation for an operator and access to equipment as required to operate the cooled equipment. A second section houses the cryogen vessel. A third section houses auxiliary equipment required for operation of the cooled equipment but which is not required to be accessed by the operator to operate the equipment. Also provided is a cryostat comprising an outer vacuum container, itself housing a cryogen vessel for containing cooled equipment, wherein space between the cryogen vessel and the outer vacuum container is evacuated. The outer vacuum container is in the form of at least a section of a standard shipping container.
    Type: Grant
    Filed: August 24, 2006
    Date of Patent: June 8, 2010
    Assignee: Siemens PIc
    Inventors: Matthew Hobbs, Neil Charles Tigwell
  • Patent number: 7728707
    Abstract: A magnet arrangement with a magnet coil system (M) with two coil systems (C, D) that are each arranged in a container (B1, B2) positioned around the z axis and that are axially mechanically separated by a split (G), wherein each coil system (C, D) comprises a first (C1, D1) and a second coil section system (C2, D2), wherein the first coil section systems (C1, D1) are exposed to attractive magnetic forces showing toward the split (G) (KC1, KD1) and the second coil section systems (C2, D2), to repulsive magnetic forces showing away from the split (G) (KC2, KD2), and containing in the split (G) at least one mechanical structure that withstands compressive loads (E1, E2) and that supports a part of the attractive magnetic forces (KC1, KD1), is characterized in that, in the split (G) within the dimensions of the containers (B1, B2), a mechanical structure (H1) is provided that mechanically withstands tensile loads in the z direction, supports a part of the repulsive magnetic forces in the axial direction (KC2, KD2
    Type: Grant
    Filed: July 31, 2007
    Date of Patent: June 1, 2010
    Assignee: Bruker Biospin AG
    Inventors: Raffaele Gilardi, Stefan Schneider, Robert Schauwecker, Pierre-Alain Bovier
  • Patent number: 7706855
    Abstract: A system and method of MR imaging is disclosed that includes reconstruction of MR images with uniform or homogeneous fat suppression. An imaging process is performed using partial asymmetric acquisitions in conjunction with zero-filling of k-space for dynamic contrast-enhanced imaging. Data acquisition is carried out in a relatively short period of time which reduces scan time, reduces the likelihood of subject discomfort and motion-induced artifacts, and increases patient throughput.
    Type: Grant
    Filed: July 20, 2004
    Date of Patent: April 27, 2010
    Assignee: General Electric Company
    Inventors: Agus Priatna, Anthony T. Vu, Xiaoli Zhao
  • Patent number: 7706856
    Abstract: A system and method for controlling thermal output of a medical device is disclosed. A thermal controller receives operational parameters for an impending use of a medical device and predicts a thermal output of the medical device from the operational parameters. The thermal controller compares the predicted thermal output to a desired limit on thermal output and, if the predicted thermal output exceeds the desired limit on thermal output, dynamically controls power consumption by the medical device to maintain an actual thermal output substantially at or below the desired limit on thermal output during use of the medical device.
    Type: Grant
    Filed: March 7, 2005
    Date of Patent: April 27, 2010
    Assignee: General Electric Company
    Inventors: David E. Dean, Ariel Friedlander
  • Patent number: 7701218
    Abstract: A magnet assembly for use in carrying out nuclear magnetic resonance experiments on a body or sample. The assembly comprises a set of superconducting coils within a cryostat, located about a bore, and arranged to generate a substantially uniform magnetic field in a primary working volume within the bore, and to generate a substantially uniform magnetic field in a secondary working volume within the coil structure and separate from the bore. At least part of a hyperpolarisation system intersects the at least one secondary working volume so as to hold a sample to be hyperpolarised in the secondary working volume.
    Type: Grant
    Filed: May 9, 2006
    Date of Patent: April 20, 2010
    Assignee: Oxford Instruments Molecular Biotools Limited
    Inventors: Paul Geoffrey Noonan, Robert Andrew Slade
  • Patent number: 7692426
    Abstract: In an arrangement with a basic field magnet and with a gradient coil of a magnetic resonance apparatus, the basic field magnet includes superconducting coils that are arranged in a reservoir with liquid helium for cooling. The helium reservoir is surrounded by a further reservoir, designated as an outer vacuum chamber. A vacuum exists between the outer vacuum chamber and the helium reservoir. A cryoshield is arranged between the outer vacuum chamber and the helium reservoir. The gradient coil is arranged in the inner chamber of the basic field magnet. The outer vacuum chamber has an additional coating with a high electrical conductivity.
    Type: Grant
    Filed: February 21, 2008
    Date of Patent: April 6, 2010
    Assignee: Siemens Aktiengesellschaft
    Inventors: Peter Dietz, Andreas Krug, Mark James Le Feuvre, Annette Lohfink, Thorsten Speckner
  • Publication number: 20100079144
    Abstract: A magnetic resonance system uses a shielded superconducting magnet to produce a dsv useful for specialist imaging in an overall short magnet system at field strengths 1.5 Tesla and above. The magnet includes at least a first central coil C1, which has a length of at least 25% of the overall length of the magnet, and is used in concert with a series of symmetric primary coils, at least one set of which carry current in a direction opposite to that of the central coil. Force balancing is advantageously used in the design of the coils. The primary coils are shielded by at least one shielding coil, which carries current in a direction opposite to the majority of the primary coils. The magnet resonance system can be used for orthopedic imaging.
    Type: Application
    Filed: October 26, 2007
    Publication date: April 1, 2010
    Inventors: Stuart Crozier, Huawei Zhao, Feng Liu
  • Patent number: 7683622
    Abstract: A radio-frequency transmission arrangement for an MR system for generation of a total B1 field which has a first antenna device that generates a first portion of the total B1 field and at least one antenna insert that generates a second portion of the total B1 field, such that the resulting B1 field is generated by the first antenna device and the at least one antenna insert.
    Type: Grant
    Filed: September 28, 2007
    Date of Patent: March 23, 2010
    Assignee: Siemens Aktiengesellschaft
    Inventors: Juergen Nistler, Wilfried Schnell
  • Patent number: 7679365
    Abstract: A current lead for the superconducting magnet of a magnetic resonance system, the superconducting magnet being refrigerated by a cold head, has a positive current lead and a negative current lead electrically connected to the superconducting magnet for magnetization thereof. The cold head is electrically connected to the superconducting magnet and is used as one of the positive and negative current leads. The cold head is used as the positive current lead or the negative current lead so as to reduce the number of current leads as well as the heat conducted by the current lead, therefore it maintains a stable superconducting environment more efficiently. Furthermore, the cold head and the current lead can be provided in the same conduit without the need to design a separated turret tube and side tube, and the structure of the current leads of the superconducting magnet of the magnetic resonance system is simplified.
    Type: Grant
    Filed: January 30, 2008
    Date of Patent: March 16, 2010
    Assignee: Siemens Aktiengesellschaft
    Inventors: Xi Yang Du, Huai Yu Pan, Zhong You Ren, Xing En Yu