Patents Assigned to CGR
  • Linear accelerator provided with self-focusing cavities having high electron capture efficiency in respect of moderate injection voltages
    Patent number: 4975652
    Abstract: Good bunching and high electron capture efficiency of a first resonant cavity of an accelerator are combined with the self-focusing properties of said cavity associated with a following second cavity by modifying the law of the modulus of the electric field set up within said cavity, the amplitude of said field being greater within a first portion of the cavity than within a second portion. It is shown that the electrons are thus naturally bunched within the first portion of the cavity. In the second portion of the cavity, they are than subjected to acceleration and then to uniform focusing which includes entry into the following cavity. The result thereby achieved is to increase the capture efficiency and electron density of the beam which is accelerated from a low-voltage electron gun.
    Type: Grant
    Filed: April 4, 1989
    Date of Patent: December 4, 1990
    Assignee: CGR MeV
    Inventor: Dominique Tronc
  • Stabilized power supply with reduced ripple factor
    Patent number: 4967333
    Abstract: The ripple factor in an electrical power supply of a dc-dc voltage raising type is reduced by using two double alternation dc/ac converters driven in phase quadrature with respect to each other. The signals delivered by the dc/ac converters are then combined by two transformers, the secondary coils of which are series connected. It is shown that the ripple factor is reduced and, similarly, that the reactive energy due to the commutation of th dc/ac converters is reduced even if it so happens that the power transmitted is doubled.
    Type: Grant
    Filed: June 13, 1989
    Date of Patent: October 30, 1990
    Assignee: General Electric CGR S.A.
    Inventors: Bernard Callier, Jean-Pierre Maynard
  • Rotating anode X-ray tube comprising anodic current flow device
    Patent number: 4964147
    Abstract: The invention relates to an X-ray tube with a rotating anode which is driven by a magnetic bearings motor. The anodic current is outflowed by a friction-type contact device which is located inside the shaft supporting the rotor of the motor. The friction contact device is actuated so as to cut off or establish an electrical contact between an inner wall of the rotor and the friction contact device.
    Type: Grant
    Filed: January 17, 1989
    Date of Patent: October 16, 1990
    Assignee: General Electric CGR SA
    Inventors: Michel Laurent, Pierre Noualhagnet, Claude Mathieu
  • Isocentric radiology stand
    Patent number: 4964151
    Abstract: The invention concerns an X-ray stand permitting isocentric movements and intended particularly for radio diagnosis. Stand includes a base supporting a binding clip having a first and second arm supporting respectively an X-ray source and receiver. According to a feature of the invention, binding clip includes a foot by which it is supported by the base by means of devices to move foot in a circular movement centered on an isocenter point.
    Type: Grant
    Filed: December 28, 1988
    Date of Patent: October 16, 1990
    Assignee: General Electric CGR SA
    Inventor: Jacques Trotel
  • Rotating anode of composite material for X-ray tubes
    Patent number: 4958364
    Abstract: A rotating anode for X-ray tube including a base body on which target is formed by the deposit of at least one layer of target material wherein said base body includes a first central section comprising at least to some extent a carbon-carbon composite material and a second part of monolithic graphite supporting target arranged at least partly at the periphery of the former with the two parts bound mechanically to one another by a means of interconnection, such as brazing at the junction point of the two parts.
    Type: Grant
    Filed: December 22, 1988
    Date of Patent: September 18, 1990
    Assignee: General Electric CGR SA
    Inventors: Christine Guerin, Jean-Marie Penato, Yves Debrouwer
  • 3-D image reconstruction using Fourier transformation with differing resolutions of image axes
    Patent number: 4958282
    Abstract: An image reconstruction method of the 3DFT type is proposed wherein the organization of the excitation and measuring sequences comprises the repetition of macro-sequences. During the macro-sequences, a selection encoding gradient which may have a small number of encoding steps (in particular, smaller than the expected resolution of the images) is applied. It is shown that this approach enables the best possible of the power and flexibility of the vectorial processors used to perform image reconstruction computations efficiently. It is shown that the images can then be produced in real time.
    Type: Grant
    Filed: July 6, 1988
    Date of Patent: September 18, 1990
    Assignee: General Electric CGR S.A.
    Inventor: Yves Barjhoux
  • Device and method for adjusting a radiofrequency antenna of a nuclear magnetic resonance apparatus
    Patent number: 4950993
    Abstract: A device and method are provided for adjusting a radiofrequency antenna of a nuclear magnetic resonance apparatus. In the invention, using capacities preset in the factory, the antenna detuning of an NMR apparatus is limited to a range such that the standing wave rate of a high frequency line which conveys the radiofrequency signal is limited. This line is cut and, at a short distance, a tuning adjustment circuit is inserted. This circuit may be automated: the electric adjustment motors, thus spaced away, do not disturb the magnetic fields of the apparatus. By measuring the real part of the admittance at the input of the adjustment circuit and the phase shift between voltage and current this circuit can be adjusted.
    Type: Grant
    Filed: January 25, 1989
    Date of Patent: August 21, 1990
    Assignee: Thomson-CGR
    Inventors: Robert Encellaz, Ng T. Y. C. Hon
  • Examination bed for NMR or tomodensitometry apparatus
    Patent number: 4944501
    Abstract: An examination bed, notably for RMN or tomodensitometry, which includes a chassis, an examination plateau, and a mechanism for driving movement of the plateau with respect to the chassis and with respect to the apparatus wherein the moving mechanism includes a moving assembly with respect to the plateau and the chassis, elongated in its shape with one end being movable with respect to the chassis and whose other end is movable with respect to the plateau.
    Type: Grant
    Filed: March 9, 1989
    Date of Patent: July 31, 1990
    Assignee: General Electric CGR SA
    Inventors: Jacques Sireul, Rene Gauthier
  • X-ray image intensifier tube with circuit to compensate for the effects fo magnetic distortion
    Patent number: 4945223
    Abstract: To compensate for the effects of magnetic distortion in an X-ray image intensifier tube, the mode of scanning the target of the television camera associated with this tube is modified. Shifts, corresponding to measured distortions, are caused in the line scan and the vertical scan. In this way, an image which can be used in morphometry is restored on a display screen.
    Type: Grant
    Filed: June 29, 1989
    Date of Patent: July 31, 1990
    Assignee: General Electric CGR S.A.
    Inventor: Jacques Beauzamy
  • Method of radio-frequency excitation in an NMR experiment
    Patent number: 4940940
    Abstract: In order to optimize the determination of radio-frequency energization in an NMR experiment, the Schrodinger equation is written relative to the amplitude of probability of the wave function of spins resonating at a given resonance frequency wherein the Hamiltonian depends on the frequency and on the radio-frequency energization to which they are subjected. Analytical polynominal expressions are deduced for the probability amplitudes at the end of the energization as a function of the resonance frequency. The coefficients are optimized by means of calculation algorithms, from which the characteristics of the energization are deduced.
    Type: Grant
    Filed: January 10, 1989
    Date of Patent: July 10, 1990
    Assignee: General Electric CGR SA
    Inventor: Patrick Leroux
  • Method for the removal of artifacts in an NMR imaging experiment
    Patent number: 4926124
    Abstract: So-called motion artifacts are removed in NMR imaging experiments by choosing a 2DFT type imaging method and by choosing a phase encoding pitch, which is a multiple of a useful encoding pitch determined by the height of the image field to be depicted. It is shown that, after the image reconstruction has been computed by Fourier transform, the central image corresponds to the depiction of the continuous components of the magnetic moments of the particles located in an examined cross-section of a body under examination, and that these continuous components are not affected by all the variations in the rate of a cyclical phenomenon which disturbs the images (in general the cardiac cycle).
    Type: Grant
    Filed: July 6, 1988
    Date of Patent: May 15, 1990
    Assignee: General Electric CGR S.A.
    Inventor: Patrick Le Roux
  • Device to monitor a patient in an apparatus for medical examination
    Patent number: 4923295
    Abstract: A device for monitoring a patient in a medical examination apparatus has a support on which are mounted a television camera and a mirror sending on an image of a part of the patient to the camera, said support being movable with respect to the frame of the apparatus but fixed with respect to the patient.
    Type: Grant
    Filed: December 7, 1988
    Date of Patent: May 8, 1990
    Assignee: General Electric CGR SA
    Inventors: Jacques Sireul, Jacob Herve, Gauthier Rene
  • Method for measuring flows in a nuclear magnetic resonance experiment
    Patent number: 4922202
    Abstract: In a nuclear magnetic resonance experiment, the flows are measured by causing the orientation of the magnetic moments of the particles located in a slice to flip and by subsequently causing the scattering of the phases of the magnetic resonance signals to be reflected only for particles which have migrated into a slice adjacent to the slice in which the flipping has been done. It is shown that the relative dynamic range of the measured NMR signal for the moving parts in relation to the measured signal for the fixed parts becomes infinite.
    Type: Grant
    Filed: May 11, 1988
    Date of Patent: May 1, 1990
    Assignee: General Electric CGR S.A.
    Inventor: Patrick Le Roux
  • Isocentric x-ray equipment stand having four axes of rotation
    Patent number: 4922512
    Abstract: In an x-ray equipment stand designed to perform isocentric scanning movements and having three axes of rotation concurrent to the isocenter O, the isocenter can be caused to rotate about a fourth axis (Axis 4) perpendicular to the second axis (Axis 2) and parallel to the third axis (Axis 3). This permits displacement of the isocenter in the horizontal plane, especially along straight lines which are secant with the third axis.
    Type: Grant
    Filed: June 2, 1989
    Date of Patent: May 1, 1990
    Assignee: General Electric CGR SA
    Inventors: Pierre Lajus, Jean Caugant
  • Compact type X-ray emitter
    Patent number: 4920554
    Abstract: An X-ray emitting device of the X-ray unit type is disclosed, the arrangement of which simplifies maintenance problems. The emitting device has a metallic casing containing an X-ray tube and supply means. According to a feature of the invention, the X-ray tube and the supply means are contained in a first and second imperviously sealed chamber, filled with oil.
    Type: Grant
    Filed: October 28, 1988
    Date of Patent: April 24, 1990
    Assignee: General Electric CGR SA
    Inventors: Emile Gabbay, Jacques Le Guen
  • Method and device for compression by the conditional encoding of digital image signals without loss of data
    Patent number: 4916544
    Abstract: To compress the values of the pixels of a digitalized image, the values of the pixels neighboring the pixel to be processed are memorized and, according to their respective values, a code number is produced leading to the encoding process according to a composed code or to the encoding of the pixel itself, with a prefix. The successive codes are formatted and concatenated to be memorized.
    Type: Grant
    Filed: September 24, 1987
    Date of Patent: April 10, 1990
    Assignee: Thomson-CGR
    Inventors: Jean Lienard, Claude Benchimol
  • Method for fast imaging by nuclear magnetic resonance
    Patent number: 4914391
    Abstract: Fast imaging in spin-spin relaxation time known as T.sub.2 is proposed. It is shown that, instead of awaiting total restoration of longitudinal magnetization of the magnetic moments of excited particles of a body subjected to the experiment, the excitation-measurement sequences of the experiment can be made to follow each other at a higher rate on condition that the angle of tilt of said magnetization is limited to a value which is distinctly lower than 90.degree., at which a good signal-to-noise ratio in response is still obtained. It is shown that, with a loss of signal-to-noise ratio of only 3 dB, there is obtained a rate of image production which is four times higher.
    Type: Grant
    Filed: November 21, 1988
    Date of Patent: April 3, 1990
    Assignee: General Electric CGR S.A.
    Inventor: Patrick Leroux
  • Device for sealing an enclosure containing an expandable fluid, especially within an electrical connection assembly
    Patent number: 4903972
    Abstract: A sealing device for an enclosure containing an expandable fluid, particularly for high-voltage connectors, ensures fluid-tightness over a broad temperature range and provides a safety function by accommodating variations in volume of the fluid by the use of an O-ring seal displaceably clamped within an annular recess. A sectional length L1 of the recess in which the seal can take up n positions is constituted by an initial-clamping space and by a clearance space into which the seal can penetrate under the pressure of fluid.
    Type: Grant
    Filed: December 21, 1987
    Date of Patent: February 27, 1990
    Assignee: Thomson-CGR
    Inventor: Etienne Ombredane
  • Method of measuring the intensity of a DC current and a device implementing this method
    Patent number: 4876503
    Abstract: A method of measuring the strength of a DC current and a device for implementing this method are provided, forming an NMR shunt for measuring high currents. A magnetic coil is placed in series in the circuit in which the current to be measured flows, the temperature of the magnet is stabilized and the magnetic field is measured in the center of the magnet using an NMR probe.
    Type: Grant
    Filed: October 3, 1986
    Date of Patent: October 24, 1989
    Assignee: Thomson-CGR
    Inventor: Guy Aubert
  • Process for imaging by nuclear magnetic resonance
    Patent number: RE33391
    Abstract: The invention proposes an imaging process by nuclear magnetic resonance in which a calculated image is given corresponding to the molecular diffusion value at each point of an investigated medium. The diffusion image is obtained by comparing images relative to same sections of the medium and acquired during two excitation sequences, whereof one is not very sensitive to the diffusion and the other is particularly sensitive thereto. These two images undergo comparison in order to produce a diffusion image.
    Type: Grant
    Filed: January 26, 1989
    Date of Patent: October 16, 1990
    Assignee: Thomson-CGR
    Inventors: Eric Breton, Denis Le Bihan, Patrick Le Roux