Patents Assigned to CGR
  • X-ray tube with a molybdenum target
    Patent number: 4876705
    Abstract: An X-ray tube, the anode of which has a molybdenum target, is disclosed. In odrer to prevent cracks from forming in the target under the effect of electron bombardment, the molybedenum is alloyed with vanadium.
    Type: Grant
    Filed: November 10, 1988
    Date of Patent: October 24, 1989
    Assignee: General Electric CGR S.A.
    Inventors: Jacques Delair, Olivier Peyret
  • Method of regulating the magnetic field delivered by a resistive magnet, a resistive magnet system using this method and an installation for forming images by nuclear magnetic resonance incorporating such a system
    Patent number: 4862085
    Abstract: A system is provided for regulating the field of a high homogeneity magnet. The fluid used for cooling the main magnet is placed in thermal contact with a high homogeneity auxiliary magnet in which is placed an NMR probe which controls the current supply to the two magnets connected in series.
    Type: Grant
    Filed: May 4, 1988
    Date of Patent: August 29, 1989
    Assignee: Thomson-CGR
    Inventors: Guy Aubert, Daniel Kaplan
  • Passive-decoupling receiving antenna, in particular for a nuclear magnetic resonance imaging apparatus
    Patent number: 4857850
    Abstract: An antenna for nuclear magnetic resonance imaging devices has two electromagnetic circuits connected to each other so as to produce mutual opposition of their electromotive force when they are placed in a uniform electromagnetic induction field. It is considered that a localized transmitter does not produce a uniform field. This antenna therefore makes it possible to detect this field if it comes close to this latter. On the other hand, this antenna does not present any reactive field to a transmitter in which it may be considered that the field opposite to said antenna is uniform.
    Type: Grant
    Filed: May 3, 1988
    Date of Patent: August 15, 1989
    Assignee: General Electric CGR SA.
    Inventors: Henri-Jose Mametsa, Herve Jacob
  • Method for the application of gradient pulses in an imaging experiment using a nuclear magnetic resonnance machine
    Patent number: 4857845
    Abstract: Gradient pulses are applied during the common periods and with homothetic shapes on each of three imaging axes of an NMR machine in order to form oblique images. This results in a simplification of programming of the supplies of the gradient pulse application device.
    Type: Grant
    Filed: March 22, 1988
    Date of Patent: August 15, 1989
    Assignee: General Electric CGR SA
    Inventor: Eric Breton
  • Diaphragm for electromagnet radiation beam and its use in a collimation device for this beam
    Patent number: 4856042
    Abstract: The diaphragm comprises at least one chamber in which there flows a deformable material that attenuates the radiation beam, the chamber being shaped so that the attenuating material can be introduced from outside the chamber and so that it can surround the passage zone of the beam inside the chamber in such a way that the surface of the passage zone varies constantly with the volume of the material present in the chamber.
    Type: Grant
    Filed: July 8, 1987
    Date of Patent: August 8, 1989
    Assignee: Thomson-CGR
    Inventors: Alain Staron, Christian Claudepierre, Francois Micheron, Edmond Chambron
  • Method for adjusting the gray scale in the reproduction of digitized images and a system for carrying out said method
    Patent number: 4852002
    Abstract: In a method for interactive adjustment of the parameters of a gray-scale window in a system for reproduction of a digitized image such as an x-ray image, one of the parameters designated as the mean-level parameter is modified at the instant of each elementary control action by a computed value of the other parameter designated as the width parameter.
    Type: Grant
    Filed: May 2, 1986
    Date of Patent: July 25, 1989
    Assignee: Thomson-CGR
    Inventor: Remy Klausz
  • Method for making a gradient coil
    Patent number: 4847985
    Abstract: To make a gradient coil, it is decided to cut the conductors of this coil out of a plate. Thus flat conductors can be used. This helps reduce the self-inductance of the coil to be made. The coil is, moreover, optimized. A calculation is made of the coefficients of the breakdown into spherical harmonics of the field created by the coil. The coil's structure is modified so as to cancel those coefficients of this breakdown which generate a divergence in this field. It is shown that, in this way, the solution is an optimum one.
    Type: Grant
    Filed: October 15, 1986
    Date of Patent: July 18, 1989
    Assignee: Thomson-CGR
    Inventor: Guy Aubert
  • Radiological installation using a camera television with low-remanence pick-up element
    Patent number: 4847686
    Abstract: An imaging installation, especially for digital type radiology, comprises a pick-up tube television camera with no remanence or low remanence with a non-linear element producing a remanence of the image signal given by the camera. The remanence varies with the level of the signal. When a recursive filter is used to obtain this remanence which is variable with the signal level, the modulation f.sub.2, introduced by the modulator connected to the output of this filter by a frames memory, is defined by the function: f.sub.2 (x)=x[.lambda.(1-g(x))+.mu.g(x)],a formula in which x is the ratio between the signal applied at the input of this modulator and the maximum value of the input signal, .lambda. and .mu. are constants, and g (x) is a linear function of x meeting the conditions: g (0) and g (1)=1.
    Type: Grant
    Filed: September 11, 1987
    Date of Patent: July 11, 1989
    Assignee: Thomson-CGR
    Inventor: Jean L. Ploix
  • Device and method for adjusting a radiofrequency antenna of a nuclear magnetic resonance apparatus
    Patent number: 4843323
    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: April 8, 1988
    Date of Patent: June 27, 1989
    Assignee: Thomson-CGR
    Inventors: Robert Encellaz, Yong C. H. Ng Tong
  • Method of bridging between contour elements in an image
    Patent number: 4843630
    Abstract: A method is provided for bridging between disjointed contour elements in an image by searching for an optimum bridging path between the facing ends of disjointed contour elements in the image. The method of the steps of defining a search window between each of the facing ends of the disjointed controur elements, considering in the window the different image points as nodes on a graph, determining an elementary cost associated with each path connecting each node to its neighboring nodes from amplitude and/or orientation data of the luminance function used for detecting the contours and in determining the optimum path by following, from the costs obtained, a line for which the luminance gradient of the detected points appears to be a maximum.
    Type: Grant
    Filed: November 24, 1986
    Date of Patent: June 27, 1989
    Assignee: Thomson -CGR
    Inventors: Jean Yves Catros, Francois Malo-Renault
  • Block for correcting magnetic-field homogeneity and a magnet fitted with blocks of this type
    Patent number: 4835504
    Abstract: A block of magnetized material for adjusting and correcting a magnetic field produced by a magnet provides adjustable correction by modifying the orientation of the magnetic moment of the block with respect to the field. A device which includes an intermediate member rotatably mounted in an orientable support and a fixing member rotatably mounted in the intermediate member makes it possible to orient a preferred direction of the block in a predetermined direction. This results in modification of magnetic disturbances produced by the block in the zone of interest of the magnet. Quantization of pointing of the orientable support is obtained by means of graduated index marks on the support, on the intermeidate member and on the fixing member.
    Type: Grant
    Filed: May 11, 1987
    Date of Patent: May 30, 1989
    Assignee: Thomson-CGR
    Inventor: Guy Aubert
  • Digital imaging system with grey scale setting, especially for the display of blood vessels
    Patent number: 4827492
    Abstract: Digital imaging system wherein a digital value is assigned to each point or zone of the image, and this value is transformed in such a way that only a range or window of values representing luminances for a display device is selected. Control means are provided to modify the two parameters which characterize the window in the transforming device.Since the system is designed to form images of one and the same category, for example X-rays of blood vessels, a pre-determined relationship is established between the two characteristic parameters of the window so that this window can be modified by actuating a single setting element.
    Type: Grant
    Filed: February 25, 1987
    Date of Patent: May 2, 1989
    Assignee: Thomson-CGR
    Inventor: Remy Klauzs
  • Device for exploring the inner volume of a cylinder and an investigation system equipped with this device
    Patent number: 4820982
    Abstract: A device is provided for exploring the inner volume of a cylinder, including a probe holder driven with a translational movement by a shaft and with a pivoting movement by a mandrel along and about the axis of the cylinder. By placing probes in housings previously formed in the probe holder, all the points inside the cylinder may be reached. The operations are carried out from inside the cylinder. The device further includes apparatus for fixing and adjusting the position of a framework holding the shaft. Associated devices allow predetermined positions to be reached not only along the axis but also in angular orientation.
    Type: Grant
    Filed: March 30, 1987
    Date of Patent: April 11, 1989
    Assignee: Thomson-CGR
    Inventor: Guy Aubert
  • High-voltage transformer
    Patent number: 4814733
    Abstract: In a high-voltage transformer of particularly small size comprising a magnetic circuit and a coil shell on which is wound a secondary winding consisting of one or a number of separate secondary coils, each secondary coil is contained within a channel closed by an insulating ring made up of two segments. The two ring segments are assembled around the channel in a movement performed in the same plane as that of the channel.
    Type: Grant
    Filed: October 19, 1987
    Date of Patent: March 21, 1989
    Assignee: Thomson-CGR
    Inventor: Gunter Menge
  • Method to measure the molecular diffusion and/or perfusion parameters of live tissue
    Patent number: 4809701
    Abstract: By synchronizing the radio-frequency excitations of a nuclear magnetic resonance experiment with the heart beat of a patient, notable improvement is obtained in the measurement of the molecular diffusion parameters of the tissues studied. In particular, good images of the brain are obtained in this way: the parameter represented is the molecular diffusion constant.
    Type: Grant
    Filed: September 23, 1987
    Date of Patent: March 7, 1989
    Assignee: Thomson CGR
    Inventors: Denis Le Bihan, Eric Breton
  • Device for supplying current to a filament of an x-ray tube
    Patent number: 4809310
    Abstract: The invention pertains to a current-supplying device used to supply heating current to a filment of an X-ray tube. The current-supplying device comprises a current inverter delivering current to a load circuit in which there is an oscillating circuit, the impedance of which is made to vary.
    Type: Grant
    Filed: April 8, 1987
    Date of Patent: February 28, 1989
    Assignee: Thomson-CGR
    Inventors: Jacques Salesses, Arthur Baghdiguian
  • Coreless solenoidal magnet
    Patent number: 4808956
    Abstract: A coreless solenoidal magnet is provided formed by a Bitter coil with improved field homogeneity. According to the invention the tie rods of the stack of disks are used for bringing the current back towards one of the axial ends of the magnet without creating a parasite field.
    Type: Grant
    Filed: August 13, 1986
    Date of Patent: February 28, 1989
    Assignee: Thomson-CGR
    Inventor: Guy Aubert
  • Rotating anode with graphite for X-ray tube
    Patent number: 4799250
    Abstract: The invention pertains to a rotating anode with graphite for an X-ray tube in which the quality of the bond with the graphite is considerably improved in comparison with the prior art, through the use of a bonder element comprising beryllium.
    Type: Grant
    Filed: January 14, 1987
    Date of Patent: January 17, 1989
    Assignee: Thomson-CGR
    Inventors: Jean M. Penato, Emile Gabbay, Yves Debrouwer
  • Picture-tube video-camera radiology installation
    Patent number: 4794630
    Abstract: In a radiology installation equipped with a picture-tube video camera for producing images in rapid succession, the electron beam of the camera tube has a first intensity at the time of readout of one image on the sensitive tube surface and a second non-zero intensity of substantially lower value than the first between readout of one image and write-in of the next. A control circuit for modifying the grid voltage of the camera tube is accordingly provided for varying the intensity of the electron beam.
    Type: Grant
    Filed: November 12, 1986
    Date of Patent: December 27, 1988
    Assignee: Thomson-CGR
    Inventor: Jean L. Ploix
  • Reception antenna for optical image formation device using nuclear magnetic resonance
    Patent number: 4792760
    Abstract: In the invention, the quality of the signal received is improved by symmetrizing the antenna. To this end, this antenna comprises two cords each of which has a symmetry with respect to one and the same plane (XOZ). These cords are linked by their ends to antenna tuning capacitors. The received signal is taken up by a high-frequency line integrated to one of the cords at the connection point of one of the tuning capacitors. Furthermore, the other end of this high-frequency line, arranged in the plane of symmetry, is linked to an impedance amplifier-transformer circuit with a high input impedance.
    Type: Grant
    Filed: February 4, 1987
    Date of Patent: December 20, 1988
    Assignee: Thomson-CGR
    Inventors: Herv/e/ Jacob, Jean Bussaeri