Patents by Inventor Stefan Popescu

Stefan Popescu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20100091936
    Abstract: An x-ray CT system for x-ray phase contrast and/or x-ray dark field imaging has a grating interferometer that has a first grating structure that has a number of band-shaped x-ray emission maxima and minima arranged in parallel, the maxima and minima exhibiting a first grating period, a second band-shaped grating structure that produces, as a phase grating, a partial phase offset of x-ray radiation passing therethrough and that exhibits a second grating period, a third band-shaped grating structure with a third grating period with which relative phase shifts of adjacent x-rays and/or their scatter components are detected, and a device for value-based determination of the phase between adjacent x-rays and/or for value-based determination of the spatial intensity curve per detector element perpendicular to the bands of the grating structures. The third grating structure has a grating period that is larger by a factor of 2 to 5 than the grating period of the first grating structure.
    Type: Application
    Filed: September 30, 2009
    Publication date: April 15, 2010
    Inventors: Christian David, Tilman Donath, Eckhard Hempel, Martin Hoheisel, Franz Pfeiffer, Stefan Popescu
  • Publication number: 20100080341
    Abstract: An x-ray CT system that generates tomographic phase contrast or dark field exposures, has at least one grating interferometer with three grating structures arranged in series in the radiation direction, with a modular design of the second and third grating structures. The distance between the first grating structure of the x-ray source and the second grating structure (fashioned as a phase grating) of the respective grating/detector modules is adapted, depending on the fan angle, corresponding to a period of the grating structure of the x-ray source projected onto the grating detector module at a respective fan angle (?i).
    Type: Application
    Filed: September 24, 2009
    Publication date: April 1, 2010
    Inventors: Stefan Popescu, Christian David, Tilman Donath, Eckhard Hempel, Martin Hoheisel, Franz Pfeiffer
  • Publication number: 20100074395
    Abstract: In a method to determine phase and/or amplitude between interfering, adjacent x-ray beams in a detector pixel in a Talbot interferometer for projective and tomographical x-ray phase contrast imaging and/or x-ray dark field imaging, after an irradiation of the examination subject with at least two coherent or quasi-coherent x-rays, an interference of the at least two coherent or quasi-coherent x-rays with the aid of an irradiated phase grating is generated, and the variation of multiple intensity measurements in temporal succession after an analysis grating is determined in relation to known displacements of one of the gratings or of an x-ray source fashioned like a grating, positioned upstream in the beam path, relative to one of the gratings.
    Type: Application
    Filed: September 24, 2009
    Publication date: March 25, 2010
    Inventor: Stefan Popescu
  • Patent number: 7673081
    Abstract: In a method and system for data and signal transfer between different sub-units of a medically-related system, in particular a CT system, digitized signals and digital data are transmitted together on a transmission line by means of serial multiplexing. The digitized signals and the digital data are transferred combined into individual packets having a length that is so small that the adherence to a predetermined updating rate of the signals is achieved. The expenditure for the wiring as well as for future expansions in medically-related systems can be significantly reduced.
    Type: Grant
    Filed: November 19, 2004
    Date of Patent: March 2, 2010
    Assignee: Siemens Aktiengesellschaft
    Inventors: Joachim Grottel, Klaus Gruber, Stefan Popescu
  • Publication number: 20100020936
    Abstract: An x-ray tube has a vacuum housing supported so that it can rotate around a rotation axis, an anode that is arranged within the vacuum housing and that is connected in a rotationally fixed manner with the vacuum housing. The anode has an anode surface fashioned substantially in the shape of a ring. The center axis of which anode surface corresponds to the rotation axis. A cathode is mounted within the vacuum housing such that it can be rotated around the rotation axis. The cathode has a cathode surface fashioned substantially in the shape of a ring. The center axis of which cathode surface corresponds to the rotational axis. The cathode surface is arranged opposite the anode surface. A first actuator rotates the vacuum housing around the rotation axis with a first rotation speed ?1. A second actuator rotates the cathode around the rotation axis with a second rotation speed ?2, wherein ?2<?1.
    Type: Application
    Filed: July 24, 2009
    Publication date: January 28, 2010
    Inventors: SVEN FRITZLER, STEFAN POPESCU, GEORG WITTMANN
  • Publication number: 20100020918
    Abstract: An x-ray computed tomography apparatus has one anode ring in a vacuum housing surrounding an examination volume, wherein a focus of an x-ray source revolves on the anode ring to expose the examination volume with an x-ray beam from different directions, and a detector system arranged on a rotating frame that can rotate around a system axis. The detector system serves to detect the x-ray radiation exiting from the examination volume, wherein the detector system and the focus can rotate around the system axis synchronously and in the same rotation direction with a rotation angle offset by 180°. The apparatus also includes a computer to process the measurement values acquired by the detector system. The anode ring can be driven such that it rotates around the system axis, and the rotation direction of the anode ring and the rotation direction of the focus around the system axis are opposite while a rotation of the focus around the system axis ensues.
    Type: Application
    Filed: July 24, 2009
    Publication date: January 28, 2010
    Inventors: Stefan Popescu, Georg Wittmann
  • Patent number: 7653177
    Abstract: A method and a measurement system are disclosed for the noninvasive determination of properties of an object to be examined and to the use of a contrast medium for X-ray phase-contrast measurement. in at least one embodiment of the invention, a mixture (suspension) consisting of a base liquid and a multiplicity of particles contained therein is used, the refractive index of the base liquid being different to the refractive index of the particles.
    Type: Grant
    Filed: June 26, 2008
    Date of Patent: January 26, 2010
    Assignee: Siemens Aktiengesellschaft
    Inventors: Joachim Baumann, Christian David, Martin Engelhardt, Jörg Freudenberger, Eckhard Hempel, Martin Hoheisel, Matthias Honal, Thomas Mertelmeier, Franz Pfeiffer, Stefan Popescu, Manfred Schuster
  • Patent number: 7646843
    Abstract: A method is disclosed for producing projective and tomographic phase contrast images of an examination object, preferably a patient, with the aid of an X-ray system, and a corresponding X-ray system for carrying out this method. In at least one embodiment of the method, X-ray optical grating sets tuned to different energy ranges are used to determine energy-dependent phase shifts upon penetration of an examination object, a difference value is formed from these energy-dependent phase shifts, and tomographic or projective images are produced therefrom.
    Type: Grant
    Filed: January 31, 2007
    Date of Patent: January 12, 2010
    Assignee: Siemens Aktiengesellschaft
    Inventors: Stefan Popescu, Björn Heismann, Eckhard Hempel
  • Patent number: 7643606
    Abstract: An x-ray computed tomography apparatus has a stationary x-ray detector that at least partially surrounds the examination volume in one plane and a stationary device for generation of x-ray radiation. The device for generation of x-ray radiation is composed of an x-ray source that extends annularly around the examination volume over an angle of at least 180° as well as one or more light scanning units with which an x-ray focus moving along the x-ray source can be generated on the x-ray target by scanning of the x-ray source with a light beam, from which x-ray target an x-ray beam is directed through the examination volume onto respective, momentarily opposite detector elements of the stationary x-ray detector. The computed tomography apparatus has one or more light scanning units are arranged and fashioned outside of a central ring axis of the x-ray source such that only an angle range <360° is respectively scanned with each light scanning unit without crossing the ring axis.
    Type: Grant
    Filed: February 14, 2007
    Date of Patent: January 5, 2010
    Assignee: Siemens Aktiengesellschaft
    Inventor: Stefan Popescu
  • Patent number: 7639786
    Abstract: An X-ray optical transmission grating of a focus-detector arrangement of an X-ray apparatus is disclosed, for generating projective or tomographic phase contrast recordings of a subject. In at least one embodiment, the grating includes a multiplicity of grating bars and grating gaps arranged periodically on at least one surface of at least one wafer, wherein the X-ray optical transmission grating includes at least two sub-gratings arranged in direct succession in the beam direction.
    Type: Grant
    Filed: January 31, 2007
    Date of Patent: December 29, 2009
    Assignee: Siemens Aktiengesellschaft
    Inventors: Joachim Baumann, Christian David, Martin Engelhardt, Jörg Freudenberger, Eckhard Hempel, Martin Hoheisel, Thomas Mertelmeier, Franz Pfeiffer, Stefan Popescu, Manfred Schuster
  • Patent number: 7636415
    Abstract: A method and an X-ray CT system are disclosed for producing tomographic pictures with the aid of an X-ray CT system including at least two X-ray sources arranged on a gantry with an angular offset to scan an examination object. In at least one embodiment of the method, in order to determine the scattered radiation distribution, pre-scanning is carried out in which the X-ray sources rotate about the examination object and the dose rate is modulated as a function of the rotation angle, no radiation dose is output over the majority of the revolution, at specific pre-scan angles a dose rate is produced briefly and individually in each case by the X-ray sources of the focus/detector systems, and the received scattered radiation is measured simultaneously by the detectors of the at least one other focus/detector system.
    Type: Grant
    Filed: February 15, 2008
    Date of Patent: December 22, 2009
    Assignee: Siemens Aktiengesellschaft
    Inventors: Stefan Popescu, Herbert Bruder, Christoph Suess
  • Patent number: 7634047
    Abstract: A computer tomography system has a stationary x-ray tube, that has an anode ring and at least one cathode ring, that extends through 360° in a system plane perpendicular to a system axis, and a vacuum region that is at least partially delimited by a light-permeable and/or infrared-permeable vacuum window is provided between the anode ring and the at least one cathode ring. A support frame is rotatable around the system axis parallel to the system plane, on which are arranged, in at least one angle position, a system with at least one laser for local activation of electron emission at the at least one cathode ring, and a filter and/or collimator set, and a radiation detector opposite the filter and collimator set.
    Type: Grant
    Filed: July 25, 2008
    Date of Patent: December 15, 2009
    Assignee: Siemens Aktiengesellschaft
    Inventors: Stefan Popescu, Georg Wittmann
  • Patent number: 7634045
    Abstract: A fifth generation x-ray computed tomography system has at least one electron beam generator that generates at least one electron beam, an anode ring or partial anode ring arranged concentrically around a system axis, from which x-ray radiation can be generated at a number of focus positions by striking the ring or partial ring with the at least one electron beam, a detector ring or partial detector ring arranged concentrically around the system axis, with a number of detector elements forming at least one detector row to detect the impinging x-ray radiation; and a rotatable support frame on which filter and collimator elements are carried. The filter and collimator elements are arranged at the focus on the support frame at at least two positions that are angularly offset relative to one another.
    Type: Grant
    Filed: August 1, 2008
    Date of Patent: December 15, 2009
    Assignee: Siemens Aktiengesellschaft
    Inventor: Stefan Popescu
  • Publication number: 20090304157
    Abstract: A field emission cathode has a field emitter and an extraction grid, and the field emitter and the extraction grid can be moved relative to one another. Such a field emission cathode is highly durable and exhibits a longer lifespan. An x-ray tube has a field emission cathode composed of a field emitter and an extraction grid that can be moved relative to one another. Such an x-ray tube is highly durable and exhibits a longer lifespan.
    Type: Application
    Filed: June 4, 2009
    Publication date: December 10, 2009
    Inventors: Jens Fuerst, Stefan Popescu, Georg Wittmann
  • Patent number: 7623617
    Abstract: A method is disclosed for scattered radiation detection and/or for scattered radiation correction. In at least one embodiment, each radiation produced is provided with an individual temporal marker/variation of known magnitude, the change in the measured radiation being investigated for these typical temporal variations, and the fraction of the scattered radiation is inferred from the temporal variation found and, if appropriate, a corresponding correction is carried out. Furthermore, a CT system is disclosed, including a computer program that carries out at least one embodiment of the method.
    Type: Grant
    Filed: April 27, 2007
    Date of Patent: November 24, 2009
    Assignee: Siemens Aktiengesellschaft
    Inventor: Stefan Popescu
  • Patent number: 7599467
    Abstract: An x-ray computed tomography apparatus has a stationary unit and a rotatable unit, carrying an x-ray source and a radiation detector. The rotatable unit rotates around an axis relative to the stationary unit, that proceeds through both units. In order to transmit signals and measured data between the rotating unit and the stationary unit, transmitting/reception devices are mounted at each unit. The transmitting/reception devices transmit directed signals and are automatically oriented toward each other during relative movement caused by rotation of the rotating unit with respect to the stationary unit.
    Type: Grant
    Filed: June 3, 2004
    Date of Patent: October 6, 2009
    Assignee: Siemens Aktiengesellschaft
    Inventor: Stefan Popescu
  • Publication number: 20090220042
    Abstract: In a device for contact-free transmission of electrical signals between two gantry parts of a computed tomography system that rotate relative to one another, at least one annular, circumferential transmitter element is mounted on one gantry part to transmit the electrical signals, and at least one receiver element to receive the signals emitted by the transmitter element is mounted on the other gantry part . The transmitter element is formed by a single conductor running on a surface, this conductor representing an electrical reference ground (zero potential). At least one dielectric immediately follows on the surface, and multiple conductive conductor structure pairs are executed in two mirror-image parts and are mounted on the at least one dielectric.
    Type: Application
    Filed: February 27, 2009
    Publication date: September 3, 2009
    Inventors: Mario Festag, Stefan Popescu, Herbert Weithmann
  • Patent number: 7564941
    Abstract: A focus-detector arrangement of an X-ray apparatus is disclosed for generating projective or tomographic phase contrast recordings with a phase grating. According to at least one embodiment of the invention, in the gaps between its bars, the phase grating includes a filler material whose linear attenuation coefficient in the relevant energy range is greater than that of the bars. The height of the filler material in the gaps is dimensioned on the one hand so that the X-radiation with the energy used for measuring the phase shift generates a phase shift in the X-radiation such that, after the phase grating, the rays which pass through the bars are phase shifted by one half wavelength relative to the rays which pass through the gaps with the filler material.
    Type: Grant
    Filed: January 31, 2007
    Date of Patent: July 21, 2009
    Assignee: Siemens Aktiengesellschaft
    Inventors: Joachim Baumann, Christian David, Martin Engelhardt, Jörg Freudenberger, Eckhard Hempel, Martin Hoheisel, Thomas Mertelmeier, Franz Pfeiffer, Stefan Popescu, Manfred Schuster
  • Patent number: 7561658
    Abstract: A method and an x-ray computed tomography system are disclosed for visualizing at least two different types of cardiac tissue, such as normally perfused tissue, hypoperfused tissue and scarred tissue.
    Type: Grant
    Filed: August 7, 2008
    Date of Patent: July 14, 2009
    Assignee: Siemens Aktiengesellschaft
    Inventors: Eckhard Hempel, Martin Hoheisel, Stefan Popescu, Rainer Raupach
  • Publication number: 20090154640
    Abstract: In a focus detector arrangement and method for an x-ray apparatus for generating projection or tomographic phase-contrast images of an examination subject, a beam of coherent x-rays is generated by an anode that has areas of different radiation emission characteristics arranged in bands thereon, that proceed parallel to grid lines of a phase grid that is used to generate the phase-contrast images.
    Type: Application
    Filed: December 6, 2006
    Publication date: June 18, 2009
    Inventors: Joachim Baumann, Christian David, Martin Engelhardt, Jorg Freudenberger, Eckhard Hempel, Martin Hoheisel, Thomas Mertelmeier, Franz Pfeiffer, Stefan Popescu, Manfred Schuster