Patents by Inventor Tetsuo Nakazawa
Tetsuo Nakazawa 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).
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Patent number: 7750308Abstract: A Compton camera device according to the invention includes first means for reading coordinate data of a scattering point of a quantum ray detected by a pre-stage detector for each Compton scattering event, second means for reading coordinate data of a reaching point of the Compton-scattered quantum ray detected by a post-stage detector for each Compton scattering event, and third means for calculating a measurement accuracy of the scattered quantum ray by the first and second means for each Compton scattering event, calculating a statistical quantity of the quantum ray for each calculated measurement accuracy, and outputting the calculated statistical quantity to image reconstruction means.Type: GrantFiled: June 11, 2007Date of Patent: July 6, 2010Assignee: Hitachi Medical CorporationInventors: Takashi Shirahata, Ryota Kohara, Tetsuo Nakazawa, Osamu Miyazaki
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Publication number: 20100036247Abstract: Previously captured three-dimensional image data of a subject from which a reference image is extracted are provided in the form of time-series volume data 14, 15 composed of two-dimensional image data groups which are recorded over at least one period of a periodically moving organ of the subject, with time-phase information of a biological signal of the subject added thereto. Two-dimensional image data whose time-phase information is identical with the time-phase information of the biological signal of the subject at the time when an ultrasonic image is captured are extracted from the three-dimensional image data so as to provide the reference image.Type: ApplicationFiled: December 2, 2005Publication date: February 11, 2010Inventors: Masa Yamamoto, Naoko Ajiki, Tetsuo Nakazawa
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Publication number: 20100019156Abstract: A nuclear medicine diagnosis apparatus comprising a mechanical collimator for effecting passage in a given direction of photons with given energy emitted from an object injected or dosed with a drug containing a radioactive isotope; a former-stage detector for detecting positional information at a point of reaction of photons having passed through the mechanical collimator and information on the momentum of charged particles generated by the reaction; a latter-stage detector disposed in the subsequent stage of the former-stage detector to detect information on the photons having been scattered by the former-stage detector; and image reconstruction means for reconstructing an image from detection information having been collected from the former-stage detector and latter-stage detector, wherein the image reconstruction means is built so that differentiation is carried out on the information on the photons having passed through the mechanical collimator and the information on the photons having been scattered bType: ApplicationFiled: September 19, 2007Publication date: January 28, 2010Inventors: Ryota Kohara, Takashi Shirahata, Tetsuo Nakazawa, Osamu Miyazaki
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Publication number: 20090304141Abstract: The photon counting type detector 122 includes a drift electrode 122a, an MSGC 122b provided at a prescribed interval and a drift region 122c formed by sealing gas between the drift electrode 122a and the MSGC 122b. The projection data outputted from the photon counting type detector 122 is discriminated by the discrimination circuit 162 for each of X-ray energies and a CT image is reconstructed based on the projection data after discrimination, thereby providing an energy discrimination type X-ray CT apparatus capable of improving image quality at lower cost.Type: ApplicationFiled: March 8, 2007Publication date: December 10, 2009Applicants: HITACHI MEDICAL CORPORATION, KYOTO UNVERSITYInventors: Tetsuo Nakazawa, Toru Tanimori, Takashi Shirahata, Osamu Miyazaki, Koichi Hirokawa
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Publication number: 20090202041Abstract: A Compton camera device according to the invention includes first means for reading coordinate data of a scattering point of a quantum ray detected by a pre-stage detector for each Compton scattering event, second means for reading coordinate data of a reaching point of the Compton-scattered quantum ray detected by a post-stage detector for each Compton scattering event, and third means for calculating a measurement accuracy of the scattered quantum ray by the first and second means for each Compton scattering event, calculating a statistical quantity of the quantum ray for each calculated measurement accuracy, and outputting the calculated statistical quantity to image reconstruction means.Type: ApplicationFiled: June 11, 2007Publication date: August 13, 2009Inventors: Takashi Shirahata, Ryota Kohara, Tetsuo Nakazawa, Osamu Miyazaki
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Patent number: 7426255Abstract: An X-ray CT apparatus comprises: motion information acquisition means that acquires periodical motion information on a motion portion of an object to be examined; a detector that rotates together with an X-ray source and detects X-rays applied to the object from the X-ray source to acquire projection data per collection region; and reconstruction means that processes the projection data resulting from the detector to reconstruct a tomogram of the object, wherein the X-ray CT apparatus further includes delay time determination means that determines a delay time by adding a time width of the collection region and a processing delay time in the X-ray CT apparatus and a time interval from the moment when the phase of the measured periodical motion information is matched with the phase of the rotation period of the X-ray CT apparatus to the moment when they are matched next time, and collection means that correlates, with the periodical motion information obtained by the motion information acquisition means, and sType: GrantFiled: February 13, 2004Date of Patent: September 16, 2008Assignee: Hitachi Medical CorporationInventors: Osamu Miyazaki, Tetsuo Nakazawa, Hiroto Kokubun
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Publication number: 20080056547Abstract: A method includes a periodic motion data input step S208 of receiving input of periodic motion data indicating changes of the periodic motion with time in an object to be examined who is a target of image data collection, a step S214 of estimating fluctuations in the time resolution of the image data with time based on the periodic motion data, designating an image collection range in the object, and adjusting the collection position of the image data such that the image data is collected in the image collection range at a suitable time of image data collection, the estimated time resolution being set in a predetermined suitable range, and an image data collection position control step S216 of relatively moving at least a part of the image data collection range and the collection position of the image data such that the part of the range and the position are superimposed on each other within a time when the image data of the image data collection range has a time resolution within the desired range based on tType: ApplicationFiled: March 11, 2005Publication date: March 6, 2008Inventors: Hiroto Kokubun, Osamu Miyazaki, Tetsuo Nakazawa
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Publication number: 20060140337Abstract: An X-ray CT apparatus comprises: motion information acquisition means that acquires periodical motion information on a motion portion of an object to be examined; a detector that rotates together with an X-ray source and detects X-rays applied to the object from the X-ray source to acquire projection data per collection region; and reconstruction means that processes the projection data resulting from the detector to reconstruct a tomogram of the object, wherein the X-ray CT apparatus further includes delay time determination means that determines a delay time by adding a time width of the collection region and a processing delay time in the X-ray CT apparatus and a time interval from the moment when the phase of the measured periodical motion information is matched with the phase of the rotation period of the X-ray CT apparatus to the moment when they are matched next time, and collection means that correlates, with the periodical motion information obtained by the motion information acquisition means, and sType: ApplicationFiled: February 13, 2004Publication date: June 29, 2006Inventors: Osamu Miyazaki, Tetsuo Nakazawa, Hiroto Kokubun
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Patent number: 7006593Abstract: In an X-ray CT apparatus having a multi-slice detector, the retrospective ECG (Electrocardiography) gating imaging is applied to helical scans. Discontinuity of projection data generated in the scans is interpolated using data at a heartbeat time phase in 180-degree opposite relation to reduce motion artifacts. Further, projection data at an arbitrary slicing position and in at arbitrary heartbeat time phase are formed utilizing continuous divided projection data obtained above, and by properly combining or gathering them, a tomogram of whole heart, a three-dimensional image thereof, and further, a three-dimensional cardiac moving image in heartbeat time phases with an arbitrary time interval can be continuously and smoothly created.Type: GrantFiled: November 28, 2002Date of Patent: February 28, 2006Assignee: Hitachi Medical CorporationInventors: Hiroto Kokubun, Tetsuo Nakazawa, Osamu Miyazaki
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Publication number: 20050115764Abstract: A muffler is disposed in an exhaust pipe extending from an internal combustion engine along a bottom side of a vehicle. The muffler includes a cylindrical outer shell having a pair of openings defined at opposing axial ends of the outer shell and a pair of outer plates each secured to the corresponding one of the opposing ends of the outer shell. The muffler has an interior defined by the outer plates and the outer shell. The muffler further includes an inlet pipe and an outlet pipe each supported by the corresponding one of the outer plates and extending in the interior of the muffler. Each of the inlet and outlet pipes has a curved portion. The curved portion is accommodated in the interior of the muffler. Accordingly, the muffler is configured relatively simple and has improved durability.Type: ApplicationFiled: November 23, 2004Publication date: June 2, 2005Inventors: Tomoki Mabuchi, Takashi Ishikawa, Eiji Asai, Tetsuo Nakazawa, Yukihito Sakai
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Publication number: 20050069081Abstract: In an X-ray CT apparatus having a multi-slice detector, the retrospective ECG (Electrocardiography) gating imaging is applied to helical scans. Discontinuity of projection data generated in the scans is interpolated using data at a heartbeat time phase in 180-degree opposite relation to reduce motion artifacts. Further, projection data at an arbitrary slicing position and in at arbitrary heartbeat time phase are formed utilizing continuous divided projection data obtained above, and by properly combining or gathering them, a tomogram of whole heart, a three-dimensional image thereof, and further, a three-dimensional cardiac moving image in heartbeat time phases with an arbitrary time interval can be continuously and smoothly created.Type: ApplicationFiled: November 28, 2002Publication date: March 31, 2005Inventors: Hiroto Kokubun, Tetsuo Nakazawa, Osamu Miyazaki
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Patent number: 6844092Abstract: The object of the present invention is to provide an optically functional element having a large change in refractive index with temperature change and a fast change rate in refractive index, a production method for the same and optical switch, temperature sensor and optical information recording medium using the same. The present invention provides a thin film formed directly on a substrate or via other layers, and the film is composed of particles with an average diameter of not larger than 13 nm, observed at film surface. The present invention also provides an optically functional element having an amount of change in refractive index of not less than 2.0×10?4/° C. The present invention further provides a production method for said thin film by sputtering under reduced pressure in an inert gas atmosphere containing 3-15% by volume of oxygen, and optical switch, temperature sensor and optical information recording medium using said element.Type: GrantFiled: February 20, 2003Date of Patent: January 18, 2005Assignee: Hitachi, Ltd.Inventors: Hiroki Yamamoto, Takashi Naito, Ken Takahashi, Motoyasu Terao, Toshimichi Shintani, Fumiyoshi Kirino, Eiji Koyama, Sumio Hosaka, Sachiko Okuzaki, Takashi Namekawa, Tetsuo Nakazawa
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Patent number: 6790502Abstract: The object of the present invention is to provide an optically functional element having a large change in refractive index with temperature change and a fast change rate in refractive index, a production method for the same and optical switch, temperature sensor and optical information recording medium using the same. The present invention provides a thin film formed directly on a substrate or via other layers, and the film is composed of particles with an average diameter of not larger than 13 nm, observed at film surface. The present invention also provides an optically functional element having an amount of change in refractive index of not less than 2.0×10−4/° C. The present invention further provides a production method for said thin film by sputtering under reduced pressure in an inert gas atmosphere containing 3-15% by volume of oxygen, and optical switch, temperature sensor and optical information recording medium using said element.Type: GrantFiled: August 22, 2002Date of Patent: September 14, 2004Assignee: Hitachi, Ltd.Inventors: Hiroki Yamamoto, Takashi Naito, Ken Takahashi, Motoyasu Terao, Toshimichi Shintani, Fumiyoshi Kirino, Eiji Koyama, Sumio Hosaka, Sachiko Okuzaki, Takashi Namekawa, Tetsuo Nakazawa
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Patent number: 6699602Abstract: An amorphous magnetic recording medium comprising a substrate and an amorphous magnetic layer, where a magnetic domain formation-controlling layer comprising a main phase and 1 to 3 kinds of discrete spherical isolating phases arranged horizontally in lines in the main phase or 1 to 3 kinds of discrete spherical phases vertically stacked one upon another in the main phase is formed on the top side or the bottom side directly or through at least one of other layers to bring the amorphous magnetic layer into a finer magnetic domain structure, can satisfy high density recording.Type: GrantFiled: March 1, 2002Date of Patent: March 2, 2004Assignee: Hitachi Maxell, Ltd.Inventors: Mitsutoshi Honda, Hiroki Yamamoto, Takashi Naito, Tatsumi Hirano, Tetsuo Nakazawa, Fumiyoshi Kirino, Teruaki Takeuchi, Akira Yano, Nobuyuki Inaba, Satoshi Matsunuma
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Patent number: 6689456Abstract: A magnetic recording medium comprising a substrate 1, an inorganic compound layer 2 which works as a shielding layer, a magnetic layer 3 and a protective layer 4 which are laminated on said substrate; wherein said inorganic compound layer 2 comprises column-like crystal particles 6 and amorphous grain boundary phases isolating said particles 6, wherein said magnetic layer 3 has magnetic particles 14 arranged regularly and epitaxially grows on said inorganic compound layer 2, and wherein the grain sizes and the standard grain size deviation of magnetic particles 14 of said magnetic layer 3 reflect those of said inorganic compound layer 2.Type: GrantFiled: February 28, 2001Date of Patent: February 10, 2004Assignee: Hitachi, Ltd.Inventors: Tetsuo Nakazawa, Yuzo Kozono, Takashi Naito, Tatsumi Hirano, Hiroki Yamamoto, Takashi Namekawa, Yasutaka Suzuki
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Publication number: 20030161986Abstract: The object of the present invention is to provide an optically functional element having a large change in refractive index with temperature change and a fast change rate in refractive index, a production method for the same and optical switch, temperature sensor and optical information recording medium using the same.Type: ApplicationFiled: February 20, 2003Publication date: August 28, 2003Applicant: HITACHI, LTD.Inventors: Hiroki Yamamoto, Takashi Naito, Ken Takahashi, Motoyasu Terao, Toshimichi Shintani, Fumiyoshi Kirino, Eiji Koyama, Sumio Hosaka, Sachiko Okuzaki, Takashi Namekawa, Tetsuo Nakazawa
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Publication number: 20020172842Abstract: An amorphous magnetic recording medium comprising a substrate and an amorphous magnetic layer, where a magnetic domain formation-controlling layer comprising a main phase and 1 to 3 kinds of discrete spherical isolating phases arranged horizontally in lines in the main phase or 1 to 3 kinds of discrete spherical phases vertically stacked one upon another in the main phase is formed on the top side or the bottom side directly or through at least one of other layers to bring the amorphous magnetic layer into a finer magnetic domain structure, can satisfy high density recording.Type: ApplicationFiled: March 1, 2002Publication date: November 21, 2002Inventors: Mitsutoshi Honda, Hiroki Yamamoto, Takashi Naito, Tatsumi Hirano, Tetsuo Nakazawa, Fumiyoshi Kirino, Teruaki Takeuchi, Akira Yano, Nobuyuki Inaba, Satoshi Matsunuma
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X-ray computerized tomograph including collimator that restricts irradiation range of X-ray fan beam
Patent number: 6445761Abstract: An X-ray CT apparatus including a collimator that restricts an irradiation range of an X-ray fan beam, in which first projection data is obtained with no restriction placed onto the X-ray irradiation range through the collimator, then, second projection data is obtained with the X-ray irradiation range restricted in accordance with a concerned region set on a tomographic image, and when reconstructing an image with the use of the second projection data, the image is reconstructed using, as data outside of the concerned region, data of a corresponding portion of the first projection data.Type: GrantFiled: September 10, 1999Date of Patent: September 3, 2002Assignee: Hitachi Medical CorporationInventors: Osamu Miyazaki, Tetsuo Nakazawa, Yoshihiro Goto -
Publication number: 20020034665Abstract: A magnetic recording medium comprising a substrate 1, an inorganic compound layer 2 which works as a shielding layer, a magnetic layer 3 and a protective layer 4 which are laminated on said substrate; wherein said inorganic compound layer 2 comprises column-like crystal particles 6 and amorphous grain boundary phases isolating said particles 6, wherein said magnetic layer 3 has magnetic particles 14 arranged regularly and epitaxially grows on said inorganic compound layer 2, and wherein the grain sizes and the standard grain size deviation of magnetic particles 14 of said magnetic layer 3 reflect those of said inorganic compound layer 2.Type: ApplicationFiled: February 28, 2001Publication date: March 21, 2002Inventors: Tetsuo Nakazawa, Yuzo Kozono, Takashi Naito, Tatsumi Hirano, Hiroki Yamamoto, Takashi Namekawa, Yasutaka Suzuki
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Patent number: 6061422Abstract: An image reconstructing method in relation to an X-ray CT apparatus for shifting, sequentially by a predetermined angle, a reconstructed image for a projection angle in a predetermined range so as to obtain a continuous reconstructed image, in which one normal reconstructed image is obtained as follows: First, 180.degree. amount of parallel beam projection data, which is obtained by converting fan beam measurement data into parallel beam data, is divided at a predetermined angle so as to obtain each partial reconstructed image for each partial segment. Then, weight-imposing is performed on the plurality of partial reconstructed images obtained, and the weight-imposed images are superposed, thus obtaining the one sheet of normal reconstructed image. At that time, concerning partial reconstructed images the view angles of which are in an opposing relationship to each other, a weighted average thereof is determined.Type: GrantFiled: April 30, 1998Date of Patent: May 9, 2000Assignee: Hitachi Medical CorporationInventors: Osamu Miyazaki, Tetsuo Nakazawa