Patents by Inventor Tetsuhiko Takahashi

Tetsuhiko Takahashi 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).

  • Patent number: 5477145
    Abstract: In an RF probe comprising a resonator and a pickup coil, the pickup coil is an 8-shaped coil, and a center portion of this pickup coil is constituted in such a manner that crossing coils become parallel to each other at the portion. The center portion where the coils of the pickup coil are parallel to each other is so disposed as to extend along, and in the vicinity of, a part of a conductor loop of the resonator.
    Type: Grant
    Filed: January 5, 1994
    Date of Patent: December 19, 1995
    Assignee: Hitachi Medical Corporation
    Inventors: Tetsuhiko Takahashi, Yoshikuni Matsunaga, Etsuji Yamamoto
  • Patent number: 5457386
    Abstract: A probe for an MRI apparatus in a vertical magnetic field system including: an array coil which is formed by arranging a plurality of unit coils, which can be driven independently of one another, in a direction perpendicularly intersecting a direction of a static magnetic field; and a compensating coil which forms a magnetic field in a direction perpendicularly intersecting both a direction of a magnetic field formed by the array coil and the direction of the magnetic field, a signal detected by the array coil and a signal detected by the compensating coil being composed so as to be in phase with each other, thereby to be outputted.
    Type: Grant
    Filed: November 25, 1992
    Date of Patent: October 10, 1995
    Assignees: Hitachi, Ltd., Hitachi Medical Corporation
    Inventors: Yoshikuni Matsunaga, Tetsuhiko Takahashi, Etsuji Yamamoto
  • Patent number: 5453692
    Abstract: An RF probe for an MRI device including a plurality of hollow cylindrical resonators arranged in series such that the respective axes of the resonators align substantially in a z-axis direction of a three dimensional orthogonal coordinate system, radio frequency power signal supply/reception pickup coils to/from the respective resonators; and loop coils situated riding on two adjacent resonators in x- and y-axis directions, and an electromagnetic shield which surrounds the hollow cylindrical resonators, pickup coils and loop coils and grounded with respect to radio frequency.
    Type: Grant
    Filed: July 29, 1993
    Date of Patent: September 26, 1995
    Assignees: Hitachi, Ltd., Hitachi Medical Corporation
    Inventors: Tetsuhiko Takahashi, Yoshikuni Matsunaga, Etsuji Yamamoto, Hiroyuki Itagaki
  • Patent number: 5384536
    Abstract: This application describes a nuclear magnetic resonance inspection apparatus. In this apparatus, a nuclear magnetic resonance signal detected by a detection coil is wirelessly transmitted to a signal processing system. In another embodiment, the nuclear magnetic resonance signal is stored in a memory medium provided to the detection coil. This memory medium can be separated from the detection coil. The signal processing system reads out the nuclear magnetic resonance signal from the memory medium separated, and processes the signal.
    Type: Grant
    Filed: March 18, 1993
    Date of Patent: January 24, 1995
    Assignee: Hitachi, Ltd.
    Inventors: Yoshiki Murakami, Tetsuhiko Takahashi, Etsuji Yamamoto
  • Patent number: 5280246
    Abstract: A nuclear magnetic resonance apparatus receives nuclear magnetic resonance signals from an object under test with an RF probe which is an array of coils, implements down-frequency conversion with frequency converters for the received signals in multiple channels such that the frequency bands of the converted signals do not virtually overlap, filters the converted signals with band pass filters each operating to cut off frequency bands of other channels, hybridizes the filtered signals of multiple channels to form a hybridized signal, and produces an image from the hybridized signal.
    Type: Grant
    Filed: November 18, 1991
    Date of Patent: January 18, 1994
    Assignees: Hitachi, Ltd., Hitachi Medical Corporation
    Inventors: Tetsuhiko Takahashi, Etsuji Yamamoto, Yoshikuni Matsunaga, Ryuichi Suzuki
  • Patent number: 5164973
    Abstract: A projection detecting apparatus for use in a third generation X-ray computer tomography includes an X-ray source and a detector array both mounted on a rotatable gantry for detecting X-ray projections of an object under inspection sequentially at a plurality of angles of the gantry, respectively. The detector array is formed by disposing consecutively a plurality of detector element blocks each constituted by a photodiode array and a scintillator array laminated together. The element blocks are so disposed as to be asymmetric to the center line of a fan-like radiation beam which line extends through the position of the X-ray source and the center of rotation of the gantry.
    Type: Grant
    Filed: January 4, 1991
    Date of Patent: November 17, 1992
    Assignee: Hitachi Medical Corporation
    Inventors: Tetsuhiko Takahashi, Manabu Nakagawa, Hideji Fujii, Minoru Yoshida
  • Patent number: 5103092
    Abstract: A method of and apparatus for radiation detection including temperature control so that the temperature of the radiation detector, which includes a photodiode with a leakage current of 0.4-18 pA, is controlled to a setup temperature plus or minus 0.35.degree. C. With this condition established, offset data and reference data of the detector are collected in the absence of a body under test, offset data immediately before an actual signal measurement is collected and thereafter signal data through the exposure of a body under test is collected. The collected data are subjected to sensitivity calibration and offset calibration, thereby to obtain projection data, and image data is obtained through image processing of the projection data.
    Type: Grant
    Filed: September 4, 1990
    Date of Patent: April 7, 1992
    Assignee: Hitachi Medical Corporation
    Inventors: Tetsuhiko Takahashi, Manabu Nakagawa, Toshihiko Shimizu
  • Patent number: 5059794
    Abstract: A radiation imaging sensor including laminate structure of a phosphorescent layer, a light-transmissive electrode, a photoconductor layer, an insulating layer and an electrode, an applied voltage to the photoconductor layer through the light-transmissive electrode and the electrode is increased sufficiently so that light emitted from the phosphorescent member causes avalanche multiplicaton of the electrons and/or positive holes generated in the photoconductor layer by field sweep inside the photoconductor layer.
    Type: Grant
    Filed: May 1, 1990
    Date of Patent: October 22, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Tetsuhiko Takahashi, Kenichi Okajima, Ken Ueda
  • Patent number: 5041729
    Abstract: A radiation detector for use on X-ray CT scanner with a plurality of elements arrayed to form a detector block, which is structured that a plurality of thin-film photodiodes consisting of amorphous silicon each are formed on the back of a scintillator block having a width to cover the plurality of elements, a platelike supporting member provided with signal lines on the back is bonded to cover the photodiodes, the photodiodes and the signal lines are connected together through wire bonding, the scintillator block is divided into each element across separators on the supporting member.
    Type: Grant
    Filed: October 24, 1988
    Date of Patent: August 20, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Tetsuhiko Takahashi, Minoru Yoshida, Hiroshi Takeuchi, Hideji Fujii, Haruo Itho, Toshikazu Shimada, Kenji Maio
  • Patent number: 4982095
    Abstract: This invention relates to a multi-element type radiation detector for an X-ray CT scanner system wherein a plurality of scintillator blocks that are isolated either optically or radiation-wise from one another are arranged integrally, and a photo-diode consisting of an amorphous silicon layer for converting the emission of each scintillator is formed on the surface of each scintillator block by thin film technique.
    Type: Grant
    Filed: September 1, 1988
    Date of Patent: January 1, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Tetsuhiko Takahashi, Hirosh Takeuch, Toshikazu Shimada, Haruo Itoh, Tadaaki Hirai, Kenji Maio, Kenichi Okajima, Minoru Yoshida, Hideaki Yamamoto
  • Patent number: 4982096
    Abstract: In a radiation detector, scintillation material flouoresces and the produced light is converted to electrical energy in an adjacent converter, separators are provided in spaces between the adjacent scintillators and converters. The separators may have a greater length than the adjacent scintillators, so that they will extend beyond to reduce cross-talk. The separators can extend toward the source of radiation for a height substantially greater than, and particularly five times, the height of the spaces between the adjacent scintillators to prevent X-ray scattering and function as a collimator. Optically opaque adhesive may be provided on the opposite ends of separators and pairs of scintillators and collimators, to prevent cross-talk.
    Type: Grant
    Filed: January 5, 1989
    Date of Patent: January 1, 1991
    Assignee: Hitachi Medical Corporation
    Inventors: Hideji Fujii, Manabu Nakagawa, Minoru Yoshida, Fumio Kawaguchi, Tetsuhiko Takahashi, Takayuki Hayakawa
  • Patent number: 4954706
    Abstract: A radiographic image pickup apparatus for diagnosis using an image detector in which a phosphor layer for converting an X-ray image into an optical image, a photoconductive layer for storing an optical image as a latent image, light-emitting means for exciting the photoconductive layer segment by segment are laminated into a plate form, wherein one of the electrodes sandwiching the photoconductive layer and the light-emitting means are respectively divided into array-formed elements in directions orthogonal to each other, and an element selection circuit for successively selecting these elements and reading out said latent image in time sequential electric signal is formed integrally on the substrate of the image detector.
    Type: Grant
    Filed: March 30, 1989
    Date of Patent: September 4, 1990
    Assignee: Hitachi, Ltd.
    Inventors: Tetsuhiko Takahashi, Kenichi Okajima, Hiroshi Takeuchi
  • Patent number: 4937454
    Abstract: In a radiation detector having a scintillator and a photodiode in combination, an amorphous silicon diode of a refractive index of 3.5 or below is used for a photodector to have a decreased junction capacitance. This shifts the spectral sensitivity characteristic of the photodetector toward the short wavelength side, thus providing a low-noise, high-sensitivity radiation detector matched well with the emission spectrum of the scintillator.
    Type: Grant
    Filed: November 21, 1988
    Date of Patent: June 26, 1990
    Assignee: Hitachi, Ltd.
    Inventors: Haruo Itoh, Toshikazu Shimada, Shin-ichi Muramatsu, Tetsuhiko Takahashi, Hiroshi Takeuchi
  • Patent number: 4806757
    Abstract: When the laser-stimulable phosphor plate of an information reading apparatus for radiation image is constituted of CsI as the base and 0.0003 to 0.03% in atomic ratio of Na, the output signal of the information reading apparatus can be increased and the decay time thereof can be shortened. When output signals are produced by detecting fluorescence emitted from a fluoroscopic plate disposed in confrontation with the laser-stimulable phosphor plate, there is provided an information reading apparatus for radiation image having an improved S/N ratio and a high efficiency of taking in laser-stimulated luminescence. Further, instead of Na or together with Na, there may be added at least one element selected from the group consisting of Li, K, Rb, Cu, Au, Be, Mg, Ca, Sr, Ba, Zn, Cd, Hg, B, Al, Ga, In, Tl, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Si, Ti, Zr, Ge, Sn, Pb, As, Sb, and Bi. In this case, the total content of these elements is set to be 0.00001 to 1% in atomic ratio.
    Type: Grant
    Filed: October 30, 1986
    Date of Patent: February 21, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Tsuyoshi Kano, Tetsuhiko Takahashi, Kenichi Okajima, Kenji Umetani, Saburo Ataka, Hisatake Yokouchi, Ryuichi Suzuki