Patents Assigned to Hitachi Medical Corporation
  • Patent number: 5528145
    Abstract: A high-speed magnetic resonance spectroscopic imaging method for obtaining information relating to an object placed in a space by irradiating the object placed in the space applied with a static magnetic field and field gradients in three different directions so as to excite a nuclear spin in the object. At least one of the field gradients is applied while inverting a sign thereof periodically and a magnetic resonance signal generated by excitation of the nuclear spin is measured. A Fourier transform is applied to the measured magnetic resonance signal thereby to obtain a chemical shift image and a measurement spectral bandwidth is set to a value not larger than a frequency difference between two different chemical shifts having frequencies remotest from each other among a plurality of chemical shifts intended to be measured, the measurement spectral bandwidth being determined by a reciprocal of an inversion period of the field gradient which is applied while inverting a sign thereof periodically.
    Type: Grant
    Filed: July 15, 1994
    Date of Patent: June 18, 1996
    Assignees: Hitachi, Ltd., Hitachi Medical Corporation
    Inventors: Satoshi Hirata, Yoshitaka Bito, Etsuji Yamamoto
  • Patent number: 5526442
    Abstract: An X-ray radiography method and apparatus in which a phantom such as a chart having elements arranged in predetermined positions is irradiated with X-rays and an X-rays detection unit detects signals thereof. An image of the chart is obtained and a center position of each of the elements in the image of the chart is obtained as well as for those elements which are not within the imaging field of view. Pixel positions for a distortion free image is obtained and a transform table is prepared making each of the pixel positions in the image of the chart correspond to each of the pixel positions in the distortion free image. A plurality of digital images of a subject to be examined are obtained and the digital images are corrected in accordance with the transform table. The corrected digital images are then joined together and a digital image is displayed, wherein common portions in the corrected images are in accordance with each other.
    Type: Grant
    Filed: October 4, 1994
    Date of Patent: June 11, 1996
    Assignee: Hitachi Medical Corporation
    Inventors: Rika Baba, Ken Ueda, Hisatake Yokouchi, Keiji Umetani, Yoichi Onodera
  • Patent number: 5517996
    Abstract: A memory for temporarily storing a transmitting signal is provided in association with each channel i.e., each transducer of a probe, a transmitting signal for transmitting an ultrasonic wave of a desired waveform is formed through a computer processing, and the thus formed transmitting signal is stored in each memory. Transmitting signals are sent simultaneously to individual channels from individual memories. This ensures that a transmitting signal of a desired waveform can be applied to each channel and the transmission of an ultrasonic wave can be controlled desirably.
    Type: Grant
    Filed: March 8, 1995
    Date of Patent: May 21, 1996
    Assignee: Hitachi Medical Corporation
    Inventors: Kazutaka Okada, Akira Sasaki, Hiroshi Kanda
  • Patent number: 5515727
    Abstract: An ultrasound signal processor has a receiving signal digitizing circuit, waveform conversion circuit for mixing a produced digital signal by a reference signal, a cumulation circuit for performing a cumulation processing of a series of converted signals, a delay circuit subject to the cumulation processing, and a circuit for adding delayed signals, whereby the frequency of the receiving signal is shifted to a lower frequency and thereafter subjected to a cumulation processing which perform over-sampling technique so that the accuracy of an analog to digital conversion can be improved drastically. The ultrasound signal processor further has a circuit for converting a receiving signal into a low frequency signal by analog-mixing and a circuit for passing a low frequency component of the analog-converted signal, whereby a higher frequency receiving signal can be digitized even if the digitizing circuit has a insufficient sampling rate.
    Type: Grant
    Filed: September 22, 1993
    Date of Patent: May 14, 1996
    Assignee: Hitachi Medical Corporation
    Inventors: Yuichi Miwa, Kageyoshi Katakura, Ryuichi Shinomura, Hiroshi Masuzawa, Yutaka Sato, Shizuo Ishikawa
  • Patent number: 5511423
    Abstract: An ultrasonic diagnostic apparatus which improves the bearing resolution by dynamically changing the weighting performed on the amplitude of transmitted ultrasonic waves and/or a received wave signal. This weighting is changed with reference to the magnitude of the received wave signal. The resolution in the bearing direction is improved by increasing the wave number of the ultrasonic wave to be transmitted and by weighting the ultrasonic wave, whereas the resolution in the distance direction is prevented from being degraded as much as possible, thus making the bearing resolution substantially equal to the distance resolution. Since controlling the wave number is comparable to control of a frequency band, similar effects can also be produced by combining the control of the frequency band of a received wave signal with the weighting.
    Type: Grant
    Filed: July 11, 1994
    Date of Patent: April 30, 1996
    Assignee: Hitachi Medical Corporation
    Inventors: Takashi Sugiyama, Jun Kubota
  • Patent number: 5506409
    Abstract: A scintillator converts radiations incident thereon into light, which is converted into an electric signal by a photoelectric converter. Formed between the scintillator and the photoelectric converter is a light-transmitting adhesive layer including a plurality of spherical, light-transmitting spacers which each have the same diameter as the thickness of the adhesive layer, whereby the scintillator and the photoelectric converter are bonded to each other with the gap therebetween held being uniform at the same value as the diameter of the spacers.
    Type: Grant
    Filed: May 23, 1994
    Date of Patent: April 9, 1996
    Assignee: Hitachi Medical Corporation
    Inventors: Minoru Yoshida, Hiromi Kobayashi
  • Patent number: 5502384
    Abstract: In an image reconstruction method in a nuclear magnetic resonance imaging apparatus, the method comprises first and second steps to get detected data S.sub.I for at least about half of region inclusive of an origin and data S.sub.IV in a region symmetric with respect to a line passing through an origin on one of axes from the detected region in the acquired data space and parallel to the other axis, respectively, third and fourth steps to perform inverse Fourier transform on the data S.sub.I and S.sub.
    Type: Grant
    Filed: May 17, 1994
    Date of Patent: March 26, 1996
    Assignees: Hitachi, Ltd., Hitachi Medical Corporation
    Inventors: Chitose Nakaya, Yoshitaka Bito, Etsuji Yamamoto, Hiroshi Nishimura, Hiroyuki Takeuchi, Shigeru Watanabe, Akihiro Miyajima, Hitoshi Arai
  • Patent number: 5502778
    Abstract: An image data compression method is disclosed, in which a sheet of image is divided into a plurality of partial images of small area, and in reconstructing an image, the fidelity to the original image is changed in accordance with the utility of the information contained in each partial image, and the image data is compressed in accordance with the particular fidelity.
    Type: Grant
    Filed: February 12, 1992
    Date of Patent: March 26, 1996
    Assignees: Hitachi, Ltd., Hitachi Medical Corporation
    Inventors: Ken Ishikawa, Shinichiro Miyaoka
  • Patent number: 5490193
    Abstract: This invention provides a compact X-ray CT system capable of obtaining an X-ray CT image having high resolution at a high speed by deflecting a predetermined electron beam and causing the finely focused electron beam to scan on an arcuate anode target inside the same plane as the arcuate anode target for an X-ray source. The anode target for an X-ray source and a detector are disposed in the form of arcs inside substantially the same plane so as to face each other. The electron beam emitted from an electron gun is guided to a deflector through a lens system, is then deflected to a arc form trajectory by a uniform magnetic field generated by the deflector and is guided to the anode target after a reverse magnetic field is applied to the electron beam at a desired position. This electron beam is caused to scan on the anode target at a high speed so as to move the generation position of the X-ray and thus to obtain a sectional image.
    Type: Grant
    Filed: July 22, 1991
    Date of Patent: February 6, 1996
    Assignees: Hitachi, Ltd., Hitachi Medical Corporation
    Inventors: Katsuhiro Kuroda, Koichi Koike, Atsuko Takafuji, Fumio Noda
  • Patent number: 5485500
    Abstract: A digital X-ray imaging system having an X-ray generator, an X-ray generator controller for controlling the X-ray generator, an X-ray detecting unit for detecting an X-ray transmitted through a subject, the X-ray detecting unit having an X-ray grid for shielding a scattered X-ray, a signal processor for acquiring a signal from the X-ray detecting unit and processing the signal to obtain a digital X-ray image of the subject, and a display device for displaying an image of the subject obtained by the signal processor. The system is provided with a position changing unit for changing a relative position between the X-ray detecting unit and the subject, a position change controller for controlling the position changing unit, and an imaging-sequence controller for controlling the position change controller and the X-ray generator controller.
    Type: Grant
    Filed: January 26, 1994
    Date of Patent: January 16, 1996
    Assignee: Hitachi Medical Corporation
    Inventors: Rika Baba, Ken Ueda, Hisatake Yokouchi, Yoichi Onodera, Keiji Umetani, Masayuki Tsuneoka
  • Patent number: 5479591
    Abstract: A method of displaying and cutting out a region of interest. Upon depicting contour lines indicating regions of interest, respectively, on a display screen, the regions of interest are displayed with contour lines differing from one region to another in accordance with the order in which the regions of interest are designated. The contour displayed is scanned in the four directions leftward, rightward, upward and downward. For the inaccessible regions which are located outside of the contour and which could not have been reached by the scanning line, one of the upward and downward scannings and one of the leftward and rightward scannings are repeated until the inaccessible regions are no longer present.
    Type: Grant
    Filed: January 26, 1994
    Date of Patent: December 26, 1995
    Assignee: Hitachi Medical Corporation
    Inventor: Yoshihiro Goto
  • 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: 5467769
    Abstract: A magnetic field generating apparatus has a permanent magnet arrangement for generating a magnetic field in a magnetic field generating space and a yoke arrangement for forming magnetic circuits for generation of the magnetic field together with the permanent magnet arrangement. The yoke arrangement includes a first pair of yokes arranged facing each other, a second pair of yokes arranged facing each other through which the first pair of yokes are magnetically connected to each other, a third pair of yokes arranged between one end of one of the first pair of yokes and one end of one of the second pair of yokes and between the other end of the one of the first pair of yokes and one end of the other of the second pair of yokes, respectively, and yoke moving units for independently moving the one of the first pair of yokes and each of the second pair of yokes with respect to the third pair of yokes, respectively.
    Type: Grant
    Filed: February 16, 1994
    Date of Patent: November 21, 1995
    Assignees: Hitachi Medical Corporation, Sumitomo Special Metals Co., Ltd.
    Inventors: Hitoshi Yoshino, Shigeo Hashimoto
  • Patent number: 5465721
    Abstract: A two-dimensional echogram or a tomogram (B-mode image) and a volume of an organ are displayed in real time while radiating an ultrasonic wave to the organ. The volume of the organ is obtained by first designating a plurality of line segments traversing the image of the organ on the two-dimensional echogram, by obtaining a pair of intersections between each line segment and the wall of the organ by using a signal intensity profile (A-mode image) of each line segment, by obtaining a length between the pair of intersections, and by calculating the volume by the Simpson method by using the obtained length. In order to improve the precision of volume calculation, the signal intensity profile is smoothed and the intensity is normalized. The intersections are displayed superposed upon the two-dimensional echogram to allow an operator to visually check easily whether the intersections are correctly aligned with the wall of the organ.
    Type: Grant
    Filed: March 8, 1995
    Date of Patent: November 14, 1995
    Assignee: Hitachi Medical Corporation
    Inventors: Shinji Kishimoto, Masa Harashima, Hiroshi Kanda, Akira Sasaki, Kozi Tanabe, Kenji Nosaka, Satoru Hanasaka, Ken Ishihara
  • Patent number: 5457996
    Abstract: A receiving beamformer is provided which simultaneously generates a plurality of receiving beam signals corresponding to receiving beams of a plurality of directions on the basis of signals received by an array of vibrator elements for receiving an ultrasonic wave. This receiving beamformer includes a variable amplifying unit for amplifying the received signals in accordance with the depth of measurement to produce output signals, an A/D converting unit for converting the output signals from the variable amplifying unit into digital signals at a predetermined sampling period, a digital delay unit for receiving each of the digital signals and for producing a plurality of delayed signals corresponding to the receiving beams for each of the digital signals, and a first adding unit for adding the delayed signals corresponding to each of the receive beams and to the respective digital signals.
    Type: Grant
    Filed: May 24, 1993
    Date of Patent: October 17, 1995
    Assignee: Hitachi Medical Corporation
    Inventors: Shin-ichi Kondo, Hiroshi Kanda, Kageyoshi Katakura, Ryuichi Shinomura, Yuichi Miwa
  • 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: 5455425
    Abstract: An X-ray detector with a multi-channel type ionization chamber has plural signal plate electrodes and plural high voltage plate electrodes respectively disposed in parallel to and alternating with the signal plate electrodes all of the plate electrodes being mounted between a pair of insulators. A conductive rubber member is provided between one of the insulators and the high voltage plate electrodes, and a long conductive member is provided along the conductive rubber member at a position where the long conductive member contacts the rubber member, but does not contact the high voltage plate electrodes. Thereby, the amount of X-rays is detected accurately in respective channels in spite of the simple construction of the X-ray detector.
    Type: Grant
    Filed: March 18, 1994
    Date of Patent: October 3, 1995
    Assignee: Hitachi Medical Corporation
    Inventor: Shinichi Migita
  • 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: 5448610
    Abstract: A digital X-ray photography device, including an X-ray tube unit, a rotation supporting unit for rotating around a subject, an image system unit installed on the rotation supporting unit, for detecting X-rays transmitted through the subject, a first image processing unit, installed on the rotation supporting unit, for constructing a rotational stereoscopic image of the subject based on a signal from the image system unit, an X-ray detector, installed on the rotation supporting unit, for detecting X-rays transmitted through the subject, a second image processing unit, installed on the rotation supporting unit, for constructing a CT image of the subject based on a signal from the X-ray detector, and a unit for controlling pulse-shaped X-rays to be continuously radiated during a forward rotation and a backward rotation of the rotation supporting unit in order to perform a rotational stereoscopic photographing.
    Type: Grant
    Filed: February 4, 1994
    Date of Patent: September 5, 1995
    Assignee: Hitachi Medical Corporation
    Inventors: Kazuo Yamamoto, Masami Shimizu, Joichi Tamura, Shyunpei Nishimura
  • Patent number: 5438264
    Abstract: A magnetic field generating apparatus has a hollow permanent magnet formed of a plurality of permanent magnet elements arranged to have a polygonal section. Magnetization directions of the end portions of the hollow permanent magnet in its longitudinal direction are made different from those of the central portion thereof so that the magnetic field generated in a predetermined region in the hollow space of the permanent magnet is increased as compared with a case where the magnetizations of the hollow permanent magnet are all directed in the same direction.
    Type: Grant
    Filed: June 29, 1993
    Date of Patent: August 1, 1995
    Assignee: Hitachi Medical Corporation
    Inventors: Hirotaka Takeshima, Hiroyuki Takeuchi, Chikako Nakamura