Patents by Inventor Shigeya Asai

Shigeya Asai 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: 7313218
    Abstract: A radiographic apparatus removes lag-behind parts from radiation detection signals taken from an FPD as X rays are emitted from an X-ray tube, on an assumption that the lag-behind part included in each X-ray detection signal is due to an impulse response formed of a plurality of exponential functions with different attenuation time constants. When a single attenuation time constant and intensity are provisionally set, checking is made whether an attenuation to a noise level of X-ray detection signals occurs in an X-ray non-emission state following an X-ray emission state. When the set attenuation time constant and intensity are found appropriate (OK), the impulse response having the single exponential function is determined valid. Corrected radiation detection signals are obtained by removing the lag-behind parts using the impulse response determined.
    Type: Grant
    Filed: July 29, 2004
    Date of Patent: December 25, 2007
    Assignee: Shimadzu Corporation
    Inventors: Shoichi Okamura, Keiichi Fujii, Susumu Adachi, Shinya Hirasawa, Toshinori Yoshimuta, Koichi Tanabe, Shigeya Asai, Akihiro Nishimura
  • Patent number: 7203279
    Abstract: In the radiographic apparatus according to this invention, when a radiographic mode designator 16 designates a non-standard radiographic mode, a signal corrector 15 uses defect information stored in one of non-standard image defect information memories 18B–18E for correcting X-ray detection signals outputted from an FPD 2. Since the pixel defect information for non-standard X-ray images is acquired by a pixel defect information converter 19 through a conversion from defect information for standard X-ray images stored in a standard image defect information memory 18A, it is unnecessary to collect output signals for pixel defect information acquisition from the FPD 2 all over again. As a result, abnormal X-ray detection signals due to defects of radiation detecting elements may be corrected promptly, regardless of how the radiation detecting elements are assigned to the pixels in the X-ray images.
    Type: Grant
    Filed: March 24, 2005
    Date of Patent: April 10, 2007
    Assignee: Shimadzu Corporation
    Inventors: Keiichi Fujii, Shoichi Okamura, Susumu Adachi, Shinya Hirasawa, Toshinori Yoshimuta, Koichi Tanabe, Shigeya Asai, Akihiro Nishimura
  • Publication number: 20050220268
    Abstract: In the radiographic apparatus according to this invention, when a radiographic mode designator 16 designates a non-standard radiographic mode, a signal corrector 15 uses defect information stored in one of non-standard image defect information memories 18B-18E for correcting X-ray detection signals outputted from an FPD 2. Since the pixel defect information for non-standard X-ray images is acquired by a pixel defect information converter 19 through a conversion from defect information for standard X-ray images stored in a standard image defect information memory 18A, it is unnecessary to collect output signals for pixel defect information acquisition from the FPD 2 all over again. As a result, abnormal X-ray detection signals due to defects of radiation detecting elements may be corrected promptly, regardless of how the radiation detecting elements are assigned to the pixels in the X-ray images.
    Type: Application
    Filed: March 24, 2005
    Publication date: October 6, 2005
    Inventors: Keiichi Fujii, Shoichi Okamura, Susumu Adachi, Shinya Hirasawa, Toshinori Yoshimuta, Koichi Tanabe, Shigeya Asai, Akihiro Nishimura
  • Publication number: 20050031088
    Abstract: A subtraction image is obtained, by a subtraction process (DSA process), from a live image and a mask image. A lag-behind part included in each X-ray detection signal is considered due to an impulse response formed of exponential functions. The lag-behind part is removed from each X-ray detection signal by a recursive computation to obtain a corrected X-ray detection signal. The live image and mask image are obtained from such corrected detection signals.
    Type: Application
    Filed: July 12, 2004
    Publication date: February 10, 2005
    Inventors: Shoichi Okamura, Keiichi Fujii, Susumu Adachi, Shinya Hirasawa, Toshinori Yoshimuta, Koichi Tanabe, Shigeya Asai, Akihiro Nishimura
  • Publication number: 20050031070
    Abstract: A radiographic apparatus removes lag-behind parts from radiation detection signals taken from an FPD as X rays are emitted from an X-ray tube, on an assumption that the lag-behind part included in each X-ray detection signal is due to an impulse response formed of a plurality of exponential functions with different attenuation time constants. When a single attenuation time constant and intensity are provisionally set, checking is made whether an attenuation to a noise level of X-ray detection signals occurs in an X-ray non-emission state following an X-ray emission state. When the set attenuation time constant and intensity are found appropriate (OK), the impulse response having the single exponential function is determined valid. Corrected radiation detection signals are obtained by removing the lag-behind parts using the impulse response determined.
    Type: Application
    Filed: July 29, 2004
    Publication date: February 10, 2005
    Inventors: Shoichi Okamura, Keiichi Fujii, Susumu Adachi, Shinya Hirasawa, Toshinori Yoshimuta, Koichi Tanabe, Shigeya Asai, Akihiro Nishimura
  • Publication number: 20050031079
    Abstract: A radiographic apparatus removes lag-behind parts from radiation detection signals taken from an FPD as X rays are emitted from an X-ray tube, on an assumption that the lag-behind part included in each X-ray detection signal is due to an impulse response formed of a plurality of exponential functions with different attenuation time constants. The lag-behind parts are removed by using impulse responses of the FPD corresponding, for example, to an X-ray dose used in a fluoroscopic image pickup and an X-ray dose used in a radiographic image pickup. X-ray images are created from corrected radiation detection signals with the lag-behind parts removed therefrom.
    Type: Application
    Filed: July 8, 2004
    Publication date: February 10, 2005
    Inventors: Shoichi Okamura, Keiichi Fujii, Susumu Adachi, Shinya Hirasawa, Toshinori Yoshimuta, Koichi Tanabe, Shigeya Asai, Akihiro Nishimura