The Experts below are selected from a list of 7785 Experts worldwide ranked by ideXlab platform

Yoshio Hayasaki - One of the best experts on this subject based on the ideXlab platform.

  • INDIN - Holographic-laser-drawing volumetric display
    2016 IEEE 14th International Conference on Industrial Informatics (INDIN), 2016
    Co-Authors: Kota Kumagai, Yoshio Hayasaki
    Abstract:

    We propose a holographic-laser-drawing volumetric display using a computer-generated hologram displayed on a liquid crystal spatial light modulator and multilayer Fluorescent Screen. The holographic-laser-drawing technique has enabled three things; (i) increasing the number of voxels of the volumetric graphics per unit time; (ii) increasing the total input energy to the volumetric display because the maximum energy incident at a point in the multilayer Fluorescent Screen is limited by the damage threshold; (iii) controlling the size, shape and spatial position of voxels. In this paper, we demonstrated (i) and (ii). The multilayer Fluorescent Screen was newly developed to display colored voxels. The thin layer construction of the multilayer Fluorescent Screen minimized the axial length of the voxels. A two-color volumetric display with blue-green voxels and red voxels were demonstrated.

  • Volumetric display with holographic parallel optical access and multilayer Fluorescent Screen.
    Optics letters, 2015
    Co-Authors: Kota Kumagai, Daichi Suzuki, Satoshi Hasegawa, Yoshio Hayasaki
    Abstract:

    We propose a volumetric display based on holographic parallel optical access and two-photon excitation using a computer-generated hologram displayed on a liquid crystal spatial light modulator and a multilayer Fluorescent Screen. The holographic parallel optical access increased the number of voxels of the volumetric image per unit time. This approach increased the total input energy to the volumetric display, that is, the total fluorescence power, because the maximum energy incident at a point in the multilayer Fluorescent Screen is limited by the damage threshold. The multilayer Fluorescent Screen was newly developed to display colored voxels. The thin layer construction of the multilayer Fluorescent Screen minimized the axial length of the voxels. A volumetric display with only blue-green voxels and a volumetric display with both blue-green and red voxels were demonstrated.

M Akisada - One of the best experts on this subject based on the ideXlab platform.

  • High-Spatial-Resolution Medical-Imaging System Using a HARPICON Camera Coupled with a Fluorescent Screen.
    Journal of synchrotron radiation, 1996
    Co-Authors: K Umetani, H Ueki, K Ueda, T Hirai, T Takeda, T Doi, Y Itai, M Akisada
    Abstract:

    A high-sensitivity HARPICON camera was developed for medical X-ray imaging using a Fluorescent Screen. It is an avalanche-multiplication-type image pick-up tube and is 32 times more sensitive than conventional tubes. The camera also has a wider dynamic range than conventional medical-imaging cameras because a maximum output signal current of 2.3 muA is obtained and, in high-illumination-intensity regions, photocurrent is not proportional to illumination intensity. The Fluorescent Screen is an intensifying Screen of the type used for radiographic Screen-film combinations in medical examination. An X-ray image on the Screen is focused on the photoconductive layer of the pick-up tube using a coupling lens with f/0.65. Experiments were performed using monochromated X-rays at the Photon Factory. An image of a spatial resolution test chart was taken in a 525 scanning-line mode of the camera. The chart pattern of 5 line-pairs mm(-1 )(spatial resolution of 100 mum) was observed at an X-ray input field of 50 x 50 mm. Real-time digital images of the heart of a 12 kg dog were obtained at a frame rate of 60 images s(-1) after injection of a contrast medium into an artery. The images were stored in digital format at 512 x 480 pixels with 12 bits pixel(-1). High-spatial-resolution and high-contrast images of coronary arteries were obtained in aortography using X-rays with energy above that of the iodine K edge; the image quality was comparable with that of conventional selective coronary angiography.

Jacobus Maarten Schippers - One of the best experts on this subject based on the ideXlab platform.

  • Performance of a Fluorescent Screen and CCD camera as a two-dimensional dosimetry system for dynamic treatment techniques
    Medical physics, 2000
    Co-Authors: S. N. Boon, P. Van Luijk, Terence Böhringer, A. Coray, Anthony Lomax, Eros Pedroni, Barbara Schaffner, Jacobus Maarten Schippers
    Abstract:

    A two-dimensionally position sensitive dosimetry system has been tested for different dosimetric applications in a radiation therapy facility with a scanning proton beam. The system consists of a scintillating (Fluorescent) Screen, mounted at the beam-exit side of a phantom and it is observed by a charge coupled device (CCD) camera. The observed light distribution at the Screen is equivalent to the two-dimensional (2D)-dose distribution at the Screen position. It has been found that the dosimetric properties of the system, measured in a scanning proton beam, are equal to those measured in a proton beam broadened by a scattering system. Measurements of the transversal dose distribution of a single pencil beam are consistent with dose measurements as well as with dose calculations in clinically relevant fields made with multiple pencil beams. Measurements of inhomogeneous dose distributions have shown to be of sufficient accuracy to be suitable for the verification of dose calculation algorithms. The good sensitivity and sub-mm spatial resolution of the system allows for the detection of deviations of a few percent in dose from the expected (intended or calculated) dose distribution. Its dosimetric properties and the immediate availability of the data make this device a useful tool in the quality control of scanning proton beams.

Kota Kumagai - One of the best experts on this subject based on the ideXlab platform.

  • INDIN - Holographic-laser-drawing volumetric display
    2016 IEEE 14th International Conference on Industrial Informatics (INDIN), 2016
    Co-Authors: Kota Kumagai, Yoshio Hayasaki
    Abstract:

    We propose a holographic-laser-drawing volumetric display using a computer-generated hologram displayed on a liquid crystal spatial light modulator and multilayer Fluorescent Screen. The holographic-laser-drawing technique has enabled three things; (i) increasing the number of voxels of the volumetric graphics per unit time; (ii) increasing the total input energy to the volumetric display because the maximum energy incident at a point in the multilayer Fluorescent Screen is limited by the damage threshold; (iii) controlling the size, shape and spatial position of voxels. In this paper, we demonstrated (i) and (ii). The multilayer Fluorescent Screen was newly developed to display colored voxels. The thin layer construction of the multilayer Fluorescent Screen minimized the axial length of the voxels. A two-color volumetric display with blue-green voxels and red voxels were demonstrated.

  • Volumetric display with holographic parallel optical access and multilayer Fluorescent Screen.
    Optics letters, 2015
    Co-Authors: Kota Kumagai, Daichi Suzuki, Satoshi Hasegawa, Yoshio Hayasaki
    Abstract:

    We propose a volumetric display based on holographic parallel optical access and two-photon excitation using a computer-generated hologram displayed on a liquid crystal spatial light modulator and a multilayer Fluorescent Screen. The holographic parallel optical access increased the number of voxels of the volumetric image per unit time. This approach increased the total input energy to the volumetric display, that is, the total fluorescence power, because the maximum energy incident at a point in the multilayer Fluorescent Screen is limited by the damage threshold. The multilayer Fluorescent Screen was newly developed to display colored voxels. The thin layer construction of the multilayer Fluorescent Screen minimized the axial length of the voxels. A volumetric display with only blue-green voxels and a volumetric display with both blue-green and red voxels were demonstrated.

Bernd Michaelis - One of the best experts on this subject based on the ideXlab platform.

  • Enhancement and associative restoration of electronic portal images in radiotherapy
    International Journal of Medical Informatics, 1998
    Co-Authors: Gerald Krell, Hamid R. Tizhoosh, Tilo Lilienblum, C.j. Moore, Bernd Michaelis
    Abstract:

    Abstract Electronic portal imaging devices use the high energy treatment beam to project the body interior of the patient during radiation onto a Fluorescent Screen that is scanned by a camera. Because of the imaging physics, the unprocessed images of very poor quality, but they are the only available information during treatment for observation of the patient’s organs. This paper presents an approach that combines an associative restoration algorithm with a fuzzy image enhancement technique. By fusion of the electronic portal image (EPI) with a pre-treatment captured simulator image (SI) a higher image quality than by conventional techniques is achieved.

  • CBMS - Enhancement and associative restoration of electronic portal images in radiotherapy
    Proceedings of Computer Based Medical Systems, 1997
    Co-Authors: Gerald Krell, Hamid R. Tizhoosh, Tilo Lilienblum, C.j. Moore, Bernd Michaelis
    Abstract:

    The Electronic Portal Imaging Device (EPID) uses a high-energy treatment beam to project the body interior of a patient on to a Fluorescent Screen that is scanned by a camera. Because of the imaging physics, the unprocessed images are very poor in quality. This paper presents an approach that combines an associative restoration algorithm with a fuzzy image enhancement technique. By fusing the electronic portal image with a pre-treatment captured simulator image, a higher image quality than by conventional techniques is achieved.