• Title/Summary/Keyword: magnetic pulse forming

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Design of RF Coil for Low Magnetic-Field Osteoblast Reformation System (저 자기장 조골세포 재형성 시스템용 RF 코일 설계)

  • Mun, Sung Hyuk;Cho, Choon Sik;Kim, Young-Jin
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.29 no.11
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    • pp.821-827
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    • 2018
  • In devices used for re-forming osteoblasts to treat osteoporosis, a magnetic field is applied from the outside of the bone, and the minerals contained in the bone are aligned in a certain direction and undergo precessional motion. When a $90^{\circ}$ RF pulse is applied by using an RF coil, protons of minerals are brought to an excited state, and phosphorus activity promoting the deposition of osteoblasts in the bone is increased, thereby reshaping the bone. Miniaturizing the RF coil that generates a signal corresponding to the harmonic of the precessional motional frequency by means of the $90^{\circ}$ RF pulse can drastically reduce the overall size of the bone reshaping system. In this study, we propose a methodology for the miniaturization of the RF coil that can be used for osteoblast re-formation using a bone reshaping system. The capacitance of the designed RF coil is 25 pF, the inductance is approximately 100 nH, and the resonance frequency is 96 MHz. The radius of the end ring of the designed RF coil is 18 cm, and the total length of the leg is $2{\times}11.6cm$. The performance of the coil is verified through post-design measurement.

Evaluation of usefulness of multi directional angles oblique scan method in optic nerve MRI (시각신경 MR 검사 시 다중 각도 스캔 기법의 유용성 평가)

  • Cho, Moo-Seong;Cho, Jae-Hwan;Bae, Jae-Yeong;Kim, Jeong-Soo;Kim, Kyeong-Keun
    • Journal of the Korean Society of Radiology
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    • v.5 no.4
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    • pp.161-169
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    • 2011
  • This research experimented on the change of the multiple colleague scan angle facing one scan object facet to many directions of the form of 3D about the visual angle nervous system forming the cubic distribution with the gradient magnetic field of the mri system and considered the existing basic angle oblique direction test coverage and comparison. MR system can freely select various pulse sequence and image slice. To oblique imaging for optic nerve viewing, we have studied the variation of scan angle between typical oblique scan method (sagittal-coronal plane) and multi directional angles oblique scan method (sagittal-coronal-axial plane) using gradient of MR system. In this study, the subjects of the experiment were normal adults in our country. As a result, we confirmed that multi directional angles oblique scan method can display anatomical information of more wider area than typical oblique scan method. In addition, to clearly display optic nerve, we also confirmed that image slice thickness and pulse sequence have effect on it.