• 제목/요약/키워드: Intensifier

검색결과 79건 처리시간 0.027초

Optimal Localization through DSA Distortion Correction for SRS

  • Shin, Dong-Hoon;Suh, Tae-Suk;Huh, Soon-Nyung;Son, Byung-Chul;Lee, Hyung-Koo;Choe, Bo-Young;Shinn, Kyung-Sub
    • 한국의학물리학회지:의학물리
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    • 제11권1호
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    • pp.39-47
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    • 2000
  • 신경 외과적 수술의 한분야인 정위적 방사선 수술은 두 개강 내의 병변의 위치 계산 후, 고선량의 방사선을 조사하여 병변을 치료하는 방법이기 때문에, 효과적인 수술을 위해서는 병변의 정확한 위치 정보가 무엇보다도 중요하다. 본 연구에서는 DSA(Digital Subtraction Angiography) 영상이 내재적으로 이미지 왜곡이라는 문제점을 가지고 있기 때문에, 이것의 보정을 통하여 더욱 정확한 target 위치를 계산하였다 이미지 왜곡을 보정하기 위하여 grid 팬텀을 제작하였고, localization 알고리즘의 정확도를 평가하기 위하여, target 팬텀을 제작하였다. Image Intensifier의 앞쪽에 grid 팬텀을 부착하고, target 팬텀을 Leksell Frame에 고정시킨 후, DSA 영상을 얻었다. 본 실험을 위하여 개발된 프로그램을 이용하여, Anterior and Posterior, Left and Right 영상에서 bilinear transform을 적용하여 왜곡을 보정한 후, target 위치를 계산하였다. 그리고, 이와 같은 방법을 통하여 계산된 target 위치 좌표와 target 팬텀의 절대 좌표의 비교를 통하여 localization 오차가 계산되었다. 이번 실험의 결과는 왜곡을 보정하지 않은 경우, localization 오차는 $\pm$0.41mm, 왜곡 보정을 한 경우는 $\pm$0.34mm이었다. 따라서 본 연구에서 개발된 알고리즘 정밀도가 인정되며, 환자의 치료에 적합한 것으로 사료된다.

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EBM 기반 구축을 위한 팔물탕 문헌 연구 분석 (Analysis of Studies on Palmul-tang for Establishment of Evidence Based Medicine)

  • 마충제;이남헌;마진열;하혜경;유영법;신현규
    • 대한한의학방제학회지
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    • 제15권2호
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    • pp.35-45
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    • 2007
  • Objective : The purpose of this report was to provide the information activity and safety of Palmul-tang by analyzing domestic/international papers and theses about Palmul-tang, Methods: Domestic/international papers and theses related to Palmul-tang were reviewed and analyzed, These papers were then classified by year, experimental method and subject, Results: The following results were obtained in this study. 1. The study of Palmul-tang started from 1985 and was continuously increased. The study was mainly forcused on experimental model rather than clinical study. 2. As these studies were classified by subject, papers related to immune intensification were most abundant by 20 papers, Besides there were several papers related to cardiovascular activity, reproductive activity, anti-apoptotic activity and cerebral hemodynamics. 3. Among the papers related to immune intensification. the studies on recovery of fatigue were mostabundant by 10 papers and the studies of on immune cell and cytokine express were six. In addition to. several studies were associated with anti-cancer activity and anti-allergic activity. Recovery of fatigue was determined by measurement of fatigue markers in a living body such as lactate. CPK, pyruvate and triglyceride and assessment of exercise capability of animals such as swimming test. slopped plate test. Rota-rod test, and activity cage test after Palmul-tang treatment. 4. According to experimental data. it is supported that Palmul-tang has been used as Qi and Blood intensifier with immune intensification and recovery of fatigue. 5. The paper related to safety of Palmul-tang was only one paper which is studied on acute toxicity of Palmul-tang with experiment with ICR mouse. There was no study on evaluating safety by observing liver and kidney functions after Palmul-tang treatment Conclusion: Palmul-tang is being used in various ways associating with immune intensification. cardiovascular activity and reproductive activity. However. studies on efficacy and mechanism of Palmul-tang should be conducted at the molecular biology level and studies on safety of Palmul-tang need to be completed at the clinical level.

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치과에서 디지털 x-선 영상의 이용 (Digital X-ray Imaging in Dentistry)

  • 김은경
    • 치과방사선
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    • 제29권2호
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    • pp.387-396
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    • 1999
  • In dentistry. RadioVisioGraphy was introduced as a first electronic dental x-ray imaging modality in 1989. Thereafter. many types of direct digital radiographic system have been produced in the last decade. They are based either on charge-coupled device(CCD) or on storage phosphor technology. In addition. new types of digital radiographic system using amorphous selenium. image intensifier etc. are under development. Advantages of digital radiographic system are elimination of chemical processing, reduction in radiation dose. image processing, computer storage. electronic transfer of images and so on. Image processing includes image enhancement. image reconstruction. digital subtraction, etc. Especially digital subtraction and reconstruction can be applied in many aspects of clinical practice and research. Electronic transfer of images enables filmless dental hospital and teleradiology/teledentistry system. Since the first image management and communications system(IMACS) for dentomaxillofacial radiology was reported in 1992. IMACS in dental hospital has been increasing. Meanwhile. researches about computer-assisted diagnosis, such as structural analysis of bone trabecular patterns of mandible. feature extraction, automated identification of normal landmarks on cephalometric radiograph and automated image analysis for caries or periodontitis. have been performed actively in the last decade. Further developments in digital radiographic imaging modalities. image transmission system. imaging processing and automated analysis software will change the traditional clinical dental practice in the 21st century.

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휴대용 적외선 야시경을 위한 전자회로설계 (Electronic Circuit Design for Portable Infrared Night Vision Scope)

  • 엄기환;김두환
    • 전자공학회논문지SC
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    • 제43권2호
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    • pp.33-39
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    • 2006
  • 본 논문에서는 휴대용 적외선 야시경의 소형 경량화 및 저전력을 위한 전자회로부를 설계하였다. 설계한 전자회로부는 전압자동변환부와 전원공급부로 구성한다. 전압자동변환부는 배터리, 스위치부, 승압부, 전압선택부 등으로 구성한다. 전원공급부는 고광원 감지회로, 배터리 전압감지회로, 적외선 발광회로, 연결감지회로, 공급제어회로 등으로 구성한다. 설계한 전자회로부의 성능은 AN/PVS-14에 비하여 소모전력 및 상온 연속사용 시간에서 우수하였다.

Extravascular Migration of a Fractured Inferior Vena Cava Filter Strut

  • Lim, Jung Hyeon;Lee, Weon Yong;Ra, Yong Joon;Jeong, Jae Han;Park, Bong Suk;Ko, Ho Hyun
    • Journal of Chest Surgery
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    • 제50권3호
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    • pp.224-227
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    • 2017
  • A 20-year-old man presented with a femur fracture and epidural hemorrhage (EDH) following a fall. One month after fracture surgery, swelling developed in both legs, and he was diagnosed as having a deep-vein thrombosis and pulmonary embolism. A retrievable inferior vena cava filter (IVCF) was inserted, because EDH is a contraindication to anticoagulants. Four months later, he complained of abdominal pain, and a computed tomography scan showed a fractured IVCF strut. After percutaneous removal failed 3 times, the IVCF was surgically removed by orthopedists using a portable image intensifier without cardiopulmonary bypass.

유조선 화물취급구역내 동력환기특성에 관한 연구 (A Study on Mechanical Ventilation Characteristics in Cargo Handling Area of Tanker)

  • 조대환
    • 해양환경안전학회지
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    • 제7권1호
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    • pp.15-23
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    • 2001
  • In regulation of IGC code 12.1 mechanical ventilation should be arranged to ensure sufficient air movement through the space to avoid the accumulation of flammable or toxic vapours and ensure a safe working environment, but in no case should the ventilation system have a capacity of less than 30 changes of air per hour baed upon the total volume of the space. In this study, a scaled mode chamber was constructed to investigate the ventilation characteristics and stagnation area in the hood room of LNG carrier and pump room in tanker. An experimental study was performed on the model by using visualization equipment with a laser apparatus and an image intensifier CCD camera. Twelve different kinds of measuring areas were selected as the experimental condition. Instant simultaneous velocity vectors in the whole fields were measured by a 2-D PIV system A three-dimensional numerical simulation was also carried out for three different Reynolds numbers. Then the CFD predictions were discussed with the experimental results. The results show the spiral L-shape flow that moves from the opening on the left wall diagonally to the upper right part dominates the ventilation structure. The stationary area of hood room in the velcoity distributions was located in the upper left stern part.

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C-arm 투시하에서 관골궁 골절의 비관혈적 정복술에 관한 고찰 (C-arm Guided Closed Reduction of Zygomatic Arch Fracture)

  • 어윤기;이동근;김정삼;장영일
    • 대한방사선기술학회지:방사선기술과학
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    • 제22권2호
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    • pp.23-26
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    • 1999
  • The Zygomatic arch is structurally protruded and is easily fractured. The classic management of zygomatic arch fracture has been mentioned the Keen, Lothrop, Dingman and Ailing and threaded K-wire. All of the above methods have advantages and disadvantages. To minimize the disadvantages, we performed threaded K-wire for the first time using C-arm image intensifier. The subjects were 16 patients with Knight North group II (Zygomatic arch fracture). Among them the C-arm was used in 12 patients and the operator used sensitivity general method in 4 patients and confirmed the operation by mobile X-ray equipment. In conclusion, both groups were satisfied surgically and cosmetically. Using the C-arm, actual image at the time operation was clear and satisfied, the surrounding tissue damage was minimized and at was more accurately completed. The operation time was shortened by 30 to 60 minutes proving it to be an efficient method. We suggest though that further studies be needed to evaluate the radiation effect on these patients.

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The Evaluation of Multiplane-Parallel Chamber Using Crystal Plate as Ionization Medium for Therapeutic Radiation Beams

  • Young W. Vahc;Park, Kyung R.;Kim, Sookil;Chul W. Joh;Kim, Tae H.
    • 한국의학물리학회지:의학물리
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    • 제9권1호
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    • pp.29-35
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    • 1998
  • There has been necessity of an air free ionization chamber using the gold-crystal-aluminium plates, henceforth called the crystal chamber. The crystal chamber formed of parallel plates is very small in size and has more response for absorbed dose of therapeutic radiation beams. The gold plate on the crystal facing the photon and electron beam acts as an intensifier of signals and crystal plate as an ionization medium respectively. Both the copper guard ring and the aluminum collecting electrode are connected to an electrometer. Using high energy photon (6, 15 MV) and electron (9, 12, 15, 18 MeV) beams, the responses of the crystal chamber are evaluated against a PTW Farmer-type chamber at a field size of 10${\times}$10cm$^2$ and 100 cm SSD. The responses of crystal chamber for therapeutic radiation electron and photon beams are greater in magnitude by several order than Farmer. The crystal chamber has good linearity without correction factor C$\_$t,p/ with respect to the signals, a reading reproduction with good accuracy and precision less than 0.5%, and has other useful functions in measuring radiation beams.

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Time-resolved PIV와 POD기법을 이용한 유량에 따른 단일노즐 버블링 유동 특성에 관한 연구 (Characteristics of Bubble-driven Flow with Varying Flow Rates by Using Time-resolved PIV and POD Technique)

  • 이승재;김종욱;김현동;김경천
    • 한국가시화정보학회지
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    • 제6권2호
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    • pp.14-19
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    • 2008
  • In this paper, the recirculation flow motion and mixing characteristics driven by air bubble flow in a rectangular water tank is studied. The Time-resolved PIV technique is adopted for the quantitative visualization and analysis. 532 nm Diode CW laser is used for illumination and orange fluorescent particle images are acquired by a PCO 10bit high-speed camera. To obtain clean particle images, 545 nm long pass optical filter and an image intensifier are employed and the flow rates of compressed air is changed from 2 l/min to 4 l/min at 0.5 MPa. The recirculation and mixing flow field is further investigated by the POD analysis technique. It is observed that the large scale counterclockwise rotation and main vortex is generated in the upper half depth from the free surface and one quarter width from the sidewall. When the flow rates are increased, the main vortex core is moved to the side and bottom wall direction.

$Gei^3ta^1$ in Taiwan Mandarin--- A Particular Construction

  • Lee, Chia-Chun
    • 한국언어정보학회:학술대회논문집
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    • 한국언어정보학회 2007년도 정기학술대회
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    • pp.268-274
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    • 2007
  • The present paper investigates a particular structure in Taiwan Mandarin, "(NP) + (intensifier) + $gei^3ta^1$ "give him/it"+ adjective" in terms of construction grammar. The structure is mostly observed in utterances of younger generation. Though it is not regarded as a grammatical or standard structure, it is still a register of language. The structure lays emphasis on speaker's attitude toward an undesired, unpleasant event. In most cases, the attitude tends to be negative. The events or propositions must have existed or been completed. The adjectives compatible with this structure belong to category of higher degree. The grammatical usage illustrates semantic bleaching of $gei^3ta^1$. And the changes from giving to a grammatical particle denoting subjective belief is a kind of subjectification. Moreover, $ta^1$ could refer to events or situation expressed by a more complicated grammatical structure, or denotes nothing as a dummy word. Though many previous studies paid attention to the newly developed structure resulted from language contact, the adequate account was not provided. It is hoped through this investigation, we will get a better understanding of this particular structure.

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