• Title/Summary/Keyword: Intensifier

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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
    • Progress in Medical Physics
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    • v.11 no.1
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    • pp.39-47
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    • 2000
  • In Stereotactic Radiosurgery (SRS), there are three imaging methods of target localization, such as digital subtraction Angiography (DSA), computed tomography (CT), magnetic resonance imaging (MRI). Especially, DSA and MR images have a distortion effect generated by each modality. In this research, image properties of DSA were studied. A first essential condition in SRS is an accurate information of target locations, since high dose used to treat a patient may give a complication on critical organ and normal tissue. Hut previous localization program did not consider distortion effect which was caused by image intensifier (II) of DSA. A neurosurgeon could not have an accurate information of target locations to operate a patient. In this research, through distortion correction, we tried to calculate accurate target locations. We made a grid phantom to correct distortion, and a target phantom to evaluate localization algorithm. The grid phantom was set on the front of II, and DSA images were obtained. Distortion correction methods consist of two parts: 1. Bilinear transform for geometrical correction and bilinear interpolation for gray level correction. 2. Automatic detection method for calculating locations of grid crosses, fiducial markers, and target balls. Distortion was corrected by applying bilinear transform and bilinear interpolation to anterior-posterior and left-right image, and locations of target and fiducial markers were calculated by the program developed in this study. Localization errors were estimated by comparing target locations calculated in DSA images with absolute locations of target phantom. In the result, the error in average with and without distortion correction is $\pm$0.34 mm and $\pm$0.41 mm respectively. In conclusion, it could be verified that our localization algorithm has an improved accuracy and acceptability to patient treatment.

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

  • Ma, Choong-Je;Lee, Nam-Hun;Ma, Jin-Yeul;Ha, Hye-Kyung;Yu, Young-Beob;Shin, Hyun-Kyoo
    • Herbal Formula Science
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    • v.15 no.2
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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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Digital X-ray Imaging in Dentistry (치과에서 디지털 x-선 영상의 이용)

  • Kim Eun-Kyung
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.29 no.2
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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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Electronic Circuit Design for Portable Infrared Night Vision Scope (휴대용 적외선 야시경을 위한 전자회로설계)

  • Eom Ki-Hwan;Kim Doo-Hwan
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.43 no.2 s.308
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    • pp.33-39
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    • 2006
  • This paper designed the electronic circuit part of Potable Infrared Night Vision Scope for a small size, light weight, and low power. Designed electronic circuit part is composed of an Auto Voltage Selecting Module, and a Power Supply Module. An Auto Voltage Selecting Modulo is composed of a switch, a battery, a step up voltage part, and a selecting voltage part. A Power Supply Module is composed of a high luminous sensing part, a battery voltage sensing part, a infrared illumination part, a connection sensing part, and a power control part. And this module controls the power of Image Intensifier Tube. To verify the performance of the designed electronic circuit part, we experimented the consumption power and continuous using time. Experimental results show that the designed electronic circuit part improves considerably on the performance of the AN/PVS-14. performance.

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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    • v.50 no.3
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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.

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

  • 조대환
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.7 no.1
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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 Guided Closed Reduction of Zygomatic Arch Fracture (C-arm 투시하에서 관골궁 골절의 비관혈적 정복술에 관한 고찰)

  • Eo, Yoon-Ki;Lee, Dong-Kun;Kim, Jeong-Sam;Jang, Young-Il
    • Journal of radiological science and technology
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    • v.22 no.2
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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.
    • Progress in Medical Physics
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    • v.9 no.1
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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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Characteristics of Bubble-driven Flow with Varying Flow Rates by Using Time-resolved PIV and POD Technique (Time-resolved PIV와 POD기법을 이용한 유량에 따른 단일노즐 버블링 유동 특성에 관한 연구)

  • Yi, Seung-Jae;Kim, Jong-Wook;Kim, Hyun-Dong;Kim, Kyung-Chun
    • Journal of the Korean Society of Visualization
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    • v.6 no.2
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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
    • Proceedings of the Korean Society for Language and Information Conference
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    • 2007.11a
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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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