• Title/Summary/Keyword: Organ modeling

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A Case Study on Precise NURBS Modeling of Human Organs (인체장기의 정밀한 NURBS 곡면 모델링 사례연구)

  • Kim H.C.;Bae Y.H.;Soe T.W.;Lee S.H.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.915-918
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    • 2005
  • Advances in Information Technology and in Biomedicine have created new uses for CAD technology with many novel and important biomedical applications. Such applications can be found, for example, in the design and modeling of orthopedics, medical implants, and tissue modeling in which CAD can be used to describe the morphology, heterogeneity, and organizational structure of tissue and anatomy. CAD has also played an important role in computer-aided tissue engineering for biomimetic design, analysis, simulation and freeform fabrication of tissue scaffolds and substitutes. And all the applications require precision geometry of the organs or bones of each patient. But the geometry information currently used is polygon model with none solid geometry and is so rough that it cannot be utilized for accurate analysis, simulation and fabrication. Therefore a case study is performed to deduce a transformation method to build free form surface from a rough polygon data or medical images currently used in the application. This paper describes the transformation procedure in detail and the considerations for accurate organ modeling are discussed.

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A Review of Organ Dose Calculation Tools for Patients Undergoing Computed Tomography Scans

  • Lee, Choonsik
    • Journal of Radiation Protection and Research
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    • v.46 no.4
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    • pp.151-159
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    • 2021
  • Background: Computed tomography (CT) is one of the crucial diagnostic tools in modern medicine. However, careful monitoring of radiation dose for CT patients is essential since the procedure involves ionizing radiation, a known carcinogen. Materials and Methods: The most desirable CT dose descriptor for risk analysis is the organ absorbed dose. A variety of CT organ dose calculators currently available were reviewed in this article. Results and Discussion: Key common elements included in CT dose calculators were discussed and compared, such as computational human phantoms, CT scanner models, organ dose database, effective dose calculation methods, tube current modulation modeling, and user interface platforms. Conclusion: It is envisioned that more research needs to be conducted to more accurately map CT coverage on computational human phantoms, to automatically segment organs and tissues for patient-specific dose calculations, and to accurately estimate radiation dose in the cone beam computed tomography process during image-guided radiation therapy.

Blood-brain barrier-on-a-chip for brain disease modeling and drug testing

  • Cui, Baofang;Cho, Seung-Woo
    • BMB Reports
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    • v.55 no.5
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    • pp.213-219
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    • 2022
  • The blood-brain barrier (BBB) is an interface between cerebral blood and the brain parenchyma. As a gate keeper, BBB regulates passage of nutrients and exogeneous compounds. Owing to this highly selective barrier, many drugs targeting brain diseases are not likely to pass through the BBB. Thus, a large amount of time and cost have been paid for the development of BBB targeted therapeutics. However, many drugs validated in in vitro models and animal models have failed in clinical trials primarily due to the lack of an appropriate BBB model. Human BBB has a unique cellular architecture. Different physiologies between human and animal BBB hinder the prediction of drug responses. Therefore, a more physiologically relevant alternative BBB model needs to be developed. In this review, we summarize major features of human BBB and current BBB models and describe organ-on-chip models for BBB modeling and their applications in neurological complications.

Structural Equation Modeling on Living and Brain Death Organ Donation Intention in Nursing Students (간호대학생의 생존 시와 뇌사 시 장기기증 의도에 관한 구조모형)

  • Kim, Eun A;Choi, So Eun
    • Journal of Korean Academy of Nursing
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    • v.45 no.6
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    • pp.802-811
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    • 2015
  • Purpose: The purpose of this study was to test and validate a model to predict living and brain death organ donation intention in nursing students. The conceptual model was based on the theory planned behavior. Methods: Quota sampling methodology was used to recruit 921 nursing students from all over the country and data collection was done from October 1 to December 20, 2013. Results: The model fit indices for the hypothetical model were suitable for the recommended level. Knowledge, attitude, subjective norm and perceived behavioral control explained 40.2% and 40.1% respectively for both living and brain death organ donation intention. Subjective norm was the most direct influential factor for organ donation intention. Knowledge had significant direct effect on attitude and indirect effect on subjective norm and perceived behavioral control. These effects were higher in brain death organ donation intention than in living donation intention. Conclusion: The overall findings of this study suggest the need to develop systematic education programs to increases knowledge about brain death organ donation. The development, application, and evaluation of intervention programs are required to improve subjective norm.

Hunminjeongeum Phonetics (I): Phonetic and Phoniatric Consideration for Explanation of Designs of Middle Vowel Letters (훈민정음 음성학(I): 중성자(홀소리) 제자해에 대한 음성언어의학적 고찰)

  • Choi, Hong-Shik
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.33 no.2
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    • pp.77-82
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    • 2022
  • Hunminjeongeum was made by the Great King Sejong, and composed of 17 consonant and 11 vowel letters. All the 28 letters were made according to the shape of vocal organ or space at the point of articulation for each letters. This review article focused on phonetic and phoniatric consideration for explanation of the designs of the middle vowel letters, especially three main vowel letters [ • (天, heaven), ㅡ (地, earth), ㅣ (人, human)] using video-fluoroscopic evaluation as well as computed tomography scanning, etc. During articulating / • / sound, a ball-like space at frontal portion of the oral cavity was found, tongue was contracted, and sound was deep (舌縮而聲深). During /ㅡ/ sound, a flat air space between oral tongue and hard palate was created. Tongue was slightly contacted neither deep nor shallow (舌小縮而聲不深不淺). During /ㅣ/ sound, tongue was not contacted and Sound is light (舌不縮而聲淺). Tongue was moved forward making longitudinal oro-pharyngeal air space. So, I'd like to suggest that we had better change the explanation drawing from a philosophical modeling to a more scientific modeling from real vocal tract space modeling during articulating middle vowels of Hunminjeongeum.

Organ Shape Modeling Based on the Laplacian Deformation Framework for Surface-Based Morphometry Studies

  • Kim, Jae-Il;Park, Jin-Ah
    • Journal of Computing Science and Engineering
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    • v.6 no.3
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    • pp.219-226
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    • 2012
  • Recently, shape analysis of human organs has achieved much attention, owing to its potential to localize structural abnormalities. For a group-wise shape analysis, it is important to accurately restore the shape of a target structure in each subject and to build the inter-subject shape correspondences. To accomplish this, we propose a shape modeling method based on the Laplacian deformation framework. We deform a template model of a target structure in the segmented images while restoring subject-specific shape features by using Laplacian surface representation. In order to build the inter-subject shape correspondences, we implemented the progressive weighting scheme for adaptively controlling the rigidity parameter of the deformable model. This weighting scheme helps to preserve the relative distance between each point in the template model as much as possible during model deformation. This area-preserving deformation allows each point of the template model to be located at an anatomically consistent position in the target structure. Another advantage of our method is its application to human organs of non-spherical topology. We present the experiments for evaluating the robustness of shape modeling against large variations in shape and size with the synthetic sets of the second cervical vertebrae (C2), which has a complex shape with holes.

Reviews Key Features of Word-Of-Mouth (WOM) Advertising and Their Impact on Sports Consumer

  • SHOKURLOO, Sakineh Lotfi Fard;SHAHBAZI, Massoumeh;SEO, Won Jae
    • Journal of Sport and Applied Science
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    • v.4 no.2
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    • pp.1-9
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    • 2020
  • Purpose: This study sought to investigate the critical features of Word of mouth (WOM) advertising and their impact on sport consumer behavior. Research design, data, and methodology: Target population of the study consisted of all sports consumer of the Federation of Special Patients and Organ Transplantation, Tehran (Iran), who had indirectly watched the World Organ Transplant Competition documentary at least once on others' advice. For this purpose, 360 sports consumers of the federation were purposefully selected and they were asked to complete the standard WOM advertising questionnaire of Asda and Ko. Pearson correlation coefficient test and modeling of structural equations were performed using Spss24 and Smart PLS software at an error level of 0.05 used to analyze the data. Results: The findings show that there is a significant relationship between experience and expertise, trust and validity, content richness, and the power of message transmission through WOM advertising and its predictability. Finally, interpersonal relationships and work involvement also had a moderating role in this regard. Conclusions: The general conclusion is that the components of WOM advertising as well as involvement and homophily with the mediating role directly as one of the presuppositions for persuasion. The sports consumer was promoting WOM.

Modeling and Experimental Validation of Earthworm-like Robot (지렁이 모사 로봇의 모델링 및 실험 검증)

  • Park Suk-Ho;Kim Byung-Kyu;Kwon Ji-Woon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.30 no.3 s.246
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    • pp.287-294
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    • 2006
  • In recent years, capsule endoscope is highlighted for the patient's convenience and the possibility of the application in the small intestine. However, the capsule endoscope has some limitations to get the image of the digestive organ because its movement only depends on the peristaltic motion. In order to solve these problems, locomotion of capsule endoscope is necessary. In this paper, we analyze the locomotive mechanism of earthworm-like robot proposed as locomotive device of capsule endoscope and derive the condition which can Judge the possibility of its mobility using theoretical analysis. Based on a biomechanical modeling and simulation, the critical stroke, that is minimum stroke of the earthworm-like robot to perform motion inside small intestine, is obtained. Also, this derived critical stroke can be validated by the moving test of fabricated earthworm-like robot. Consequently, it is expected that this study can supply useful information to design of earthworm-like robot for mobility of capsule endoscope.

Digital Elderly Human Body Modeling Part I : Standard Anthropometry and Exterior/Interior Geometries (디지털 고령 인체 모델 구축 Part I : 표준 Anthropometry 및 내외형상)

  • Han, Ji-Won;Choi, Hyung-Yun;Yoon, Kyong-Han;Park, Yo-Han
    • Transactions of the Korean Society of Automotive Engineers
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    • v.17 no.1
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    • pp.96-104
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    • 2009
  • An anatomically detailed elderly human body model is under development. Using the anthropometric database of domestic nation-wide size survey, SizeKorea, a standard size and shape of 50th %tile elderly was constructed. Through the local recruitment process, a male volunteer with 71 years of age, 163cm of height and 63kg of weight has been selected. The exterior (skin) and interior (skeleton and organ) geometries were acquired from whole body 3D laser scan and various medical images such as CT, X-ray, and Ultrasonic of the volunteer. A particular attention has been paid into the combining process of exterior and interior geometries especially for joint articulation positions since they were measured at different postures (sitting vs. supine). A whole ribcage of PMHS which possessed similar anthropometry and age of standard 50th %tile elderly was prepared and dissected for the precise gauge of cortical rib bone thickness distributions. After completing the morphological construction of elderly human body, the finite element modeling will be processed by meshing elements and assigning mechanical properties to various biological tissues which reflect the aging effect.