• Title/Summary/Keyword: diagnostic method

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Automatic Segmentation of Retinal Blood Vessels Based on Improved Multiscale Line Detection

  • Hou, Yanli
    • Journal of Computing Science and Engineering
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    • v.8 no.2
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    • pp.119-128
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    • 2014
  • The appearance of retinal blood vessels is an important diagnostic indicator of serious disease, such as hypertension, diabetes, cardiovascular disease, and stroke. Automatic segmentation of the retinal vasculature is a primary step towards automatic assessment of the retinal blood vessel features. This paper presents an automated method for the enhancement and segmentation of blood vessels in fundus images. To decrease the influence of the optic disk, and emphasize the vessels for each retinal image, a multidirectional morphological top-hat transform with rotating structuring elements is first applied to the background homogenized retinal image. Then, an improved multiscale line detector is presented to produce a vessel response image, and yield the retinal blood vessel tree for each retinal image. Since different line detectors at varying scales have different line responses in the multiscale detector, the line detectors with longer length produce more vessel responses than the ones with shorter length; the improved multiscale detector combines all the responses at different scales by setting different weights for each scale. The methodology is evaluated on two publicly available databases, DRIVE and STARE. Experimental results demonstrate an excellent performance that approximates the average accuracy of a human observer. Moreover, the method is simple, fast, and robust to noise, so it is suitable for being integrated into a computer-assisted diagnostic system for ophthalmic disorders.

The Effect Measures for Diagnostic Test: A Graph Approach (진단검사에서 측도들의 효과적인 표현: 그래프를 활용한 방법)

  • Cho, Tae-Kyoung;Son, Chang-Kyoon
    • The Korean Journal of Applied Statistics
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    • v.26 no.1
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    • pp.15-22
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    • 2013
  • In clinical study or epidemic research, the $2{\times}2$ frequency table is useful to present a summary statistic The values of four cells in $2{\times}2$ table use to calculate the effect measures such as risk ratio, relative ris ratio or odds ratio. In this paper, we suggest that the improved visualization method using a radar diagram supported by MS-office Excel from the $2{\times}2$ frequency table is able to understand and draw easily betweendiagnosti measures such as sensitivity, specificity, predictivity, and likelihood ratio. We use some numerical example in order to show the usage of the proposed method.

Recent 9-year Experience With Biliary Atresia Utilizing a New Ultrasonographic Diagnostic Technique (최근 9년간의 담도폐쇄증 경험 - 새로운 초음파 진단법 소개 -)

  • Park, Woo-Hyun;Choi, Soon-Ok
    • Advances in pediatric surgery
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    • v.6 no.1
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    • pp.19-26
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    • 2000
  • This paper reports our 9-year experience treating 34 infants with biliary atresia utilizing a new non-invasive diagnostic method, ultrasonographic "triangular cord"(TC) sign. The TC sign is present when there is visualization of a triangular or a band-like echogenicity just cranial to the portal vein. The ultrasonographic TC sign appears to be a simple, non-invasive, time-saving and useful tool in the diagnosis of biliary atresia. Sensitivity is 84 %. Active bile excretion was restored in 90 % of the patients who were treated between 31-60days, 78 % of those between 61-90 days, and 33 % of those being 91days or older. The incidence of postoperative cholangitis was 36 %. Construction of an antireflux valve in the Roux-en-Y loop did not affect the incidence of postoperative cholangitis(p=0.18). Among 34 infants with biliary atresia, 23(68 %) are alive for 2-102 months after operation, and 12 are alive for more than 5 years. Five-year estimate survival by Kaplan-Meier method was 66 %.

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An Experimental Study on Flame Structure and Combustion Characteristics of Turbulent Diffusion Flame(II) (난류확산화염의 화염구조와 연소특성에 관한 실험적 연구(2))

  • Choe, Byeong-Ryun;Jang, In-Gap;Choe, Gyeong-Min
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.20 no.3
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    • pp.1050-1060
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    • 1996
  • Recently, attention has been paid to the flame diagnostic by noncontact methods which dose not deform the flame shape. One of them is a method which is using the radical luminous intensity. Generally, this diagnostic method using radical luminous has been investigated its reliability by applying to laminar flame. This study, however, investigated each radical luminous signals through stocastical analysis like auto-correlation, cross-correlation, phase and coherence which were acquired from measuring radical luminous intensity of OH, CH, $O_{2}$, radicals in turbulent diffusion flame. To compare radical luminous intensity in flame with temperature, ion current and concentration , radious distribution of each properties was investigated and considered. In radical luminous intensity, correlation in the reaction zone of flame was higher than in correlation in combusted gas zone. And radious distribution of radical luminous intensity was corresponded with radious distribution of temperature, ion current and concentration. The result of the study confirms that a radical luminous flame diagnosis is possible in the turbulent diffusion flame.

Clinical Usefulness of Helicobactor pylori Ag Stool Test (Immunochromatographic Assay) for Diagnosis of H. pylori Infection (Helicobacter pylori 감염진단에 있어 H. pylori Ag Stool 검사 (면역크로마토그라피법)의 임상적 유용성)

  • Seo, Seol
    • Korean Journal of Clinical Laboratory Science
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    • v.42 no.1
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    • pp.38-45
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    • 2010
  • The aim of this study was to assess the Clinical Usefulness of Helicobacter pylori Stool Antigen (HpSA) immunochromatographic assay for the diagnosis of H. pylori infection. In this study, we had compared HpSA-immunochromatographic assay with CLO test and UBT test. From a total of 140 patients (M:F=88:52) with upper endoscopy, biopsy specimens were obtained for CLO test. Stool specimens was collected from all patients and tested using a HpSA-immunochromatic assay. H. pylori infection status was defined as infected if the results of both CLO test and UBT test were positive. CLO test and UBT test findings showed that 92 patients were H. pylori positive and 48 patients were H. pylori negative. According to this definition, the sensitivity, specificity, and positive or negative predictive value (PPV, NPV) of HpSA-immunochromatographic assay were 97.8%, 100%, 100%, and 96%, respectively. Cross reactivity test of HpSA-immunochromatographic assay were performed with 10 enteric bacteria strains in fecal habitat, and there were no false positive reaction. We evaluated the usefulness of HpSA assay for eradication therapy with 10 of 92 H. pylori positive patients, positive results of them at pre-eradication therapy were converted to negative at post-eradication. The HpSA-immunochromatographic assay is a highly sensitive and specific non-invasive diagnostic method for detection of H. pylori infection, a useful diagnostic method for H. pylori in post eradication stage.

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A Study on Multi-Fault Diagnosis for Turboshaft Engine of UAV Using Fuzzy and Neural Networks (퍼지 및 신경망을 이용한 무인 항공기용 터보축 엔진의 다중손상진단에 관한 연구)

  • Kong, Chang-Duk;Ki, Ja-Young;Kho, Seong-Hee;Koo, Young-Ju;Lee, Chang-Ho
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.37 no.6
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    • pp.556-561
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    • 2009
  • The UAV(Unmanned Aerial Vehicle) that is remotely operating in various and long flight environments must have a very reliable propulsion system. Precise fault diagnosis of the turbo shaft engine for the Smart UAV that has the vertical take-off, landing and forward flight behaviors can promote reliability and availability. This work proposes a new diagnostic method that can identify the faulted components from engine measuring parameter changes using Fuzzy Logic and quantify its faults from the identified fault pattern using Neural Network Algorithms. The proposed diagnostic method can detect not only single fault but also multiple faults.

A Comparison of the Interval Estimations for the Difference in Paired Areas under the ROC Curves (대응표본에서 AUC차이에 대한 신뢰구간 추정에 관한 고찰)

  • Kim, Hee-Young
    • Communications for Statistical Applications and Methods
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    • v.17 no.2
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    • pp.275-292
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    • 2010
  • Receiver operating characteristic(ROC) curves can be used to assess the accuracy of tests measured on ordinal or continuous scales. The most commonly used measure for the overall diagnostic accuracy of diagnostic tests is the area under the ROC curve(AUC). When two ROC curves are constructed based on two tests performed on the same individuals, statistical analysis on differences between AUCs must take into account the correlated nature of the data. This article focuses on confidence interval estimation of the difference between paired AUCs. We compare nonparametric, maximum likelihood, bootstrap and generalized pivotal quantity methods, and conduct a monte carlo simulation to investigate the probability coverage and expected length of the four methods.

Validation Data Augmentation for Improving the Grading Accuracy of Diabetic Macular Edema using Deep Learning (딥러닝을 이용한 당뇨성황반부종 등급 분류의 정확도 개선을 위한 검증 데이터 증강 기법)

  • Lee, Tae Soo
    • Journal of Biomedical Engineering Research
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    • v.40 no.2
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    • pp.48-54
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    • 2019
  • This paper proposed a method of validation data augmentation for improving the grading accuracy of diabetic macular edema (DME) using deep learning. The data augmentation technique is basically applied in order to secure diversity of data by transforming one image to several images through random translation, rotation, scaling and reflection in preparation of input data of the deep neural network (DNN). In this paper, we apply this technique in the validation process of the trained DNN, and improve the grading accuracy by combining the classification results of the augmented images. To verify the effectiveness, 1,200 retinal images of Messidor dataset was divided into training and validation data at the ratio 7:3. By applying random augmentation to 359 validation data, $1.61{\pm}0.55%$ accuracy improvement was achieved in the case of six times augmentation (N=6). This simple method has shown that the accuracy can be improved in the N range from 2 to 6 with the correlation coefficient of 0.5667. Therefore, it is expected to help improve the diagnostic accuracy of DME with the grading information provided by the proposed DNN.

A Review Studies on the Treatment of Anorexia Nervosa in Traditional Chinese Medicine (신경성 식욕부진증의 치료에 관한 임상연구 동향 -중의학 논문을 중심으로-)

  • Min-Jae Kim;Chan-Young Kwon
    • Journal of TMJ Balancing Medicine
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    • v.13 no.1
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    • pp.1-12
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    • 2023
  • Objectives: This study was performed to review the research trends in the treatment of anorexia nervosa (AN) in Traditional Chinese Medicine (TCM). Methods: Studies were searched through The China National Knowledge Infrastructure (CNKI) database. The search term for the subject were 'Eating Disorder', and 'Anorexia Nervosa'. Clinical research that conducted TCM treatment for AN patients were included. Studies were analyze according to study design, therapy method, diagnostic criteria, population and intervention. Results: 23 articles were selected. According to study design, studies were classified into two randomized controlled trial (RCT), three single group before-and-after studies, and 18 case reports. According to therapy method, they included 19 herbal medicine studies, two acupuncture treatment studies, and two complex treatment studies. The most common pattern identification was 'liver depression with spleen deficiency' (肝鬱脾虛), and the most used herb was 'Root of Bupleurum falcatum' (柴胡). Most of the studies showed effective results in increasing appetite and weight. Conclusions: The results of our study demonstrate that TCM treatments for AN has been effective in alleviating chief symptoms. However, in terms of evidence-based medicine, lack of RCT on TCM treatments for AN and absence of objective diagnostic criteria in case reports are limitations. Therefore well-designed further clinical studies should be performed based on the results of this study are recommended.

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A study of sedimentation processes in Seamangeum coastal area (새만금지구의 퇴적과정에 관한 연구)

  • Sin Mun-Seop;Yu Cheol-Ung;Kim Ik-Jung
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 1997.10a
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    • pp.73-76
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    • 1997
  • The purpose of this study is to find sedimentation patterns variation in Saemangeum coastal sea region. Water circulations are calculated diagnostically from the observed water temperature and salinity data and wind data and tidal residual current. Three dimensional movements of injected particles due In currents, turbulence and sinking velocity are tracked by the Euler-lagrange method. Calculated sedimentation patterns of riverine material are highly similar to the observed ones.

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