• Title/Summary/Keyword: Diagnostic Errors

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Clinical Situations in which Musculoskeletal Ultrasound is Helpful (근골격계 초음파검사가 도움이 되는 진료 상황)

  • Cho, Kil-Ho
    • Journal of Yeungnam Medical Science
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    • v.18 no.2
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    • pp.170-186
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    • 2001
  • Musculoskeletal ultrasound (MSUS) has newly evolved by the mechanical improvement of the machine over past several years, becoming a part of imaging techniques for the evaluation of variable diseases in the musculoskeletal system. MSUS has proven diagnostic superiority in pathologies including rotator cuff disease of the shoulder, lateral epicondylitis of the elbow, diseases of the peripheral nerve, detection of intra-articular loose bodies and soft tissue foreign bodies, and in evaluating small superficial soft tissue tumors such as ganglion, epidermoid cyst, and glomus tumor. Besides, MSUS is very useful for obtaining tissue or fluid via percutaneous fine needle aspiration and/or biopsy for the histopathologic diagnosis. Combining MSUS with MR would play a great role in the field of the diagnostic imaging of the musculoskeletal system. The MSUS examiner should have the knowledge of cross-sectional anatomy, and of the mechanical and physical properties of ultrasound in order to interpret the ultrasound findings accurately and properly, and to avoid diagnostic errors due to variable artifacts subsequently. The goal of this article is to introduce the capabilities of MSUS in certain kinds of clinical situation and to familiarize the reader with MSUS. For the purpose, author intends to describe this article according not to the disease-, or organ-based, but to the clinical problem-based format.

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A Study on Developing the Teachers' Guide Book for Diagnosis and Prescription of Students' Mathematical Errors (수학과 오류의 진단과 처방에 관한 교사용 자료 개발 연구)

  • 김수미
    • School Mathematics
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    • v.5 no.2
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    • pp.209-221
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    • 2003
  • This study focuses on the necessity of developing the material for teachers who are involved in diagnosing and prescribing students' mathematical errors. And it also intends to stimulate the related research of this area. For this, it tries to suggest the fundamental components-(1)types and frequencies of errors, (2) diagnostic test kit, (3)causes of errors, (4)ideas for prevention, (5)ideas for correction, (6)practice for settlement, and (7) performance test kit and frame of the teaching guide book for the teachers according to the general procedure of diagnosis and prescription. Finally it provides the concrete research areas for the future study.

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The Effect of the Fault Tolerant Capability due to Degradation of the Self-diagnostics Function in the Safety Critical System for Nuclear Power Plants (원자력발전소 안전필수시스템 고장허용능력에 대한 자가진단기능 저하 영향 분석)

  • Hur, Seop;Hwang, In-Koo;Lee, Dong-Young;Choi, Heon-Ho;Kim, Yang-Mo;Lee, Sang-Jeong
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.8
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    • pp.1456-1463
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    • 2010
  • The safety critical systems in nuclear power plants should be designed to have a high level of fault tolerant capability because those systems are used for protection or mitigation of the postulated accidents of nuclear reactor. Due to increasing of the system complexity of the digital based system in nuclear fields, the reliability of the digital based systems without an auto-test or a self-diagnostic feature is generally lower than those of analog system. To overcome this problem, additional redundant architectures in each redundant channel and self-diagnostic features are commonly integrated into the digital safety systems. The self diagnostic function is a key factor for increasing fault tolerant capabilities in the digital based safety system. This paper presents an availability and safety evaluation model to analyze the effect to the system's fault tolerant capabilities depending on self-diagnostic features when the loss or erroneous behaviors of self-diagnostic function are expected to occur. The analysis result of the proposed model on the several modules of a safety platform shows that the improvement effect on unavailability of each module has generally become smaller than the result of usage of conventional models and the unavailability itself has changed significantly depending on the characteristics of failures or errors of self-diagnostic function.

Convergence Study on Diagnostic Agreement between Occurrence of Osteoporosis and Doctor's Diagnosis of Osteoporosis (골다공증 유무와 골다공증 의사진단여부와의 진단 일치율 융합연구)

  • Kim, Young-Ran;Park, Chang-Soo
    • Journal of Digital Convergence
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    • v.17 no.1
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    • pp.281-286
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    • 2019
  • This study, which checked diagnostic agreement at the femoral region and lumbar region during diagnosis of osteoporosis and surveyed errors related with choosing measured parts, aimed at providing basic date for right diagnosis of osteoporosis. The study, using the first, second years of the fifth period from initial data from National Nutrition Survey, surveyed 1,637 men and 2,128 women at the age of 50 years or older. The study used kappa test to grasp the agreement between the occurrence of osteoporosis at the femoral region and lumbar region and whether or not received doctor's diagnosis. Women showed diagnostic agreement of osteoporosis at all of the femoral region and lumbar region, with diagnostic agreement of the lumbar region being higher than that of the femoral region. While, men showed diagnostic agreement of osteoporosis only at the lumbar region. Bone density changes with the age and varies depending on parts, and so, the study believes, measuring bone density should conduct all of the femoral region and lumbar region and diagnosis had better be made focused on the lumbar region.

COMPARATIVE STUDY OF DIGITAL AND CONVENTIONAL RADIOGRAPHY FOR THE DIAGNOSTIC ABILITY OF ARTIFICIAL PROXIMAL SURFACE CARIES (디지털방사선사진과 구내방사선사진의 인접면 인공우식진단능에 관한 비교연구)

  • Cho, Young-Gon;Park, Si-Seung
    • Restorative Dentistry and Endodontics
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    • v.27 no.2
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    • pp.113-121
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    • 2002
  • Conventional intraoral radiography continues to be the most widely used image modality for the diagnosis of dental caries. But, conventional intraoral radiography has several shortcomings, including the difficulty of exposing and processing intraoral film of consistently acceptable quality. In addition, radiographic retaking that was the result of processing errors, may result in increased discomfort and radiation dose to the patient. Recently, various digital radiographies substitute for conventional intraoral radiography to overcome these disadvantages. The advantages of digital radiography are numerous. One of advantages Is the elimination of processing errors. In addition, the radiation dose for digital system is approximately 20% to 25% of that required for conventional intraoral radiography Another potential advantage of digital imaging is the ability to perform image quality enhancements such as contrast and density modulation, which may increase diagnostic accuracy. The purpose of this study was to compare the diagnostic ability of artificial proximal defects to conventional intraoral radiography, direct digital image(CDX2000HQ$^{\circledR}$) and indirect digital image(Digora$^{\circledR}$). Artificial defects were made in proximal surfaces of 60 extracted human molars using #1/2, #1, #2 round bur. Five dentists assessed proximal defects on conventional intraoral radiography, direct digital image(CDX2000HQ$^{\circledR}$) and indirect digital image(Digora$^{\circledR}$). ROC(Receiver Operating Characteristic) analysis and Two-way ANOVA test were used for the evaluation of detectability, and following results were acquired. 1. The mean ROC area of conventional intraoral radiography, direct digital image(CDX2000HQ$^{\circledR}$) and indirect digital Image(Digora$^{\circledR}$) were 0.6766, 0.7538, 0.6791(Grade I), 0.7176, 0.7594, 0.7361(Grade II), and 0.7449, 0.7608, 0.7414(Grade III), respectively. 2. Diagnostic ability of direct digital image was higher than other image modalities. But, there was no statistically significant difference among other imaging modalities for Grade I, II, III lesion(p>0.05). In conclusion, when direct and indirect digital system are comparable with conventional intraoral radiography. these systems may be considered an alternative of conventional intraoral radiography for the diagnosis of proximal surface caries.

Neuro-Fuzzy Diagnostic Technique for Performance Evaluation of a Chiller (뉴로 퍼지를 이용한 냉동기 성능 진단 기법)

  • Shin, Young-Gy;Chang, Young-Soo;Kim, Young-Il
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.27 no.5
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    • pp.553-560
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    • 2003
  • On-site diagnosis of chiller performance is an essential step fur energy saving business. The main purpose of the on-site diagnosis is to predict the COP of a target chiller. Many models based on thermodynamics background have been proposed for this purpose. However, they have to be modified from chiller to chiller and require deep insight into thermodynamics that most of field engineers are often lacking in. This study focuses on developing an easy-to-use diagnostic technique that is based on adaptive neuro-fuzzy inference system (ANFIS). Quality of the training data for ANFIS, sampled over June through September, is assessed by checking COP prediction errors. The architecture of the ANFIS, its error bounds, and collection of training data are described in detail.

Diagnostic Value of Ultrasound-Guided Fine Needle Aspiration Biopsy in Malignant Thyroid Nodules: Utility for Micronodules

  • Unal, Betul;Sezer, Cem
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.20
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    • pp.8613-8616
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    • 2014
  • Background: The diagnostic approach to thyroid nodules involves ultrasound-guided fine needle aspiration biopsy (US-FNAB). We especially aimed to evaluate the contribution and the place of US-FNAB in preoperative evaluation of the malignant cases and draw attention to discordant cases diagnosed with papillary thyroid microcarcinoma (PTMC). Materials and Methods: A total of 276 cases were retrospectively reviewed who were subsequently diagnosed with a malignancy and who underwent US-FNAB. Results: Some 45 were found to have previously undergone the US-FNAB procedure. Of the patients in whom the surgical specimen was diagnosed with a malignancy, 21 (46.7%) were diagnosed as malignant or suspicious for malignancy, and 24 (53.3%) were concluded as benign or insufficient for diagnosis. Patients with the diagnosis of PTMC outnumbering the others was a striking finding (11 cases, 24%). Conclusions: We suggest performing repeat aspiration biopsy considering sampling errors in cases where inconsistency exists between clinical findings and cytological results in thyroid nodules smaller than 10 mm in diameter and with suspicious findings on ultrasonography.

Cytological Diagnosis of Lung Cancer: The Diagnostic Accuracy and Pitfalls (폐암의 세포진단: 진단의 정확도와 함정)

  • Kim, Wan-Seop
    • The Korean Journal of Cytopathology
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    • v.19 no.1
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    • pp.1-8
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    • 2008
  • The role of respiratory cytology is to detect and classify pulmonary disease, with an emphasis of neoplastic disease, so that proper therapy can be instituted. As in many branches of cytology, the recognition of malignancy in the cells obtained from the respiratory tract is more straightforward than identifying the type of tumor cell. It is important to accurately determine the true cytopathological cell type in cases of primary lung cancer and to know the accuracy of the diagnosis achieved by the cytological procedures. The well differentiated tumors have characteristic cytoplasmic and nuclear abnormalities that enable physicians to firmly categorize these lesions, as in squamous cell or adenocarcinoma, but some moderately and most poorly differentiated tumors show few distinctive features. This article reviews the malignant and reactive pulmonary cytologic findings and we also report on some of their pitfalls and the cytologic criteria.

Diagnostic Study of Problems under Asymptotically Generalized Least Squares Estimation of Physical Health Model

  • Kim, Jung-Hee
    • Journal of Korean Academy of Nursing
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    • v.29 no.5
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    • pp.1030-1041
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    • 1999
  • This study examined those problems noticed under the Asymptotically Generalized Least Squares estimator in evaluating a structural model of physical health. The problems were highly correlated parameter estimates and high standard errors of some parameter estimates. Separate analyses of the endogenous part of the model and of the metric of a latent factor revealed a highly skewed and kurtotic measurement indicator as the focal point of the manifested problems. Since the sample sizes are far below that needed to produce adequate AGLS estimates in the given modeling conditions, the adequacy of the Maximum Likelihood estimator is further examined with the robust statistics and the bootstrap method. These methods demonstrated that the ML methods were unbiased and statistical decisions based upon the ML standard errors remained almost the same. Suggestions are made for future studies adopting structural equation modeling technique in terms of selecting of a reference indicator and adopting those statistics corrected for nonormality.

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Actuator Fault Diagnostic Algorithm based on Hopfield Network

  • Park, Tae-Geon;Ryu, Ji-Su;Hur, Hak-Bom;Ahn, In-Mo;Lee, Kee-Sang
    • Journal of the Korean Institute of Intelligent Systems
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    • v.10 no.3
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    • pp.211-217
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    • 2000
  • A main contribution of this paper is the development of a Hopfield network-based algorithm for the fault diagnosis of the actuators in linear system with uncertainties. An unknown input decoupling approach is introduced to the design of an adaptive observer so that the observer is insensitive to uncertainties. As a result, the output observation error equation does not depend on the effect of uncertainties. Simultaneous energy minimization by the Hopfield network is used to minimize the least mean square of errors of errors of estimates of output variables. The Hopfield network provides an estimate of the gains of the actuators. When the system dynamics changes, identified gains go through a transient period and this period is used to detect faults. The proposed scheme is demonstrated through its application to a simulated second-order system.

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