• Journal of the Korea Institute of Military Science and Technology
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• v.3 no.1
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• pp.138-145
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• 2000

This paper presents a robust fault diagnosis and fault tolerant control method for the control systems in closed-loop affected by unknown inputs or disturbances. The fault diagnostic scheme is based on the disturbance-decoupled state estimation using a 2-stage state observer for state, actuator bias and sensor bias. The estimated bias show the occurrence time, location and type of the faults directly. The estimated state is used for state feedback to achieve fault tolerant control against the faults. Simulation results show that the method has definite fault tolerant ability against actuator and sensor faults, moreover, the faults can be detected on-line, isolated and estimated simultaneously.

• Sleep Medicine and Psychophysiology
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• v.10 no.1
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• pp.5-11
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• 2003

Sleep apnea syndrome is a common clinical disorder characterized by intermittent cessation of airflow at nose and mouth during sleep. The clinical significance of this syndrome is that it is one of the most common causes of excessive daytime sleepiness. It can also cause neuropsychiatric, cardiovascular, and cerebrovascular complications. The standard for diagnosis of sleep apnea syndrome is nocturnal polysomnography. Because polysomnography is a time-consuming and expensive test, many efforts have been made to replace polysomnography with a simpler system of monitoring, but no method has yet been approved as a definitive investigation method. The goals of treatment for this syndrome are to eliminate excessive daytime sleepiness and to reduce the risk of possible cardiovascular complications. Continuous positive airway pressure is the most definite and widely accepted treatment for achieving these goals. Other treatments such as surgical treatment, oral appliances, and behavioral therapy may be useful for selected patients who are mildly affected.

• The Korean Journal of Cytopathology
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• v.1 no.2
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• pp.179-184
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• 1990

Bone metastasis of hepatocellular carcinoma appears to be peculiar when clinical manifestation of liver disease is not apparent, and initial diagnosis of metastatic hepatocellular carcinoma by fine needle aspiration cytology is rarely obtained. We experienced a case of 45-year-old man with metastatic hepatocellular carcinoma in the sacrum, which was diagnosed by fine needle aspiration cytology. The intrahepatic mass, measuring 1.2 cm in diameter and kept unchanged in size for two years, was never proved to be hepatocellular carcinoma histopathologically. The aspirated neoplastic cells were mostly in sheets, showing abundant acidophilic cytoplasm and large, round, centrally located nuclei with single, prominent acidophilic mucleoli. In the cell block section, diagnosis of metastatic well-differentiated hepatocellular carcinoma was made without difficulty, and definite trabecular fashion with sinusoidal endothelial cell lining was found.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.6 no.1
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• pp.40-51
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• 2006

Purpose: A personal computer-based system was developed for automated metabolic profiling of organic aciduria and aminoacidopathy by gas chromatography-mass spectrometry and data interpretation for the diagnosis of metabolic disorders Methods: For automatic data profiling and interpretation, we compiled retention time, two target ions and their intensity ratio for 77 organic acids and 13 amino acids metabolites. Metabolites above the cut-off values were flagged as abnormal compounds. The data interpretation was a based on combination of flagged metabolites. Diagnostic or index metabolites were categorized into three groups, "and", "or" and "NO" compiled for each disorder to improve the specificity of the diagnosis. Groups "and" and "or" comprised essential and optional compounds, respectively, to reach a specific diagnosis. Group "NO" comprised metabolites that must be absent to make a definite diagnosis. We tested this system by analyzing patients with confirmed Propionic aciduria and others. Results: In all cases, the diagnostic metabolites were identified and correct diagnosis was founded to be made among the possible disease suggested by the system. Conclusion: The study showed that the developed method could be the method of choices in rapid, sensitive and simultaneous screening for organic aciduria and amino acidopathy with this simplified automated system.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.11 no.sup1
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• pp.72-82
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• 2008

Wilson disease (WD) is an autosomal recessive disorder of copper metabolism that results in accumulation of copper primarily in the liver, the brain and the cornea. Mutations in the WD gene, ATP7B cause failure of copper excretion from hepatocyte into bile and a defective synthesis of ceruloplasmin. More than 370 mutations are now recognized, scattering throughout the ATP7B gene. Since WD has protean clinical presentations, awareness of WD in clinical practice is important for the early diagnosis and prevention of accumulated copper toxicity. None of the laboratory parameters alone allows a definite diagnosis of WD. There are numerous pitfalls in the diagnosis of WD. Low serum ceruloplasmin concentrations, increased 24 hour urinary copper excretion, increased hepatic copper concentrations and the presence of Kayser-Fleischer rings in the cornea are major diagnostic points. A combination of any two of these 4 laboratory findings is strong support for a diagnosis of WD. Molecular methods are now being used to aid diagnosis. Molecular genetic testing has confirmed the diagnosis in individuals in whom the diagnosis is not clearly established biochemically and clinically. Siblings should be screened for WD once an index case has been diagnosed. Discrimination of heterozygotes from asymptomatic patients is essential to avoid inappropriate lifelong therapy for heterozygotes. Genetic testing, either by haplotype analysis or by mutation analysis, is the only reliable tool for differentiating heterozygote carriers from affected asymptomatic patients. Currently, genetic testing is of limited value in the primary diagnosis. However, genetic testing will soon play an essential role in diagnosing WD as rapid advancement of biomedical technology will allow more rapid, easier and less expensive mutation detection.

• The Korean Journal of Pain
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• v.6 no.2
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• pp.224-230
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• 1993

Most patients who have suffered from pain and muscle weakness on femoral nerve distributing area show no definite pathologic finding on X-ray or laboratory examinations. Therefore proper diagnosis is difficult to determine for the proper treatment of the symptoms. Based on my clinical experiences and anatomical studies, I have found most of these symptoms are a result of femoral nerve compression on trigger point of psoas major muscle. Accordingly, releasing the compression of femoral nerve by Laser stimulation and local anesthetic injection to the identified trigger point of psoas major muscle was found to be an effective treatment for femoral neuralgic pain.

• The Korean Journal of Cytopathology
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• v.7 no.2
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• pp.218-224
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• 1996

We describe two cases of metastatic Wilms' tumor in the lung with emphasis on the cytologic features of specimens obtained by needle aspiration. One of them was extrarenal Wilms' tumor. The findings were correlated with the histopathologic features of the primary lesion. Cellular components in the fine needle aspiration cytology (FNAC) slides included blastemal, epithelial, stromal and inflammatory cells with immature tubular differentiation and rosette formation. Recognition of these cellular components in FNAC smears help in establishing FNAC diagnosis of Wilms' tumor. The blastemal cells were represented by small to medium sized cells with scanty cytoplasm having ill-defined borders and round to slightly oval nuclei with evenly dispersed chromatin and small marginated nucleoli. They were seen in our two cases. The differential diagnosis includes neuroblastoma, malignant lymphoma, malignant rhabdoid tumor, clear cell sarcoma, Ewing's sarcoma and embryonal rhabdomyosarcoma. In conclusion, making a definite cytologic diagnosis of metastatic Wilms' tumor may be possible by light and electron microscopy and immunohistochemical staining. The above findings may contribute to the diagnosis of FNAC of metastatic Wilms' tumor.

• Korean Journal of Cleft Lip And Palate
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• v.15 no.2
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• pp.83-88
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• 2012

Macroglossia is a relatively uncommon condition that occurs in pediatric patients for several reasons and contributes to variety of functional problems. Most of macroglossia arises from tissue overgrowth and tongue muscle hypertrophy. There are no definite guideline in prenatal management or diagnosis in this conditions. However, macroglossia is often associated with syndrome or congenital disease, prenatal diagnosis is important in early detection. There are difficulty in measurement of tongue size, and standardization. Macroglossia can be risky in some aspects, such as airway obstruction. In this review, the author suggest prenatal ultrasonographic findings of macroglossia, investigate differential diagnosis of conditions associated with macroglossia, and management in clinical situation. Macroglossia, when present, can cause a number of functional and aesthetic problems for individuals. Treatment of this problem is challenging and controversial.

• Journal of Korean Foot and Ankle Society
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• v.11 no.1
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• pp.104-106
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• 2007

Pseudoaneurysm of the anterior tibial artery is a rare cause of pain and swelling of the lower leg and the foot following minor sports injuries. When there is no definite musculoskeletal cause of pain, it is important to consider pseudoaneurysm. Early diagnosis and management are essential for the successful outcome. MRI and angiogram are useful for early diagnosis. We report a case of pseudoaneurysm of the anterior tibial artery following minor sports injury. The patient experienced complete relief of the symptoms after resection of the pseudoaneurysm.

• Annals of Clinical Neurophysiology
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• v.10 no.1
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• pp.33-37
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• 2008

Diabetic polyneuropathy (DPN) is the most common form of diabetic neuropathy, and causes a significant morbidity with an impact on the quality of life in the patients with diabetes. Since DPN frequently induces foot deformity and ulceration, which finally leads to foot amputation, the early detection and treatment is very important for the prevention of a permanent structural change. In the early stage of DPN, the diagnostic methods which can evaluate the function or structure of small nerve fibers should be employed because small nerve fibers are first involved in the course of DPN. However, the nerve conduction study cannot reflect the function of the small nerve fibers, and thus, has a definite limitation in the early diagnosis of DPN. For the early detection of DPN, electrodiagnostic data should be interpreted on a clinical context, along with the careful evaluation of the small nerve fiber functions using the tests such as the analysis of intraepidermal nerve fiber density.