• Journal of the Korea Society of Computer and Information
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• v.18 no.8
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• pp.131-139
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• 2013

In this paper, we look into previous research in relation to each processing step for ECG diagnosis and propose detection and classification method of arrhythmia using rhythm features of ECG signal. Rhythm features for distribution of rhythm and heartbeat such as identity, regularity, etc. are extracted in feature extraction, and rhythm type is classified using rule-base constructed in advance for features of rhythm section in rhythm classification. Experimental results for all of rhythm types in the MIT-BIH arrhythmia database show detection performance of 100% for arrhythmia with only normal rhythm rule and applicability of classification for rhythm types with arrhythmia rhythm rules.

• Journal of Chest Surgery
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• v.38 no.3 s.248
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• pp.221-228
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• 2005

Reduction aortoplasty has been advocated for dilatation of the ascending aorta associated with aortic valve disease in older, high-risk patients. We report our results with modification of reduction aortoplasty and aortic valve replacement. Material and Method: Between July 2001 and December 2002, 14 consecutive patients who underwent modification of reduction aortoplasty, suture plication technique without excision of the dilated aortic wall, were reviewed. The mean age was 63.7$\pm$6.7 (50 to 75) years. Ten patients had congenital bicuspid aortic valve, Twelve patients had severe aortic valve stenosis and 6 had regurgitation of grade III$\~$IV. The diameter of the ascending aorta was measured before and immediately after surgery and 6 and 12 months postoperatively using echocardiography or computed tomography. Follow-up was complete in an average of 14.7$\~$5.4 (7 to 24) months. Result: There were no early postoperative deaths and no bleeding complications. Reduction aortoplasty with suture plication technique decreased the diameter of ascending aorta from 49.4$\pm$3.5 mm preoperatively to 33.2$\pm$3.4 mm postoperatively (p <0.001). During follow-up, there were no late deaths and no aneurysm recurrence on the ascending aorta. Conclusion: Suture plication technique of reduction aortoplasty without excision of the dilated aortic wall offers good early and short-term results in older, high-risk patients with dilatation of the ascending aorta associated with aortic valve disease. Surgical long-term results of our technique should be evaluated in further studies.

• Journal of Chest Surgery
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• v.41 no.6
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• pp.687-694
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• 2008

Background: Although aortic valve sclerosis causes no significant hemodynamic alterations, it is associated with an increased risk of cardiovascular death and myocardial infarction. However, the role of ${\beta}_3$ integrin in aortic valve sclerosis remains unclear. Material and Method: Twenty male New Zealand rabbits were divided into two groups. Group 1 rabbits (n=10) received a normal chow diet, while group 2 (n=10) rabbits received a diet containing 1% cholesterol for 12 weeks. After the rabbits were euthanized, their aortic valves and ascending aortas were excised for analysis. Result: Total serum cholesterol ($2,148.3{\pm}1,012.5\;mg/dL$ versus $53.7{\pm}31.8\;mg/dL$, p<0.05), triglyceride ($240.4{\pm}218.3\;mg/dL$ versus $31.6{\pm}6.4\;mg/dL$, p<0.05), and low density lipoprotein (LDL)-cholesterol($2,065.3{\pm}960.9\;mg/dL$ versus $29.1{\pm}30.9\;mg/dL$, p<0.05) levels were significantly higher in the cholesterol diet group compared with the normal diet group. Myofibroblasts and macrophages were more highly expressed in the aortic valve leaflets of rabbits in the cholesterol diet group than of those in the normal diet group. A real-time polymerase chain reaction revealed decreased ${\beta}_3$ integrin mRNA levels in the hypercholesterolemic aortic valves and aortas. Conclusion: The present study shows that hypercholesterolemia induces aortic valve sclerosis. These findings suggest that alterations in ${\beta}_3$ integrin may playa role in the development of aortic valve sclerosis.

• Journal of Chest Surgery
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• v.30 no.12
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• pp.1197-1204
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• 1997

Between April 1981 and June 1996, 65 patients had aortic root replacement at our institution. Disease entities were pure aortic annuloectasia in 31 patients(47.7%), Stanford type A aortic dissection with annuloectasia in 8(43.1%), atherosclerotic aneurysm with aortic regurgitation in 4(6.2%), and paravalvular leakage after aortic valve replacement in 2(3.1 %). 34 patients(52.3%) had the clinical stigmata of the Marfan syndrome. The operative procedures were Bentall operation in 61 patients(93.8%); 3 of conventional procedure and 58 of Cabrol's modification, aortic valve-sparing operation in 2(3.1 %), and root replacement with homograft in 2(3.1%). Hospital deaths occurred in 3 patients(4.8%) because of uncontrolled bleeding(1) and bypass weaning failure due to low cardiac output(2), and all had emergency operation with Cabrol's procedure. Postoperative complications developed in 19(29.2%) patients and most of them were transient. Surviving 62 patients have been followed up to cumulative total 315.0 patient-years(mean 60.2 $\pm$42.4 months). Late deaths occurred in 7 patients(11.3%), aneurysmal changes of remaining aorta were detected in 12 patients(19.4%). Actuarial survival rate at 10 years was 72.0 $\pm$ 9.7%, and the subsequent aortic operation-free rate at 10 years was 68.0$\pm$ 8.9% In a multivariate analysis, Marfan syndrome, emergency operation, preoperative dissection, combined arch replacement, and total circulatory arrest emerged as significant risk factors for hospital death or subsequent aortic operation. Over 60 years of age was the only risk factor for late death. Our 16 years'cummulative experience shows that aortic root replacement, mainly by means of Cabrol's procedure, can be applied successfully to variety of aortic root disease. However, long-term follow up will be needed to determine the late result of aortic valve-saving operation and root replacement with homograft. When dissection is present or the distal native aorta is diseased in'Marfan patients, close follow-up is necessary because of the subsequent aneurysmal change of remaining aorta.

• Analytical Science and Technology
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• v.9 no.3
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• pp.310-319
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• 1996

According to the element analysis of Korean Quartz Porphyry, the ignition loss related to porosity was 7.03, 3.36, 2.09 and 0.73% in the order of Suanbo, Yeachen, Angang and Kyongsan. Extraction of minerals in deionized water and elimination effect of heavy metals in water by Quartz Porphyry were examined. When the Quartz Porphyry of the Suanbo, Yeachen of 0.5~2.0% concentration and the Quartz Porphyry of the Angang of 1.5% concentration were immersed and stirred in deionized water for 3 hours at 180rpm, various minerals concentration of the all stirred water were suitable for potable water. But Quartz Porphyry of the Yeachen was not suitable for potable water because of excess extraction of iron. The elimination rate of lead in single solution was 99% by Quartz Porphyry of the Suanbo, Yeachen and Angang of 3% concentration, Cadmium by Quartz Porphyry of the Suanbo of 7% concentration was eliminated about 98% in 1 hour. The copper was significantly eliminated in Quartz Porphyry of low concentration. Especially in Quartz Porphyry of Angang at 0.4% concentration, the rate of ion exchange was 99% in 4 hours. But elimination effect of arsenic in water by Korean Quartz Porphyry was very low.

• Journal of Yeungnam Medical Science
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• v.3 no.1
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• pp.279-285
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• 1986

Carbamazepine is a derivative of iminostilbene with carbamyl group and related chemically to the tricyclic antidepressants. Carbamazepine has been introduced for treatment of trigeminal neuralgia. Recently it is used as an antiepileptic agent such as diphenylhydantoin. Antiepileptic drugs are known to affect experimentally induced cardiac arrhythmia and are now widely used clinically for treatment of ventricular tachyarrhythmias, particularly those produced by digitalis intoxication. Steiner et al.(1970) reported that carbamazepine was found to be very effective in converting ventricular tachycardia due to digitalis toxicity to normal sinus rhythm. Clinically bradycardia, complete heart block, ventricular standstill and Adams-stokes attack were reported in the course of carbamazepine treatment. The purpose of this study was to investigate the effects of carbamazepine on the ouabain-induced arrhythmia in vivo. The rabbits of either sex, weighing from 1.6 to 3.2kg were anesthesized by urethane. After the trachea was cannulated, the rabbits were ventilated with room air using a respirator. Drugs were given into polyethylene cannula in the femoral vein. Blood pressure were recorded by physiograph via pressure tranducer connected with the cannula in the femoral artery. EKG were recorded by Physiograph via electrode implanted in both fore leg and left hind leg. The results are summarized as follows; 1. Arrhythmia was induced by continuous infusion of ouabain.($64{\pm}8.8{\mu}g/kg$) 2. Single administration of ouabain($64{\mu}g/kg$) induced arrhythmia which was persisted for 7-8 min. 3. Ouabain induced arrhythmia was restored to normal sinus rhythm by administration of carbamazepine.(The more dosage, the less frequent and the longer duration) 4. Severe bradycardia, A-V block, atrial fibrillation were seen on the EKG after injection of carbamazepine alone. By the above results, it may be concluded that carbamazepine inhibits the ouabain-induced arrhythmia by dose-dependent.

• Journal of the Korean Society of Radiology
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• v.84 no.6
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• pp.1324-1336
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• 2023

Purpose This study aimed to compare the diagnostic performance of cardiac CT and transthoracic echocardiogram (TTE) depending on the degree of valvular calcification and bicuspid aortic valve (BAV) subtype. Materials and Methods This retrospective study included 266 consecutive patients (106 with BAV and 160 with tricuspid aortic valve) who underwent cardiac CT and TTE before aortic valve replacement. Cardiac CT was used to evaluate the morphology of the aortic valve, and a calcium scoring scan was used to quantify valve calcium. The aortic valves were classified into fused and two-sinus types. The diagnostic accuracy of cardiac CT and TTE was calculated using a reference standard for intraoperative inspection. Results CT demonstrated significantly higher sensitivity, negative predictive value, and accuracy than TTE in detecting BAV (p < 0.001, p < 0.001, and p = 0.003, respectively). The TTE sensitivity tended to decrease as valvular calcification increased. The error rate of TTE for CT was 10.9% for the twosinus type of BAV and 28.3% for the fused type (p = 0.044). Conclusion Cardiac CT had a higher diagnostic performance in detecting BAV than TTE and may help diagnose BAV, particularly in patients with severe valvular calcification.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.4
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• pp.323-329
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• 2013

This study attempts to simulate the structure of a woody leaf netted venation system by using topology optimization techniques. Based on finite element method (FEM) analysis of an incompressible fluid, a topology optimal design is applied to those woody leaf netted venation models. To solve the transverse shear locking problem of a thin plate caused by the Mindlin-Reissner plate model where a leaf netted venation is assumed to be a thin plate, a P1-nonconforming element and selective reduced integration are employed. Topology optimal design is applied to multiple physical domains. Combined with the Darcy-Stokes flow problems and extended to the optimal design of fluid channels, the multiple physical models of the flow system are analyzed and venation patterns of leafs are simulated. The calculated optimal shapes are compared with the natural shapes of woody leaf venation patterns. This interdisciplinary approach may improve our understanding of the leaf venation system.

• Journal of Chest Surgery
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• v.30 no.2
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• pp.200-204
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• 1997

This is a report of a successful management of a patient with infective endocarditis involving native aortic valve, mitral valve, tricuspid valve, and Interventric lar septum. A 16 year-old patient who underwent VSD patch closure, and aortic valvuloplasty at the age of 1 1 years showed Intractable congestive heart failure during antibiotics treatment for infective endocarditis. Operative findings revealed that there were large defect along the previous patch, aortic regurgitation with multiple perforations and vegetations, mitral regurgitation with vegetation, aortic paraannular abscess, interventricular myocardial abscess, and tricuspid regurgitation with perforations and vegetations. We reconstructed the interventricular defect with Dacron patch extending to the aortic valve annulus after radical debridement of all infected or devitalized tissues, and could implant aortic valve by anchoring to the reconstructed Dacron patch. Mitral valve was replaced and tricuspid valve was repaired with patient's own pericardium. The patient was discharged after antibiotics treatment for 6 weeks and in good condition without any sequelae for 12 months.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.4
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• pp.948-953
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• 2015

Recently, the finger vein recognition based on NIR and CCD sensor camera is investigating the technology to identify a personal using by biometrics. The performance difference of finger vein recognition is generated according to methods that are to separate the vein and background from noises such as finger thickness, ambient light, skin temperature, etc. To improve these problems, in this study, we are proposing the methods for rotation, ROI extraction, and enhancement of vein image captured by NIR LED and CCD camera, and were evaluated performances of these methods. In results of the experiment, the accuracy of the proposed method for image rotation and ROI extraction was 99.8%. And the proposed filter bank method in vein enhancement has shown better performance than retinex algorithm. The proposed method for results of these experimentations will provide better recognition rate when applied to the preprocessing of finger vein recognition.