• Journal of Biomedical Engineering Research
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• v.19 no.1
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• pp.39-46
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• 1998

In this paper, we present a neural network identification and a control of highly complicated nonlinear left ventricular assist device(LVAD) system with a pneumatically driven mock circulation system. Generally, the LVAD system needs to compensate for nonlinearities. It is necessary to apply high performance control techniques. Fortunately, the neural network can be applied to control of a nonlinear dynamic system by learning capability. In this study, we identify the LVAD system with neural network identification(NNI). Once the NNI has learned the dynamic model of the LVAD system, the other network, called neural network controller(NNC), is designed for a control of the LVAD system. The ability and effectiveness of identifying and controlling the LVAD system using the proposed algorithm will be demonstrated by computer simulation.

• Journal of Biomedical Engineering Research
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• v.27 no.2
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• pp.47-52
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• 2006

The purpose of this study was to predict successful defibrillation in ventricular fibrillation using parameters extracted by wave analysis method and neuro-fuzzy. Total 15 dogs were tested for predicting successful defibrillation. Feature parameters were extracted for return of spontaneous circulation (ROSC) and non-ROSC by wave analysis method, and these parameters are an irregularity factor, spectral moments, mean power of level-crossing spectrum, and mean of alpha-significant value. Additionally, two parameters by analyzing method of frequency were extracted into a mean of power spectrum and a mean frequency. Then extracted parameters were analyzed in which parameters result to have high performance of discriminating ROSC and non-ROSC by a statistical method of t-test. The average of sensitivity and specificity were 62.5% and 75.0%, respectively. The average of positive predictive factor and negative predictive factor were 61.2% and 75.8%, respectively.

• Journal of Veterinary Clinics
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• v.33 no.3
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• pp.160-164
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• 2016

A Turkish angora cat with a one-week history of anorexia and vomiting was diagnosed with hepatic lipidosis. During hospitalization and treatment, the cat suddenly showed respiratory-related clinical signs, including coughing and dyspnea, 13 days after initial diagnosis. Due to the poor response to treatment, the patient was euthanized at the owner's request. A postmortem histopathologic examination of the cat's heart showed dilation and wall thinning of the right atrium and ventricle, with fibrofatty infiltration corresponding to an arrhythmogenic right ventricular cardiomyopathy (ARVC). This is a case report of ARVC concurrent with hepatic lipidosis in a cat; both diseases are related to disturbances in lipid metabolism.

• Journal of Chest Surgery
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• v.36 no.10
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• pp.766-771
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• 2003

It is known that low birth weight is a risk factor for poor outcome in cardiac surgery for many cardiac defects. Truncus arteriosus is a rare congenital anomaly that has an unfavorable natural course. We report a successful surgical correction of truncus arteriosus in an 13-day-old premature infant with body weight of 1.5 kg and gestational age of 32 weeks. We used autologous untreated pericardial conduit without valve in right ventricular outflow reconstruction. The patients remains in good condition with normal body weight (50 percentile) and wide right ventricular outflow tract 20 months after the operation.

• Journal of Chest Surgery
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• v.35 no.8
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• pp.590-593
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• 2002

Absent pulmonary valve syndrome with intact ventricular septum(APVS with IVS) is a rare congenital anomaly. The severe form of this syndrome, characterized by severe respiratory distress presented soon after birth, has been attributed to the compression of the airways caused by aneurysmal dilatation of pulmonary artery. Several operative treatments such as pulmonary valve insertion, or reductive angioplasty of pulmonary artery have been applied. We present a 3-day-old male who showed improvement after PDA ligation, reductive angioplasty of pulmonary artery, pulmonary valve reconstruction, and ASD closure.

• Journal of Chest Surgery
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• v.34 no.11
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• pp.854-857
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• 2001

Double-outlet left ventricle(DOLV) is a rare congenital cardiac malformation, defined as the origin of both the aorta and the pulmonary artery being entirely or predominantly above the morphologically left ventricle, which is difficult to diagnose accurately. A 3-year old male was admitted for cyanosis and dyspnea. At the age of 2 months, he had undergone pulmonary artery banding and coarctoplasty. He was diagnosed as DOLV with subaortic ventricular septal defect(VSD). Biventricular repair was achieved by patch closure of VSD, primary closure of PFO, and pulmonary trunk translocation from left ventricle to right ventricle. The advantages of this procedure using native tissue for right ventricular outflow tract reconstruction are growth potential and preserved valve function, which contribute to a decreased likelihood of reoperation related to the right ventricular dysfunction related to pulmonary insufficiency.

• Journal of Chest Surgery
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• v.27 no.9
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• pp.746-751
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• 1994

We reviewed our entire experience of 44 consecutive patients undergoing the arterial switch operation [ASO] for transposition of the great arteries [TGA] since March 1985.There were 28 patients with simple TGA[group I] and 16 with associated ventricular septal defect[VSD] [Group II] There were five hospital deaths[11.4%, 5/44], two related to single right coronary artery anatomy. There have been no late deaths. For group I hospital mortality was 14.3%[4/28], and for group II this was 6.25%[1/16]. Mean follow-up was 3.3 years[range 1 month to 8 years] and was completed for all patients. Actuarial survival at 7 years for hospital survivors was 85 $\pm$ 3.2 % in group I and 94 $\pm$ 3.5% in groupII. One patient has mild asymptomatic left ventricular outflow tract obstruction, and five patients [12.8 %,5/ 39] have right ventricular outflow tract gradients[RVOTO] exceeding 25 mmHg; only one patient has required reoperation for RVOTO. Mild neoaortic regurgitation is present in one patient. All survivors are currently in NYHA class I without medicalion, and all are in sinus rhythm. The ASO is associated with low operative risk and excellent medium-term outcome in most subsets of patients undergoing this operation. With more experience, improved results can be expected also in those patients currently at higher risk.

• Journal of Chest Surgery
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• v.25 no.4
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• pp.406-411
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• 1992

Thirty-four patients were received bidirectional cavopulmonary shunt[BCPS] from Aug. 1989 to Apr. 1991 at Sejong General Hospital, Puchon, Korea. Their ages were from 43 days to 21 years old with 19 cases of infant, 10 from 1 to 5 years old and 5 cases above 6 years old. Their diagnoses were as follows: 13 cases with uni-ventricular heart, 9 tricuspid atresia, 6 double outlet of right ventricle, 4 pulmonary atresia with intact ventricular septum, and 2 transposition of great arteries with pulmonary stenosis. Among them, 10 patients had received other palliative operations before. The BCPS operations were performed under the cardiopulmonary bypass and 10 patients who had bilateral superior vena cava received bilateral BCPS. Other associated procedures were 9 cases of takedown of Blalock-Taussig shunt, 3 pulmonary artery angioplasty, 1 unifocalization, 1 repair of total anomalous pulmonary venous return, 1 Damus procedure, 1 relief of sub-aortic stenosis, 1 right ventricular outflow tract reconstruction and one case of tricuspid valve obliteration. There were 3 operative deaths[8.8%] and two late deaths. The remainders show good postoperative state and their oxygen saturation was increased significantly. Conclusively, the bidirectional cavopulmonary shunt is very effective and safe palliative or pre-Fontan stage operation for the many complex congenital anomalies with low pulmonary blood flow especially for the patients who have the risk of Fontan repair.

• Journal of The Korean Society of Clinical Toxicology
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• v.5 no.1
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• pp.67-70
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• 2007

Aconitum is an extremely dangerous plant that contains various toxic diterpenoid alkaloids, primarily concentrated in the roots. We report a case of acute intoxication of a 60-year-old man admitted to our emergency department after ingestion of a large amount of homemade aconitine decoction. At presentation about one hour after intake, the patient was unconscious and electrocardiographic analysis showed a ventricular tachycardia/fibrillation. Several times defibrillation was applied and antiarrhythmic agents were administered, but the patient still exhibited a refractory ventricular fibrillation and failed to return to spontaneous circulation. Sustained cardiopulmonary resuscitation finally produced a pulsatile cardiac rhythm at two hours after intake. The patient was discharged from our hospital on day 8. The authors stress that clinicians must be aware of the possible occurrence of life-threatening ventricular arrhythmia in cases of aconitine intoxication and be prepared to persist with prolonged CPR as necessary.

• Journal of Chest Surgery
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• v.33 no.5
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• pp.385-390
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• 2000

Background: To review the experience that used both ventricular assist device(VAD) and extracorporeal membrane oxygenation(ECMO) for children with congential heart disease requiring postcardiotomy mechanical circulatory support. Material and Method: Between March 1993 and May 1995, we applied mechanical assist device using centrifugal pump to the 16 patients who failed to be weaned from cardiopulmonary bypass(n=15) or had been in cardiogenic shock in intensive care unit(n=1). The diagnosis were all congenital heart diseases and the ages of patients ranged from 20 days to 10 years (mean age=2.5$\pm$3.5 years). Result: The methods of mechanical circulatory support were LVAD(n=13), BVAD (n=1), and ECMO(n=2). The mean assist times were 54.0$\pm$23.7 hours. Post-assist complications were in orders: bleeding, acute renal failure, ventricular failure, respiratory failure, infection, and neurologic complication. It was possible for 9 patients(56.3%) to be weaned from assist device and 5 patients(31.3%) were discharged from hospital. There was no statistical significant between hospital discharged group and undischarged group by age, body weight, cardiopulmonary bypass time, and assist time. Conclusion: The ventricular assist device is an effective modality in salvaging the patient who failed to be weaned from cardiopulmonary bypass, but multiple factors must be considered for improving the results of mechanical circulatory support ; such as patient selection, optimal time of starting the assist device, and prevention and management of the complications.