• Proceedings of the KTCVS Conference
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• 1998.04a
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• pp.60-61
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• 1998

• Proceedings of the KTCVS Conference
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• 1996.10a
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• pp.110-110
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• 1996

• Proceedings of the KTCVS Conference
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• 1996.10a
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• pp.56-56
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• 1996

• Journal of Chest Surgery
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• v.33 no.11
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• pp.906-909
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• 2000

심폐바이패스를 사용하지 않고 심장박동 상태에서 시행하는 관상동맥 우회수술은 심 비대와 좌심실 기능저하가 동반된 협증심 환자에서는 심장 뒤쪽에 위치한 관상동맥에 대한 접근이 어렵고 수술 중 혈역학적으로 불안정하여 시행하기에 어려운 경우가 많다. 우심실 보조장치 하의 심장박동 상태에서 시행하는 관상동맥 우회수술은 대동맥의 삽관을 피하고, 심폐바이패스의 합병증을 줄일 수 있으며, 심장 뒤쪽에 위치한 혈관의 문합시에도 안정된 혈역학적 상태를 유지 할 수 있어 고위험군 환자에게 도움을 줄 수 있다. 좌심실 기능저하와 심 비대가 동반된 환자에서 우심실 보조장치 하의 심장박동 상태에서 시행한 관상동맥 우회수술을 2례 시행하여 좋은 결과를 얻어 보고하고자 한다.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.4
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• pp.83-90
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• 1998

In this paper, we present neural network for control of Left Ventricular Assist Device(LVAD) system with a pneumatically driven mock circulation system. Beat rate(BR), Systole-Diastole Rate(SDR) and flow rate are collected as the main variables of the LVAD system. System modeling is completed using the neural network with input variables(BR, SBR, their derivatives, actual flow) and output variable(actual flow). It is necessary to apply high perfomance control techniques, since the LVAD system represent nonlinear and time-varing characteristics. 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 and control the LVAD system by PID controller and neural network feedforward controller. The ability and effectiveness of controlling the LVAD system using the proposed algorithm will be demonstrated by experiment.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.150-155
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• 1997

In this paper,we present neural network for control of Left Ventricular Assist Device(LVAD)system with a pneumatically driven mock cirulation system. It is necessary to apply high perfomance control techniques, since the LVAD system represent nonlinear and time-varing characteristics. Fortunately, the neural network can be applied to control of a nonliner dynamic system by learning capability. In this study,we identify the LVAD system with neural network and control the LVAD system by PID controller and neural network feedforward controller. The ability and effectiveness of controlling the LVAD system using the proposed algorithm will be demonstrated by computer simulation and experiment.

• Journal of Chest Surgery
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• v.33 no.3
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• pp.252-256
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• 2000

There have been few reports documenting the outcome of arterial swich operations(ASO) in selected patients with transposition of great arteries(TGA) and with left ventricular outflow tract obstruction(LVOTO). In the case of TGA with LVOTO, if the atrial septal defect(ASD) is large and the ventricular septal defect(VSD) is restricive, this deprives the left ventricle(LV) of approporiate preload and could lead to underdevelopment of the ventircular mass and lead poor LV performance after the arterial switch operation, dspite a high pressure in the LV preoperatively. Because an increase in the systolic ventricular pressure is not necessarily paralleled by an increase in ventricular mass, which is also essential for optimal ventricular performance after the operation. We report here a case of rapid LV training after ASO in TGA with unprepared LV (because of large ASD and restrictive VSD) despite a high pressure in the LV(due to LVOTO) preoperatively.

• Journal of Chest Surgery
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• v.36 no.8
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• pp.602-605
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• 2003

A patch design using bovine pericardial patch for aortic enlargement in the Nowood procedure has been introduced to avoid problems related to homograft availability. We report 2 successful cases of Norwood procedure with home-made bovine pericardial patch. The first case was a 23-day-old (2.2 kg) patient with multi-level left ven-tricular outflow tract obstruction with ductal-dependent systemic circulation. The other case was a 9-day-old (3 kg) patient with hypoplastic lefi heart syndrome. This technique was relatively easy to perform, reproducible and quite effective like homograft patch.

• Journal of Chest Surgery
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• v.30 no.4
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• pp.419-422
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• 1997

In small children with left ventricular outflow tract obstruction, a few methods of surgical treatment could be considrred. The pulmonary autogrart provides a promising options for aortic valve replacement as part of the aortoventriculoplasty procedure in children. We report a successfully treated congenital aortic stcnoinsufricicncy with severe left ventricular dysfunction in an early infant with the aortoventriculoplasty using thc pulmonary autograft (the Ross-Konno procedure).

• Journal of Chest Surgery
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• v.36 no.4
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• pp.277-279
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• 2003

A 15 year-old boy was referred to us because of mild dyspnea on exertion and incidentally found heart murmur. On echocardiography, a mass involving mainly interventricular septum and causing left ventricular outflow tract obstruction was detected. Cardiac catheterization demonstrated a transaortic pressure gradient of 20 mmHg. Partial excision of the septal mass was performed via aortotomy under cardiopulmonary bypass. The pathologic diagnosis revealed myocardial hamartoma. The lesion was mainly composed of mature, severely hypertrophic myocytes and intervening fibrosis. During the 5 year of follow-up after the surgery, no evidence of arrhythmia or tumor recurrence was documented.