• Journal of Chest Surgery
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• 제10권1호
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• pp.113-117
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• 1977

The tetralogy of Fallot is one of the most frequent and serious congenital cardiac malformation accompanied cyanosis. For relief of cyanosis, the Waterston operation is a successful, palliative procedure in infant & young child under age of five with obstructive lesions of the right: side of the heart who require a systemic-pulmonary arterial shunt for survival. A patient, aged 3 and weighing 13 kg., who had been cyanotic since one month after birth,. was admitted to the University of Severance Hospital under a diagnosis of tetralogy of Fallot, The side to side anastomosis between the right pulmonary artery & the ascending aorta was performed in March 1976. The anastomotic channel was made only 4 ram. in diameter, thereafter massive unilateral pulmonary congestion on the side of the anastomosis developed shortly after operation. And the. patient died of congestive heart failure within a hour. And so the purpose of this report is describe the immediate & late effect of systemic-pulmonary shunt for T.O.F. with review of literatures.

• Journal of Korean Neurosurgical Society
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• 제37권6호
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• pp.432-435
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• 2005

Objective: This study was performed to evaluate the usefulness of early operation in children with traumatic subdural hygroma. Methods: The subjects were nine patients (Glasgow coma scale (GCS) score was below 10 and age was below 10 years old) who developed subdural hygroma after trauma between January 2000 to December 2002. Subduroperitoneal shunt was performed in one group and not performed in the other group. We analyzed the GCS score on admission and at 1 year after operation. Overall clinical results were evaluated retrospectively. Results: Patients who underwent operation exhibited higher GCS scores at 1 year after trauma compared to those in the patients who were treated by conservative therapy(p<0.05). Conclusion: The early operation could be an effective treatment to children with subdural hygroma who showed delayed improvement of consciousness and to patients with hygroma that didn't decrease or was above moderate amount.

• Journal of Korean Neurosurgical Society
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• 제52권1호
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• pp.58-61
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• 2012

Various surgical procedures for the treatment of post-traumatic syringomyelia have been introduced recently, but most surgical strategies have been unreliable. We introduce the concept and technique of a new shunting procedure, syringo-subarachnoid-peritoneal shunt. A 54-year-old patient presented to our hospital with a progressive impairment of motion and position sense on the right side. Sixteen years before this admission, he had been treated by decompressive laminectomy for a burst fracture of L1. On his recent admission, magnetic resonance (MR) imaging studies of the whole spine revealed the presence of a huge syrinx extending from the medulla to the L1 vertebral level. We performed a syringo-subarachnoid-peritoneal shunt, including insertion of a T-tube into the syrinx, subarachnoid space and peritoneal cavity. Clinical manifestations and radiological findings improved after the operation. The syringo-subarachnoid-peritoneal shunt has several advantages. First, fluid can communicate freely between the syrinx, the subarachnoid space, and the peritoneal cavity. Secondly, we can prevent shunt catheter from migrating because dural anchoring of the T-tube is easy. Finally, we can perform shunt revision easily, because only one arm of the T-tube is inserted into the intraspinal syringx cavity. We think that this procedure is the most beneficial method among the various shunting procedures.

• 대한전자공학회논문지SD
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• 제44권10호
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• pp.33-37
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• 2007

본 논문에서는 vertical shunt symmetric inductor를 이용하여 CMOS LNA의 설계에 있어서 회로의 면적을 줄이는 설계기술 및 구현에 관한 내용을 제시하고자 한다. 본 연구에 있어서 vertical shunt symmetric inductor는 LNA의 입력단과 출력단을 3GHz로 정합하기 위해서 사용되었다. 이렇게 구현된 보다 면적에 있어서 효율적인 증폭기를 0.18um digital logic공정으로 구현되었다. 본 논문에서는 일반적으로 LNA에서 사용하고 있는 inductor를 이용하는 경우와, vertical shunt symmetric inductor를 이용하여 LNA를 설계하는 경우에 대한 부분을 비교하였고, 최종적으로 면적에 효율적인 회로설계 기술을 제시하고자 한다.

• Journal of Chest Surgery
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• 제25권4호
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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 Korean Neurosurgical Society
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• 제29권7호
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• pp.968-972
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• 2000

Post-shunting subdural hemorrhages are usually small and self-limited, and they can be recognized on the routine post-operative CT examinations. However, delayed subdural bleeding may occur without any clinical symptoms or signs. Thus the hematoma remains undetected, and it can be increased in size and sometimes become calcified with time. We experienced a case of 15-year-old male with a large calcified subdural hematoma who had undergone shunt operation 10 years previously. With pertinent review of the literatures, we discuss the possible mechanism of calcification and the proper way of treatment in calcified chronic subdural hematoma.

• Journal of Chest Surgery
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• 제30권4호
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• pp.378-382
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• 1997

쇄골하동맥과 폐동맥 사이 에 PTFE 인조혈관으로 연결하는 변형 Blalock-Taussig 문합술은 청색증 심 기 형 환자에 탁월한 고식적 보존 술식으로서 신생 아에서도 적절한 폐혈류를 공급하는 방법이다. 신생아 에서 변형 Blalock-Taussig문합술의 효과와 위험 요소를 평가하기 위하여 본 교실에서는 1991년 12월부 터 1996년 2월까지 본 동아대병원 흉부외과에서 수술받은 21명의 신생아를 대상으로후향성 조사를하 여 수술 사망율, 단락 개존율, 술후 폐동맥 이상 유무 등을 분석하였다. 수술시 환아들의 연령은 1일에서 30일 사이로 평균 11.7일이었다. 몸무게는 2.4 kg에서 4.5 kg으로 평균 3.1 kg이었다. 주된 병변은 활롯씨 사증후군이 11 례, 폐동맥협착이 있는 단일심 형태가 10례였다. 술 전 Prostaglandin E1 의 지속적 투여가 필요한 환아는 13 명이었다. 술전 평균 말초산소포화도 30. ImmHg 에서 술후 46.2mmHg 로 상승되었다. 단락술은 좌측 개흉술로 11 례가 시행되었고 나머지 10 례는 우측 개흉술로 시행되었다. 사용된 PTFE 인조혈관의 크기는 15 례에서 직경 5 mm를, 나머지 6 례에서 직경 4 mmHg를 사용하였다. 조기 단락 폐쇄율은9.5%(2례)로이\ulcorner은다조기 사망하였다. 통 계학적 검증(Fisher's exact test)에 의하여 위 험 요소를 분석한 결과 몸무개 2.6 kg 이하(p=0.021), 폐동맥 직경 3 mm 이하(p=0.008), 인조혈관 직경 4 mm사용한 경우(p=0.021)등이 조기 단락 실패 및 사망의 위험 요소로 나타났다. 생존한 19 명을 평균 11.3 개월간 추적 조사한 결과 단락 폐쇄는 없었고 이중 10 명에서 심도자 및 폐혈관 조영술을 시행한 결과 폐동맥의 변형은 관찰되지 않았다. 이상의 결과 변형 Blalock-Taussig단락술은 신생아에서 청색증 심기형의 보존 요법으로 비교적 안전하 게 사용할 수 있는 술식으로 사료된다.

• Journal of Power Electronics
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• 제13권2호
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• pp.232-242
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• 2013

To obtain phase currents information in AC drives, shunt sensing technology is known to show great performance in cost-effectiveness and therefore it is widely used in low cost applications. However, shunt sensing methods are unable to acquire phase currents in certain operation conditions. This paper deals with the derivation of the boundary conditions for phase current reconstruction in three-shunt sensing inverters and proposes a voltage injection method to expand the measurable areas. As the boundary conditions are deeply dependent on the switching patterns, they are typically analyzed on the voltage vector plane for space vector pulse width modulation (SVPWM) and discontinuous pulse width modulation (DPWM). In the proposed method, the voltage injection and its compensation are conducted within one sampling period. This guarantees fast current reconstruction and the injected voltage is decided so as to minimize the current ripple. In addition to the voltage injection method, a sampling point shifting method is also introduced to improve the boundary conditions. Simulation and experimental results are presented to verify the boundary condition derivation and the effectiveness of the proposed voltage injection method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 F
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• pp.2249-2251
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• 1997

Total 144 quadrupole magnets are installed in PLS. The magnets are connected in series with groups of two or 24. Each group is powered by a high-precision constant-current DC power supply. For the purpose of the beam based alignment of beam position monitors in the PLS, it is necessary to adjust the current of each quadrupole independently. To achieve this, a high current shunt regulator is designed. It can shunt a maximum 50 A of the quadrupole magnet current. The shunt regulator is programmable and the current amplitude can be varied linearly with a 12-bit resolution. Power transistors are used in the current shunt regulator. The operation of transistors is in linear region. The RS232C protocol is used for remote control and status report of the shunt regulator to the main control centre of the PLS. Preliminary result indicates that the calibration accuracy of the beam position monitor can be achievable in less than $10{\mu}m$.

• 한국정밀공학회지
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• 제24권10호
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• pp.123-130
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• 2007

Hypoplastic left heart syndrome is currently the most lethal cardiac malformation of the newborn infant. Survival following a Norwood operation depends on the balance between systemic and pulmonary blood flow, which is highly dependent on the fluid dynamics through the interposition shunt between the two circulations. The purpose of this study is an optimization of the systemic-to-pulmonary artery shunt. In this study, We used computational fluid dynamic(CFD) models to determine the velocity profile in a systemic-to-pulmonary artery shunt and suggested a simplified method of calculating the blood flow in the shunt based on Ultrasound systems. We analyzed the flow characteristic variations and oscillatory shear index(OSI) due to the anastomosis angle and shunt diameter changing. Four different CFD models were constructed with the shunt sizes ranging from 3 to 3.5mm. The angle between the brachiocephalic trunk(BCT) and the shunt were $30^{\circ}$ and $45^{\circ}$, respectively. When the diameter is 3.0 mm, the oscillatory shear index decreased by 1.2% at $30^{\circ}$ as opposed to at $45^{\circ}$. When the diameter is 3.5 mm, it increased by 18% more at $30^{\circ}$ as opposed to at $45^{\circ}$. When the joint angle is $30^{\circ}$ and the diameter is 3.0 mm, the oscillatory shear index decreased by 4.1% in comparison with the 3.5 mm diameter. When the angle is $45^{\circ}$ and the diameter is 3.0 mm, the index increased by 14.6% in comparison with the 3.5 mm diameter.