• Journal of Korean Neurosurgical Society
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• 제44권3호
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• pp.170-173
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• 2008

Ventriculoperitoneal (VP) shunt is commonly and effectively used to treat hydrocephalus. Intracardiac migration of the shunt catheter is a rare complication. A 68-year-old woman underwent ventriculoperitoneal shunting for hydrocephalus secondary to subarachnoid hemorrhage due to anterior communicating artery aneurysm rupture. Two weeks after the shunt surgery, she had suffered from the abdominal pain. Plain chest x-rays, computed tomography, and echocardiography revealed the distal catheter which was in the right ventricle of the heart. We tried to remove the catheter through the internal jugular vein by fluoroscopic guidance. But, the distal catheter was kinked and knotted; therefore, we failed to withdraw the catheter. After then, we punctured the right femoral vein and pulled down the multi-knotted shunt catheter to the femoral vein using the snare catheter. Finally, we removed the knotted distal catheter via the femoral vein and a new distal catheter was placed into the peritoneal cavity. We report a case in which the distal catheter of the VP shunt migrated into the heart via the internal jugular vein. We emphasize the importance of careful and proper placement of the distal catheter during the tunneling procedure to prevent life-threatening complications.

• 대한방사선기술학회지:방사선기술과학
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• 제20권1호
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• pp.21-27
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• 1997

Total laryngectomy has become an usual treatment for any advanced carcinoma of the laynx, but most patients who have undergone total laryngectomy have shown permanant disability in voice production. I compared the first three formant frequencies estimated from MRI to those measured directly from speech data of the T-E patients and the normal. It was to estimate the accuracy of MRI and to compare the vocal tract shape of the normal to T-E patients. The obtained results were as follows : 1. The middle sagittle section of the MRI represents vocal tract well during pnonation. The vocal tract shape of the T-E shunt patients are lack of pharyngeal space and superior space of the glottis. 2. The length of the normal subject's vocal tract is 17 cm. For the T-E shunt patients, the length from lip to shunt opening is 17.5 cm in case 1, and 18.5 cm in case 2. That of the true resonante chamber is 13 cm and 13.5 cm for each case respectively. 3. T-E shunt patients phonated strained voice. The intensity of the higher formant frequency decreased especially in /o/, /u/. 4. The vocal tract is shortened during the phonation by T-E shunt patients. In case of /e/ and /i/, front cavities are constricted while back cavities are shortened. 5. The pseudoglottis of the T-E shunt patients is located at $14{\sim}15\;cm$ below from lips.

• 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.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.296-297
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• 2005

We have investigated the quench performance of shunt reactors in the parallel connection of resistive type superconducting fault current limiter (SFCL) components based on YBCO films. To increase voltage rating, components are connected in series and to increase current level, they are connected in parallel. This method has cauesd the unbalanced quench between each components. To improve the problem, we have compared the quench properties between the current limiting components without and with shunt reactors connected in parallel. To improve the quench performance, across individual SFCL components connected the shunt reactor in parallel. The components with shunt reactors successfully produced simultaneous quench, resulting from the bypass of the fault current in the direction of the shunt reactor.

• 대한핵의학회지
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• 제21권2호
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• pp.199-205
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• 1987

The fact there are increase of intrapulmonary arterioveneous shunt amount in the liver cirrhosis patient has been known since 1950. And the method of shunt amount calculation by radionuclide method using $^{99m}Tc-MAA$ was introduced in the middle of 1970. We measured intrapulmonary shunt amount by means of perfusion lung scan using $^{99m}Tc-MAA$ in the various type of liver diseases especially in chronic liver diseases and acute liver disease. The results were as followed. 1) The amount of arteriovenous intrapulmonary shunt in the total case of liver disease was $9.3{\pm}3.9%$, and that of in the control group was $4.6{\pm}2.1%$. 2) The amount of arteriovenous intrapulmonary shunt in the chronic liver disease was $10.8{\pm}4.4%$, and that of in the acute liver disease was $7.2{\pm}2.8%$. We observed significant differences between normal control group and liver disease group, and between chronic liver disease group and acute liver disease group in the amount of shunt by the nucleolide method.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.403-406
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• 2004

In this paper, the design of damped structures associated with the piezoelectric shunt circuits is undertaken and it is applied to optical disk drive (O.D.D) main base in order to reduce unwanted vibration. In order to design effective piezoelectric structure, the admittance of the structure is introduced as the performance index of the piezoelectric shunt system. And the admittance offset of the shunt performance is theoretically investigated. It is also presented that the admittance can be calculated by commercial finite elements program. To verify the admittance calculated by F.E.M, admittance measurement is performed by impedance analyzer. In this verifying process, the validity of the finite element admittance analysis is found. As a practical approach, to reduce the vibration of the O.D.D. main base, piezoelectric shunt system is designed using the proposed admittance analysis and shunt effect is evaluated at all prescribed frequencies.

• Journal of Korean Neurosurgical Society
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• 제62권1호
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• pp.123-129
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• 2019

Objective : Ventriculoperitoneal (VP) shunt surgery is a common and effective treatment for hydrocephalus and cerebrospinal fluid disorders. Infection remains a major cause of morbidity and mortality after a VP shunt. There is evidence that a deep skin flora microbiome may have a role to play in post-operative infections. In this technical note, we present a skin preparation technique that addresses the issue of the skin flora beyond the initial incision. Methods : The patient is initially prepped, as standard, with. a single layer of 2% CHG+70% isopropyl alcohol. The novel stage is the 'double incision' whereby an initial superficial incision receives a further application of povidone-iodine prior to completing the full depth incision. Results : Of the 84 shunts inserted using the double-incision method (September 2015 to September 2016), only one developed a shunt infection. Conclusion : The double incision approach to skin preparation is a unique operative stage in VP shunt surgery that may have a role to play in reducing acute shunt infection.

• Pediatric Infection and Vaccine
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• 제19권3호
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• pp.141-148
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• 2012

목 적 : 뇌실-복강 단락 수술은 수두증이 있는 소아 환자에서 중요한 치료 방법 중 하나이다. 뇌실-복강 단락에서 단락 감염은 중요한 합병증이며 수술의 예후를 결정하는 중요한 요인이다. 이 연구는 소아 환자에서의 뇌실-복강 단락 감염의 역학적 특성과 임상 증상, 치료와 예후를 파악하고 진단 및 치료에 도움이 되고자 하였다. 방 법 : 1995년 4월부터 2010년 6월까지 뇌실-복강 단락 수술을 시행 받은 18세 이하의 환자를 대상으로 하였으며 후향적으로 의무 기록을 분석하였다. 결 과 : 총 190명(여자 82명, 남자 107명)의 환자에서 327건의 뇌실-복강 단락 수술을 시행하였다. 중위 연령은 2.4세이며(0.02-17.9세) 뇌실-복강 단락 수술의 가장 흔한 원인은 악성 뇌종양이었다. 수술 1건 당 감염률은 6.7% (22/327건), 환자 1명 당 감염률은 9.5% (18/190명)이며 100건의 수술-년 당 감염은 0.45건 이었다. 가장 흔한 원인 균은 coagulase-negative staphylococcus (7건) 이며 methicillin resistant Staphylococcus aureus에 의한 감염은 1건 이었다. 10건의 감염에서 vancomycin과 beta-lactam antibiotics (cephalosporin or carbapenem)의 복합 정주 치료를 시행하였으며 7건의 감염에서 vancomycin 단독 정주 치료를 시행하였다. 치료 기간의 중앙값은 26일(7-58일)이었으며 수술적 치료는 18건에서 시행하였다(18/22건, 81.8%). 결 론 : 본 연구는 단일 기관에서 15년 동안의 뇌실-복강 단락 감염의 역학을 요약한 연구로 소아 환자에서의 뇌실-복강 단락 감염의 역학적 정보는 적절한 치료를 시행하는데 큰 도움이 될 것이다. 향후 단락 감염의 발생과 관련한 위험 인자에 대한 추가적인 연구가 필요할 것으로 사료된다.

• Journal of Korean Neurosurgical Society
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• 제30권sup1호
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• pp.79-84
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• 2001

목 적 : 뇌실 복강간 단락술 부전의 기여인자를 조사 및 분석하여 뇌실 복강간 단락술의 합병증 및 재수술의 가능성을 줄이는 데에 목적이 있다. 대상 및 방법 : 1995년 1월부터 1998년 12월까지 본원에서 뇌실 복강간 단락술을 시행 받은 237명의 수두증 환자를 후향적 방법으로 고찰하여 뇌실 복강간 단락 부전의 기여인자 및 단락기 생존율을 통계학적으로 분석하였다. 결 과 : 수두증의 원인은 종양, 출혈, 감염, 선천성 기형, 정상 뇌압 수두증, 외상 등이었다. 68명의 환자에서 109회의 재수술이 이루어졌다. 재수술의 이유는 폐색, 근위부 카세타의 위치이상, 감염 등이었다. 단락기 생존율은 1년, 2년, 3년에 각각 77.1%, 75.4%, 74.1%이었다. 10세 이하의 환자에서 재수술의 빈도가 통계학적으로 의의 있게 높았다. 그리고 수두증의 원인에 따라서 통계학적으로 의의 있게 재수술의 빈도 차이가 있었다. 결 론 : 대부분의 뇌실 복강간 단락 부전은 술후 1년내에 발생하였다. 환자의 나이 및 수두증의 원인이 뇌실 복 강간 단락 부전의 주요 기여인자였다.

• Journal of Korean Neurosurgical Society
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• 제64권2호
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• pp.297-308
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• 2021

Objective : Shunt infection is a common complication while treating hydrocephalus. The antibiotic-impregnated shunt catheter (AISC) was designed to reduce shunt infection rate. A meta-analysis was conducted to study the effectiveness of AISCs in reduction of shunt infection in terms of age, follow-up time and high-risk patient population. Methods : This study reviewed literature from three databases including PubMed, EMBASE, and Cochrane Library (from 2000 to March 2019). Clinical studies from controlled trials for shunt operation were included in this analysis. A subgroup analysis was performed based on the patient's age, follow-up time and high-risk population. The fixed effect in RevMan 5.3 software (Cochrane Collaboration) was used for this meta-analysis. Results : This study included 19 controlled clinical trials including 10105 operations. The analysis demonstrated that AISC could reduce the infection rate in shunt surgery compared to standard shunt catheter (non-AISC) from 8.13% to 4.09% (odds ratio [OR], 0.48; 95% confidence interval [CI], 0.40-0.58; p=0.01; I2=46%). Subgroup analysis of different age groups showed that AISC had significant antimicrobial effects in all three groups (adult, infant, and adolescent). Follow-up time analysis showed that AISC was effective in preventing early shunt infections (within 6 months after implant). AISC is more effective in high-risk population (OR, 0.24;95% CI, 0.14-0.40; p=0.60; I2=0%) than in general patient population. Conclusion : The results of meta-analysis indicated that AISC is an effective method for reducing shunt infection. We recommend that AISC should be considered for use in infants and high-risk groups. For adult patients, the choice for AISC could be determined based on the treatment cost.