열수축을 하는 필라멘트 와인딩 복합재료 관의 설계

정태은,신효철 대한기계학회 1993 대한기계학회논문집 Vol.17 No.10

Thermal deformations and stresses due to temperature changes are the serious problems in cryogenic structures such as the torque tube in a superconducting generator, In this paper, the equations of thermal expansion coefficients expressed only by material properties and winding angles are derived for the filament wound composite tubes. The experimental results of thermal contraction of CFRP tubes are compared with those from theoretical approach. Composite tubes with optimally regulated thermal expansion coefficient are designed on the basis of the study for the torque tube in the superconducting generator with temperature distributions varying from 300K to 4.2 K. The filament winding angle of composites resisting thermal stresses properly is sought by the finite element method using layered shell elements. The results show that the composite tubes designed for the requirements in cryogenic environments can effectively cope with the thermal stress problem.

難治性인 尿路感染症에 대한 Bactrim의 臨床成績

鄭太銀 우석대학교 의과대학 1971 우석의대잡지 Vol.8 No.1

In spite of highly developed antibiotics and chemotherapeutics, genitourinary tract infection still remaines as troublesome subjects for urologists. New bactericidal agent, Bactrim (trimethoprim-sulfamethoxazole) was administered in 18 cases of genitourinary tract infection, which were resistant to mast antibiotics and following results were obtained. 1) Among 9 cases of non-gonococcal urethritis, 5 cases were cured completely, 4 cases were improved. 2) Among 7 cases of chronic prostatitis, one case was cured but only mild improvement were noted in remaining 6 cases. 3) 2 cases of pyelonephritis showed improvement in both clinically and bacteriologically.

이면성 심초음파도로 구한 대동맥판륜부 크기와 실제 치환된 판막크기와의 비교연구

정태은 대한흉부심장혈관외과학회 1988 Journal of Chest Surgery (J Chest Surg) Vol.21 No.6

Calcium channel blockers may prevent myocardial injury during cardioplegia and reperfusion. This study was done to evaluate the effects of diltiazem cardioplegia on myocardial protection during ischemic arrest and recovery of myocardial function after reperfusion. Four formulations of crystalloid cardioplegic solutions, GIK solution[group I, n=12], diltiazem[lug/ml GIK] in GIK solution[group II, n=7], ],diltiazem[2ug/ml GIK] in GIK solution[group III, n=6] and diltiazem[4ug/ml GIK] in GIK solution[group IV, n=6] were compared in isolated working rat heart subjected to a long period [2 hours] of hypothermic arrest with multi-dose infusion. Diltiazem cardioplegia[group II, III and IV]was found to be superior in nearly all aspects. Diltiazem cardioplegia showed faster recovery of regular rhythm and lower incidence of ventricular fibrillation than group I did. In comparing mechanical function in all experimental hearts, the mean postischemic recoveries of aortic flow, cardiac output, peak aortic pressure, stroke volume and stroke work[expressed as a percentage of its preischemic control] were significantly greater in group II, III and IV[diltiazem cardioplegia] than in group I. The infused amount of cardioplegic solution was more increased by the addition of diltiazem to GI K solution. [p < 0.01] Creatine kinase leakage tended to be lower in hearts receiving diltiazem cardioplegia, especially in group III and IV[p<0.05] than in those receiving GIK solution only[group I]. Diltiazem cardioplegia results in the increased flow of cardioplegic solution and the decreased ischemic injury of myocardium during ischemic arrest and the improved recovery of myocardial function after reperfusion, and a dose-response relation must be established before clinical use.

腎盂結石 除去術의 새로운 手術方法에 關한 硏究

鄭太銀 고려대학교 의과대학 1979 고려대학교 의과대학 잡지 Vol.16 No.3

심실중격결손 봉합이 우심실 수축기 시간 간격에 미치는 영향

정태은,이영환 대한흉부심장혈관외과학회 1999 Journal of Chest Surgery (J Chest Surg) Vol.32 No.2

배경: 심실 중격 결손으로 인한 좌우 단락은 폐정맥 환류의 증가로 인한 좌심방 및 좌심실의 비대를 유발할 뿐만 아니라, 폐동맥압이나 폐혈관 저항을 증가 시키므로 우심실의 후부하에 간접적인 영향을 미친다. 따라서 폐동맥 고혈압을 추정하는 하나의 지표로 사용되고 있는 우심실 수축기 시간 간격의 변화를 추적하여 우심실 부하의 변화 정도를 확인하고, 이를 심실 중격 결손 환아의 술 후 관리 지침에 반영하고자 본 연구를 시도하였다. 대상 및 방법: 1995년 1월부터 1996년 12월까지 영남대학교 의과대학 부속병원에서 다른 심기형이나 증후군을 동반하지 않은 단순형 심실중격결손으로 진단받고, 봉합술을 전후하여 어떠한 전신 질환이나 합병증을 동반하지 않은 12명을 대상으로, M-mode 및Doppler 심초음파도를 이용하여 봉합술 전, 술후 3개월 그리고 술후 6개월에서 1년 사이(평균9.5$\pm$1.8개월)의 심박수, 좌심방/대동맥 내경비(LA/Ao), 우심실 박출 전기(right ventricular pre-ejection period : RVPEP)와 우심실 박출 기간(right ventricular ejection time : RVET)을 구하여 그 비(RVPEP/RVET)의 변화를 알아 보았다. 결과:심박수는 술후 실시한 두 차례의 검사에서 유의한 감소를 보였다(137.1$\pm$13.7 vs 114.4$\pm$21.1 and 104.1$\pm$10.2, p<0.01). 좌심방/대동맥 내경비는 술후 실시한 두 차례의 검사에서 유의한 감소를 보였다(1.71$\pm$0.32 vs 1.47$\pm$0.33 and 1.390.23, p<0.05). RVPEP/RVET는 술후 두 차례의 검사에서 유의한 감소를 보였으며(0.38$\pm$0.09 vs 0.32$\pm$0.08 and 0.29$\pm$0.09, p<0.01) 각각을 심박수로 교정한 RVPEP/RVET는 술후 3개월에는 유의한 감소를 보이지 않았으나 술후 6개월에서 1년 사이에는 유의한 감소를 보였다(0.32$\pm$0.03 vs 0.30$\pm$0.05 and 0.28$\pm$0.06, p<0.05). 결론: 심실중격결손으로 인한 좌우 단락은 폐동맥압의 증가를 유발하여 우심실의 후부하에 영향을 미친다는 사실을 우심실 수축기 시간 간격의 변화를 통하여 간접적으로 확인할 수 있었으며, 우심실의 과부하 상태가 수술적 교정 직후부터 정상으로 회복되기 시작하나, 단순형 심실중격결손이라 할지라도 술후 6개월 이상까지 지속되는 것을 확인할 수 있었다. Background: Ventricular septal defect(VSD) that causes pulmonary hypertension increase right ventricular workload. Echocardiographic assessment of right ventricular systolic time interval (RVSTI) has been used to predict pulmonary artery pressure in various cardiopulmonary diseases. This study was undertaken in infants with simple VSD to observe the alteration of the right ventricular workload through the changes of RVSTI after repair of VSD. Material and Method: We evaluated heart rate, the ratio of the left atrium/aortic root diameter (LA/Ao), right ventricular pre-ejection period(RVPEP), right ventricular ejection time(RVET), and its ratio(RVPEP/RVET) as a predictor of right ventricular workload in 12 children with simple VSD. These were measured three times at the preoperative period, at the 3 month and between 6 month and 1 year(average 9.5${\pm}$1.8month) after repair of VSD by M-mode & Doppler echocardiograph from the pulmonic valve echogram. Result: Heart rate was decreased significantly after repair(137.1${\pm}$13.7 vs 114.4${\pm}$21.1 and 104.1${\pm}$10.2, p<0.01). LA/Ao ratio was decreased significantly after repair(1.71${\pm}$0.32 vs 1.47${\pm}$0.33 and 1.39${\pm}$0.23, p<0.05). RVPEP/RVET were decreased after repair (0.38${\pm}$0.09 vs 0.32${\pm}$0.08 and 0.29${\pm}$0.09, p<0.01). Heart rate corrected RVPEP/RVET were significantly decreased only after 6 months(0.32${\pm}$0.03 vs 0.30${\pm}$0.05 and 0.28${\pm}$0.06, p<0.05). Conclusion: We found elevated right ventricular workload was progressively decreased until more than 6 months after repair and the RVSTI may serve a useful guide in postoperative care for children with VSD.

영아기 심실중격결손 봉합술의 임상적 고찰

정태은,이장훈,이동협,이정철,한승세,김세연,지대림 영남대학교 의과대학 2002 Yeungnam University Journal of Medicine Vol.19 No.2

Background: Simple ventricular septal defect(VSD) is the most common congenital heart disease. Although closure of VSD is currently associated with a relatively low risk, experience with younger and smaller infants has been variably less satisfactory. We assessed the results of surgical closure of VSD in infant. Materials and Methods: Between 1996 and 2000, 45 non-restrictive VSD patients underwent patch repair and retrospective analysis was done. Patients were divided into two groups based on weight: group I infants weighed 5kg or less(n=16), and group II infants weighed more than 5kg(n=29). Both groups had similar variation in sex, VSD location, aortic cross clamp time and total bypass time. But combined diseases (ASD, PDA, MR) were more in group I. We closed VSD with patch and used simple continuous suture method in all patients. Results: There were no operative mortality, no reoperation for hemodynamically significant residual shunt and no surgically induced complete heart block. As a complication, pneumonia(group I: 2 cases, group II: 2 cases), transient seizure(group II: 2), wound infection(group I:, group II:1), urinary tract infection(group I: 1) and chylopericardium(group I: 1) developed, and there was no significant difference between two groups(p>0.05). Conclusion: Early primary closure with simple continuous suture method was applicable in all patients with non-restrictive VSD without any serious complications.

충격후 잔류압축강도시험에 의한 복합재료 적층판의 설계

정태은,박경하,류정주 대한기계학회 1995 대한기계학회논문집 Vol.19 No.9

The compressive tests under impact conditions were performed to establish a design guide for impact damage tolerance. The composition of layup was selected for the real cases of composite aircraft structure. The energy level of visible of visible damage threshold was determined as 7 Joules. It was found that the normalized bending stiffnesses in the direction of closely fixed boundary affected the area of damage. Graphite/epoxy used in the tests exhibited 60% reduction in compression strength at the energy level of visible damage threshold. Wet-conditioned specimens represented 9% reduction in residual compressive strength in comparison with room temperature ambient specimens. In this study, a design factor of 2.1 was proposed for the low velocity impact damage.

허혈성 심질환의 치료에서 관동맥우회술의 임상적 고찰

정태은 영남대학교 의과대학 1996 Yeungnam University Journal of Medicine Vol.13 No.2

허혈성 심질환의 치료로서 시행되는 관동맥 우회술은 최근 국내에서도 보편적으로 시행되고 있는데 1992년부터 1996까지의 영남대학교 의과대학 흉부외과학교실에서 시행한 63례의 관동맥 우회술을 대상으로 수술성적 및 술전 위험인자들이 술 후 합병증에 미치는 영향을 조사하여 다음과 같은 결론을 얻었다. 환자의 성별 및 연령을 보면 총63례의 환자 중 남자가 44례, 여자가 19례였으며 연령분포는 36세에서 71세까지 평균 58.3±8.6세 였으며 50대와 60대에서 대부분을 차지하였다 원위문합수는 환자당 평균 3.5개의 원위부 문합을 하였으며 수술사망은 6례였으며 술후 합병증으로 부정맥이 7례, 창상감염이 5례, 술후 출혈이 4례, 술중 및 술후 심근경색이 4례, 뇌졸증이 4례, 그리고 위장관 및 신장 합병증이 5례에서 발생하였다. 술후 합병증 발생의 요소를 분석 해 본 결과 술전 관동맥 질환 발생의 위험인자 중 흡연환자에서 합병증의 발생빈도가 유의하게 증가하였으며(p<0.05) 술전 위험인자로 정맥으로 Nitroglycerin의 투여가 필요했던 경우와 대동맥 차단시간이 2시간 이상인 경우에 경우 합병증의 발생빈도가 유의하게 증가하였으며(p<0.05) 특히 65세 이상의 고령환자의 경우 수술사망율이 유의하게 증가하였다(p<0.05). 이상의 결과로 흡연, 65세 이상의 고령, 술전 정맥으로 Nitrogloycerin의 투여가 필요했던 경우 그리고 이식혈관의 수가 많아 대동맥 차단시간이 긴 경우 술중 및 술후 관리에 더욱 섬세한 주의가 필요함을 알 수 있었다. From August 1992 to July 1996, 63 consecutive patients underwent coronary artery bypass surgery. The mean age of these patient was 57 years(range form 30 to 71years). There were 44 men and 19 women. Preoperative 12 patients had stable angina pectoris and 23 patients were unstable angina pectoris. 8 patients had previous myocardial infarctation history and emergency or urgent myocardial revascularization were performed in 9 cases. In the risk factors of coronary atherosclerosis, 25 patients(40%) were hypercholesterolemia, 38 patients(60%) have smoking history and 19 patients(30%) have hypertension history. In the patterns of disease, 9 patients were single vessel disease, 18 patients were two vessele disease and 33 patients were three vessel disease. We performed total 284 distal anastomosis(mean 3.5 anastomosis per patient) and performed one case of ascending aorta graft interposition, two cases of mitral valve replacement, one case of aortic valve replacement, one case of ventricular septal defect repair and one case of atrial septal defect repair and the mean aortic cross clamp time was 115.3 minutes. The common complications were arrhythmia(7cases), wound infection(5cases), perioperative myocardial infarction(4cases), reoperation for bleeding control(4cases) and stroke(4cases). There were six hospital deaths due to low cardiac output syndrome, ventricular arrhythmia and respiratory failure. In the evaluation of operative risk factors, preoperative intravenous nitroglycerin requirement and prolonged aortic cross clamp time(>2hours) were found to be predective factor of morbidity and old age(>65years) was found to be predective factor of mortality.

관상동맥 우회술 환자의 술 후 합병증 예견에 대한 BNP의 역할

정태은,이동협,이장훈,도형동,한승세 대한흉부외과학회 2008 Journal of Chest Surgery (J Chest Surg) Vol.41 No.1

Background: Circulating levels of brain natriuretic peptide (BNP) provide prognostic information for patients with heart failure. The aim of our study was to investigate whether preoperative and postoperative BNP levels could predict postoperative complications and outcomes in patients after coronary artery bypass graft (CABG). Material and Method: Data was collected prospectively on 30 patients (M/F=19/11, age 60.0±9.6 years) undergoing conventional CABG during a 1-year period beginning on January 1, 2005. Patients underwent off-pump CABG, and combined surgery was excluded. The BNP assay was performed preoperatively, immediate postoperatively at the intensive care unit (ICU), and 1, 3, 5, and 7days postoperatively. Result: Preoperative BNP levels significantly correlated with preoperative echocardiographic ejection fraction and an ICU stay of 5 days or more (r= 0.4, p=0.028; r=0.39, p=0.031, respectively). A preoperative BNP cut-off value above 263 pg/mL demonstrated high specificity (90.5%) for predicting postoperative complications using the receiver operating characteristics curves. Preoperative and postoperative (7 days) BNP levels were different depending on the abscence (mean BNP=99±23 pg/mL vs. 296±74 pg/mL, p<0.05) and presence (mean BNP=212±29 pg/mL vs. 408±23 pg/mL, p<0.01). Conclusion: Preoperative BNP levels >263 pg/mL predict postoperative complications in patients receivingCABG.

腎盂結石 除去術의 새로운 手術方法에 關한 硏究

鄭太銀,金世景 고려대학교 의과대학 1979 고려대 의대 잡지 Vol.16 No.3

Fifty cases of kidney pelvic stone were admitted to the Department of Urology, Korea University Medical College during the period from Jan. 1968 to Dec. 1977 for the surgical removal of stone. The age of patient ranged from 6 to 54 and 38 cases were male and 12 cases were female. A new technique of pyelolithotomy was performed with incision made over the lower portion of renal pelvis as shown in Fig. 3 through the extraperitoneal subcostal arcuate anterolateral kidney approach with semilateral position and the following results were obtained. 1. In all fifty cases kidney pelvic stones were not spherica1 but flat in shape, and their removal were easily performed through the incision made over the lower portion of the renal pelvises. 2. Anatomically, very few distribution of the blood vessels were found in the lower area of the kidney pelvis and the maniplaotin for removal of the stone was easier than that of other area of the kidney pelvis. 3. During the manipulation of stone removal damages of the renal parenchyma or mucosal damages in the kidney pelvis if any could be kept at a minimum. 4. When the kidney was eqosed by extraperitoneal subcostal arcuate antero-lateral approach, the exposure of the lower portion of the hilum and the area of the kidney pelvis was easily made by mobilization and retraction of the kidney lower pole to the lateral side and this technique was found to be very convenient in removal of most kidney pelvic stones.