• Journal of Chest Surgery
• /
• v.17 no.4
• /
• pp.678-686
• /
• 1984

Between Jan. 1978, and Dec. 1983, a total and consecutive 117 patients have undergone cardiac valve replacement using various artificial tissue valve. Out of 117 patients, single valve surgery was 78 consisted of MVR 74, AVR 3 and AVR & supracoronary ascending aorta replacement 1. Multiple valve surgery was 39 cases consisted of MVR+TAP 20, MVR+AVR 13 and so on. Early death with 30 days after operation was 12 cases [early mortality 10.3%] and causes of death were cardiac origin 5, technical problem 4, and others 3. The 105 early survivors were followed-up for a total of 190.5 years over a period of 2 to 64 months [Mean\ulcornerD:21.9\ulcorner4.9 months]. During follow-up, 7 cases died [late mortality:6.7%]. The rate of thromboembolism was 2.1% episodes per patient-year and bleeding due to anticoagulant was 3.1% episodes per patient-year and valve failure was 1.6% episodes per patient-year. Actuarial analysis of late results indicated an expected survival rate at 5 years of 84.6% for patients with single valve surgery and 82.1% for patient with multiple valve surgery and overall was 83.8%. Symptomatically, 86.7% of patients were in NYHA class I or II at the end of follow-up.

• Proceedings of the KIEE Conference
• /
• 1999.11c
• /
• pp.670-673
• /
• 1999

In this paper, we present a robust motion controller based on Adaptive-Fuzzy technique is proposed that multifunctional vehicle(MVR) for two DOF mobile robot can perform detailed inspection of physical conditions of sewage pipes as well as can effectively repair the damaged portions of the inner walls. The main difficulties in controlling this multifunctional robot vehicles lie in the fact that vehicles usually have three degrees of freedom in position and orientation in spite of having only two degrees of freedom for motion control in tracking mode. Decomposition of error between the reference posture and the current posture makes control of speed and steering possible. The Gyro compass part and Inclonometer of the robot is configured in order to realize position of robot. The proposed Adaptive-Fuzzy motion controller has two main characteristics: The one guarantees that the MVR follows the reference trajectory; the other one compensates the dynamics of the MVR. Simulation results are provided to validate the proposed controller. Experiments have been used to verify the effectiveness and robustness of the motion controller.

• Journal of Chest Surgery
• /
• v.28 no.12
• /
• pp.1122-1131
• /
• 1995

One hundred eighty-eight patients[August.23,1988,through July.30,1994 underwent aortic[AVR , mitral[MVR , or double [DVR valve replacement with the St.Jude Medical prosthesis. The author analyzed 100 patients with valvular heart disease,who underwent valve replacement with the St.Jude Medical prothesis from 1990 to 1994, at Hanyang University hospital Cardiovascular department. Information on volume and functional change of the heart chamber can be obtained by cardiac echocardiography and cartheterization. Out of 100 patients, 40 patients were male[40% and 60 patients were female [60% . Age ranged from 13 years to 68 years, with mean age of 42.6 years. Mean height was 160.3cm and mean body weight was 54.9Kg. According to NYHA functional classification, class III is most frequent and 60 patients could be classfied under it. MVR [involved Redo MVR was performed in 40 patients, AVR [involved Redo AVR was performed in 18 patients, and DVR [involved Redo DVR was performed in 42 patients. Warfarin [Coumadin anticoagulation was recommended for all patients. Life long warfarin anticoagulation was necessary to all patients who underwent valve replacement with St.Jude Medical prosthesis. Ideal prothrombin time was maintained about 30% during warfarinization. There were no case of mechanical failure. It followed a comparison of echocardiography before and after valve replacement at Hanyang University hospital [30 patients and a preoperative evaluation of cardiac catheterization and angiography [64 patients . The St.Jude Medical cardiac valve is a viable alternative in the surgical therapy of valvular heart disease.

• Journal of Chest Surgery
• /
• v.27 no.8
• /
• pp.664-668
• /
• 1994

A total of 217 patients underwent single mitral valve replacement [MVR] with the St. Jude Medical valve between September 1984 and the end of 1992. There were 86 males and 131 females with a mean age of 34.6 $\pm$ 14.4 years[range 5 months-61 years]. A previous valve replacement had been performed in 46 patients [21.2 %]. An early mortality rate was 7.4 % [5.2 % in primary MVR; and 15.2 %in re-replacement MVR]. Early survivors of 201 patients were followed up for a total of 934.5 patient-years[mean 4.7 $\pm$ 2.1years]. A late mortality rate was 2.5 % or 0.54%/patient-year. The linearized rates of thromboembolism, valve thrombosis and anticoagulation-related bleeding were 1.301 %, 0.214 % and 0.428 %/patient-year, respectively. The actuarial survival including operative mortality was 89.9 % $\pm$ 2.1% at postoperative 10 years. The freedom from thromboemolism was 91.3 %$\pm$ 2.5% and the actuarial estimate of incidence free from late deaths and all complications were 80.9 % $\pm$ 3.8 % at 10 years. There were no mechanical failures. In summary, the St. Jude Medical prosthesis performed satisfactorily with an acceptable rate of late complications.

• Journal of Chest Surgery
• /
• v.55 no.1
• /
• pp.69-76
• /
• 2022

Background: While the use of bioprosthetic valves for mitral valve replacement (MVR) is increasing, very few studies have compared bovine pericardial and porcine valves in the mitral position to help guide bioprosthetic selection. Methods: In the present study, patients who underwent MVR using bovine pericardial valves were compared with those who underwent MVR with porcine bioprostheses between January 1996 and July 2018. Those with prior MVR, infective endocarditis, congenital mitral valve disease, or ischemic mitral regurgitation were excluded. The primary outcomes were structural valve deterioration (SVD) and mitral valve reoperation from any cause, and death was regarded as a competing risk. Competing risk analysis and propensity score-matching were used for comparisons. Results: Among the 388 patients enrolled, pericardial and porcine bioprostheses were implanted in 217 (55.9%) and 171 (44.1%), respectively. Propensity score-matching yielded 122 pairs of patients that were well-balanced for all baseline covariates. No significant differences were observed between the groups in unadjusted (p=0.09) and adjusted overall survival (hazard ratio [HR], 1.13; 95% confidence interval [CI], 0.72-1.76; p=0.60). Competing risk analysis revealed no significant differences in the risks of mitral reoperation (HR, 1.07; 95% CI, 0.50-2.27; p=0.86) and development of SVD (HR, 1.57; 95% CI, 0.56-4.36; p=0.39) between the groups. Matched population analysis confirmed similar results regarding reoperation (HR, 0.99; 95% CI, 0.40-3.22; p=0.98) and SVD (HR, 1.39; 95% CI, 0.41-4.73; p=0.60). Conclusion: No significant differences in survival or valve durability were observed between bovine pericardial and porcine bioprosthetic MVR. These findings require further validation through studies with larger sample sizes.

• 유체기계공업학회:학술대회논문집
• /
• 2004.12a
• /
• pp.609-613
• /
• 2004

• Environmental engineer
• /
• s.137
• /
• pp.16-19
• /
• 1998

• Journal of Chest Surgery
• /
• v.21 no.5
• /
• pp.899-904
• /
• 1988

In Behcet syndrome, cardiac involvements are rare and have been reported pericarditis, myocarditis, right heart endocardial fibrosis, right ventricle mural thrombus with pulmonary embolism, active endocarditis, granulomatous endocarditis, conduction disturbance, acute aortic insufficiency, mitral valve prolapse. Our three patients underwent AVR because of aortic insufficiency and ascending aorta enlargement combined with Behcet syndrome. Two patients had mitral regurgitation too. So one underwent MAP and the other underwent MVR concomitantly. One who underwent AVR have been well for 50 months. Another who underwent AVR+MAP and redo AVR due to aortic paravalvular leakage was died of congestive heart failure. The other who underwent AVR+MVR and repeated AVR three times because of aortic paravalvular leakage is in condition of aortic paravalvular leakage. Paravalvular leakage is considered to recur due to progressive dilatation and fragility of aortic root that is the result of pathologic change of Behcet syndrome in it. If Open heart surgery is needed in Behcet`s syndrome during inflammatory reaction is active, postoperative complications such as paravalvular leakage or suture line rupture may be prevented with pre- and postoperative anti-inflammatory management.

• Journal of Chest Surgery
• /
• v.16 no.1
• /
• pp.49-54
• /
• 1983

Fifty-Seven Cases of tricuspid valve replacement were done from April 1976 to January 1983. Fourteen congenital and 43 acquired cases were found. In 13 cases tricuspid valve alone was replaced with 2 operative deaths and one late deaths. In 35 cases TVR and MVR were done with 6 operative deaths and 6 late deaths. In 9 cases TVR, MVR, and AVR were done with one operative deaths. Over all operative mortality was 15.8% and late mortality 12.3% among the 48 survivors. Over all Survival rate was 71.9% during follow-up period ranging from 8 months to 6 years and 9 months. In every case TVR was done with bioprosthetic xenograft valves.

• Journal of Chest Surgery
• /
• v.27 no.12
• /
• pp.1031-1035
• /
• 1994

Mechanical valve thrombosis is a serious and potential lethal complication unless early diagnosis & prompt therapy are made. We have been experienced 3 cases of valve thrombosis. From Aug. 1988 to July 1994, reoperations of mitral valve replacement [MVR] with mechanical prostheses [all mitral] were performed in three patients[2 men, 1 woman] due to valve thromboses. All three patients were diagnosed by means of cineradiography. Preoperative status of was shock status and he was applied intra-aortic balloon pump [IABP]. All three cases of prosthetic valve failure [PVF] were treated by Redo-MVR. Time intervals of reoperations were 5months, 40months, and 35months, respectively. In all cases, valve thromboses were excised successfully. Cineradiography provided an accurate diagnosis in all cases, which was utilized as safe, reliable & noninvasive imaging modalities. There were no operative death & complication. All three patients were fully recovered and returned to their employements, and active lives.