• Journal of Chest Surgery
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• v.28 no.12
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• pp.1122-1131
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• 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 Biomedical Engineering Research
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• v.15 no.4
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• pp.489-497
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• 1994

The most serious problems related to the cardiovascular prothesis are thrombosis and hemolysis. It is known that the flow pattern of cardiovascular prostheses is highly correlated with thrombosis and hemolysis. Laser Doppler Anemometry (LDA) is a usual method to get flow pattern, which is difficult to operate and has narrow measure region. Particle Image Velocimetry (PIV) can solve these problems. Because the flow speed of valve is too high to catch particles by CCD camera, high-speed camera (Hyspeed : Holland-Photonics) was used. The estimated maximum flow speed was 5m/sec and maximum trackable length is 0.5 cm, so the shutter speed was determined as 1000 frames per sec. Several image processing techniques (blurring, segmentation, morphology, etc) were used for the preprocessing. Particle tracking algorithm and 2-D interpolation technique which were necessary in making gridrized velocity pronto, were applied to this PIV program. By using Single-Pulse Multi-Frame particle tracking algorithm, some problems of PIV can be solved. To eliminate particles which penetrate the sheeted plane and to determine the direction of particle paths are these solving methods. 1-D relaxation fomula is modified to interpolate 2-D field. Parachute artificial heart valve which was developed by Seoul National University and Bjork-Shiely valve was testified. For each valve, different flow pattern, velocity profile, wall shear stress and mean velocity were obtained.

• Journal of Chest Surgery
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• v.33 no.7
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• pp.552-559
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• 2000

Background; The aim of this study is to evaluate our clinical experience with the Carbomedics heart valve prosthesis. Material and Method; Between Aug. 1988 and Dec. 1998, 294 Carbomidics valves were implanted in 235 patients(mitral; 143, mitral and aortic; 59, aortic; 33) The mean age at operation is 40.0$\pm$12.3 years(range 7 to 68 years); 63.8% (150patients) were woman. Follow up was 97.4% complete and mean follow up time was 5.7years with a total of 1209.2 patient-years. Result; The hospital mortality was 8.9%(mitral; was 95.2$\pm$1.6%(mitral ; 94.9$\pm$2.1%, mitral and aortic 95.0$\pm$3.7%, aortic 96.2$\pm$3.8%). Actual freedom rates from complications(linearized rates in parentheses) were fllowings; thromboembolism 96.2$\pm$1.5%(0.59%pt-yr), valve thrombosis 96.7$\pm$1.4%(0.5%/pt/yr), anticoagulant related hemorrhage 98.3$\pm$1.0%(0.25%/pt-yr), perivalvular leak 99.0$\pm$1.4%(0.5%/pt-yr), endocarditis 98.7$\pm$1.0%(0.25%/pt-yr), perivalvular leak 99.0$\pm$0.7%(0.17%pt-yr), endocarditis 98.7$\pm$1.0%(0.17%$\pm$pt-yr) and overall valve-related complications 88.9$\pm$2.5%(1.68%/pt-yr). Conclusion; The clinical performance of the Carbomedics valve was quite satisfactory with a low incidence of valve related mortality and morbidity.