• Journal of Chest Surgery
• /
• v.26 no.10
• /
• pp.753-760
• /
• 1993

The CarboMedics valve is a bileaflet prosthesis with excellent hemodynamic characteristics, but the long term surgical experience with this valve, its durability and its biocompatibility are unknown. During a 5 year period from october 1988 to July 1993, 748 prostheses [402 mitral, 261 aortic, 58 tricuspid, 27 pulmonic] were inserted in 552 patients [mean age 40.2 years]. The operative mortality was 6.6% [37/560, 13.2% in age group below 15 years and 5.7% above 15 years]. and the main causes of death were complex congenital malformation and left ventricular failure. Follow up was totaled 1182 patient- years and mean follow up was 28.3 months/patient. No structural failure has been observed. Hemorrhage was the most frequent valve related complication[1.78% / Patient-year]. Embolism occurred at a rate of 0.93% / Patient-year. There were 5 cases of valve thrombosis [0.42% / Patient-year, two fatal]. There occurred 11 late deaths[6 valve related] and 42 valve related complications. Actuarial survival at 5 years is 97.18 0.94% and actuarial complication free survival at 5 years is 89.07 1.54%. In summary, the CarboMedics valve stands for a durable valve substitute, with low valve related complications.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.17 no.5
• /
• pp.7-15
• /
• 2009

This paper introduces a new variable valve actuation mechanism with movable second cam center. Valve lift and open duration can be continuously varied according to engine speed and load conditions. A new method to analyze the kinematic relations between the first and second cam profiles and valve motion are also introduced. Because of rocker motion of the second cam, conventional motion conversion program could not be used in this problem. An example shows continuous variations of valve motion and adequate ramp incorporation throughout all valve lift modes. Valve acceleration profile at the high lift mode is similar to that of conventional valvetrains. Contact geometry analysis of the mechanism gives basic information on the load conditions between the components.

• Journal of Chest Surgery
• /
• v.18 no.4
• /
• pp.655-662
• /
• 1985

From January 1985 to July 1985, prosthetic heart valves were replaced in 5 patients at Keimyung University Dongsan Medical Center. The patients included three women and two men ranging in age from 22 to 41 years. Three mitral valve replacements, one aortic valve replacement and one double valve replacement [mitral and aortic valve replacement] were done at the first valve operations. Reoperation were performed 2 to 76 months after the first operations, Prosthetic valve endocarditis occurred in 3 patients, early in one and late in two and primary valve failure occurred in 2 patients. In operative findings, vegetation in prosthetic valve endocarditis and calcification in primary valve failure were found. All except one had relatively successful operative results. One died of early fungal prosthetic valve endocarditis due to relapsed prosthetic valve endocarditis with heart failure and block.

• Journal of Chest Surgery
• /
• v.7 no.2
• /
• pp.189-200
• /
• 1974

The mitral valve replacement with Beall prosthetic valve was performed on three patients, and double valve replacement. aortic and mitral valve, was performed in this department.1) The preoperative studies about the first case were compatible with mitral steno-insufficency.The diseased mitral valve was replaced with the medium sized Beall prosthetic valve under the cardiopulmonary hypass using hypothermic hemodilution technique. The total perfusion time was eighty minutes. Immediate postoperative course was smooth, but this patient was died of asphyxia due to tracheomalacia complicated after tracheostomy 3 months after operation. Autopsy on this patient revealed that no thrombus and no ball variance could be found, and endothelization on the valve cuff was satisfactory. 2) The preoperative studies on the second case were compatible with mitral insufficiency. The diseased mitral valve was replaced with the medium sized Beall prosthetic valve under the cardiopulmonary bypass using hypothermic hemodilution technigue. The total perfusion time was 123 minutes. This patient was discharged in good condition and follow-up study after 16 months revealed the patient had enjoyed healthy life. 3) The preoperative studies about the third case were compatible with aortic insufficiency and mitral stenoinsufficiency. The diseased valves were replaced with type 2 sutureless Magovern aortic valve and the medium sized Beall mitral prosthesis under cardiopulmonary bypass using hypothermic hemodilution technIque and coronary artery perfusion. The total perfusion time was 155 minutes. This patient was discharged in good condition, but thromboembolism was developed 2 months after discharge. 4) The preoperative studies about the fourth case were compatible with mitral insufficiency. The diseased mitral valve was replaced with the medium sized Beall prosthetic valve. The total perfusion time was 132 minutes. The atrioventricular block developed just after operation but converted to normal sinus rhythmn on the third postperative day. The preoperative NYHA functional classification IV was converted to Class 1 or 11 at the time of discharge and this patient enjoyed healthy life. Attendum; The fifth case, nineteen years old male with mital insufficiency underwent Beall valve replacement and his course was uneventful 2 weeks after operation.

• Journal of Chest Surgery
• /
• v.17 no.2
• /
• pp.212-222
• /
• 1984

A total of and consecutive 291 patients underwent isolated mitral valve replacement using the Ionescu-Shiley bovine pericardial xenograft valve during the 5-year period between October 1978 and June 1983. Thirty-two patients were the children under 15 years of age. There were 15 deaths within 30 days after surgery [operative mortality, 5.2%]. All early survivors except 6 children were placed on the long-term oral anticoagulation longer than postoperative 3 months. A total follow-up period extended for 398.2 patient-years, and 12 patients died [late mortality, 4.1%, or 3.0%/patient- year]. Ten patients experienced the thromboembolic complication [2.51%/patient-year], occurring in 8 patients within the first 3 postoperative months, and 4 died. Three patients had the late prosthetic valve endocarditis [0.75%/patient-year] and 2 died. The incidence of overall valve failure according to the criteria was 3.01%/patient-year, or 12 patients, and 2 had replacement of the failed bioprostheses [primary tissue failure, 0.5%/patient-year]. The long-term survival rate was 87.8%\ulcorner2.6% at 5 years postoperatively, and 84% of the late survivors were in NYHA Class I at the end of the follow- up. The probability remaining free from thromboembolism and overall valve failure was 89.8%\ulcorner6.3% and 81.2%\ulcorner.8% at 5 years respectively. These clinical results confirm the safety of mitral valve replacement. The only remaining clinical problem is the structural and functional durability of the bovine pericardial xenograft valve, and its use in young patients may be stopped in preference to the mechanical prosthetic valves.

• Journal of Fisheries and Marine Sciences Education
• /
• v.28 no.2
• /
• pp.350-355
• /
• 2016

This research aims to evaluated the structure improvement and new product development of valve tester. A valve tester was redesigned for structure improvement and new product development using 3-D design program CATIA. In addition, behavior analysis was conducted on the modeled valve tester using the ANSYS program. The total deformation, stress and strain were obtained by the internal pressure change. This result was applied to the new product development of valve tester.

• Journal of Chest Surgery
• /
• v.25 no.6
• /
• pp.661-671
• /
• 1992

From March 1988 to May 1991, 140 CarboMedics cardiac valve prostheses[75 mitral, 9 aortic and 28 double aortic-mitral] were implanted in 112 consecutive patients[mean age 36.7$\pm$11.6 years, male/female 48/76] by one surgical team operating on adult cardiac patients at Kyoungpook University Hospital Associated Surgical procedures were performed in 19 patients[16.9%]. Total follow up represented 2,345 patient-months[mean 22.4 months] and was 100% complete. Eighty-two patients[73%] were in NYHA functional class IIIor IV preoperatively and 102 patients [95%] were in class I or II postoperatively. Hospital[30 day] mortality was 4.4%, [3/75 mitral, 1/9 aortic, 1/28 double valve replacement] and late death was 1.7%. [1 /74 mitral, 1 /28 double valve replacement] The actuarial survival at 36 months was 94.0% after mitral, 80% after aortic, 92% after double valve replacement, and 93.2% for the total group. The linearized incidence of valve relater death, prosthetic valve thrombosis, anticoagulant related hemorrhage, and reoperation was 1.00%/pt-yr, 0.51%/pt/yr, 0.51%/pt-yr, and 0.51%/pt-yr respectively. The 36 month rates of freedom from valve replated death, thromboembolism, endocarditis, anti-coagulant related hemorrages, and reoperation were 98.75%, 99.08%, 100%, 99.04%, and 99.08% respectively. The 36 month rate of freedom from all valve related complications and deaths including hospital mortality was 90.2%. These fact suggest that the CarboMedics heart valve has excellent short-term result, low incidence of valve-related complications and valve dysfunction, and additional long term follow up study is necessary.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.11 no.3
• /
• pp.35-40
• /
• 2012

The 3/2-way valve supplies the high pressure air to ship engine for starting engine. In this paper, the high pressure 3/2 way valve for ship engine has the goal as reverse engineering by searching the fluid characteristic at this valve. The reverse engineering of 3/2-way valve is measured directly by Verier-calipers and is compared with 3D scanner. The fluid characteristic in this valve is used for a simulation method by ANSYS CFX 12.1. On the contrary, discs and the shaft are as the important components on numerical simulation by controlling the air flow at this valve. The fluid characteristics are seen to make high velocity and complicated vortex around the shaft. And the flow coefficient is calculated in order to apply for industrial field.

• Journal of Chest Surgery
• /
• v.29 no.10
• /
• pp.1102-1110
• /
• 1996

Between Oct. 1985 and July 1995, 230 patients underwent mitral valve replacement. There were 77 men and 153 women whose mean age was 35.7 years, range 9 to 62 The concomitant operations were 40 aortic valve replacements(17.4%), 25 tricuspid annuloplasties(10.4%), 8 aortic valve replacements & tricuspid annuloplasties(3.5%), 2 tricuspid valve replacements(0.9%) and others, We used 139 mechanical (76 51. Jude medical, 33 CarboMedics, 30 Sorin) and 91 tissue 386 Carpentier-Edwards, 5 lonescu-Shiley) valves. The early postoperative complications occurred in 28 cases. There were 8 low cardiac output syndrome, 5 pleural effusion, 3 significant arrhythmia, 2 cardiac rupture and others. There were 6 early hospital deaths (2.6%) due to low cardiac output syndrome(2), arrhythmia(2) and ventricul r rupture(2). The cuAmulative notal follow-up period was 764. 4 patient-years with a mean of 4).9 months. The long term follow-up information was available for 212 patients(94.6%). There were 21 cases of valve-related complications. Prosthetic valve failure(10), anti-coagulation related bleeding (5), prosthetic valve endocarditis (4), and thromboembolism (2) occurred at rates of 1.3, 0.7, 0.5, and 0.3%Ipt-yr respectively. Late death occurred In 5 cases (0.7%/pt-yr) associated with prosthetic valve endocarditis (2), heart failure (2) and anti-coagulation related bleeding (1). There was no difference in the rate of freedom from prosthetic valve failure between the mechanical and tissue valve group at 6 years (100%), but there was significant difference at 9 years between the tissue (34.4%) and mechanical valve (100%) group (p=0.032). Actuarial survival rates were 98. 8% in tissue valve. 9).7% in mechanical valve group and 96.6% in total patients at 9 years.

• Journal of Chest Surgery
• /
• v.13 no.4
• /
• pp.422-434
• /
• 1980

Since 1968 up to the end of October 1980, 448 valves were replaced in 354 patients in Seoul National University Hospital. There were 238 mitral, 38 aortic, 7 tricuspid, 45 aortic with mitral, 23 tricuspid with mitral, and 3 triple valve replacement aortic mitral and tricuspid cases. Annual increase of mitral valve replacement cases and decrease of operative maortality were remarkable. Recently operative mortality of mitral valve replacement is about 5%. Sex ratio of mitral valve replacement is almost equal and there were 12 cases of pediatric patients (5%) among 238 cases, and patients under the age of 20 years were 34 (14.3%). Mitral valve replacement was done for 199 single mitral, 38 double valve and one triple valve lesions. Among 238 mitral valve replacement paients left atrial thrombus in 23(9.7%), atrial fibrillation in 132 (55.5%), and reoperation after blind mitral commissurotomy in 12(5%) cases were noted. In recent cases bioprosthetic valves, mainly lonescu-shiley valve were utilized to overcome the difficulties of postoperative late complications in anticoagnuation, especially for the rural patients and pediatric cases, in addition to the hemodynamic advantages of lonesocu valve. Among 354 patients 16 cases were congenital heart anomaly related, 5 ventricular septal defect related aortic and 4 Ebstein related tribuspid valve replacement cases. There were 2 congenital anomaly related mitral valve replacements, one for congenital mitral insufficiency of 7 years old boy and one for corrected transposition of the great vessels associated with mitral insufficiency. Among total 354 valve replacements 49 operative deaths (13.3%) were noted and in 238 mitral valve replacement 24 operative deaths occurred (10.1%). In 39 patients among 354 total valve replacements late complications were found. In 238 mitral valve replacement cases late complications were noted in 26 patients, among whom 16 cases expired. Main late complications were thrombe-embolism, subacute becteerial endocarditis, arrythmia cerebral hemorrhage due to unsatisfactory anticoagulation, and congestive heart failure in the incipient period of valve replacement were also noted. In mitral valve replacement cases long-term survival rate was 83.2% who showed marked clinical improvement. Ther were no evidences of calcification during the 2 years follow-up period for the lonescu-valve replacement cases among 19 pediatric patients. In conclusion 238 cases of mitral valve replacement were done with 24 operative deaths and 26 late complication cases among whom 16 expired. The long term survival was 83.2% of the cases. In pediatric cases in place of coumadin anticoagulation Persantin **** 75 and aspirin were administered after valve replacement. In adult cases who have difficulaties with coumadin anticoagulation and for those even with bioprosthetic heart valve replacement who needs long-term or permanent anticoagulation persantin 75 and aspirin combination regimen were administered with antisfactory results.