• International Journal of Fluid Machinery and Systems
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• v.7 no.4
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• pp.142-150
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• 2014

In the cardiopulmonary support system with an ECMO (extracorporeal membrane oxygenation), a higher pump head is demanded for a blood pump. In order to realize a blood pump with higher pump head, higher anti-hemolysis and thrombosis performances, a study on the development of unprecedented multistage blood pump was conducted. In consideration of the application of the blood pump for pediatric patients, a miniature two-stage centrifugal blood pump with the impeller's diameter of 40mm was designed and the performance was examined in experiments and computations. Some useful knowledge for a design of the blood pump with higher anti-hemolysis and thrombosis performances was obtained.

• Journal of Chest Surgery
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• v.44 no.2
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• pp.193-196
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• 2011

Bronchogenic carcinoma involving the carina has remained a challenging problem for thoracic surgeons. Carinal resection and reconstruction is limitedly indicated because this aggressive surgical approach has been reported to be associated with significant morbidity and mortality while long-term outcome has not been determined. Wesuccessfully performed carinal reconstruction and sleeve right upper lobectomy assisted with ECMO for a 60-year-old male with squamous cell carcinoma in the right upper lobe extending to the carina.

• Kosin Medical Journal
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• v.33 no.2
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• pp.215-222
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• 2018

An incidentaloma is a tumor found incidentally without clinical symptoms or suspicion; the lesion may be adrenal, pituitary, or thyroidal. We report the case of an asymptomatic individual with preoperatively undiagnosed pheochromocytoma (size: 4.86 cm) that was revealed using elective nonadrenal surgical procedures. The patient demonstrated peri- and post-operative hypertensive crisis and tachycardia. Three days after the dramatic onset of symptoms, the patient expired due to pulmonary edema, multiple organ failure, and terminal sepsis, despite administration of extracorporeal membrane oxygenation-assisted cardiopulmonary resuscitation. A left medial kidney mass obtained at autopsy confirmed pheochromocytoma.

• Journal of Biomedical Engineering Research
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• v.42 no.4
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• pp.193-200
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• 2021

Flowmeter and oxygen sensors are listed in COVID-19 essential medical devices. This article reports a Teensy microcontroller-based Oxygen mass flow controller (MFC), core part of the oxygen respirator or extracorporeal membrane oxygenation (ECMO). The developed MFC consisting of the microcontroller, MEMS flow sensor, and solenoid valve was able to accurately control 0 to 100 sccm of oxygen flow rate. The pressure of vacuum chamber increased proportionally to the flow rate (0.998 of Pearson correlation coefficient). The experimental results proved that the developed MFC exhibits comparable performance to a commercial MFC in accuracy, settling time, linearity with pressure, and repeatability of oxygen mass flow control. It is expected that this simple and cheap MFC is utilized for oxygen therapy against the severe acute respiratory syndrome coronavirus 2.

• Membrane Journal
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• v.15 no.3
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• pp.224-232
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• 2005

The use of the lung assist device (LAD) would be well suited for acute respiratory failure (ARF) patients, combining the simplicity of mechanical ventilation with the ability of extracoporeal membrane oxygenators (ECMO) to provide temporary relief for the natural lungs. This study's specific attention was focused on the effect of membrane vibration in the LAD. Quantitative experimental measurements were performed to evaluate the performance of the device, and to identify membrane vibration dependence on blood hemolysis. We tried to decide upon excited frequency band of limit hemolysis when blood hemolysis came to through a membrane vibration action. The excited frequency of the module type 5, consisted of 675 hollow fiber membranes, showed the maximum gas transfer rate. We concluded that the maximum oxygen transfer rate seemed to be caused by the occurrence of maximum amplitude and the transfer of vibration to hollow fiber membranes. It was excited up to $25{\pm}5$ Hz at each blood flow rate of module type 5. We found that this frequency became the 2nd mode resonance riequency of the flexible in blood flow. Blood hemolysis was low at the excited frequency of $25{\pm}5$ Hz. Therefore, we decided that limit hemolysis frequency of this LAD was $25{\pm}5$ Hz.

• Tuberculosis and Respiratory Diseases
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• v.82 no.4
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• pp.328-334
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• 2019

Background: Although the frequency of respiratory viral infection in patients with pulmonary acute respiratory distress syndrome (ARDS) is not uncommon, clinical significance of the condition remains to be further elucidated. The purpose of this study was to compare characteristics and outcomes of patients with pulmonary ARDS infected with influenza and other respiratory viruses. Methods: Clinical data of patients with pulmonary ARDS infected with respiratory viruses January 2014-June 2018 were reviewed. Respiratory viral infection was identified by multiplex reverse transcription-polymerase chain reaction (RT-PCR). Results: Among 126 patients who underwent multiplex RT-PCR, respiratory viral infection was identified in 46% (58/126): 28 patients with influenza and 30 patients with other respiratory viruses. There was no significant difference in baseline and clinical characteristics between patients with influenza and those with other respiratory viruses. The use of extracorporeal membrane oxygenation (ECMO) was more frequent in patients with influenza than in those with other respiratory viruses (32.1% vs 3.3%, p=0.006). Co-bacterial pathogens were more frequently isolated from respiratory samples of patients with pulmonary ARDS infected with influenza virus than those with other respiratory viruses. (53.6% vs 26.7%, p=0.036). There were no significant differences regarding clinical outcomes. In multivariate analysis, acute physiology and chronic health evaluation II was associated with 30-mortality (odds ratio, 1.158; 95% confidence interval, 1.022-1.312; p=0.022). Conclusion: Respiratory viral infection was not uncommon in patients with pulmonary ARDS. Influenza virus was most commonly identified and was associated with more co-bacterial infection and ECMO therapy.

• Journal of Korean Critical Care Nursing
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• v.3 no.2
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• pp.49-59
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• 2010

Purpose: The purpose of this study was to investigate in-service education needs in order to develop clinical competence of critical care nurses', and to identify contents which have to include in-service education according to nurses' characteristics. Methods: Data was collected using Critical Care Nurse Job Analysis Tool that was modified by professional team. Collected data was analyzed using the SPSS program. Results: Total 148 critical care nurses, who had worked at adult intensive care unit of one tertiary hospital in Seoul, filled out questionnaire. The results showed the participants highly needed education about cardiological nursing practices such as ECMO, pacemaker, cardiac tamponade. And there were significant correlations among in-service educational needs and ICU careers, preceptors experience, and charge nurse experience. Conclusion: It will be necessary for better nursing to develop in-service education is based on critical care nurse's need and their characteristics. Especially, it is important to develop and provide in-service education programs, which consider ICU nurse's differences for their career ladder and nursing preceptors.

• International Journal of Fluid Machinery and Systems
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• v.8 no.1
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• pp.1-12
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• 2015

In cardiopulmonary support systems with a membrane oxygenation such as a percutaneous cardiopulmonary support (PCPS) or an extracorporeal membrane oxygenation (ECMO), blood pumps need to generate the pressure rise of approximately 200mmHg or higher, due to the high hydraulic resistances of the membrane oxygenation and of the cannula tubing. In order to realize the blood pump with higher pressure rise, higher anti-hemolysis and thrombosis performances, the development of novel centrifugal blood pump composed of two-stage has been conducted by the authors. In the present paper, effective attempts to decrease the wall shear stress and to suppress the stagnation are introduced for the prevention of hemolysis and thrombosis in blood pumps. The hemolysis test was also carried out and it was clarified that the decrease of wall shear stress is effective as a guideline of design of blood pumps for improving the anti-hemolysis performance.

• Journal of computational fluids engineering
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• v.20 no.3
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• pp.79-86
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• 2015

A blood pump is an important part of a cardiac assist device. Since the shear rate in blood is known to be a primary factor on hemolysis generation, it has been very important to evaluate hemolysis inside blood pumps for understanding performance and reliability of cardiac assist devices. In this study, hemolysis generation inside blood pumps is analyzed using CFD with power-law based models for the blood damage index(BDI), in order to overcome difficulties in measuring hemolysis by experiment. The BDI values in blood pumps can be evaluated using Lagrangian or Eulerian approaches. In this study, several Lagrangian and Eulerian approaches are compared to estimate the efficiency of the numerical methods in a practice sense. It is found that the Eulerian approaches are advantageous in terms of the efficiency and robustness. Two different Eulerian approaches are used to evaluate the BDI values of a few commercial blood pumps. For the conditions of extracorporeal membrane oxygenator(ECMO) and ventricular assist device(VAD), local generation of hemolysis is analyzed using divided regions of blood pumps, in order to investigate the effects of the pump geometry.

• Journal of Chest Surgery
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• v.24 no.11
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• pp.1045-1057
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• 1991

Over the past four decades after World War II a great deal of data and clinical experiences have been accumulated relating to the diagnosis and surgical treatment of cardiovascular diseases in Korea. Clinical data after the first open heart surgery by Professor Yung Kyoon Lee on August 7, 1959 up to 1984 revealed the total number of cardiovascular surgery in Korea as 13,100 cases performed in 22 institutes with overall hospital mortality of 7.7%[Cardiovascular Surgery in Korea 1985], Publishing committee of the Korean Thoracic and Cardiovascular Surgical Society collected the data of cardiovascular surgical cases in Korea again in between 1985 and 1990 from 38 institutes out of total 42 institutes of open heart centers in Korea. The results are: 1. The survey reply ratio was 90.5%[38 out of 42 institutes]. 2. Of the total 30,061 cases of cardiovascular surgery reported from 38 institutes 1,402 cases were failed as hospital mortality of 4.7%[4.5% of the 21,761 operations for congenital, and 5.2% of the 8,300 operations for acquired heart diseases]. Out of the total congenital cases, 17,303 cases were acyanotic group with a operative mortality as 2.0%, and 4,458 cases were cyanotic group with a hospital mortality as 14.le The incidence of corrective operations for complex congenital cardiac anomalies were increasing recently with decreasing age group. 3. During the year in 1990, 38 institutes performed 5,427 cardiovascular surgery with a hospital mortality of 3.4%. 4. Of the total cumulative 6,458 cases for cardiac valve surgery more than 90% cases were put to prosthetic valve replacement with hospital mortality as 4.8%. And the incidence of re-Do valve surgery was increasing recently as 13.1% in 1990. 5. Coronary artery bypass graft was increasing recently with 7.9% of hospital mortality in total 440 cases. Intracardiac operation for intractable arrhythmia was started since 1987 as 49 cases in total. Experiences on VAD and ECMO were also reported sporadically in recent year. 6. Home made oxygenator[OXYREX] is now in clinical use, and under animal experiment for clinical trial in near future.