• Membrane Journal
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• v.13 no.1
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• pp.20-28
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• 2003

In this study, we try to formularize simultaneous equations to make a prediction about pressure drop for designing intravascular artificial lung assist device. Designing parameters to predict the effect of pressure drop and designed modules under various conditions were studied through an experimental modeling before inserting the artificial lung assist device into as venous. We measured pressure drop in various number of hollow fiber membranes, when the inside diameter of shell is fixed in 3 cm, and tried to develope the prediction equations by curve fitting based on the correlation between the experimental pressure drop and the device frontal area or packing density. The results showed that pressure drop increased with 2nd order functional formula as the liquid flow rate, the frontal area, and the packing density increased. Also, we can estimate the pressure drop as a function of the frontal area or packing density. The pressure drop obtained from the experiment was similar to that from the equation, confirming the usefulness of the equation.

• Proceedings of the Membrane Society of Korea Conference
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• 2003.05a
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• pp.133-136
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• 2003

• Journal of Biomedical Engineering Research
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• v.27 no.4
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• pp.143-153
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• 2006

The purpose of this work was to assess and quantify the beneficial effects of gas exchange, while testingto the various frequencies of the sinusoidal wave that was excited by the PZT actuator, for patients suffering from acute respiratory distress syndrome (ARDS) or chronic respiratory problems. Also, this paper considered a simulator to design a hollow type artificial lung, and a mathematical model was used to predict a behavior of blood. This simulation was carried out according to the Montecarno's simulation method, anda fourth order Runge-Kutta method was used to solve the equation. The experimental design and procedure are then applied to the construction of a new device to assess the effectiveness of the membrane vibrations. As a result, the vibration method is very effective in the increase of gas transport. The gas exchange efficiency for the vibrating intravascular lung assist device can be increased by emphasizing the following design features: consistent and reproducible fiber geometry, and most importantly, an active means of enhancing convective mixing of water around the hollow fiber membranes. The experimental results showed the effective performance of the vibrating intravascular lung assist device. Also, we concluded that important design parameters were blood flow rates, fiber outer diameter and oxygen pressure drop. Based on the present results, it was believed that the optimal level of blood flow rates was 200$cm^3$/min.

• 순환기질환의공학회:학술대회논문집
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• 2003.11a
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• pp.26-27
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• 2003

• Journal of Biomedical Engineering Research
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• v.24 no.5
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• pp.391-399
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• 2003

Intravascular oxygenation represents an attractive. alternative support modality for therapy originated with acute respiratory distress syndrome(ARDS). However. the clinical study concluded that more gas exchange was needed for intravascular oxygenation to be clinically effective in ARDS treatment. In this study, we tried to enhance gas exchange on the VIVLAD using microencapsulation of hemoglobin and perfluorocarbon emulsion(PFC emulsion). Blood gas measurements were performed by collecting blood samples from the arterial and venous sides of the circuit, and processing them in a blood/gas analyzer. The function of hemosome. blood/hemosome mixed solution. and blood/PFC emulsion mixed solution were tested by an oxygen dissociation curve using a blood/gas analyzer. As a result, it was shown that the oxygen transfer of hemosome and blood/hemosome mixed solution were higher than that of whole blood. Also. it showed that the carbon dioxide transfer of whole blood/PFC emulsion mixed solution was higher than that of others. Therefore, we determined that hemosome and PFC emulsion could increase oxygen transfer and carbon dioxide transfer. respectively.

• Journal of Mechanical Science and Technology
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• v.16 no.11
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• pp.1470-1476
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• 2002

The goal of this work is to design and build an implantable artificial lung that can be inserted as a whole into a large vein in the body with the least effect on cardiovascular hemodynamics. The experimental results demonstrate that the pressure drop is not entirely related to viscosity effects. The friction factor decreases with an increase in the number of tied-hollow fibers at a constant Reynolds number A uniform flow pattern without stagnation is observed at all numbers of tied hollow fibers tested. The tied hollow fiber module, built in this study with 3 cm of outer diameter of module. 380 m of outer diameter of tied hollow fiber, and 700 number of tied hollow fiber with length of 60 cm, which shows a pressure drop of 13-16 mmHg, satisfies the required pressure drop qualifying 15 mmHg as an intravascular artificial lung.

• Archives of Pharmacal Research
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• v.10 no.1
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• pp.42-49
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• 1987

This study is to evaluate the potential use of aclarubicin-loaded gelatin microspheres as an intravascular biodegradable drug delivery system for the regional cancer therapy. The diameter of the microspheres prepared by water in oil emulsion polymerization could be controlled by adjusting the stirring rate in the range of 10-50 $\mu$m : D(in $\mu$m) = -73.8 log (rpm) + 262.7. The addition of proteolytic enzyme increased the in vitro aclarubicin release but it did not change the amount of the initial burst release which reached about 45%. Microspheres injected intravenously into the mouse tail vein embolized only to the lung when observed by fluorescence microscopy. From histological examination following injection of gelatin microspheres into mouse femoral muscle, mild inflammation was observed from the appearance of neutrophils after 2 days and rapid repair process was confirmed thereafter. Biodegradation process of gelatin microspheres lodged on the pulmonary capillary bed was followed up by microscopic observation; degradation was taking place by about 36 hrs, followed by severe damage on the spheerical shape and microspheres was no longer found 10 days after injection.

• Tuberculosis and Respiratory Diseases
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• v.40 no.3
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• pp.301-307
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• 1993

Intravascular bronchioloalveolar tumor is now recognized as a pulmonary form of hemangioendothelioma(HE). HE is an unusual tumor of adult life which is characterized by proliferation of an "epithelioid" or "spindle" endothelial cell. In the lung it usually presents as multiple bilateral slowly growing nodules less than 2 cm in diameter. The aetiology and pathogenesis of this disease are unknown. Spindle cell HE occurs at any age, but approximately one half of patient are 25 years of age or younger and males are affected twice more frequently than females. On light microscopic examination, the tumor show mild cellular atypia, nearly absent mitoses and electron-microscopic studies reveal evidence of endothelial cell differentiation. Intracytoplasmic localization of Factor VIII-related antigen is demonstrated on immunohistochemical study, which confirmed the endothelial origin of the tumor. No effective therapy is yet known for HE, but survival of this tumor can be quite long. However, one half of the patient have died, usually of progressive pulmonary insufficiency. This 19-yr-old male complained of Rt. chest pain and intermittent hemoptysis. Simple chest film and chest CT scan showed the Rt. pleural effusion, variable sized bilateral pulmonary nodules, irregular large heterogenous tumor with well enhancement and extensive necrosis in the anterior mediastinum. The mediastinal mass was biopsied and diagnosed as spindle cell HE by light microscopic finding and immunohistochemical studies.

• Membrane Journal
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• v.14 no.1
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• pp.18-25
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• 2004

The purpose of this paper was to find out the proper equation to predict the gas transfer rate for designing intravenous artificial lung assist device. The prepared hollow fiber modules were examined under various experimental conditions through experimental modeling before inserted the artificial lung assist d $\varepsilon$ vice into as venous. As a result, we can estimate the gas transfer as a function of the packing density. The gas transfer obtained from the experiment was similar to that from the equation, confirming the usefulness equation. Therefore, we can conclude the gas transfer of the intravenous artificial lung assist device as a function of the packing density, and this functions are very useful for predicting the gas transfer of the intravenous artificial lung assist device.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1332-1335
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• 2003

This paper presents the enhancement of oxygen transfer efficiency using the vibrating intravascular lung assist device (VIVLAD) in in-vitro experiments for patients having chronic respiratory problems. The test section was a cylinder duct with the inner diameter of 30 mm. The flow rate was controlled by the pump and monitored by a built-in flow meter. The vibration apparatus was composed of a piezo-vibrator, a function generator. and a power amplifier. The direction of vibration was radial to the fluid flow. Gas flow rates of up to 6 l/min through the 120-cm-Jong hollow fibers have been achieved by exciting a piezo-vibrator. The output of PVDF sensor were investigated by various frequencies in VIVLAD. The experimental results showed that VIVLAD would be enhance oxygen transfer efficiency.