• Proceedings of the KOSOMBE Conference
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• v.1989 no.05
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• pp.1-3
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• 1989

We have treated polymer surfaces such as polyethylene, polystyrene and polyester by various physicochemical and biological surface modification methods to be suitable for cell adhesion. The physicochemical methods we used were $O_2$ plasma discharge, corona discharge, sulfuric acid and chloric acid treatments. For the biological treatments, blood proteins such as plasma protein, serum protein and fibronectin were adsorbed onto the polymer surfaces. Chinese Hamster Ovary (CHO) cells were cultured on the surface-modified polymers and the cell-compatibility of those surfaces were compared. The chloric acid and fibronectin treatments were found to be the best methods of rendering the polymer surfaces adhesive for CHO cells.

• Proceedings of the KOSOMBE Conference
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• v.1989 no.05
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• pp.5-6
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• 1989

Polyurethane surface was chemically modified to have different hydrophilic polyethyleneoxide(PEO)/hydrophobic dodecanediol(DDO) groups and negatively charged sulfonate group to investigate the effect to the antithrombogenicity. The hydrophilicity of the surface was significantly increased after PEO grafting or sulfonation. Lowering in-vitro platelet adhesion led to a prologation in the ex-vivo occlusion time. Especially, the sulfonated PU-PEO surface showed most enhanced blood compatibility due to the synergistic effects of PEO and $SO_3$ groups.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.227-228
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• 1998

Lumbrokinase, potent fibrinolytic enzyme purified from earthworm, was immobilized onto polyurethane valves using photoreaction, photoreactive polyallyl-amino as a photoreactive linker. For evaluation of blood compatibility, lumbrokinase immobilized polymer valves were assembled into the total artificial heart (TAH). This TAH was implanted to 60kg healthy lamb for 1-3 days with the cardiac output 5 L/min. In the control lamb, the valves were untreated, in ore other, only valves on the right were treated, and in the remaining animal, only those on the left. To facilitate the thrombus formation, low doses of heparin were administered. For evaluation of the immobilized lumbrokinase, thrombus formation, proteolytic and fibrinolytic activity was measured. This data shows that lumbrokinase-treated polyurethane valves lead to decreased thrombus formation in vivo, and that their biocompatibility is therefore higher than that of untreated valves.

• Journal of Biomedical Engineering Research
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• v.19 no.3
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• pp.215-224
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• 1998

This paper is fundamental study to develope the extracorporeal liver support system for patient with fulminant hepatic failure(FHF) or being expected for orthotopic liver transplantation. The polyurethane foam, which is composed of the density of 33kg/m3, the average pore diameter of 500${\mu}{\textrm}{m}$, the closed window of 60-70%, was manufactured with the prepolymer of 15% NCO-, Hepatocytes were inoculated to form spheroids in polyurethane foam. The time of spheroid formation in BSA(Bovine Serum Albumin) coated polyurethane foam was shorter than that in raw polyurethane foam. To verify the function of hepatocyte spheroids, we measured ammonia removal rate, urea and albumin secretion rate. Polyurethane foam was suitable for culture of hepatocyte spheroids. And culture of hepatocyte spheroids in polyurethane foam has high possibility in using as an extracorporeal liver support system.

• Applied Chemistry for Engineering
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• v.4 no.1
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• pp.188-195
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• 1993

Polyelectrolyte complexes and graft copolymers as biomaterials were synthesized from the water soluble cellulose derivatives. Polyelectrolyte complexes have been prepared from carboxymethyl cellulose (CMC) and gelatin. Graft copolymers(Mc-g-AA) were synthesized by grafting acrylic acid (AA) onto methyl cellulose(MC). (Mc-g-AA) and gelatin polyelectrolyte complexes were also prepared. The optimum conditions of each sample were investigated after chemical crosslinking or heat treatment. The preliminary results show that these materials might be interesting for biomedical applications.

• Journal of Biomedical Engineering Research
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• v.20 no.3
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• pp.265-274
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• 1999

In this paper, we propose a novel interframe coding algorithm especially appropriate for 3-D medical images. The proposed algorithm is based on a video coding algorithm using motion estimation/ compensation and transform coding. In the algorithm, warping is adopted lor motion compensation (MC). Then, by using adaptive mode selection, a motion compensated residual image and original image are mixed up in the wavelet transform domain for improvement in coding performance. The mixed image is then compressed by the zerotree coding method. We prove that the adaptive mode selection technique in the wavelet transform domain is very useful lor 3-D medical image coding. Simulation results show that the proposed scheme provides good performance regardless of inter-slice distance and is prospective for 3-D medical image compression.

• Journal of Biomedical Engineering Research
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• v.17 no.1
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• pp.11-18
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• 1996

The toxic metal ion release behaviour and the cytotoxicity of a super stainless steel (S.S.S, 22cr-20Ni -6Mo-0.25N) were investigated The measurement of the amount of static and wear- induced trace metal ion released from the steels was conducted in Hank's balanced salt solution using an electrothermal atomic absdrption spectrometry equiped with Uaphite furnace. And the in vitro cytotoxicity of the materials was assesed in cell culture. The static dissolution rates of Fe and Cr ions from the S.S.S were significantly lower than those of 316L SS. However, the Ni ion release from the S.S.S during the first 4 weeks was yester than that from 316L 55 by 15-45%. Also, the wear-in- duces dissolution rates from the steels were not correlated either with their elemental composition rates or with the static metal ion release rates. The S.S.S did not deteriorate the osteoblasts viability. And no toxic response was observed from the macrophages cultured for 7 days in RFMI 1640 medium immersed with the S.S.S specimens.

• Journal of the Korea Society of Computer and Information
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• v.17 no.12
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• pp.1-10
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• 2012

In this paper, we propose an patient monitoring system which is suitable for mobile healthcare system. The mobile healthcare system is using portable device such as smartphone and it consists of small computing device. The mobile healthcare system is carry out same performance with desktop computer. We designed medical message structure based on TinyOS to transmit patient's biometric data on the smartphone of medical team, patient and family over the mobile carrier environment, and ported successfully in HBE-Ubi-ZigbeX using NesC. And We confirmed reliable transmission of biometric data on the smartphone by implementing the Android OS based patient information monitoring application to check the status of patient for medical team, patient and family.

• Journal of Biomedical Engineering Research
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• v.15 no.1
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• pp.19-26
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• 1994

Sulfonated poly (ethyleneoxide)-grafted polyurethane (PU-PEO-$SO_3$) prepared by bulk modification was coated on a blood sac for electrohydraulic left ventricular assist device (ELVAD) implanted in dogs and its in vivo blood compatibility on shear stress was studied as compared with untreated Po. The effect of the wall shear stress on the protein adsorption unlike platelet adhesion is dependent on the surface characteristics of the material, although less proteins seem to be adsorbed in the region of the high shear stress. The thickness of total proteins adsorbed on PU-PEO-SOJ (400 ${\AA}$) by trans¬mission electron microscopy(TEM) was considerably lower than that of untreated PU(l,000~1,600 ${\AA}$), but PU-PEO-$SO_3$ showed high albumin adsorption, low fibrinogen and IgG adsorption, and low platelet adhesion as compared with untreated PU, suggesting that PU-PEO-$SO_3$ is more in vivo blood compatible. Therefore, it appears that such a blood compatible PU-PEO-$SO_3$ is useful for blood contacting biomaterials including artificial organs.

• Journal of Biomedical Engineering Research
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• v.22 no.6
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• pp.479-486
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• 2001

Spirometer is a medical equipment which diagnoses respiratory function by measuring 9as volume across Patient's lunes through airway. Because a little overdose of anesthesia medicine can take away Patient's life in the ventilator for a surgical operation. an exact measurement of respiring volume is very important. This Paper Presented an exact flow volume calculation method from factors having an influence on measurement and introduced a spirometry system for an anesthesia ventilato. This system, using differential Pressure sensor measured flow by mutual relation with Pressure. temperature. gas density and linearization from the 2nd order characteristics of differential pressure with flow.