• Investigative Magnetic Resonance Imaging
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• v.21 no.2
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• pp.91-96
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• 2017

Purpose: To describe technical methods for functional magnetic resonance imaging (fMRI) study with arterial spin labeling (ASL) compared to blood oxygenation level-dependent (BOLD) technique and discuss the potential of ASL for research and clinical practice. Materials and Methods: Task-based (n = 1) and resting-state fMRI (rs-fMRI) (n = 20) were performed using ASL and BOLD techniques. Results of both techniques were compared. Results: For task-based fMRI with finger-tapping, the primary motor cortex of the contralateral frontal lobe and the ipsilateral cerebellum were activated by both BOLD and ASL fMRI. For rs-fMRI of sensorimotor network, functional connectivity showed similar results between BOLD and ASL. Conclusion: ASL technique has potential application in clinical and research fields because all brain perfusion imaging, CBF measurement, and rs-fMRI study can be performed in a single acquisition.

• 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.

• Korean Journal of Materials Research
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• v.15 no.8
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• pp.521-527
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• 2005

Surface modification of polypropylene hollow fiber membranes was peformed in order to develop blood-compatible biomaterials for use in the blood contacting and oxygenation membranes of a lung-assist device(LAD). Blood compatibility was determined by using anticoagulation blood and evaluating formation of blood clots on their surfaces as well as activation of plasma coagulation cascade, platelet adhesion, and aggregation. It was verified that the number of platelets on the silicone coated fibers was significantly lower than those on polypropylene. It was also found that the polypropylene hollow fiber membranes using plasma treatment exhibited suppression of complement activation in blood compatibility test.

• Clinical and Experimental Pediatrics
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• v.46 no.12
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• pp.1207-1211
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• 2003

Purpose : This study was performed to observe the relationship of plasma L-arginine level and the severity of disease and pulmonary artery pressure in respiratory distress syndrome of premature infants. Methods : Peripheral blood samples were obtained at 1st, 3rd and 7th day from 21 premature infants with respiratory distress syndrome to analyze the L-arginine concentration. Oxygenation index (OI), an indicator of the severity of the disease, was calculated at the same time of the blood sampling. And pulmonary artery pressure was measured by Doppler echocardiography at each period. Plasma L-arginine level, OI and right ventricular systolic time interval(RVSTI) were analyzed. Results : Plasma L-arginine concentration of the 1st day was lower than 3rd and 7th day. OI and RVSTI were significantly correlated with each other(r=0.772, P<0.01). Plasma L- arginine level was correlated with oxygenation index(r=-0.346, P<0.01) and RVSTI(r=-0.416, P<0.01). Conclusion : Plasma L-arginine level was lowest in the 1st day during the study period. Plasma L-arginine concentration correlated significantly with the severity of respiratory distress syndrome and pulmonary artery pressure in premature infants.

• Proceedings of the Korean Society of Veterinary Clinics Conference
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• 2008.05a
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• pp.132-132
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• 2008

• Journal of Chest Surgery
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• v.49 no.3
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• pp.199-202
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• 2016

A 7-month-old girl with no medical history was treated with mechanical circulatory support due to myocarditis. Her cardiac contractility did not improve despite more than one week of extracorporeal membrane oxygenation treatment. Thus, we planned a heart transplant. However, a high level of cytomegalovirus was found in blood laboratory results by quantitative polymerase chain reaction. The patient's heart contractility recovered to normal range four days after ganciclovir treatment. She was discharged with slightly decreased cardiac contractility with a left ventricular ejection fraction of 45%.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.571-574
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• 1997

fMRI, functional MRI introduced recently appears based on the gradient echo technique which is sensitive to the field inhomogeneity developed due to the local susceptibility changes of blood oxygenation and deoxygenation. Common to all the gradient echo techniques is that the signal due to the susceptibility effects is generally decreased with increasing inhomogeneity due to the $T2^*$ effect or conventionally known as blood oxygenation level dependent (BOLD) effect. It is, also found that the BOLD sensitivity is also dependent on the imaging modes, namely whether the imaging is in axial, or coronal or sagittal mode as well as the directions of the vessels against the main magnetic field. We have, therefore, launched a systematic study of imaging mode dependent signal change or BOLD sensitivity as well as the signal changes due to the tilting angle of the imaging planes. Study has been made or both TRFGE sequence and CGE sequence to compare the distinctions of the each mode since each technique has different sensitivity against susceptibility effect. Method of computation and both the computer simulations and their corresponding experimental results are presented.

• Journal of Biomedical Engineering Research
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• v.15 no.3
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• pp.265-274
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• 1994

This paper proposes a method of noninvasive reflectance light to measure the blood fractional volume (Vb) and oxygen saturation ($SO_2$) of biological tissue. We chose the red light of 660nm and infrared light of 880nm. In Vivo reflectance data were obtained by the physiological changes front the surface of the skin over the calf in human subject. The reflected light intensity from different layers within a biological tissue was measured by specially designed reflectometer to apply photon path diffusion model. The collected data represent the changes of blood (ractional volume and oxygen saturation at each reflected light wavelengths. The data evaluation was assessed by examining the slopes of the plotted indices for the changes in oxygen saturation and blood (ractional volume. The results presented in this paper claim that light reflectance can separately discriminate the change of blood volume and that of oxygenation in muscle and also in skin.

• Archives of Plastic Surgery
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• v.41 no.6
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• pp.668-672
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• 2014

Background Negative-pressure wound therapy (NPWT) is believed to accelerate wound healing by altering wound microvascular blood flow. Although many studies using laser Doppler have found that NPWT increases perfusion, recent work using other modalities has demonstrated that perfusion is reduced. The purpose of this study was to investigate the influence of NPWT on tissue oxygenation of the foot, which is the most sensitive region of the body to ischemia. Methods Transcutaneous partial pressure of oxygen ($TcpO_2$) was used to determine perfusion beneath NPWT dressings of 10 healthy feet. The sensor was placed on the tarso-metatarsal area of the foot and the NPWT dressing was placed above the sensor. $TcpO_2$ was measured until it reached a steady plateau state. The readings obtained at the suction-on period were compared with the initial baseline (pre-suction) readings. Results $TcpO_2$ decreased significantly immediately after applying NPWT, but gradually increased over time until reaching a steady plateau state. The decrease in $TcpO_2$ from baseline to the steady state was 2.9 to 13.9 mm Hg (mean, $9.3{\pm}3.6$ mm Hg; $13.5{\pm}5.8%$; P<0.01). All feet reached a plateau within 20 to 65 minutes after suction was applied. Conclusions NPWT significantly decrease tissue oxygenation of the foot by 2.9 to 13.9 mm Hg. NPWT should be used with caution on feet that do not have adequate tissue oxygenation for wound healing.

• Membrane Journal
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• v.15 no.3
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• pp.233-240
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• 2005

Surface modification of polypropylene hollow fiber membranes was performed in order to develop blood-compatibility biomaterials for use in the blood contacting surfaces and oxygenation membranes of a lung assist device (LAD), important medical device even more useful. Blood compatibility of materials was determined by using anticoagulation blood and evaluating formation of blood clots on their surfaces as well as activation of plasma coagulation cascade, platelet adhesion, and aggregation. It was verified that the number of platelets on the silicone coated fibers was significantly lower than that on untreated fiber membrane, indicating improved blood compatibility. It was also found that the polypropylene hollow fiber membranes using plasma treatment exhibited suppression of complement activation in blood compatibility test.