Research Areas > Circulatory Vascular Flows and Biomedical Imaging

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In vivo measurement of hemodynamic information in stenosed rat blood vessels using X-ray PIV

Post Image  3D clips fabricated with a 3D printer were applied to the abdominal aorta of a rat cadaver to induce artificial stenosis in the real blood vessel of an animal model. The velocity and WSS information of blood flows in the stenosed vessel were obtained and compared at various stenosis severities. In vivo measurement was also conducted by fastening a stenotic clip on a live rat model through surgical intervention to reduce the flow rate to match the limited temporal resolution of the present X-ray PIV system. Further improvement of the temporal resolution of the system might be able...   내용 보기

Study on the deformation of endothelial cells using a bio-inspired in vitro disease model

Post Image Based on the observation that abnormal endothelial cells(blue arrows) and denatured collagen fibers(red arrows) in blood vessels of a normal zebrafish fed with high cholesterol diet were indicated, a bio-inspired in vitro model was established to investigate the basic biophysics of atherosclerotic disease. Endothelial cells on the collagenase-treated collagen films were non-homogeneously aggregated into cell clusters compared to control group(endothelial cells on the collagen film) depending on time. In addition, the various focal adhesion proteins and biomarkers of endothelial dysfunc...   내용 보기

Biophysiochemical properties of endothelial cells cultured on bio-inspired collagen films

Post Image Endothelial cells cultured on the denatured-collagen films have different biophysiochemical properties compared to those cultured on the normal films. Specifically, surface of HUVECs on the denatured-collagen films was highly disorganized with the formation of clusters and rough surface. Degree of expression of MMP-1, and MMP-2, which regulate the extracellular matrix degradation, was also examined and was highly activated in collagenase-treated endothelial cells but intensity of MMP-2 cannot be discriminated. E-selectin, VCAM, and CD146 were used as biomarkers of endothelial cells inj...   내용 보기

Whole-Body Imaging of a Hypercholesterolemic Female Zebrafish by Using Synchrotron X-Ray Micro-CT

Post Image Visualizing whole-volume of the zebrafish tissues is limited by pigmentation and hard tissues. The 3D microstructures of a high-cholesterol zebrafish are visualized by synchrotron X-ray micro-computed tomography(SR-μCT). Various microstructure organs of the zebrafish are  observed by high-contrast staining and embedding a protocol to improve the image contrast of soft tissues. The internal organs and cells of a hypercholesterolemic zebrafish are compared. The SR- μCT is powerful method to understand the pathogenesis of circulatory vascular diseases by detecting the modificat...   내용 보기

Microfluidic method for diagnosis of malaria-infected blood

Post Image For an effective ESR measurement, a disposable syringe filled with blood is turned upside down and aligned at 180° with respect to gravitational direction. The variation of hematocrit is evaluated by consecutively capturing images and conducting digital image processing technique for 10min. The proposed method can be used to measure ESR with superior reliability The proposed method can also be used to quantify ESR of blood collected from malaria-infected mouse under in vivo condition. As a result, the biophysical properties, including ESR and viscosity of blood, are significantly influ...   내용 보기

Effect of malaria infection in spleen

Post Image Malaria infection affects to the erythrocytes viscosity. We treated antioxidants in malaria-infected in vivo and in vitro models. Antioxidants show the protective effects on malaria-induced oxidative stress in erythrocytes and organs. They inhibit the malaria-induced inflammatory responses. These results could suggest that antioxidants have protective roles in malaria-induced oxidative stress and inflammatory responses.   내용 보기

Beneficial fluid-dynamic features of swirling flow in end-to-side anastomosis

Post Image Pathological fluid-dynamic characteristic sin a 45° end-to-side anastomosis were experimentally investigated using a particle image velocimetry technique. The fluid dynamic features of the pulsatile swirling flow are expected to be beneficial in designing vascular grafts that can suppress pathological hemodynamic characteristics in the recipient host vessel.   내용 보기

Fluid-dynamic optimal design of helical vascular graft for stenotic disturbed flow

Post Image The swirling flow in a helical graft was hypothesized to have beneficial influences on a disturbed flow structure such as stenotic flow. The characteristics of swirling flows generated by helical tubes with various helical pitches and curvatures were investigated to prove the hypothesis. An optimized helical design with a maximum Gn* was suggested for the future design of a vascular graft   내용 보기

Measurement of pulsatile blood flow using X-ray PIV

Post Image In this study, the proposed X-ray PIV technique was used to obtain hemodynamic information on rat blood flows using the rat extracorporeal loop system without any noticeable adverse effect. The X-ray PIV technique combined with CO2 microbubbles has strong potential for investigating the hemodynamic diagnosis of cardiovascular diseases.   내용 보기

Hybrid model for monitoring biophysical properties

Post Image A hybrid system is proposed for measurement of biophysical properties under ex vivo condition. The system is composed of an ultrasound system and a microfluidic device. The extracorporeal bypass loop consists of a pulse-free chamber (air cavity = 0.5 mL), a microfluidic device, and a vascular phantom for ultrasound imaging. As a result, the biophysical parameters including RBC aggregation, viscosity, velocity, and pressure of blood flows are reasonably measured without blood collection from the rat. It can be used to understand the relation between biophysical parameters and cardiova...   내용 보기