• Proceedings of the KSME Conference
• /
• 2007.05b
• /
• pp.2935-2940
• /
• 2007

To diagnose circulatory diseases in the viewpoint of hemodynamics, we need to get quantitative hemodynamic information of blood flows related with the vascular diseases with high spatial resolution of tens micrometer and high temporal resolution in the order of millisecond. For investigating in-vivo hemodynamic phenomena, a new diagnosing technique combining medical radiography and PIV method was newly proposed and developed. This angiographic PIV technique consists of a medical X-ray tube, an X-ray CCD camera, a shutter module for double pulses of X-ray, and a synchronizer. The feasibility of the angiographic PIV technique was tested and quantitative flow velocity field distribution of a flow inside an opaque conduit was acquired by the developed system. It can be used for measuring flow phenomena of nontransparent fluids inside opaque conduits.

• Korean Journal of Veterinary Research
• /
• v.6 no.1
• /
• pp.76-81
• /
• 1966

This study was conducted to observe the condition of the ramification of the bronchus and pulmonary blood vascular system by injection of vinylite into the bronchial tree and pulmonary blood vessels in normal adult swines. The results obtained were summarized as follows. 1. Lungs of swine were composed of the same pulmonary territories as in lungs of human and dog. 2. Bronchial tree of swine also were axial divergency in the patterns. 3. Ramification of the left and right apical lobes are especially complex patterns but cardiac and diaphragmatic lobes are a little monotonous. 4. Intermediate lobe corresponding to mediobasalis branch of human lungs formed only one lobe in swine lung. 5. Pulmonary artery of right apical lobe was mono branch form in all case by authors observation. 6. $B._2$ streched into the seg. dorsalis of the right apical lobe was especially developed compare to $B._1$, $B._3$ of the seg, apicalis and seg, ventralis.

• Toxicological Research
• /
• v.11 no.2
• /
• pp.169-173
• /
• 1995

The effects of tumor necrosis factor alpha $(TNF-{\alpha})$ on growth and tubular formation of bovine aortic endothelial cells were examined using an in vitro angiogenesis model system. The growth of endothelial cells was enhanced in a dose-dependent manner when the cells were cultured with $TNF-{\alpha}$ for 3 days, but $TNF-{\alpha}$, at the concentration of 1 nM or higher, produced a growth inhibition of endothelial cells when the cells were cultured for 8 days. The endothelial cells incubated with $TNF-{\alpha}$ for 48-h exhibited a typical morphologic change. Then, they showed a fibroblastoid organization of overlapping, elongated, and spindle-shaped cells. $TNF-{\alpha}$, at the concentration of O. 1 nM or higher, inhibited the tubular formation of vascular endothelial cells in an in vitro anglogenesis model using a 3-dimensional culture system.

• BMB Reports
• /
• v.49 no.5
• /
• pp.255-262
• /
• 2016

The disease known as cerebral cavernous malformations mostly occurs in the central nervous system, and their typical histological presentations are multiple lumen formation and vascular leakage at the brain capillary level, resulting in disruption of the blood-brain barrier. These abnormalities result in severe neurological symptoms such as seizures, focal neurological deficits and hemorrhagic strokes. CCM research has identified 'loss of function' mutations of three ccm genes responsible for the disease and also complex regulation of multiple signaling pathways including the WNT/β-catenin pathway, TGF-β and Notch signaling by the ccm genes. Although CCM research is a relatively new and small scientific field, as CCM research has the potential to regulate systemic blood vessel permeability and angiogenesis including that of the blood-brain barrier, this field is growing rapidly. In this review, I will provide a brief overview of CCM pathogenesis and function of ccm genes based on recent progress in CCM research.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2017.05a
• /
• pp.179-182
• /
• 2017

Cerebral nervous system intervention procedures have been reported frequently due to radiation exposure such as skin baldness, hair loss, and redness due to prolonged procedures. Therefore, the bismuth shield designed to reduce the radiation exposure of the target organ located in the anterior part of the human body sensitive to skin and radiation sensitivity during CT (computed tomography) scan is applied to the cerebral vascular system intervention by ergonomic design, To reduce the radiation dose of sensitive scalp, we propose a study.

• Journal of Mechanical Science and Technology
• /
• v.19 no.spc1
• /
• pp.343-349
• /
• 2005

There are many things in common between hemodynamics in arterial systems and multibody dynamics in mechanical systems. Hemodynamics is concerned with the forces generated by the heart and the resulting motion of blood through the multi-branched vascular system. The conventional hemodynamics model has been intended to show the general behavior of the body arterial system with the frequency domain based linear model. The need for detailed models to analyze the local part like coronary arterial tree and cerebral arterial tree has been required recently. Non-linear analysis techniques are well-developed in multibody dynamics. In this paper, the studies of hemodynamics are summarized from the view of multibody dynamics. Computational algorithms of arterial tree analysis is derived, and proved by experiments on animals. The flow and pressure of each branch are calculated from the measured flow data at the ascending aorta. The simulated results of the carotid artery and the iliac artery show in good accordance with the measured results.

• Clinical Endoscopy
• /
• v.51 no.6
• /
• pp.563-569
• /
• 2018

Background/Aims: To evaluate patients with portal hypertension (PH) of varied etiologies for portal hypertensive enteropathy (PHE) using the PillCam SB3 capsule endoscopy (CE) system. Methods: Consecutive patients with PH presenting with unexplained anemia and/or occult gastrointestinal bleeding were evaluated using the PillCam SB3 CE system. Abnormal findings were categorized as vascular or non-vascular. The patients with ongoing bleeding caused by PHE were treated. The correlation of the CE scores of PHE with the clinical, laboratory, and endoscopic features was determined. Results: Of the 43 patients included in the study, 41 (95.3%) showed PHE findings. These included varices (67.4%), red spots (60.5%), erythema (44.2%), villous edema (46.5%), telangiectasia (16.3%), and polyps (16.3%). The CE scores varied from 0 to 8 ($mean{\pm}standard$ deviation, $4.09{\pm}1.8$). Five patients (11.6%) showed evidence of ongoing or recent bleeding due to PHE. Three of these five patients underwent endotherapy, and one patient underwent radiological coil placement. Conclusions: The PillCam SB3 CE system revealed a high prevalence of PHE in the patients with PH. Using this system, evidence of bleeding due to PHE was found in a small but definite proportion of the patients.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 1997.10b
• /
• pp.33-33
• /
• 1997

• Journal of Biomedical Engineering Research
• /
• v.28 no.4
• /
• pp.449-454
• /
• 2007

An electrohydraulic (EH) pump-driven closed-loop blood pressure regulatory system was developed based on flow-mediated vascular occlusion using the vascular occlusive cuff technique. It is very useful for investigating blood pressure-dependant physiological variability, in particular, that could identify the principal mediators of renal autoregulation, such as tubuloglomerular feedback (TGF) and myogenic (MYO), during blood pressure regulation. To address this issue, renal perfusion pressure (RPP) should be well regulated under various experimental conditions. In this paper, we designed a new EH pump-driven RPP regulatory system capable of implementing precise and rapid RPP regulation. A closed-loop servo-controlwas developed with an optimal proportional plus integral (PI) compensation using the dynamic feedback RPP signal from animals. An in vivo performance was evaluated in terms of flow-mediated RPP occlusion, maintenance, and release responses. Step change to 80 mmHg reference from normal RPP revealed steady state error of ${\pm}3%$ during the RPP regulatory period after PI action. We obtained rapid RPP release time of approximately 300 ms. It is concluded that the proposed EH RPP regulatory system could be utilized in in vivo performance to study various pressure-flow relationships in diverse fields of physiology, and in particular, in renal autoregulation mechanisms.

• Journal of the Korean Magnetics Society
• /
• v.21 no.5
• /
• pp.180-184
• /
• 2011

The changes in the blood flow in the peripheral vascular system under strong pulsed magnetic fields (pMF) were studied by digital infrared thermal imaging (DITI). After pMF stimulus temperatures in stimulated area were commonly increased in both groups of age and gender. In order to reduce heat generated from coil in pMF stimulus system plastic moldings were fabricated, so that certain distance was kept between stimulus system and the skin and to prevent direct contact to the skin. It is believed that skin temperature is increased by internal electromagnetic energy stimulated the peripheral vascular system by non-contact method.