• Proceedings of the KOSOMBE Conference
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• v.1996 no.05
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• pp.207-212
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• 1996

We developed pneumatic blood pump and its driving system as a pediatric ventricular assist device. The blood pump is diaphragm type system and its blood contacting area is coated with Bio-Span. The driving unit Is consists of dual pumps, valves for the reliable blood pumping and its controller uses 80C196(Intel) as a main processor. The acute animal experiment was performed with dogs and its body weight is about 20 kg. The maximum cardiac output is about 2.1 l/min and the pressure and flow curves showed reliable operation as assist device.

• Journal of Biomedical Engineering Research
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• v.21 no.4
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• pp.411-417
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• 2000

This paper describes the analysis of the oscillometric method based on the shape of arterial pressure and proposal of a new algorithm for estimating the blood pressure by computer simulation. In the first step, the arterial pressure model which is able to control the shape of arterial pressure was designed and then we simulated the oscillometric model using both the existing exponential model showing the static arterial pressure-volume relation and the designed arterial pressure model. By analyzing the correlation of characteristic ratio based on the shape of arterial pressure, we could find that the characteristic ratio was not the only standard parameter for estimating systolic and diastolic pressure. We were able to estimate the shape of arterial pressure by computing the correlation of arterial pressure shape with oscillation shape. Finally, we proposed an algorithm which is able to estimate systolic and diastolic pressure according to pressure(Pp) table constructed from the relation of maximum amplitude of oscillation and arterial pressure shape. We tested 60 arterial pressure waveforms having various arterial pressure shape and pulse. As a results, the absolute deviation average values of the estimation of systolic, diastolic and mean pressure were 1.62%, 2.40% and 2.20%, respectively. In conclusions, the proposed algorithm showed the possibility of usefullness in estimating the blood pressure.

• Journal of Biomedical Engineering Research
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• v.18 no.2
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• pp.147-156
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• 1997

Various prosthetic heart valves have been developed and used clinically, but they have problems, such as thrombogenecity, hemoltsis, high cost and low durability. New types of trileaflet polymer heart valves have been developed in order to use them as inlet and outlet valves in a ventricular assist device. The aim of this study is to determine the hydrodynamic effectiveness of the newly designed trileaflet polymer valves and their feasibility for temporary use in the blood pumps. Trileaflet polymer valves are made of polyurethane, because of its good blood compatibility, high tonsil strength and good resistance to fatigue. An in vitro experimental investigation was perf'ormed in order to ev91ua1e hydrodynamic performance of the trileaflet polymer valves having different design and fabrication tech- niques. The St. Jude Medical valve (SJMV) and floating-type monoleaflet polymer valve (MLPV) were also tested The pressure drop across the valve, leakage volume, and the flow patterns mere investigated for valves. The result of comparative tests showed that the trileaflet polymer valves had a better hydrodynamic performance than the others. TPV which has two stable membrane shape showed the lowest back flow. The pressure hops of TPVs were lower than that of MLPV, but slightly higher than SJMV. The hydrodynamic performance of valves under the pulastile flow showed the similar results as steady flow. The velocity profiles and turbulent intensities were measured at the distal sites of valves using a hot-film anemometer. Central flow was maintained in trileaflet polymer valves, and the maximum turbulent intensities were lower in TPVs comparing to MLPV.

• Archives of Pharmacal Research
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• v.18 no.3
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• pp.169-172
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• 1995

The changes in blood pressure may relate to the alterations of the responsiveness to vasoconstrictors and vasodilators, and these alterations can arise the modifications in the properties of angiotensin II (AII) receptor. In order to examine the changes of AII receptor in the hypertensive mechanism of renin-dependent hypertensive rats (RHRs; two-kidney, one-ligated type), we compared the equilibrium binding characteristics of $[^3H]$All in adrenal cortex and medulla from RHRs and normotensive rats. The dissociation constants of AII binding in both tissues of RHRs were very similar to those in the respective tissue of normotensive rats. However, the maximum binding was increased from 805 to 1050 fmole/mg protein in the adrenal cortex of RHRs, and decreased from 172 to 126 fmole/mg protein in the adrenal medulla of RHRs. These results imply that the up- and down-regulation of the All receptor population on the cell surface of adrenal glands from RHRs are consorted with the elevation of blood pressure and the activation of renin-angiotensin system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.559-564
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• 2001

In order to apply into a compact and reliable centrifugal blood pump, this paper introduces a self-bearing motor in which a rotor is rotated without contact. The rotor is actively controlled in only radial directions, while the axial and tilting motions are passively stable owing to the disk-shape structure of the rotor. A prototype was made in outer-rotor type that is far better in the compactness than inner-rotor type. The prototype could be driven up to 8000 rpm with the rotor vibration under 0.12mm. The maximum cardiac output and pressure head were 9 L/min and over 200 mmHg, respectively. These experimental results show that the proposed self-bearing motor has sufficient performance for application to a real blood pump.

• Korean Journal of Adult Nursing
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• v.16 no.3
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• pp.460-469
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• 2004

Purpose: The purpose was to investigate the physiological parameter and physical health status and health perception in the elderly, and to find the correlation between these variables. The subjects were 139 in Kyungi senior center. Method: The instruments for this study were physiological parameters, which were composed of vital capacity, blood pressure, pulse oxygenation, hand grip power, body fat and physical health status scale developed by researcher, and health perception scale developed by Ware(1976). The data were analyzed by the SPSS-PC 11.0 version. Results: 1) 7.9% of subjects were included in abnormal range of vital capacity, 40.3% were systolic hypertension and 11.5% were diastolic hypertension. And 92.1% were included in normal range of pulse oxygenation, 79.8% were weakened hand grip power, and 10.1% of subjects were included in normal range of body fat. 2) The total mean score of the physical health status was 26.34 of a possible maximum score of 45. The physical health status score of women was lower than man's. 3) The mean score of man's health perception was 24.52 and women's was 20.39 of a possible maximum score of 44. 4) There was a significant positive correlation between hand grip power and physical health status(r=.28, p=.001). And a significant correlation between physical health status and health perception was found (r=.24, p=.004). Conclusion: It is concluded that the blood pressure, hand grip power and body fat among the physiological parameters of elderly subjects in Kyungi senior center were included in abnormal range. The factors were related life style. therefore, it is suggested that the health education to change life style for the elderly is needed.

• Korean Journal of Acupuncture
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• v.19 no.2
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• pp.41-49
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• 2002

Objectives : The aim of the present study is to observe effects of acupuncture related with the nerve system, Inferior mesenteric nerve activity(IMNA) was examined on BL60 acupuncture closely connected with the bladder and HT8 with little tied. Materials and methods : Acupunctures were performed during 100 seconds after stabilization. IMNA was measured by micromanipulator, preamplifier, mean arterial pressure(MAP) and heart rate were observed by blood pressure transducer, 4-channel transducer amplifier in anesthetized rat. Results : On BL60 acupuncture, the heart rate was not significantly decreased but IMNA, MAP were significantly decreased and Maximum peak of IMNA was increased during inserted acupuncture, decreased after ejected acupuncture respectively. On HT8 acupuncture, IMNA was decreased during acupuncture than before acupuncture but the others did not showed signigicant difference. Conclusions : Our results demonstrated a meridian interaction between BL60 acupoint in the bladder channel and Inferior mesenteric sympathetic nerve related to the bladder. This fact suggest that BL60 acupuncture have effect on the bladder through the nerve system. Meanwhile, IMNA was decreased during HT8 acupuncture. This result is supposed HT8 to have not meridian function but acupoint function by another mechanism. It needs to be closely examined other meridians and nerve by the optimal approaching method.

• Journal of Korea Entertainment Industry Association
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• v.14 no.4
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• pp.333-340
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• 2020

This study aims to examine the effects of squat exercise on the vitality and balanced capacity of female university students in their 20s with lower blood flow control. This study selected 40 volunteers from normal adult women in their twenties. Blood flow restriction used Blood Flow Restriction bands (BFR bands). The application method was to put on a blood flow restriction belt in the lower leg of the restricted blood flow area and put 120 mmHg of pressure to limit blood flow while the subject was standing comfortably. It was found that there were statistically significant differences in Height, Maximum concentric power and Take off speed between two groups(p<.05), There was statistically unimportant differences in foot scan between two groups(p>.05). This study found that to find out the changes in balance and alacrity, the experimental and control groups were divided into two groups. In conclusion, there were no significant differences in balance capability, but there were significant differences over time in net power.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.2
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• pp.136-143
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• 2018

The rate pressure product (RPP) is expressed as a product of the heart rate and systolic blood pressure as an index indirectly measuring the myocardial oxygen consumption, and it indicates the burden on the myocardium. The aim of this study was to determine the optimal level of RPP for preventing metabolic syndrome in a treadmill exercise test in Korean adults. Metabolic syndrome was the diagnosis of the third executive summary report on the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) criteria. According to the criteria, the metabolic syndrome diagnosis group (MetS, N=25), pre-metabolic syndrome group (Pre-MetS, N=106), and non-risk factor group (Non-MetS, N=65) were classified. The exercise stress test was performed based on the Bruce protocol. The RPP was calculated as (heart rate${\times}$systolic blood pressure)${\div}1,000$. The results showed that the maximum systolic blood pressure was high despite the low daily dose reached in the diagnostic group of metabolic syndrome. The optimal threshold of the RPP at the time of the exercise treadmill test for a metabolic syndrome prediction was $12.56mmHg{\times}beats/min{\times}10^{-3}$ in the first stage of the exercise stress test. The second stage of the exercise test was $16.94mmHg{\times}beats/min{\times}10^{-3}$, and at the third stage of the exercise test was $21.11mmHg{\times}beats/min{\times}10^{-3}$.

• Proceedings of the Korean Society of Life Science Conference
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• 2002.12a
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• pp.48-60
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• 2002

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a cytokine that stimulates the production of granulocytes, macrophages, and white blood cells. The effects of osmotic pressure on secretion of human GM-CSF into the culture medium were investigated in suspension cultures of transgenic tobacco cells. An increase in osmotic pressure caused by the addition of mannitol decreased the cell size index, with the effect being more pronounced when cells were measured wet rather than dry. Increased osmotic pressure enhanced the secretion of hGM-CSF. At 90 g/L mannitol, the maximum concentration tested, hGM-CSF was present in the culture medium at 980 ug/L. As the concentration of mannitol increased, the total amount of protein secreted also increased, but was disproportionately enriched in GM-CSF NaCl, another osmoticum, had very similar effects on cell growth and hGM-CSF production, but did not cause enrichment for hGM-CSF Additionally, protein-stabilizing polymer was added to culture broth to enhance stability of secreted recombinant protein. Finally, above two method were applied together to maximize the productivity.