• Title/Summary/Keyword: Blood flow area

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Implementation of the Blood Pressure and Blood Flow Variation Rate Detection System using Impedance Method (임피던스법을 이용한 혈압 및 혈류 변화량 검출 시스템 구현)

  • Ro, Jung-Hoon;Bae, Jin-Woo;Ye, Soo-Young;Shin, Bum-Joo;Jeon, Gye-Rok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.8
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    • pp.1926-1938
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    • 2009
  • In this study, detection system of the blood flow variation rate was implemented using the variation effect of bio electric impedance at time of the blood pressure measurement by means of impedance method. The blood pressure measurement was performed by the oscillometric method. The mean arterial pressure was calculated using maximum amplitude algorithm. The systolic and diastolic pressure were estimated by establishment of the various characteristic ratio according to mean arterial pressure range. Alternative static current source and lock_in amplifier were introduced to impedance measurement. The variation of blood volume was measured using variation bio impedance according to induced cuff pressure at measuring area.

Computational Study of the Magnetically Suspended Centrifugal Blood Pump (2nd Report: Pressure Fluctuation and Stability of Impeller Rotation for Different Volute Shapes)

  • Ogami, Yoshifumi;Matsuoka, Daisuke;Horie, Masaaki
    • International Journal of Fluid Machinery and Systems
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    • v.4 no.4
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    • pp.375-386
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    • 2011
  • The turbo-type blood pump studied in this paper has an impeller that is magnetically suspended in a double volute casing. The impeller rotates with minimal fluctuations caused by fluid and magnetic forces. In order to improve stability of the rotating impeller and to facilitate long-term use, a careful investigation of the pressure fluctuations and of the fluid force acting on the impeller is necessary. For this purpose, two models of the pump with different volute cross-sectional area are designed and studied with computational fluid dynamics software. The results show that the fluid force varies with the flow rate and shape of the volute, that the fluctuations of fluid force decrease with increasing flow rate and that the vibratory movement of the impeller is more efficiently suppressed in a narrow volute.

THE PROCESS OF THE DEVELOPMENT OF HYPOXIA IN AN ABNORMAL BLOOD FLOW

  • Kwak, Min-Kyu;Shin, Byeong-Chun;Go, Jae-Gwi
    • Honam Mathematical Journal
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    • v.30 no.1
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    • pp.75-89
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    • 2008
  • Interrupted blood flow diminishes the concentration of oxygen in tissues. Hypoxia first appears in the region distal to the capillaries and grows throughout the entire t issue. However, the time-wise evolution of hypoxic area is diverse when some of capillaries are blocked in a multi-capillary domain with different oxygen squirt. The process of the development of hypoxia through time course is analyzed mathematically in the domain. Each source in steady state is controlled by a time sensitive function to simulate the occlusion.

Analysis of hemodynamics in cerebral artery related to moyamoya disease (모야모야병과 연관된 뇌동맥에서의 혈류역학 분석)

  • Lee, Seung-Cheol;Lim, Ki-Moo;Shim, Eun-Bo
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1647-1650
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    • 2008
  • The moyamoya disease is a type of cerebrovascular disease which produces thin abnormal blood vessels like haze in the brain base because the end of internal carotid artery which supplies about 80% of blood is blocked. Regarding this moyamoya disease, the shearing stress and thrombus generation are mentioned as its main causes. This study three-dimensionally implemented the ICA, ACA, and MCA parts of the cerebrovascular configuration related to the moyamoya disease, and analyzed the hydrodynamic phenomenon with the commercial program ADINA. In particular, the correlations between shearing stress and speed distribution according to the branch angle of ACA and MCA. A numerical analysis found that the greater the branch angle of ACA and MCA, the lower the shearing stress and the greater the stationary area of the flow.. Put Abstract text here.

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Development of Cerebral Blood Flow (뇌혈류 측정 기기의 개발)

  • Kim, Jeong-Lae;Kim, Jeong-Yeol;Kim, Deok-Won;Nam, Moon-Hyon
    • Proceedings of the KOSOMBE Conference
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    • v.1989 no.05
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    • pp.67-69
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    • 1989
  • In this paper, principles of Rhcoencephalography(RBG) was described and RBG was designed and developed. Using the developed instrument, RBG waveforms of the left and right brain, RBG waveform changes by posture, were observed. It was found that RBG waveforms could be observed noninvasively. RBG can be easily applied for testing the effect of various drugs related to CBF(Cerebral blood flow) since it is quite sensitive to the relative changes of CBF. Various cerebral diseases can be diagnosed by analyzing the RBG waveforms. The area of restricted cerebral blood vessels can be located by arranging the appropriate electrode configuration.

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Automatic Proximal Isovelocity Surface Area Determination using Non-hemispherical Flow Model and Region Based Contour Scheme for Blood Flow Rate Estimation (비반구 유동모델과 영역기반 윤곽선 기법에 기초한 자동근위 등속표면적의 결정 및 혈류량 추정)

  • 진경찬;조진호
    • Journal of Biomedical Engineering Research
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    • v.21 no.5
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    • pp.449-455
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    • 2000
  • 순간적으로 승모판에서 혈류가 역류하는 영역을 측정하기 위해서, PISA 방법이 자주 이용되고 있다. 이 방법은 물질보존법칙에 근거하여, 구멍을 통과하는 유체량을 isotach 표면적과 이에 대응하는 속도의 곱으로 구하는 것이다. 이러한 PISA 방법에서 사용되는 유동모델은 반구모델과 비반구모델의 형태인데, 이는 isotach 표면적이 반구이거나 비반구임을 가정하여 계산된 것이다. 이러한 isotach 모델링에서는 isotach의 높이와 폭의 결정이 유체량을 추정하는데 아주 중요한 변수가 된다. 본 연구에서는 in-vitro 칼라 도플러 영상으로부터 PISA 영역을 추정을 위하여 영역기반을 근간으로 하는 비반구모델에 대한 표면적 추정방법을 제안하였다. 이 방법의 타당성을 알아보기 위해 180개의 칼라 도플러 영상에 대해 isotach의 높이와 폭을 추정한 결과, 기존의 에지기반방법이 19개 영상에서 에러를 가지는 반면, 제안한 방법에서는 에러영상이 없음을 알 수 있었다.

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Effect of Relaxin Expressing Adenovirus for Rat Skin Flap Viability (Relaxin을 분비하는 아데노바이러스가 피판의 생존에 미치는 영향)

  • Yun, In-Sik;Park, Yong-Sun;Cheon, Young-Woo;Jeon, Yeo-Reum;Lee, Won-Jai;Yun, Chae-Ok;Rah, Dong-Kyun
    • Archives of Plastic Surgery
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    • v.37 no.5
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    • pp.519-525
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    • 2010
  • Purpose: Of various effects of relaxin, we assumed that anti-fibrotic effects, neovascularization effects and vasodilatation effects of relaxin might enhance the survival rate of skin flap. In the current study, we used adenovirus expressing relaxin genes to examine whether these genes could enhance the survival rate of a skin flap. Methods: A total of 30 Sprangue-Dawley rats were divided into three groups: RLX group (10; relaxin virus injected group), CTR group (10; no gene coded virus injection group), and PBS group (10; PBS injected group). Each group was intradermally injected with the virus ($10^7$ PFU) and PBS 48 hours before and immediately before the flap elevation. A distally based flap $3{\times}9\;cm$ in size was elevated on the dorsal aspect of each rat. Following this, a flap was placed in the original location and then sutured using a #4-0 Nylon. A surviving area of the flap was measured and then compared on postoperative days 3, 7 and 10. Using a laser Doppler, the amount of blood flow was measured. On postoperative day 10, tissues were harvested for histologic examination and the number of blood vessels was counted. Results: There was a significant increase in the area of the flap survival in the RLX group on postoperative days 3 and 7. The Doppler measurement also showed significantly increased blood flow immediately after the operation and on postoperative days 7 and 10. The number of blood vessels was significantly greater in the RLX group in the tissue harvested on postoperative day 10. The VEGF concentration was significantly higher in the RLX group than others in the tissues harvested on postoperative day 10. Conclusion: Following an analysis of the effects of relaxin-secreting adenovirus on the survival of a flap, the surviving area of the flap and the blood flow also increased. A histopathology also showed an increase in the number of blood vessels and the concentration of VEGF.

Trans-Aortic Flow Turbulence and Aortic Valve Inflammation: A Pilot Study Using Blood Speckle Imaging and 18F-Sodium Fluoride Positron Emission Tomography/Computed Tomography in Patients With Moderate Aortic Stenosis

  • Soyoon Park;Woo-Baek Chung;Joo Hyun O;Kwan Yong Lee;Mi-Hyang Jung;Hae-Ok Jung;Kiyuk Chang;Ho-Joong Youn
    • Journal of Cardiovascular Imaging
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    • v.31 no.3
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    • pp.145-149
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    • 2023
  • BACKGROUND: 18F-sodium fluoride positron emission tomography/computed tomography (18F-NaF PET/CT) has been proven to be useful in identification of microcalcifications, which are stimulated by inflammation. Blood speckle imaging (BSI) is a new imaging technology used for tracking the flow of blood cells using transesophageal echocardiography (TEE). We evaluated the relationship between turbulent flow identified by BSI and inflammatory activity of the aortic valve (AV) as indicated by the 18F-NaF uptake index in moderate aortic stenosis (AS) patients. METHODS: This study enrolled 18 moderate AS patients diagnosed within the past 6 months. BSI within the aortic root was acquired using long-axis view TEE. The duration of laminar flow and the turbulent flow area ratio were calculated by BSI to demonstrate the degree of turbulence. The maximum and mean standardized uptake values (SUVmax, SUVmean) and the total microcalcification burden (TMB) as measured by 18F-NaF PET/CT were used to demonstrate the degree of inflammatory activity in the AV region. RESULTS: The mean SUVmean, SUVmax, and TMB were 1.90 ± 0.79, 2.60 ± 0.98, and 4.20 ± 2.18 mL, respectively. The mean laminar flow period and the turbulent area ratio were 116.1 ± 61.5 msec and 0.48 ± 0.32. The correlation between SUVmax and turbulent flow area ratio showed the most positive and statistically significant correlation, with a Pearson's correlation coefficient (R2) of 0.658 and a p-value of 0.014. CONCLUSIONS: The high degree of trans-aortic turbulence measured by BSI was correlated with severe AV inflammation.

Injury and inflammation detection by the application of microcurrent through the skin

  • Hui, Timothy;Petrofsky, Jerrold
    • Physical Therapy Rehabilitation Science
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    • v.2 no.1
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    • pp.31-38
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    • 2013
  • Objective: To determine the efficacy and reliability of measuring direct current microcurrent applied through the skin to determine injury in the underlying tissues. Design: Case control study. Methods: First, microcurrent was measured as decreased blood flow induced hypoxia in healthy subjects. Next, reliability was assessed by measuring over ten days with set variations in pressure and distance between the electrodes. Finally, measurements over sprained ankle were compared to measurements over comparable uninjured areas on the same injured subject. Results: For the blood flow test phase, microcurrent significantly decreased an average of 17% after 5 minutes (p<0.05), remained decreased for 30 seconds, and returned to non-occlusive levels after 2 minutes of normal circulation. The results indicate that the microcurrent decrease was not due to blood flow, and most likely from hypoxic cellular damage. For the reliability phase, the coefficients of variation averaged 10.3% for the shoulder, 14.8% for the low back, and 29.1% for the knee. Changing distance 2.5 cm between the electrodes resulted in insignificant changes. Changes in pressure had some significant effect after an increase in force of 2.6 N, affirming the need for consistent pressure for measurement. For the injury test phase, a significant 69% decrease occurred comparing injured areas to the same area on the uninjured side, and a significant 74% occurred comparing injured and non-injured areas on the same limb. Conclusions: Microcurrent through the skin shows promise as an objective method of assessing a soft tissue injury by detecting damage likely due to hypoxia.

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Analysis of Scopoletin Content and Effect on Regional Cerebral Blood Flow (인진쑥의 scopoletin함량 분석 및 뇌혈류량에 미치는 영향)

  • Ko, Jin-Sik
    • The Journal of Traditional Korean Medicine
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    • v.15 no.1
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    • pp.90-96
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    • 2006
  • In this study, Artemisia capillaris, which has been used as oriental medicine area and folks remedy, was investigated for effective substance (scopoletin) analysis. As an attempt to develop new functional beverage by using medicinal herb, Artemisia capillaris. Therefore we investigate the effect of scopoletin in Artemisia capillaris on vessel and regional cerebral blood flow (rCBF) of rats. Artemisia capillaris extract was significantly decreased vessel constraction and significantly increased rCBF. Artemisia capillaris has often been cited in medical literature for its medicinal effects. Although the Korean Food and Drug Administration indicated Artemisia capillaris as the In-Jin-Sook which was allowed as a food stuff. From the view point of the subjects who eat In-Jin-Sook products, most of them ingested it for a certain pharmacological efficacy rather than as a beverage or a food. According to this facts, we need develop functional foods using In-Jin-Sook. Also scopoletin, get known to smooth muscle relaxation content was 326.13 ug/g. These results demonstrate that Artemisia capillaris has pharmaceutical effects and balanced nutritional contents. In according with Artemisia capillaris has a sufficiency of the terms use of food stuff in functional foods.

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