• 제목/요약/키워드: Blood flow rate

검색결과 486건 처리시간 0.028초

동맥 유동해석을 위한 스펙트럴 요소의 개발 (Spectral Element Modeling for the Blood Flow through Artery)

  • 장인준;서보성;이우식
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2007년도 춘계학술대회논문집
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    • pp.383-386
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    • 2007
  • As the blood flow characteristics have been recognized to be closely related to various cardiovascular diseases, it is very important to predict them accurate enough in an efficient way. Thus, this paper proposes a one-dimensional spectral finite element model for the human blood vessels. The spectral finite element model is formulated in the frequency-domain by using the exact frequency dependent shape functions and applied to an ascending aorta.

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인조혈관 동정맥루의 혈액 투석량에 따른 인조혈관 내부 유동 특성에 관한 수치해석 연구 (NUMERICAL STUDY ON BLOOD FLOW CHARACTERISTICS IN A ARTERIOVENOUS GRAFT WITH DELIVERED DOSE DURING HEMODIALYSIS)

  • 김재열;노경철;유홍선
    • 한국전산유체공학회지
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    • 제16권4호
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    • pp.84-91
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    • 2011
  • Hemodialysis is essential for patients with end stage renal failure. It is important to improve the patency rate and to minimize occurrence of the stenosis. Also, the blood flow to the artificial kidney can affect the blood flow characteristics through arteriovenous graft. Thus, the delivered dose are important factors for analyzing hemodynamic characteristics during hemodialysis access. In this study, the numerical analysis was performed for the effect of the delivered dose during hemodialysis access on the blood flow through the graft. As a result, The adverse pressure gradient occurred in case of a larger delivered dose through a catheter than standard dose and the flow instability increased. Also the circulation flow appeared largely at anastomotic site of the vein when the delivered dose was exceeded about half blood flow of inlet blood flow.

혈액 투석 시 주사침에서의 투석량에 따른 인조혈관 내부 유동 특성에 관한 수치해석 연구 (Numerical Study on Blood Flow Characteristics in a Arteriovenous Graft with Delivered dose During Hemodialysis)

  • 김재열;노경철;유홍선
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2011년 춘계학술대회논문집
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    • pp.469-476
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    • 2011
  • Hemodialysis is essential for patients with end stage renal failure. It is important to improve the patency rate and to minimize occurrence of the stenosis. Also, the blood flow to the artificial kidney can affect the blood flow characteristics though arteriovenous graft. Thus, the delivered dose are important factors for analyzing hemodynamic characteristics during hemodialysis access. In this study, the numerical analysis was performed for the effect of the delivered dose during hemodialysis access on the blood flow through the graft. As a result, The adverse pressure gradient occurred in case of a larger delivered dose through a catheter than standard dose and the flow instability increased. Also the circulation flow appeared largely at anastomotic site of the vein when the delivered dose was exceeded about half blood flow of inlet blood flow.

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백서의 피부 및 뇌혈류에 미치는 고려홍삼 사포닌 및 비사포닌의 영향 (Effects of Crude Saponin and Saponin-free Fraction of Korea Red Ginseng on the Skin and Cerebral Blood Flow in the Rats)

  • 김신희;김국성;박진봉;한찬수;김광진;김신혜;김세훈;남기열;전병화
    • Journal of Ginseng Research
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    • 제26권3호
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    • pp.132-138
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    • 2002
  • 본 연구에서는 혈류량의 변화를 실시간으로 측정할 수 있는 레이져 도플러 혈류량측정장치를 이용하여 피부혈류 및 뇌혈류량에 미치는 고려홍삼의 사포닌과 비사포닌의 효능을 연구하고자 고려홍삼의 정맥내 복강내 및 구강내로 주입하고 혈류의 변화를 관찰하여 다음과 같은 결론을 얻었다. 고려 홍삼의 사포닌 성분은 피부혈류량에는 영향을 주지 않으나 뇌혈류량을 증가시키는 효능이 있다. 고려 홍삼의 비사포닌 성분은 피부혈류량 및 뇌혈류량에 거의 영향을 주지 않았다. 고려홍삼사포닌에 의한 뇌혈류량의 증가는 복강내 및 경구로 투여할 경우는 관찰할 수 있으나 정맥내로 직접 투여할 경우는 관찰되지 않았다. 이상의 결과를 종합해 볼 때 고려홍삼의 사포닌 성분은 뇌혈류량을 증가시키는 혈류개선작용이 있는 것으로 사료된다.

The Effect of Sun Ginseng on Hemodynamics and Body Temperature in Healthy Young Men

  • Lee, Jeeh-Wan;Cho, Jung-Ah;Ki, Chan-Young;Park, Jeong-Hill;Park, Man-Ki
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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    • pp.317.2-318
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    • 2003
  • The current study was performed to observe the effect of Sun Ginseng (SG) on hemodynamics such as blood flow rate (BF), blood flow velocity (BV), heart rate (HR), systolic blood pressure (SBP) and diastolic blood pressure (DBP), and body temperature (BT) in healthy young men. This is a randomized, single-blind study observed during 6 hrs after orally single administration of SG. (omitted)

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혈류지수를 이용한 비침습적 대뇌혈류증가 장치의 구현 (Implementation of Non-Invasive Cerebral blood Increasing Platform using PI)

  • 권성태;이진;김영길
    • 한국정보통신학회논문지
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    • 제21권9호
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    • pp.1761-1770
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    • 2017
  • 대뇌혈류증가 치료는 뇌경색에 가장 중요한 치료방법중 하나이다. 기존의 대뇌혈류증가 치료가 침습적으로 행해져옴에 따라 다수의 합병증을 유발할 수 있다는 문제점이 제기되고 있다. 따라서 이러한 문제점을 보완하기 위해 최근에는 비침습적 대뇌혈류증가 장치가 등장하였다. 하지만 현재 구현된 비침습적 대뇌혈류증가 장치는 속도와 정확성이 떨어지는 문제점이 제기되고 있다. 본 논문에서는 기존의 구현된 비침습적 대뇌혈류증가 장치의 단점을 보완하고자 다른 방식으로 시스템을 구현하여 대뇌 부위로 가는 혈류량을 우회적으로 증가시켜 최종대뇌 손상부위를 최소화 하는 것으로 목표로 한다. 본 논문에서 구현한 시스템은 사지압박을 진행함과 동시에 사지의 혈류지수를 측정하여 혈류지수가 일정 수치 이하로 떨어지는 압력을 찾아 사지압박을 통해 대뇌부위로 가는 혈류량을 우회적으로 증가시켜 혈류증강 치료를 실시한다. 이는 기존의 침습적 대뇌혈류증가 치료와 비교하여 합병증의 우려가 없고, 최종실험 결과 혈류량을 20% 이상 증가시키기에 환자에게 선택적으로 사용될 수 있다.

정상인(正常人) 및 각종(各種) 간질환(肝疾患) 환자(患者)에서 $^{198}Au$교질(膠質)의 혈중소실율치(血中消失率値)와 체위변동(體位變動)에 따른 간혈류량변화(肝血流量變化)에 관한 연구(硏究) (The Blood Disappearance Rate of $^{198}Au$-Colloid and Changes of Hepatic Blood Flow During Position Change in Normal Persons and in Patients with Various Hepatic Diseases)

  • 조보연;홍기석;고창순;이문호
    • 대한핵의학회지
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    • 제11권1호
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    • pp.33-37
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    • 1977
  • To evaluate the diagnostic significance of the blood disappearance rate of $^{198}Au$-colloid and to evaluate the change of hepatic blood flow during position change from supine to erect, we measured the half time of blood disappearance rate of $^{198}Au$-colloid using external counting method in 94 normal persons and in 77 patients with various hepatic diseases. The results obtained were as follows: 1. In normal control, the mean blood disappearance half time of $^{198}Au$-colloid in supine position was $2.7{\pm}0.4$ minutes. There was no significant difference of hepatic blood flow in age and sex. 2. In acute hepatitis, chronic hepatitis and hepatic cirrhosis, the mean blood disappearance half times in supine position were $3.0{\pm}0.45,\;3.5{\pm}0.74,\;7.2{\pm}3.6$ minutes respectively. The hepatic blood flow of the patients with chronic hepatitis and hepatic cirrhosis were significantly decreased than that of normal control. 3. In the normal control and acute hepatitis, the decreaces of the hepatic blood flow during the position change from supine to erect were 27.7% and 22.6% respectively.

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봉약침 자극이 사상체질별 건강인의 심박변이도, 맥파, 뇌혈류에 미치는 영향 (Effects of bee venom acupuncture on heart rate variability, pulse wave, and cerebral blood flow for types of Sasang Constitution)

  • 이상민;김구;오승윤;권영미;주종천
    • 대한약침학회지
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    • 제12권1호
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    • pp.35-42
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    • 2009
  • 1. Objectives To evaluate effects of bee venom acupuncture on cardiovascular system and differences according to each constitution. 2. Methods Heart rate variability, pulse wave and the velocity of cerebral blood flow were measured before bee venom acupuncture(BVA), right after and after 30 minuets, had been applied to 20 subjects. 3. Results 1. BVA did not have effects on measurement variables of heart rate variability. 2. BVA had effects on pulse wave, showing total time, radial augmentation index up and height of percussion wave, time to percussion wave, sum of pulse pressure down. 3. BVA did not have effects on the cerebral blood flow velocity when considering not Sasang Constitution. 4. Considering Sasang Constitution, BVA demonstrates different responses in time to preincisura wave, mean blood flow velocity, peak systolic velocity and end diastolic velocity. 4.Conclusion From those results, the following conclusions are obtained. Cause BVA alters pulse wave and makes differences in the cerebral blood flow velocity according to Sasang Constitution. Various methods of BVA treatment are needed considering Sasang Constitution.

사상체질별(四象體質別) 뇌혈류(腦血流) 변화(變化)에 대한 임상적(臨床的) 고찰(考察) (The Clinical Study about Difference of Cerebral Artery Blood Flow Velocity according to the Sasang Constitution)

  • 안탁원
    • 혜화의학회지
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    • 제11권1호
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    • pp.1-9
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    • 2002
  • 1. Purpose We inquire into difference of blood flow velocity according Sasang Constitution. 2. Method We selected observation group that they are 251 patients among of the patients who are had a medical early examination of stroke. We classified observation group by Sasang Constitution and compared each of measured blood flow velocity by TCD. 3. Result 1) We found out that Taeumin is highest in fat rate, height and blood pressure. 2) Blood flow mean velocity of MCA is not found out significant difference by Sasang Constitution. But, Taeumin is found out highest in left and right. 3) Taeumin is found out that blood flow velocity of Siphon sinus ICA is highest.

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정상인의 한냉자극에 대한 심박변이도 및 도플러 초음파 혈류계를 이용한 말초 혈류관찰 (Clinical Observation on Heart Rate Variability and Peripheral Blood Flow by Doppler Ultrasound in Healthy Subjects Stimulated by Cold Stress)

  • 임성근;이상훈;배영민
    • 대한한의학회지
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    • 제31권2호
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    • pp.114-123
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    • 2010
  • Objectives: This study was performed to investigate the effect of cold stress on heart rate variability and peripheral blood flow by Doppler ultrasound in healthy subjects. Methods: We classified the subjects by their Yin or Yang tendency using a Yin-Yang questionnaire. Cold stress was taken on the left hand of subjects for 10 seconds. Heart rate variability and peripheral blood flow were measured on the right radial artery before and after cold stress. Results: The Yang tendency group showed a significant decrease of heart rate after cold stress which was not seen in the Yin tendency group. The Yang tendency group showed a decrease of LF, total power, and increase of HF after cold stress, while the Yin tendency group showed the opposite. However, there were no statistically significant differences of heart rate variability analysis between the results of the two groups before and after cold stress. Recovery time of blood flow velocity by ultrasound Doppler was significantly different between the Yin and Yang tendency groups after cold stress. Conclusion: These results suggest that people with Yin or Yang tendency may show different responses in the autonomic nervous system. Further modified studies may include the responses to various manipulation techniques in acupuncture treatment and the individual responses according to pattern identification in traditional Korean medicine.