• 센서학회지
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• 제20권5호
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• pp.343-350
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• 2011

The compliance and stiffness of artery are closely related with disease of arteries. Pulse wave velocity(PWV) in the blood vessel is a basic and common parameter in the hemodynamics of blood pressure and blood flow wave traveling in arteries because the PWV is affected directly by the conditions of blood vessels. However, there is no standardized method to measure the PWV and it is difficult to measure. The conventional PWV measurement has being done by manual calculation of the pulse wave transmission time between coronary arterial proximal and distal points on a strip chart on which the pulse wave and ECG signal are recorded. In this study, a pressure sensor consisting of strain gauges is used to measure the blood pressure of arteries in invasive method and regular ECG electrodes are used to record the ECG signal. The R-peak point of ECG is extracted by using a reference level and time windowing technique and the ascending starting point of blood pressure is determined by using differentiation of the blood pressure signal and time windowing technique. The algorithm proposed in this study, which can measure PWV automatically, shows robust and good results in the extraction of feature points and calculation of PWV.

• 한국한의학연구원논문집
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• 제13권3호
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• pp.111-117
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• 2007

The study aims to measure and analyze the thickness and depth of blood vessel on the pulse diagnosis locations and the blood velocity through the use of ultrasonic waves (LOGIQ5PRO, GE Medical, U.S.) in order to understand the structural difference of pulse diagnosis locations. The subjects included 44 healthy men and women(22.28${\pm}$2.62 age) considered normal in terms of Body Mass Index(BMI). The thickness and depth of the blood vessel and the blood velocity were measured three times on CHON, KWAN and CHUCK to obtain the average value. Results showed there is a statistically significant difference among the variables measured on CHON, KWAN and CHUCK. A difference according to gender was also observed. This explains why an oriental medical doctor can tell the difference in pulses depending on the location of CHON, KWAN and CHUCK. In addition, the difference in pressure between CHON and KWAN was higher than that in pressure between KWAN and CHUCK. The findings explain why oriental medical doctors take pulses by dividing CHON, KWAN and CHUCK in the short length of the three fingers. It can be used to develop a pulse diagnosis device enabling accurate measurement according to the characteristics of blood vessel structure based on where the pulse is taken. Furthermore, the results can be used as basic data for the development of a pulse diagnosis simulator.

• 대한약침학회지
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• 제6권2호
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• pp.91-104
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• 2003

Objective : This study was carried to make out the connection between cerebral artery blood flow velocity and ischemic theory that presumed the cause of Bell's palsy. Method : We measured cerebral artery blood flow velocity each external carotid artery, internal carotid artery, common carotid artery, siphon, superficial temporal artery by TCD to 20 patients who diagnosed as facial nerve palsy from march 2001 to July 2001 and all objectives devided two groups as palsy side. A group is right side facial nerve palsy and B group is left facial nerve palsy. Results : 1. There is no effective change of blood flow in external carotid artery either A, B group. 2. There is no effective change of blood flow in internal carotid artery either A, B group. 3. There is no effective change of blood flow in common carotid artery either A, B group. 4. There is no effective change of blood flow in siphon artery either A, B group. 5. There is no effective change of blood flow in superficial temporal artery either A, B group.

• 한국가시화정보학회지
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• 제8권1호
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• pp.46-52
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• 2010

In the present study, we employed the confocal laser scanning microscopy (CLSM) system to visualize the blood flow field with $1{\times}1{\mu}m^2$ spatial resolution. Based on the confocal microscopic image of red blood cells (RBCs), we performed the velocity vector field measurement and evaluated characteristics of cell migration from the cell depleted layer thickness calculation. The rat and mouse's blood were supplied into a micro glass tubes in vitro. The line scanning rate of confocal microscopy was 15 kHz for a $500{\times}500$ pixels image. As a result, the red blood cell itself can be used as a tracer directly without any kind of invasive tracer particle to get the velocity vector field of blood flow by performing particle image velocimetry (PIV) technique.

• Physical Therapy Rehabilitation Science
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• 제3권2호
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• pp.86-92
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• 2014

Objective: Whole body vibration (WBV) and plyometrics are common training techniques which increase strength, blood flow, and lower body force and power. The effects these techniques have on sedentary population is unknown. It is our aim to assess the effectiveness of WBV and plyometrics on sedentary population. Design: Experimental study. Methods: Twenty-seven sedentary subjects were assigned to either the control group, jumping only group, or jumping with vibration group. Jump height (myotest or vertec), velocity, force, blood lactates, and rating of perceived exertion (RPE). Subjects were measured on the initial, seventh, and eighteenth visits. Control group attended measurements only. Jumping only and jumping with vibration groups performed jumping from a vibrating platform to a surface 7 1/2 inches higher for 3 bouts of 20 seconds. Each subject in jumping only and jumping with vibration groups attended three times per week for six weeks. Vibration was set at 40 Hz and 2-4 mm of displacement. Results: There was no significant change among groups in force, velocity, vertec height, and myotest height. However there was a significant increase in vertec height from initial to final measure (p<0.05) for jumping with vibration group. RPE was significantly higher between control group and jumping with vibration group after intervention (p<0.05). Conclusions: WBV with vibration increased jump height. Jumping with vibration group experienced increased exertion than for controls. WBV with plyometrics had no effect on force, velocity, blood lactates, or calculated jump height. Further studies controlling for initial measure of blood lactates and using an external focus may be necessary to elicit velocity, force and jump height changes.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.105-106
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• 2008

As a carrier of malaria and sneak of blood, mosquitoes are an unpleasant insect. However, there are several unknown natural secretes related with mosquitoes. Among them, we focused on the blood sucking process of a female mosquito. The main objective of this study is to understand the mosquito's blood sucking mechanism that can be used to resolve the problem encountered in the injection or transport of infinitesimal biological fluids in a micro-chip. At first, the velocity fields of blood-sucking flow in a proboscis were measured using a micro-particle image velocimetry (PIV) technique. The velocity signals of flow in the proboscis show periodic variation. This seems to be resulted from the beating of the pharyngeal pump which works as driving power. To analyze the pumping mechanism, the temporal variation of the pharyngeal pump was visualized using the synchrotron X-ray micro-imaging technique. The volume variation was estimated by the help of digital image processing techniques. Once the main mechanism of blood sucking process was found, a effective micro-pumping system with high efficiency would be developed in near future.

• Korea-Australia Rheology Journal
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• 제21권2호
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• pp.119-126
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• 2009

A numerical analysis is performed to investigate the effect of rotation on the blood flow characteristics with four different angular velocities. The artery has a cylindrical shape with 50% stenosis rate symmetrically distributed at the middle. Blood flow is considered a non-Newtonian fluid. Using the Carreau model, we apply the pulsatile velocity profile at the inlet boundary. The period of the heart beat is one second. In comparison with no-rotation case, the flow recirculation zone (FRZ) contracts and its duration is reduced in axially rotating artery. Also wall shear stress is larger after the FRZ disappears. Although the geometry of artery is axisymmetry, the spiral wave and asymmetric flow occur clearly at the small rotation rate. It is caused that the flow is influenced by the effects of the rotation and the stenosis at same time.

• 대한의용생체공학회:의공학회지
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• 제7권1호
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• pp.75-79
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• 1986

In this paper, a multigate pulsed doppler system with parallel signal processing which enables the transcutaneous assesment of the blood-flow velocities of five adjacent sample volumes is developed. The outputs of the system are audio signals, velocity curves and velocity profiles of 5 adjacent sample volumes. We have applied to the major superficial arteries and obtained the detailed information about the time dependent blood-flow behavior.

• 대한의용생체공학회:의공학회지
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• 제26권3호
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• pp.157-161
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• 2005

Direct injection of a fibrinolytic agent to the intraarterial thrombosis may increase the effectiveness of thrombolysis by enhancing the permeation of thrombolytic agents into the blood clot. Permeation of fibrinolytic agents into a clot is influenced by the surface pressure, which is determined by the injection velocity of fibrinolytic agents. In order to calculate the pressure distribution on the clot surface for different jet velocities (1, 3, 5 m/sec) and nozzle arrangements (1, 9, 17 nozzles), computational fluid dynamic methods were used. Thrombolysis of a clot was mathematically modeled based on the pressure and lysis front velocity relationship. Direct injection of a thrombolytic agent increased the speed of thrombolysis significantly and the effectiveness was increased as the ejecting velocity increased. The nine nozzles model showed about $20\%$ increase of the lysed volume, and the one and seventeen nozzles models did not show significant differences. The wall shear stress decreased as the number of nozzles increased, and the wall shear stress in most vessel wall was lower than 25 Pa. The results implied that thrombolysis could be accelerated by direct injection of a drug with the moderate velocity without damaging the blood vessel wall.

• 대한수의학회지
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• 제37권3호
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• pp.661-668
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• 1997

Portal blood flow was measured with pulsed doppler ultrasound in thirty normal dogs. In normal dogs, the average portal blood flow velocity was $17.03{\pm}1.75cm/sec$ and the average portal blood flow was $41.59{\pm}10.10ml/min/kg$. The incident angle between the doppler beam and the portal vein averaged $65^{\circ}$. The average portal vein sectional area was $0.41{\pm}0.14cm^2$. The Congestion index was $0.0245{\pm}0.0081cm{\cdot}sec$. Conclusively, the spectral doppler ultrasonography was quick, non-invasive and simple diagnostic method in circulatory disorders of liver.