• 대한방사선기술학회지:방사선기술과학
• /
• 제31권4호
• /
• pp.379-387
• /
• 2008

반접현상(Aliasing)을 제거하기위한 방법 중 속도범위(velocity scale)를 높이는 방법은 동일 조건하에서 속도범위를 높여줌으로써 혈류의 방향이 반대로 나타나는 현상이 점차 사라지는 것을 확인할 수 있었다. Doppler angle을 $0^{\circ}$에 가깝게 하는 실험에서는 각도의 변화에 따른 스펙트럼 파형에서 유의한 차이점을 발견을 하지 못했다. 실제 초음파 검사(Ultrasonography)를 시행할 때는 검사의 편의성과 신속성, 정확성을 고려해서 속도범위에 변화를 주어 검사함으로써 보다 정확한 검사가 시행되리라고 본다. 또한 Doppler Angle에 따라 혈류속도는 기하학적으로 증가하였으며, $70^{\circ}$ 이상에서는 측정불가능 할 정도로 수치가 급상승하여 혈류속도가 Doppler Angle에 크게 의존한다는 것을 알 수 있었다. 혈류의 방향에 따른 실험에서는 입사각이 $60^{\circ}$ 이상에서 오차범위가 증가하였고, $70^{\circ}$ 이상에서는 매우 큰 차이를 보였다. 따라서 입사각은 $60^{\circ}$ 이하가 적당하다고 보며, 사지 혈관(extremity vessel)의 혈류속도를 구하는 데 있어서 Doppler 각도는 $45^{\circ}$에서 $60^{\circ}$가 적절한 것으로 사료된다.

• 동의생리병리학회지
• /
• 제23권6호
• /
• pp.1491-1496
• /
• 2009

Stroke is usually associated with the cerebral blood flow of the central nervous system. However, studies concerning the effects of neurologic sysmptoms induced from stroke on the peripheral blood flow has not taken place sufficiently. To ascertain the feasibility of a blood flow meter adopting to use doppler ultrasonogrphy, under the prospect that hemiparesis induced from stroke may have effect on the peripheral blood flow, the peripheral blood flow velocity was observed. The control group made up of healthy people without any factors capable of effecting the peripheral blood flow velocity, and patient group which consist of hemiparetic people induced from stroke, were recruited. Volumes of recruitment are 21 persons in the patient group, and 29 persons in the control group, but the final numbers of people are 17 and 21 respectively because of the inconsistancy in the method of the test. The non-invasive method of Doppler effect of Ultrasound was used to measure the blood flow velocity. The blood flow velocity in the peripheral part of left and right fourth fingers:dorsal branches of proper palmar digital artery to dorsum of distal phalanges, was measured in the control group and patient group through Doppler Ultrasound. In comparison of the control group and the patient group, the systolic blood flow velocity from the peripheral part of the upper extremity was lower in the patient group than that of the control group. According to such results, it is concluded that hemiparesis induces the reduction of the peripheral blood flow velocity in the systolic phase.

• 대한약침학회지
• /
• 제12권1호
• /
• pp.35-42
• /
• 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.

• 대한정형도수물리치료학회지
• /
• 제8권2호
• /
• pp.5-17
• /
• 2002

The aim of study carried out to determine the effects of myofascial release on the cranial arteries velocity from November 11, 2001 to March 29, 2002 the objects were 10 patients who having the tension-type headache at H-hospital This research compared with measure the mean flow velocity middle cerebral artery, posterior cerebral artery, vertebral cerebral artery. Result obtain were as follows; 1. Middle cerebral artery blood velocity between pre treatment and after treatment for 10days experiment was significantly increased 9.76cm/s(p<0.05)in right, 4.88cm/s(p<0.05)in left. 2. Posterior cerebral artery blood velocity between pre treatment and after treatment experiment was difference 6.35cm/s(p<0.01)in right, 5.14cm/s(p<0.01)in left, between pre treatment and after treatment for 5days experiment was 11.48cm/s(p<0.01)in right, 10.74cm/s(p<0.01)in left, between pre treatment and treatment for 10days experiment was 12.92cm/s(p<0.001) in right, 12.68cm/s(p<0.001) in left. 3. Vertebral artery blood velocity between pre treatment and post treatment experiment was difference 4.48cm/s(p<0.05)in right, 6.10cm/s(p<0.05) in left, between pre treatment and after treatment for 5days experiment was 12.50cm/s(p<0.001)in right, 14.40cm/s(p<0.001)in left, between pre treatment and after treatment for 10days experiment was 14.70cm/s(p<0.001)in right, 13.90cm/s(p<0.001)in left.

• 대한의용생체공학회:의공학회지
• /
• 제31권2호
• /
• pp.99-105
• /
• 2010

In order to obtain velocity profile of blood flow with high spatial resolution, a micro PIV technique consisted of a fluorescent microscope, double-pulsed YAG laser, cooled CCD camera was applied to in-vitro blood flow experiment through a micro round tube of a diameter $100{\mu}m$. Velocity distributions of blood flow for rabbit were obtained. The viscosity profiles for shear rate were found at flowing condition. To provide hemorheological characteristics of blood flow, the viscosities for shear rate were evaluated. The viscosity of blood also steeply increase by decreasing shear rate resulting in Non-Newtonian flow, especially in low shear rate region caused by RBC rheological properties. The results show typical characteristics of Non-Newtonian characteristics from the results of velocity profile and viscosity for blood flow. From the inflection points, cell free layer and two-phase flow consisted with plasma and suspensions including RBCs can be separated.

• 한국가시화정보학회:학술대회논문집
• /
• 한국가시화정보학회 2006년도 추계학술대회 논문집
• /
• pp.111-112
• /
• 2006

In order to investigate flow characteristics of blood flow in a micro tube ($100{\mu}m$ in diameter) according to hematocrit, in-vitro experiments were carried out using a micro-PIV technique. The micro-PIV system consists of a microscope, a 2 head Nd:YAG laser, a 12 bit cooled CCD camera and a delay generator. Blood was supplied into the micro tube using a syringe pump. Hematocrit of blood was controlled to be 20%, 30% and 40%. The blood flow has a cell free layer near the tube wall and its thickness was changed with increasing the flow rate and hematocrit. The hemorheological characteristics such as shear rate and viscosity were evaluated using the velocity field data measured. As the flow rate increased, the blunt velocity profile in the tube center was sharpened. The viscosity of blood was rapidly increased with decreasing shear rate, especially in the region of low shear rate, changing RBC rheological properties. The variation of velocity profile and blood viscosity shows typical characteristics of Non-Newtonian fluids. On the basis of inflection points, the cell free layer and two-phase flow consisting of plasma and suspensions including RBCs were clearly discriminated.

• 한국전문물리치료학회지
• /
• 제9권2호
• /
• pp.107-113
• /
• 2002

This study was conducted to determine the effects of deep breathing exercise and ankle exercise on blood flow velocity in the femoral vein. Sixteen healthy male students were recruited from Yonsei University, at Wonju. The blood flow velocities in the femoral vein were measured under three different conditions: resting, deep breathing, and ankle exercise. All subjects were given a 5-minute relaxing time in supine position prior to the study. Using a doppler ultrasound with a 8 MHz probe, the peak blood flow velocities were collected in a twenty-second-period at each condition. The subjects took a rest in between trials for the blood flow to return to its resting levels. The result showed a significant difference in peak blood flow velocities under those three conditions (p<.001). The peak blood flow velocity was highest in ankle exercise condition. The peak blood velocity was significantly higher in deep breathing condition compared with the resting condition. As a result, it is revealed that not only the muscular contractions but also the deep breathing exercises induced facilitating effects of venous return. Either of the exercise methods can be recommended to prevent blood stasis in patients with risk of deep vein thrombosis after cardiac or lower extremity surgery.

• Journal of the Optical Society of Korea
• /
• 제14권1호
• /
• pp.42-48
• /
• 2010

We used video-rate Confocal Laser Scanning Microscopy (CLSM) to observe the motion of blood cells in a micro-channel. Video-rate CLSM allowed us to acquire images at the rate of 30 frames per second. The acquired images were used to perform Particle Image Velocimetry (PIV), thus providing the velocity profile of the blood in a micro-channel. While previous confocal microscopy-assisted PIV required exogenous micro/nano particles as the tracing particles, we employed blood cells as tracing particles for the CLSM in the reflection mode, which uses light back-scattered from the sample. The blood flow at various depths of the micro-channel was observed by adjusting the image plane of the microscope. The velocity profile at different depths of the channel was measured. The confocal micro-PIV technique used in the study was able to measure blood velocity up to a few hundreds ${\mu}m/sec$, equivalent to the blood velocity in the capillaries of a live animal. It is expected that the technique presented can be applied for in vivo blood flow measurement in the capillaries of live animals.

• 대한한의학회지
• /
• 제17권1호
• /
• pp.345-360
• /
• 1996

Background and Purpose: To evaluate the blood flow velocity using doppler ultrasound of the carotid artery, vertebral artery, and basilar artery in stroke patients Material and Methods: To evaluate the blood flow, I measured the peak systolic velocity and mean velocity of the common carotid artery(CCA), internal carotid artery(ICA), external carotid artery (ECA). vertebral artery(VA), and basilar artery(BA) in 44 stroke patients and 15 healthy adults. To investigate the difference between ischemic stroke patients and normal healthy adults, I selected 44 ischemic stroke patients diagnosed by brain CT and brain MRI, and 15 healthy adults who did not have any symptoms of stroke, hypertension, heart disease, and diabetes melitus. Results: Peak velocity in normal adults was 50.6${\pm}$1.6cm/sec in the CCA, 67.2${\pm}$1.7cm/sec in the ICA, 62.5${\pm}$2.4cm/see in the ECA, 45.5${\pm}$1.9cm/sec VA. and 50.5${\pm}$3.5cm/sec in the BA. Mean velocity in normal adults was 26.9${\pm}$1.1cm/sec in the CCA, 43.7${\pm}$1.4cm/sec in the ICA, 26.7${\pm}$1.3cm/sec in the ECA. 31.6${\pm}$1.9cm/sec in the VA and 33.0${\pm}$2.6cm/sec in the BA. In this study, there was a significant increase in the velocity of ICA, ECA, and VA of ischemic stroke patients in comparison with normal healthy adults. And the blood flow velocity of this study in the CCA and ECA was different from other reported foreign values and the other known values in my country. Conclusion: There was a significant difference in the blood flow velocity between ischemic stroke patients and normal healthy adults. And the blood flow velocity of this study was different from other reported foreign values and the other known values in my country. Therefore, it needs more detailed studies about old aged Korean and ischemic stroke patients than previous studies.

• The Korean Journal of Pain
• /
• 제14권1호
• /
• pp.37-40
• /
• 2001

Background: It had been reported by authors that linear polarized infrared light radiation (Superizer: SL) near the stellate ganglion had a similar effect on the change of skin temperature of hand compared with the stellate ganglion block (SGB). We hypothesized that this was due to dilatation of vessels and an increased blood flow. The aim of this study was to measure the velocity of blood flow in peripheral vessels after linear polarized infrared light radiation near the stellate ganglion and to compare the effect of SL with that of SGB using local anesthetics. Methods: Forty patients whose clinical criteria were matched for the symptoms of SGB were selected for study. We radiated the stellate ganglion by linear polarized infrared light radiation and measured the blood flow of radial artery using Ultrasound Doppler blood flow meter before and after 10, 20 and 30 minutes post-radiation. After 3 days, SGB was performed using 8 ml of 1% mepivacaine to the same patient, and the radial artery blood flow was measured in the same manner. Results: The blood flow velocity was increased by 40% and 27% at 10 min and 20 min after SL and by 42% and 41% at 10 min and 20 min after SGB. However, there was no statistically significant difference in blood flow velocity between SGL and SGB. Conclusions: We could conclude that linear polarized radiation is a clinically simple and useful noninvasive therapeutic tool in clinical area.