• Korean Journal of Clinical Laboratory Science
• /
• v.42 no.3
• /
• pp.155-160
• /
• 2010

Transcranial Doppler ultrasonography (TCD) allows measurement of blood flow velocity to be made from the basal intracerebral vessels. Blood flow velocity in TCD is highly affected not only by blood vessel diameter, blood flow volume, blood viscosity, but also age and sex. Therefore, the study is focused on the correlation between TCD measurement index and sex/age. Subjects were 214 (male 147, famale 67) who had TCD for headache and stroke evaluations at Dongguk University Ilsan Hospital neurology department from December 2009 to April 2010. Sex did not show significant differences with mean flow velocity (MFV), peak systolic flow velocity (PSFV), end diastolic flow velocity (EDFV), pulsatility index (PI) and resistance index (RI) in middle cerebral artery (MCA). Although age also did not show significant differences with MFV and PSFV, EDFV has statistically decreased with age, and PI and RI has statistically increased with age. In addition, age showed significant correlation with MFV, EDFV, PI and RI, but not with PSFV. Therefore, TCD is definitely correlated with age and sex, so that those influencial factors must be considered when being tested.

• Journal of the Korean Magnetics Society
• /
• v.26 no.4
• /
• pp.142-148
• /
• 2016

To evaluate the effect of flip angle on flow rate measurements obtained with phase contrast MRI according to the flip angle degree in ascending aorta and velocity encoding (VENC) was (150 m/s). 1.5T MRI in patients 17 (female: 8, male: 9, mean age $57.9{\pm}15.4$) as a target by applying a non-breath holding techniques to flip angle VENC (150 cm/s) in each of the ascending aorta was measured by changing $20^{\circ}$, $30^{\circ}$ and $40^{\circ}$. Blood was obtained a peak velocity, average velocity, net forward volume, net forward volume/body surface area. Ascending aorta from average velocity (AV) measured the average value of the flip angle $20^{\circ}$ (9.87 cm/s), $30^{\circ}$ (9.6 cm/s) and $40^{\circ}$ (10.05 cm/s). Blood flow VENC in was blood flow change in flip angle change was high most blood flow measurement when the flip angle $30^{\circ}$ in VENC, crouching each blood flow is also proportional to the increases in the $20^{\circ}$ to $40^{\circ}$ and was increased, the deviation of the peak velocity and the average velocity is the smallest deviation from the flip angle $30^{\circ}$. Flip angle $20^{\circ}$, $30^{\circ}$ and $40^{\circ}$ in peak velocity, average velocity, net forward volume, net forward volume/body surface area was no statistically significant difference (p > .05). Blood flow velocity and blood flow is measured by applying to adjust the flip angle accurately calculate the blood flow is important information for diagnosis and treatment of cardiovascular diseases, and can help in the examination on the blood flow measurement.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
• /
• v.19 no.2
• /
• pp.31-37
• /
• 2013

Background: The purpose of this study was to identify the effects of cervical manipulation for improve blood velocity and flow in the subjects with asymmetric vertebral artery. Methods: Twenty-four subjects on asymmetric vertebral artery with right side have less blood flow than left side participated in this study for apply to non-specific cervical manipulation on lower portion. Measurement method were using duplex ultrasound with colour doppler imaging for blood velocity and flow on left and right vertebral artery. Results: Compared changes of blood velocity and flow on unilateral after the cervical manipulation, the left blood velocity decreased significantly (p<.01) and the right blood velocity increased significantly (p<.01). The left blood flow no significant changes and the right blood flow increased significantly (p<.01). Compared changes of blood velocity and flow on bilateral, the left and right blood velocity and flow made significantly difference on pre-manipulation (p<.01). However, both side no significantly difference on post-manipulation. Conclusions: These findings suggest that the non-specific cervical manipulation took effect for improve blood velocity and flow in the subjects with asymmetric vertebral artery. Therefore, therapeutic approaches for improve to asymmetric vertebral artery should be consider non-specific cervical manipulation.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.44 no.2 s.314
• /
• pp.10-17
• /
• 2007

The echo signal on ultrasonic transducer is a mixed signal from tissues, blood vessel walls, blood cells and noise. In this mixed-signal, the signal reflected from tissues and blood vessel walls is called clutter. It is necessary to extract pure blood signal from this mixed-signal, when measuring blood flow velocity with medical ultrasonic system The quality of measured blood flow velocity is highly dependent on sufficient attenuation of the clutter signals. In this paper, we suggest a clutter rejection method using ICA For simulation, the echo signals are generated by Field n ultrasonic simulation program In this echo signals, independent signals are separated by using ICA Then the blood signal is obtained from the separated signals. Blood flow velocity is measured by 2D autocorrelation method. We compare ICA clutter rejection method with PCA-based eigen filter method using both measured blood flow velocity profiles by 2D autocorrelation. In simulation results, ICA clutter rejection method can be better applied measuring blood flow velocity in noisy echo signals.

• International Journal of Vascular Biomedical Engineering
• /
• v.1 no.2
• /
• pp.30-35
• /
• 2003

Flow characteristics of blood flow in a micro channel were investigated experimentally using a micro-PIV (Particle Image Velocimetry) velocity field measurement technique. The main objective of this study was to understand the real blood flow in micron-sized blood vessels. The Reynolds number based on the hydraulic diameter of micro-channel for deionized (DI) water was about Re=0.34. For each experimental condition, 100 instantaneous velocity fields were captured and ensemble-averaged to get the spatial distributions of mean velocity. In addition, the motion of RBC (Red Blood Cell) was visualized with a high-speed CCD camera. The captured flow images of nano-scale fluorescent tracer particles in DI water were clear and gave good velocity tracking-ability. However, there were substantial velocity variations in the central region of real blood flow in a micro-channel due to the presence of red blood cells.

• Journal of the Korean Society for Precision Engineering
• /
• v.24 no.9
• /
• pp.23-31
• /
• 2007

• Proceedings of the KIEE Conference
• /
• 1988.07a
• /
• pp.705-708
• /
• 1988

Ultrasound Doppler Diagnostic System utilizes the Doppler effect for measurement of blood velocity. The sign of the Doppler frequency shift represents blood flow direction. Pulsed Doppler System uses Phase detector and zerocrossing method to produce simultaneous independent audio and velocity signals for forward and reverse blood flow direction in the time domain, had been fabricated. But time-domain analyzing such as audio evaluation and zerocrossing detection for instantaneous and mean frequency measurement doesn't, provide both an accurate and quantitative result. Therefore, it is necessary to adopt frequency domain technique to improve system performance. In this paper, we describe a unit which is composed of Pulsed Doppler System and real-time spectrum analyzer (installed TMS 32010 DSP Chip). This unit shows time-dependent spectrum variation and mean velocity of blood Signal.

• Proceedings of the KIEE Conference
• /
• 1988.07a
• /
• pp.709-712
• /
• 1988

Ultrasonic Doppler Diagnostic System utilizes the Doppler effect for measurement of blood velocity. The sign of the Doppler frequency shift represents blood flow direction. CW(Continuous-Wave) Doppler System uses quadrature detection and phase rotation method to produce simultaneous independent audio and velocity signals for forward and reverse blood flow direction in the time-domain, had been fabricated. But time-domain analyzing such as audio evaluation and zero- crossing detection for instantaneous and mean frequnecy measurement do not provide both an accurate and quantitative result. Therefore, it is necessary to adopt frequency-domain technique to improve system performance. In this paper, we describe a unit which is composed of CW Doppler System and real-time spectrum analyzer (installed TMS 32010 DSP Chip). This unit shows time-dependent spectrum variation and mean velocity of Blood signal.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2001.05a
• /
• pp.516-519
• /
• 2001

To diagnose a patient's blood vessel disease, apoplexy, hypertension, arteriosclerosis, the blood velocity is very important. Determining the blood velocity methods using ultrasound are Continuous Doppler System and Pulse Doppler System. In using the Pulse Doppler System, we can obtain the position of blood velocity. But it is more complex hardware than Continuous Doppler System and it has low SNR(signal-noise ratio). So in this study, to obtain a believable information we use the Continuous Pulse Doppler System. Thus system have analog part and digital part. In analog part is composed of ultrasound generating part, the amplifying part to amplify the received signal from ultrasound sensor, the demodulation part to detect blood velocity and the filtering part to remove the noise. In digital part is composed of the A/D conversion part, digital signal processing part, and the communication part to communicate the PC. In this study to implement efficient ultrasound blood velocity measurement system, we can get the patient's blood velocity information in realtime. Thus, It is a useful in the accurate diagnosis with C.T(computered tomography), M.R.I(magnetic resonance imaging).

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.30 no.4 s.247
• /
• pp.314-319
• /
• 2006

To analyze in-vivo blood flow characteristics in a chicken embryo, in-vivo experiment was carried out using micro-PIV technique. Because endothelial cells in blood vessels are subject to shear stress of blood flow, it is important to get velocity field information of the placental blood flow. Instantaneous velocity fields of an extraembryonic blood vessel using a high-speed camera and intravital microscope. The flow images of RBCs were obtained with a spatial resolution of $20\times20{\mu}m$ in the whole blood vessels. The mean velocity field data confirm that the blood flow does show non-Newtonian fluid characteristic. The blood in a branched vessel merged smoothly without any flow separation into the main blood vessel with the presence of a slight bump. This in-vivo micro-PIV measurement technique can be used as a powerful tool in various blood flow researches.