Results 231 to 240 of about 5,737,446 (284)

Decorrelation-based blood flow velocity estimation: effect of spread of flow velocity, linear flow velocity gradients, and parabolic flow

IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 2002
In recent years, a new method to measure transverse blood flow, based on the decorrelation of the radio frequency (RF) signals has been developed. In this paper, we investigated the influence of nonuniform flow on the velocity estimation. The decorrelation characteristics of transverse blood flow using an intravascular ultrasound (IVUS) array catheter ...
Frits Mastik, Chris de Korte, Antonius F. W. van der Steen   +2 more
exaly   +5 more sources

Effects of blood donation on cerebral blood flow velocity

Transfusion, 1990
Eighteen healthy male blood donors, nine with hematocrit (Hct) of 0.40 to 0.45 (normal Hct) and nine with Hct of 0.49 to 0.52 (upper‐limit Hct), were monitored by continuous‐wave internal carotid Doppler sonography and hematologic tests for 28 days after blood donation, to ascertain whether and to what extent a single standard donation may modify the ...
Silvani C, Zanella A, Rossi F, Cabrini G, Ferrari C, CESANA, Bruno Mario, Sirchia G.   +6 more
openaire   +3 more sources

Estimating Blood Flow Velocity in Liver Vessels

2009
Orthogonal polarization spectroscopy (OPS) is a technique for taking images to finally characterise microcirculation. Current image analysis algorithms have limitations when applied to image sequences obtained from the liver. We developed an automatic analysis tool which enables detection of liver vessels, measurement of vessel diameters, and ...
Müller, Michael, Keimling, René, Lang, Sascha, Pauli, Josef, Dahmen, Uta, Dirsch, Olaf   +5 more
openaire   +1 more source

Effect of Adenosine on Cerebral Blood Flow Velocity

Journal of Neuroimaging, 2001
ABSTRACTBackground and Purpose. Evidence suggests that adenosine (ADN) is a potent vasodilator of cerebral vessels. However, the feasibility of manipulating human cerebral vascular resistance with AND has not been assessed by means of TCD. The purpose of this study was to quantitatively estimate the change in middle cerebral artery cerebral blood flow ...
C, Zanferrari, A Y, Razumovsky, P M, Lavados, S, Sen, S M, Oppenheimer   +4 more
openaire   +2 more sources

Blood flow velocity in pulmonary microvessels of bullfrog

Respiration Physiology, 1979
Flow velocity in the pulmonary microvessels of the exposed lung of bullfrogs was measured by means of a laser Doppler microscope of an oblique backward mode, together with a signal-analyzing system having a time sharing circuit triggered by the R-wave of the ECG.
M, Horimoto, T, Koyama, H, Mishina, T, Asakura, M, Murao   +4 more
openaire   +2 more sources

VELOCITY OF BLOOD FLOW IN SCHIZOPHRENIA

Archives of Neurology And Psychiatry, 1938
Our purpose in this study was to determine the rate of blood flow in patients with schizophrenia. The work of Blumgart 1 has stimulated interest in studies on the velocity of blood flow. The circulation time, while it does not directly determine the velocity of blood flow, is the denominator in the equation distance of pathway/circulation time equals ...
openaire   +1 more source

Effects of aging on cardiac blood flow velocities

Journal of Clinical Ultrasound, 1988
AbstractThe effects of aging on cardiac blood flow velocities are important as a description of the natural history of the aging process and as a reference for evaluation of the aging cardiovascular system. We therefore studied these effects in 215 healthy volunteers, 120 males and 95 females, between 1 and 65 years old.
I, van Dam, P, Wijn, T, de Boo, J, Hopman, A, van Oort, J, Fast, A, Heringa, T, van der Werf, O, Daniëls   +8 more
openaire   +2 more sources

Astaxanthin increases choroidal blood flow velocity

Graefe's Archive for Clinical and Experimental Ophthalmology, 2011
Previous studies have reported that astaxanthin (AXT) has antioxidative and anti-inflammatory effects in addition to its ability to shorten blood transit times. As laser speckle flowgraphy (LSFG) can noninvasively visualize the hemodynamics of the choroidal circulation, we used the technique to evaluate whether continuous ingestion of 12 mg of AXT per ...
Michiyuki, Saito, Kazuhiko, Yoshida, Wataru, Saito, Akio, Fujiya, Kazuhiro, Ohgami, Nobuyoshi, Kitaichi, Hiroki, Tsukahara, Susumu, Ishida, Shigeaki, Ohno   +8 more
openaire   +2 more sources