Inlfuence of ADP, blood flow velocity, and vessel diameter on the laser-induced thrombus formation

Objectives: To measure the effect of graduated compression stocking (GCS) length and body position on peak femoral venous blood flow velocity (PVV) and vessel diameter (VD). Methods: Twenty healthy adult volunteers had PVV and VD measured, using colour Doppler ultrasound, at baseline in three body positions. Knee- or thigh-length GCS were assigned randomly.Arandom sequence of the three positions was used to measure PVV and VD. The procedure was repeated, after a two-hour washout period, using the other length GCS. Results: There was no significant difference in the mean change of PVV ( P =0.74) or VD ( P =0.54) measurements from the baseline between thigh- and knee-length GCS. However, significant mean changes in PVV ( P =0.02) and VD ( P <0.001) measurements were observed for the three body positions, after adjusting for baseline values. Conclusions: In healthy volunteers, thigh- and knee-length GCS do not have an effect on PVV or VD, and body position affects PVV significantly, with or without GCS.

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Blood Flow Velocity in the Pial Arteries of Cats, with Particular Reference to the Vessel Diameter

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.1984.15 ◽

1984 ◽

Vol 4 (1) ◽

pp. 110-114 ◽

Cited By ~ 39

Author(s):

Masahiro Kobari ◽

Fumio Gotoh ◽

Yasuo Fukuuchi ◽

Kortaro Tanaka ◽

Norihiro Suzuki ◽

...

Keyword(s):

Blood Flow ◽

Flow Velocity ◽

Flow Rate ◽

Blood Flow Velocity ◽

Blood Flow Rate ◽

Video Camera ◽

Vessel Diameter ◽

Pial Arteries ◽

Cross Sectional ◽

Pial Artery

The blood flow velocity and diameter of feline pial arteries, ranging in diameter from 20 to 200 μm, were measured simultaneously using a newly developed video camera method under steady-state conditions for all other parameters. There was a linear relationship between blood flow velocity and pial artery diameter ( y = 0.340 x + 0.309), the correlation coefficient being 0.785 (p < 0.001). The average values for blood flow velocity in pial arteries <50 μm, ≧50 but <100 μm, ≧100 but <150 μm, and ≧150 μm in diameter were 12.9 ± 1.3, 24.6 ± 3.4, 42.1 ± 4.7, and 59.9 ± 5.3 mm/s, respectively. Blood flow rate was calculated as a product of the cross-sectional area and the flow velocity. The blood flow rate increased exponentially as the pial artery diameter increased ( y = 2.71 × 10−4 x2.98). The average values for blood flow rate in pial arteries <50 μm, ≧50 but <100 μm, ≧100 but <150 μm, and ≧150 μm in diameter were 12.8 ± 1.5, 122.1 ± 24.8, 510.2 ± 74.8, and 1524.2 ± 174.4 10−3 mm3/s, respectively. Hemorheological parameters such as the wall shear rate and Reynolds' number were also calculated. The data obtained provide a useful basis for further investigations in the field of cerebral circulation.

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Video Camera Method for Simultaneous Measurement of Blood Flow Velocity and Pial Vessel Diameter

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.1982.48 ◽

1982 ◽

Vol 2 (4) ◽

pp. 421-428 ◽

Cited By ~ 16

Author(s):

F. Gotoh ◽

F. Muramatsu ◽

Y. Fukuuchi ◽

H. Okayasu ◽

K. Tanaka ◽

...

Keyword(s):

Blood Flow ◽

Flow Velocity ◽

Blood Flow Velocity ◽

Simultaneous Measurement ◽

Vessel Diameter ◽

Time Difference ◽

Lingual Artery ◽

Desktop Computer ◽

Cranial Window ◽

Pial Vessel

A new method for the simultaneous measurement of blood flow velocity and pial vessel diameter is described. The system consists basically of a high-sensitivity vidicon camera, camera control, width analyzer, video densitometer, TV monitor, desktop computer, and multi-pen recorder. The pial vessels are visualized through a cranial window at 25–200x magnification on the TV monitor. The diameter of three target vessels can be recorded simultaneously on the recorder by adjustment of controllable video signal gates using the width analyzer. At the same time, the optical densities of two targets at points upstream and downstream of the pial vessel are measured continuously with video densitometers, and their outputs are recorded on the polygraph and analyzed by the computer. The time difference in the two peaks of time–con centration curves, produced every 2–3 s at the highest frequency by the injection of a small amount of saline through the lingual artery, is measured on-line using the computer. The flow velocity in the vessel is calculated from the time difference and the distance between the two targets. The system was shown to be stable, reliable, and rapid in response. This method may provide a useful tool for research in the field of blood circulation in the brain or any other organ.

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