Biomaterial Database

Pulsatile velocity distribution and wall shear rate measurement using pulsed Doppler ultrasound. 1994

P E Hughes, and T V How

Department of Clinical Engineering, University of Liverpool, U.K.

Instantaneous pulsatile velocity profiles were measured in a cylindrical tube using a 20 MHz pulsed Doppler ultrasound system. The spatial resolution of the device was improved with deconvolution using a procedure which employed frequency-domain windowing to suppress high-frequency noise. After deconvolution both the instantaneous velocity profiles and flow waveforms were compared with established theoretical predictions and good agreement was obtained. The average error in a velocity measurement was 7.9 +/- 0.9%, and the average error in the flow rate was 4.7 +/- 1.7%. The wall shear rate was determined from the gradient of the velocity profile both before and after deconvolution. The results were compared to the theoretical value of wall shear rate to quantify the accuracy of the technique under pulsatile flow conditions. Although the velocity profiles agreed well with theory, the wall shear rate was obtained less accurately. The average error in the mean wall shear rate and peak-to-peak wall shear rate was 28 +/- 7% and 11 +/- 3%, respectively. However, some of this discrepancy, was attributed to the method of evaluation. In all cases deconvolution significantly improved the accuracy of the wall shear rate determination.

UI	MeSH Term	Description	Entries
D008955	Models, Cardiovascular	Theoretical representations that simulate the behavior or activity of the cardiovascular system, processes, or phenomena; includes the use of mathematical equations, computers and other electronic equipment.	Cardiovascular Model,Cardiovascular Models,Model, Cardiovascular
D009991	Oscillometry	The measurement of frequency or oscillation changes.	Oscillometries
D011673	Pulsatile Flow	Rhythmic, intermittent propagation of a fluid through a BLOOD VESSEL or piping system, in contrast to constant, smooth propagation, which produces laminar flow.	Flow, Pulsating,Perfusion, Pulsatile,Flow, Pulsatile,Flows, Pulsatile,Flows, Pulsating,Perfusions, Pulsatile,Pulsatile Flows,Pulsatile Perfusion,Pulsatile Perfusions,Pulsating Flow,Pulsating Flows
D001783	Blood Flow Velocity	A value equal to the total volume flow divided by the cross-sectional area of the vascular bed.	Blood Flow Velocities,Flow Velocities, Blood,Flow Velocity, Blood,Velocities, Blood Flow,Velocity, Blood Flow
D001794	Blood Pressure	PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.	Systolic Pressure,Diastolic Pressure,Pulse Pressure,Pressure, Blood,Pressure, Diastolic,Pressure, Pulse,Pressure, Systolic,Pressures, Systolic
D001809	Blood Viscosity	The internal resistance of the BLOOD to shear forces. The in vitro measure of whole blood viscosity is of limited clinical utility because it bears little relationship to the actual viscosity within the circulation, but an increase in the viscosity of circulating blood can contribute to morbidity in patients suffering from disorders such as SICKLE CELL ANEMIA and POLYCYTHEMIA.	Blood Viscosities,Viscosities, Blood,Viscosity, Blood
D001810	Blood Volume	Volume of circulating BLOOD. It is the sum of the PLASMA VOLUME and ERYTHROCYTE VOLUME.	Blood Volumes,Volume, Blood,Volumes, Blood
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D012212	Rheology	The study of the deformation and flow of matter, usually liquids or fluids, and of the plastic flow of solids. The concept covers consistency, dilatancy, liquefaction, resistance to flow, shearing, thixotrophy, and VISCOSITY.	Flowmetry,Velocimetry,Velocimetries
D013314	Stress, Mechanical	A purely physical condition which exists within any material because of strain or deformation by external forces or by non-uniform thermal expansion; expressed quantitatively in units of force per unit area.	Mechanical Stress,Mechanical Stresses,Stresses, Mechanical