Biomaterial Database

The derivation of theoretical ultrasonic Doppler blood flow spectrum. 1998

N F Güler, and S Ozer

Department of Electronics and Computer Education, Faculty of Technical Education, Gazi University, Besevler, Ankara-Türkiye.

This paper deals with theoretical aspects of blood flow and the ultrasonic Doppler spectrum. Blood flow in the vessel can be considered as a pipe flow with a circular cross-section. Blood flow is, in general, complex and pulsatile. Navier-Stokes and the continuity equations are the governing equations for the blood flow, and the Navier's equations for the blood vessel. If the flow is pulsatile with a large Womersely number, the velocity profile becomes blunt due to the inertia forces. Since the ultrasonic Doppler flowmeter detects the velocities of blood cells across the vessel, Doppler power spectrum is dependent on the velocity profile. If the velocity profile is blunt, the Doppler power spectrum will be narrow banded. If the flow is sinusoidal, the Womersely number is only a parameter describing the pulsatility. Blood flow waveforms, however, differ from the sinusoidal wave. They consist of a steady flow component and many harmonics with amplitudes and phases. In this study, the influence of the harmonic contents and the Womersely number on velocity profiles and the Doppler power spectrum are examined.

UI	MeSH Term	Description	Entries
D008954	Models, Biological	Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.	Biological Model,Biological Models,Model, Biological,Models, Biologic,Biologic Model,Biologic Models,Model, Biologic
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
D001775	Blood Circulation	The movement of the BLOOD as it is pumped through the CARDIOVASCULAR SYSTEM.	Blood Flow,Circulation, Blood,Blood Flows,Flow, Blood
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
D001808	Blood Vessels	Any of the tubular vessels conveying the blood (arteries, arterioles, capillaries, venules, and veins).	Blood Vessel,Vessel, Blood,Vessels, Blood
D004912	Erythrocytes	Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.	Blood Cells, Red,Blood Corpuscles, Red,Red Blood Cells,Red Blood Corpuscles,Blood Cell, Red,Blood Corpuscle, Red,Erythrocyte,Red Blood Cell,Red Blood Corpuscle
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000465	Algorithms	A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.	Algorithm
D018056	Hemorheology	The deformation and flow behavior of BLOOD and its elements i.e., PLASMA; ERYTHROCYTES; WHITE BLOOD CELLS; and BLOOD PLATELETS.	Hemorrheology
D018608	Ultrasonography, Doppler	Ultrasonography applying the Doppler effect, with frequency-shifted ultrasound reflections produced by moving targets (usually red blood cells) in the bloodstream along the ultrasound axis in direct proportion to the velocity of movement of the targets, to determine both direction and velocity of blood flow. (Stedman, 25th ed)	Doppler Ultrasonography,Doppler Ultrasound,Doppler Ultrasound Imaging,Doppler Ultrasound Imagings,Doppler Ultrasounds,Imaging, Doppler Ultrasound,Imagings, Doppler Ultrasound,Ultrasound Imaging, Doppler,Ultrasound Imagings, Doppler,Ultrasound, Doppler,Ultrasounds, Doppler