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In "retrograde" flow, the flow would reverse (e.g. veins flow away from heart or arteries flow towards the heart). However, "retrograde" flow can be both abnormal or normal. For example, in portal hypertension , there is an abnormal portal venous flow where it flows away from the liver (hepatofugal flow) instead of the normal flow towards liver ...
For this reason, the blood flow velocity is the fastest in the middle of the vessel and slowest at the vessel wall. In most cases, the mean velocity is used. [18] There are many ways to measure blood flow velocity, like videocapillary microscoping with frame-to-frame analysis, or laser Doppler anemometry. [19]
Medical ultrasound includes diagnostic techniques (mainly imaging techniques) using ultrasound, as well as therapeutic applications of ultrasound. In diagnosis, it is used to create an image of internal body structures such as tendons, muscles, joints, blood vessels, and internal organs, to measure some characteristics (e.g., distances and velocities) or to generate an informative audible sound.
Doppler measurements using Doppler effect can show the direction of the blood flow and its relative velocity, and color Doppler is the provision of color to help interpret the image, showing, for example, the blood flow toward the probe in one color and that flowing away in another. While the equipment itself is costly, the procedure is not.
C a = the oxygen concentration of arterial blood (oxygenated blood) C v = the oxygen concentration of venous blood (deoxygenated blood) The usual unit for a-vO 2 diff is millilitres of oxygen per 100 millilitres of blood (mL/100 mL), [1] however, particularly in medical uses, other units may be used, such as micro moles per millilitre (μmol/mL ...
In vertebrates, the circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the body. [1] [2] It includes the cardiovascular system, or vascular system, that consists of the heart and blood vessels (from Greek kardia meaning heart, and Latin vascula meaning vessels).
Wave intensity analysis is based on the 1-D equations for the conservation of mass and momentum of the blood in the elastic arteries (first published by Euler in 1775) and a relationship between the cross-sectional area of the artery and the pressure within it (generally called a 'tube law').
Doppler echocardiography is a procedure that uses Doppler ultrasonography to examine the heart. [1] An echocardiogram uses high frequency sound waves to create an image of the heart while the use of Doppler technology allows determination of the speed and direction of blood flow by utilizing the Doppler effect.