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The flow profiles was first derived by John R. Womersley (1907–1958) in his work with blood flow in arteries. [1] The cardiovascular system of chordate animals is a very good example where pulsatile flow is found, but pulsatile flow is also observed in engines and hydraulic systems, as a result of rotating mechanisms pumping the fluid.
It is a dimensionless expression of the pulsatile flow frequency in relation to viscous effects. It is named after John R. Womersley (1907–1958) for his work with blood flow in arteries. [1] The Womersley number is important in keeping dynamic similarity when scaling an experiment. An example of this is scaling up the vascular system for ...
The pumping action of the heart generates pulsatile blood flow, which is conducted into the arteries, across the micro-circulation and eventually, back via the venous system to the heart. During each heartbeat, systemic arterial blood pressure varies between a maximum ( systolic ) and a minimum ( diastolic ) pressure. [ 33 ]
The classic definition by MP Spencer and AB Denison of compliance is the change in arterial blood volume due to a given change in arterial blood pressure ().They wrote this in the "Handbook of Physiology" in 1963 in work entitled "Pulsatile Flow in the Vascular System".
[13] [14] [15] In some pulsatile pumps (that use compressed air as an energy source [16]), the volume occupied by blood varies during the pumping cycle. If the pump is contained inside the body then a vent tube to the outside air is required. Continuous-flow VADs are smaller and have proven to be more durable than pulsatile VADs. [17]
measure of pulsatile blood flow The arterial resistivity index (also called as Resistance index , abbreviated as RI ), developed by Léandre Pourcelot [1] , is a measure of pulsatile blood flow that reflects the resistance to blood flow caused by microvascular bed distal to the site of measurement.
To quantify CSF flow, it is important to define the region of interest, which can be done using a cross-sectional area measurement, for example. Then, velocity versus time can be plotted. Velocity is typically pulsatile due to systole and diastole, and the area under the curve can yield the amount of flow.
The primitive heart within the first few days of contraction is best described as a peristaltic pump, however after three days the flow becomes pulsatile. [9] Pulsatile flow plays an important role in vascular remodelling, as flow patterns can affect the mechanotransduction of stress to endothelial cells. [7] [13]