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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 ]
In particular, wide-field imaging of pulsatile motion induced by blood flow can be measured on the thumb by digital holography. The results are comparable to blood pulse monitored by plethysmography during an occlusion-reperfusion experiment. [22]
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]
[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]
[7] [8] [9] The material is currently [when?] used in the Thoratec PVAD pulsatile-flow biventricular device. [10] [11] By 2000, the Thoratec VAD System was the only device approved by the FDA for left, right, or biventricular support for both providing a bridge until heart transplant and for recovery of the heart after open-heart surgery. [5]
Peripheral Arterial Tone (PAT) is a noninvasive measure designed to track pulsatile volume changes in peripheral arterial beds. The collected information gives specialists important insight into the autonomic nervous system and the cardiovascular system.