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The relationship between arterial stiffness and pulse wave velocity was first predicted by Thomas Young in his Croonian Lecture of 1808 [11] but is generally described by the Moens–Korteweg equation [12] or the Bramwell–Hill equation. [13] Typical values of PWV in the aorta range from approximately 5 m/s to >15 m/s. [14]
Pulse wave velocity (PWV) is the velocity at which the blood pressure pulse propagates through the circulatory system, usually an artery or a combined length of arteries. [1] PWV is used clinically as a measure of arterial stiffness and can be readily measured non-invasively in humans, with measurement of carotid to femoral PWV (cfPWV) being ...
A procedure for ultrasonic testing is outlined in ASTM C597 - 09. [9]In India, till 2018 ultrasonic testing was conducted according to IS 13311-1992.From 2018, procedure and specification for Ultrasonic pulse velocity test is outlined in IS 516 Part 5:Non destructive testing of concrete Section 1:Ultrasonic Pulse Velocity Testing.
The Moens–Korteweg equation states that PWV is proportional to the square root of the incremental elastic modulus, (E inc), of the vessel wall given constant ratio of wall thickness, h, to vessel radius, r, and blood density, ρ, assuming that the artery wall is isotropic and experiences isovolumetric change with pulse pressure.
The device was a system of levers hooked to a scale-pan in which weights were placed to determine the amount of external pressure needed to stop blood flow in the radial artery. Although the instrument was cumbersome and its measurements imprecise, the basic concept of Vierordt's sphygmograph eventually led to the blood pressure cuff used today.
A thrombin generation assay (TGA) or thrombin generation test (TGT) is a global coagulation assay (GCA) and type of coagulation test which can be used to assess coagulation and thrombotic risk. [ 1 ] [ 2 ] [ 3 ] It is based on the potential of a plasma to generate thrombin over time, following activation of coagulation via addition of ...
The spectral shear is typically generated by sum-frequency mixing the test pulse with two different quasi-monochromatic frequencies (usually derived by chirping a copy of the pulse itself), although it can also be achieved by spectral filtering or even with linear electro-optic modulators for picosecond pulses.
This system generally offers data rates of up to 10 bits per second. In addition, many of these tools are also capable of receiving data from the surface in the same way, while mud-pulse-based tools rely on changes in the drilling parameters, such as rotation speed of the drillstring or the mud flow rate, to send information from the surface to ...