Measuring Vascular Function and Ventricular/Arterial Coupling Dynamics

“… Now this Velocity is only the Velocity of the Blood at its firft entering into the Aorta, in the Time of the Syftole; in confequence of which the Blood in the Arteries, being forcibly propelled forward, with an accelerated Impetus, thereby dilates the Canal of the Arteries, which begin again to contract at the Infstant the Syftole ceafes: By which curious Artifice of Nature, the Blood is carried on in the finer Capillaries, with an almoft even Tenor of Velocity, in the fame manner as the fpouting Water of fome fire-Engines, is contrived to flow with a more even Velocity, not withftanding the alternate Syftoles and Diaftoles of the rifing and falling Embolus or Force; and this by the means of a large inverted Globe, wherein the compreffed Air alternately dilating or contracting, in Conformity to the workings to and fro of the Embolus, and thereby impelling the Water more equably than the Embolus alone would do, pufhes it out in a more nearly equal Spout.…”1