Blood pressure simplified / published by Medical Department of Taylor Instrument Companies.

Date:
[1917], ©1917
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Licence: Public Domain Mark

Credit: Blood pressure simplified / published by Medical Department of Taylor Instrument Companies. Source: Wellcome Collection.

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    notably those of Mosso, it remained for Masing in 1901 to suggest measuring the minimal pressure by the point at which the radial pulse became the largest. At about that time Janeway estimated the min- imal pressure at the point where the oscillation of the mercury column in the manometer became greatest. Shortly after, Erlanger (3) developed his Re- cording Sphygmomanometer and elaborated the oscillatory method of determining blood-pressure. The greatest advance, however, was in 1905, when the Russian, Korotkoff, brought out his auscultatory method. Since then blood-pressure technique has been considerably developed, largely through the simplicity and exactness of this method. Blood-pressure determinations of both maximal and minimal pressure are rapidly becoming a routine practice in the physical exam- ination of every patient. MECHANISM OF THE CIRCULATION The force by which the blood is driven from the heart into the ramifications of the arterial tree is derived almost entirely from the contraction of the left ventricle. The ventricle is doing effective work during only a part of the period of its con- traction, because the intraventricular pressure must not only equal, but must overcome the static column of blood in the aorta and the resistance of the aortic valve before the blood can be thrown into its channels. As shown by Huerthle and Porter (2) the pres- sure in the ventricle remains tolerably constant