A manual of human physiology, including histology and microscopical anatomy, with special reference to the requirements of practical medicine . ght of the blood-pressure is obtained by drawing ordinates fromthe curve to the abscissa, measuring their length, and multiplying by two.] (5.) Spring-Kymograph.—A. Fick (1864) constructed a spring-kymo-graph on the principle of Bourdons manometer (Fig. 72, II). A hollow C-shaped metallic spring, F, is filled with alcohol. One end of thehollow spring is closed, and t he other end, covered by a membrane, is brought intoconnection with a blood-vessel by
A manual of human physiology, including histology and microscopical anatomy, with special reference to the requirements of practical medicine . ght of the blood-pressure is obtained by drawing ordinates fromthe curve to the abscissa, measuring their length, and multiplying by two.] (5.) Spring-Kymograph.—A. Fick (1864) constructed a spring-kymo-graph on the principle of Bourdons manometer (Fig. 72, II). A hollow C-shaped metallic spring, F, is filled with alcohol. One end of thehollow spring is closed, and t he other end, covered by a membrane, is brought intoconnection with a blood-vessel by a junction-piece filled with a solution of sodiumcarbonate. As soon as the communication with the artery is opened, the pressurerises, and the spring, of course, tends to straighten itself. To the closed end, b, ESTIMATION OF THE BLOOD-PRESSURE IN MAN. 165 there is fixed a vertical rod attached to a series of levers, /<, i, k, e, one of whichwrites its movements upon a surface moving at a uniform rate. The blood-pressureand the periodic variations of the pulse are both recorded, although the latter ianot done with absolute Fig. 74. Blood-pressure curve of the carotid of a dog obtained with a mercurial - x = line of no pressure, zero line, or abscissa; y-y is the blood-pressuretracing with small waves, each one caused by a heart-beat, and the largewaves due to the respiration. A millimetre scale shows the height of thepressure in millimetres of mercury. [Bering improved Picks instrument (Fig. 75). a, b, c, is the hollow spring filledwith alcohol, and communicating at a with the lead tube, d, passing to the cannulain the artery. To c is attached a series of light wooden levers with a writing-style, s. The lower part of 4 dips into a vessel, e, filled with oil or glycerine whichserves to damp the vibrations of the levers. At f is a syringe communicatingwith the tube, d, filled with solution of sodic carbonate, and used for regulatingthe amount of fluid
Size: 1672px × 1494px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, booksubjectphysiology, bookyear1
