. The clinical study of blood-pressure : a guide to the use of the sphygmomanometer in medical, surgical, and obstetrical practice, with a summary of the experimental and clinical facts relating to the blood-pressure in health and in disease . astic membrane. One vessel wasconnected with the pressure cylinder and recording manometerof his sphygmomanometer, the other with a mercury manom-eter, and with a pump used to imitate the heart in a model ofthe circulation. At the start of the experiment the pressureregistered 76 mm. Hg. in each vessel. The membrane, there-fore, was perfectly vertical. I
. The clinical study of blood-pressure : a guide to the use of the sphygmomanometer in medical, surgical, and obstetrical practice, with a summary of the experimental and clinical facts relating to the blood-pressure in health and in disease . astic membrane. One vessel wasconnected with the pressure cylinder and recording manometerof his sphygmomanometer, the other with a mercury manom-eter, and with a pump used to imitate the heart in a model ofthe circulation. At the start of the experiment the pressureregistered 76 mm. Hg. in each vessel. The membrane, there-fore, was perfectly vertical. If the pressure was raised on eitherside, it was, of course, bulged out toward the opposite , while increasing the pressure on the side of the sphygmo-manometer by successive steps, he produced plusation of thewater in the other vessel, which was transmitted through themembrane to his recording manometer. The tracing shown in 70 INDIRECT MEASUREMENT OF BLOOD-PRESSURE Fig. 18 resulted. It is perfectly evident that the greatest pul-sation is at 76 mm., the level of equal pressure on the two sidesof the membrane. Howell and Brush have verified the principle for the arteryitself. They used an apparatus devised by Walden, and shown. Fio, 18.—Tbaoinq of the pulsations tkansmitted through an elastic membrane SEPAKATINO TWO VESSELS. (From Mosso, Arch. Ital. de Biol., 1895, vol. xxili, p. 177.) in Fig. 19. The tube D was connected with a mercury ma-nometer and with a Fick spring manometer, the latter magni-fying and recording the pulsations. This is the general arrange-ment of Erlangers sphygmomanometer. The left carotid of adog was placed in this apparatus, and the right connected witha mercury manometer provided with maximum and minimumvalves. The pressure in the closed cylinder was then raised10 mm. at a time, and the pulsations at each pressure recordedby the Fick manometer. No difficulty was met in determiningthe greatest amplitude of the pulse-wave. The only source ofer
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectbloodpr, bookyear1904
