Studies in blood-pressure : physiological and clinical . Era. 1. By kind permission of the Editor of The Practitioner. manometer is inserted firmly into the socket atthe centre of the cross-shaped stand, and wehave an upright manometer firmly fixed for obser-vation (Fig. 2). The manometer differs from the ordinary U--shaped instrument in having a separate scaleallotted to each limb. The scale affixed to the 4 STUDIES IN BLOOD-PRESSURE left limb, reading to 200 mm. Hg., suffices forthe general run of cases; and that on the rightlimb, reading from 200 to 300 mm. Hg., providesfor the exceptional
Studies in blood-pressure : physiological and clinical . Era. 1. By kind permission of the Editor of The Practitioner. manometer is inserted firmly into the socket atthe centre of the cross-shaped stand, and wehave an upright manometer firmly fixed for obser-vation (Fig. 2). The manometer differs from the ordinary U--shaped instrument in having a separate scaleallotted to each limb. The scale affixed to the 4 STUDIES IN BLOOD-PRESSURE left limb, reading to 200 mm. Hg., suffices forthe general run of cases; and that on the rightlimb, reading from 200 to 300 mm. Hg., providesfor the exceptional cases. The employment of. Fig. 2. By kind permission of the Editor of The Practitioner. one or the other of these scales is determined bythe direction of the arrow on the brass disc. Whenthis is turned home well to the right, the arrowpoints to the scale on the right limb ; but when APPARATUS 5 to the left, until the arrow is directed downwards,it points to the scale on the left limb. When the brass disc is turned home to the right,the air beyond the mercury is closed ; and whento the left, the mercury is free to measure thearterial blood-pressure in the ordinary way atatmospheric pressure. This arrangement of supple-menting an ordinary manometer reading to 200 , enables us, by closure, to extend the scale to300 mm. Hg., without lengthening the fact, 4 inches in length are thus saved. The manometer tube is made with a bore ofeither 2 or 3 mm. in diameter, as the observerprefers. The smaller calibre is just sufficient todamp down oscillation without impairing accuracy :it therefore practical
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Keywords: ., bookcentury1900, bookdecade1910, bookid, booksubjectbloodpressure
