A textbook of human physiology / translated from [the] 6th German edition by W. Stirling.

  • Landois, Leonard
Date:
1888
Catalogue details

Licence: Public Domain Mark

Credit: A textbook of human physiology / translated from [the] 6th German edition by W. Stirling. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

    150/980 page 98
    elastic spring (tig. /^v; •^■^^^'^ ~, ^.^ i,..v. —, , ,■ f ivory pad, y, which is pressed by the spring upon the radial artery. On the upper surlace ot the pad tliere is a vertically-placed fine toothed rod, which is presse A) is fixed at one end, free at the other end, and provided with an J t... ^1 : X,. _ artery. On the upper surlace of pressed upon by a weak spring, e, Fig. 7-2. Scheme of Mareys sphygniograpli. A, spring with ivory pad, //, which rests on the artery; c, weak spring pressing k into I ; r, writing lever; P, piece of smoked glass or paper moved by clock-work, U ; H, screw to limit excursion of A ; S, arrangement for fixing the instru- ment to the arm of the ]>atient. .so that its teeth dovetail with similar teeth in the small wheel, t, from whose axis there pro- jects a long, light, wooden lever, c, running nearly parallel with the elastic spring. This lever has a fine style at its free end, s, which writes upon a smoked plate, P, moved by clock-work, U, in front of the style. Marey's instrument, as improved by Mahomed and others, has been very largely used. [Its more complete form, as in fig. 73. where it is shown applied to the arm, consists of—(1) a steel spring, A, which is provided with a pad resting on the arter}', and moves with each movement of the arteiy ; (2) the lever, C, which records the movement of the artery and spring in a magnified form on the smoked paper, G ; (3) an arrangement, L, whereby the exact pressure exerted upon the artery is indicated on tlie dial, ; (4) the clock-work, H, which moves the smoked paper, G, at a uniform rate; (5) a iVamework to which the various parts of the instrument are attached, and by means of whicli the instrument is fastened to the arm by straps, K, K {B]irom Bramwcll).^ [Application.—In applying the spliygmogrn])!), cause the patient to seat himself beside a low table, and place his arm on tlie double-inclined plane (fig. 73). In the newer form of instru- C Fig. 73. Marey's improved sphygmograpli. A, steel spring ; B, first lever ; C, writing lever ; C, its free writing end ; D, screw for liringing B in contact with C ; G, slide with smoked paper ; H, clock-work ; L, screw for increasing the pressure ; M, dial indicating the pressure ; K, K, .straps for fixing the instrument to the arm, and the arm to the double-inclined plane or support. ment, the lid of the box is so arranged as to unfold to make this support. The fingers ought to be semi-flexed. Mark the position of the radial artery with ink. See that the clock-w?rk is wound up, and apply the ivory ])ad exactly over the radial artery where it lies upon the radius fixing It to tlie arm l)y the non-elastic straps, K, K. Fix the slide holding the smoked paper m position. 1 lie best paper to use is that with a very smooth surface, or an enamelled card smoked over the flame of a turpentine lamp, over a piece of burning camphor, or over a fan- tailed gas-burner. The writing-style is so arranged as to write upon the smoked paper with the least possible friction. It is most important to regulate the pressure exerted iipon the
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