A treatise on the diseases of the nervous system . nts a and b, traction on the cords will approxi-mate the two sides of the ellipse, and thus push the steel arm so as tomove the indicator as before. THE DYNAMOGRAPH. This instrument, which is of great value in the diagnosis of diseasesof the nervous system, is shown in Fig. 6. It consists of the dynamometer B B, to which a toggle-joint, mov-ing a steel rod, is attached. This steel rod plays through a hole in theend of the elliptical spring and moves the lever which raises the pencilD. At A is a screw which varies the point at which the rod tou
A treatise on the diseases of the nervous system . nts a and b, traction on the cords will approxi-mate the two sides of the ellipse, and thus push the steel arm so as tomove the indicator as before. THE DYNAMOGRAPH. This instrument, which is of great value in the diagnosis of diseasesof the nervous system, is shown in Fig. 6. It consists of the dynamometer B B, to which a toggle-joint, mov-ing a steel rod, is attached. This steel rod plays through a hole in theend of the elliptical spring and moves the lever which raises the pencilD. At A is a screw which varies the point at which the rod touchesthe lever, and thus increases or lessens the delicacy of the is a silvered plate upon which the paper is fastened by clips. To the INTRODUCTION. 27 iower part of this plate, a strip of gilt brass, with cogs cut in it, is at-tached. E is a gilt-brass box containing a watch-movement like thatof the sphygmograph. A cog-wheel which projects above the upperside of this box fits into the cogs on the plate which carries the paper. The wheel for winding up the clock-work, and the lever for stopping itor setting it in motion, are not seen in the figure, they being on theopposite side of the box. To set the instrument in action, the sphygmograph movement is at-tached to the dynamometer at A. The clock-work is then w*ound up,and the plate holding the paper placed in the groove on top of the boxE. The dynamometer is then grasped by the hand and squeezed firm-ly ; the lever is thus moved, and the plate with the paper is carriedalong by the cog-wheel. As it moves, the pencil traces a line on thepaper, the height and regularity of which depend upon the firmness andsteadiness with which the dynamometer is pressed. As seen in the cut,the plate with the paper is in motion, and has about half completed itscourse. The patient should not look at the paper while using the in-strument. The dynamograph, therefore, writes down the muscular power andtone of the individual, and li
Size: 1674px × 1492px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, booksubjectnervoussystem, bookye
