Volume 1

Radiography and radio-therapeutics / by Robert Knox.

  • Knox, Robert, 1868-1928
Date:
1917-1918
Catalogue details

Licence: In copyright

Credit: Radiography and radio-therapeutics / by Robert Knox. Source: Wellcome Collection.

    151/536 (page 111)
    ROTATING PLATE-CHANGING STAND A Rotating Plate-changing Stand in Modern Radiographic Work A simple method for the rapid changing of plates is often required. It is often necessary to take a number of plates in quick succession, and the advantage of doing so will be readily appreciated by any one who has to examine stomach conditions by means of the opaque meal. The ordinary methods employed do not allow of a sufficiently rapid change of plate to enable us to study the peristaltic wave of the stomach ; particularly is it necessary closely to observe the behaviour of the pyloric end of the stomach and the duodenum. The screen examination is extremely useful, and gives the observer all the information he seeks, but when he attempts to obtain , the same effects on a plate, or a series of plates, then he finds the need for a more accurate mechanical arrangement than most of the plate-changers in use. Gregory Cole has solved the problem in radiography of the stomach in the prone position. Howard Pirie has recently described another form of table for the prone position. For the upright position we have not been so fortunate. Rosenthal and Rieder have used for several years a most complicated apparatus for the production of a pseudo-cinematographic effect by taking a number of plates, about six to a second. Dessauer has still more recently introduced a plate-changer, designed to give a cinemato¬ graphic effect, on much the same principle as Rieder and Rosenthal. In both the principle of the falling plate has been adopted. Both also suffer from the same disadvantages, extreme expensiveness, coupled with a doubt¬ ful efficiency in practical work. Some time ago the subject was discussed with Mr. Caulfeild, and he designed and put together the apparatus described below. This combines extreme simplicity of design with a remarkable efficiencv in execution, a combination somewhat infrequently met with in X-ray apparatus. The following details of construction will enable any intelligent carpenter to make the apparatus. At the usual speed of operation six plates can be exposed in 12 seconds. The stand can be used for two or more plates, and the intervals between each exposure can be varied in several ways. The apparatus can be worked by hand instead of automatically, when the intervals between the exposures may be as long as we desire, or by alter¬ nating the cassette or plates with dummies the intervals of time between exposures may be as follows : 6 exposures in 2 seconds interval. 12 seconds in all. 3 ,, 4 „ ,, 12 » >5 2 ,, 6 ,, 5 5 ” In stomach work these combinations will be found useful, as it is only necessary to examine the movements of the organ on the screen to determine what interval is necessary to get a complete cycle on the six plates. The plate-changer can also be utilised for stereoscopic work, when the plates auto¬ matically change position, while in the interval the tube may be displaced by hand or automatically, whichever is the more convenient method. The