We have tried to enlarge or cantract the focus by applying positive or negative voltage to a grid of an ordinary X-ray tube (which has no srecial structure and is on sale to the public) and applied this method to an usual radiography. This method, by applyins high negative voltage, also can be used as a vacuum tube switch. The following are the actual results we have heretofore collected on the above-mentioned.
For stereoscopic roentgenograph, two photographs are taken from two optically determined positions and viewed with a stereoscope. A film changer for exposures and a prism type of stereoscope have been devised to be attached to an ordinary X-ray apparatus for medical examination. A factor T is conceived with which the stereoscopic perception can be controlled. Manipulation is made easy by an adjusting device to suit different individuals. An attachment for measuring the exact position of any particular object in the visual field is provided.
We often find the diseased part of the tuberculosis at the back of the upper part of the lung. so that, in tomography, it is necessary to remain the shadow of the diseased part and to take off the shadow of the costal bow (which is in the closely neighbourhood of the diseased part and has large contrast). Here is described the new method of decreasing the contrast between these shadows by using stroboscopic method.
Recently the case of the X-Ray apparatus being applied for medical use is remarkably increasing and larger size of this apparatus has been popularized. Consequently, its adapters is alsos howing an incessant progress. Compared with above facts, an importance of a dark room, which is indispensable for X-ray apparutus is too often neglected. Turning our attention to this fact. We have made the report (as described hereunder) on the rebuilding of a dark room in our hospital.