Patent ID: 7796724

Claim:
An X-ray fluoroscopic system comprising: an X-ray source; an X-ray camera disposed at a position to which X-ray from said X-ray source is made incident; an XY table that is provided between said X-ray source and said X-ray camera and used for positioning an object of fluoroscopy mounted thereon; and a tilting mechanism that relatively tilts said X-ray camera to said XY table, wherein the system further comprises: tilting tracking means for calculating a moving amount of said XY table necessary in maintaining the state where an observed point of said object of fluoroscopy is positioned within the field of view of said X-ray camera, in order to automatically move said XY table for tracking said observed point, by an arithmetic operation that uses each tilt angle at each time when said X-ray camera is relatively tilted to said XY table, and a distance h between said X-ray source and said observed point; and update means of data for tracking which uses a defined value or an arbitrary input value as an initial value of said distance h between said X-ray source and said object of fluoroscopy, which is used in said arithmetic operation by said tilting tracking means, and updates said distance h used by said tilting tracking means, by using a shift amount of said observed point which is obtained by specifying said observed point on an image after tracking.