Abstract: An X-ray film cassette holder which is small, lightweight, simple and economical to construct and use, having a base carrying an expandable frame incorporating two upwardly expandable risers releasably lockable in a plurality of expanded positions, said risers separated by a releasably lockable variable distance; and two film cassette clamps, each of which is pivotably carried by one of said upwardly expandable risers, and releasably lockable in fixed relation thereto, as well as provision for releasably lockable rotatable mounting of a cassette tray sized within a range determined by the variable distance between said risers on said frame, collectively adapted to hold cassettes steadily in a range of vertical positions above a surface whereon it is placed, at any inclination, and being rotatable on said surface, providing desirable adjustability for positioning an X-ray film cassette adjacent a portion of a patient's anatomy for convenient imaging thereof.

Abstract: A joystick mechanism having a barrel rotator is capable of multiple axis movement and multiple axis analog signal control. The joystick mechanism can be selectively spring centered on two axes, spring centered on one axis and frictionally positioned on the other, or frictionally positioned on both axes. A pair of switch mechanisms, one for each axis of movement, selectably engage or disengage the respective centering spring mechanism. The analog signal generators are adjustable from the outside to provide biasing as required.