C-Arm Diagnostic Equipment

This invention relates to a C-arm X-ray diagnostic equipment and also to a ceiling suspended C-arm for use in diagnostic examinations and medical treatments.

The use of a C-arm diagnostic equipment in diagnostic examinations and surgical procedures is well known, and such C-arms heretofore have been controlled utilizing various devices and constructions for effecting needed movements.

Improvements in C-arms, however, deemed to be useful and/or needed in some applications. In particular, now known C-arms have failed to provide a sufficient range of orbital movement of the C-arm and a counterbalanced variable distance between an image source and an image receptor, have ceiling rails directly above a patient undergoing a treatment and hence precluding complete sterilization of this zone.

This invention provides an improved C-arm apparatus for use in diagnostic and/or medical procedures and which enables substantially sufficient range of orbital displacement of the C-arm (with respect to the curvature of the C-arm) and provides a counterbalanced variable distance between the image source and the image receptor, and further, allows to moveably mount the C-arm on the ceiling rails laterally displaced from, and not extending over, the patient being treated.

It is therefore an object of this invention to provide an improved C-arm useful in diagnostic and surgical procedures.

It is another object of this invention to provide an improved C-arm which C-arm has an adequate orbital rotation of the C-arm and yet allows for varying the distance between the image source and image receptor.

It is still another object of this invention to provide an improved C-arm which has all the movements counterbalanced for effective use.

It is still another object of this invention to provide an improved ceiling suspended C-arm which C-arm is moveably mounted on the ceiling rails laterally displaced from, and not extending over, a patient undergoing the treatment and, thus, facilitating maintaining sterile condition and parking the C-arm away when not in use.

FIG. 1 is an isometric view of the C-arm diagnostic equipment according to the present invention.

FIG. 2 is a side view of the C-arm.

FIG. 3 illustrates the actuating means for varying the distance between the X-ray tube and the image intensifier.

FIG. 4 illustrates the suspension means of the C-arm structure.

FIG. 5 is a cross section through a line A--A of FIG. 2.

The description of this invention is illustrated in relation to a ceiling suspended C-arm diagnostic equipment. A C-arm diagnostic equipment according to this invention is best known by the isometric drawing of FIG. 1, augmented by the side view of FIG. 2.

As shown, C-arm diagnostic equipment comprises:

(1) a C-arm structure 1 being an arc structure 2 with an image source such as an X-ray tube 4 (with an X-ray 7 collimator disposed on the window of said tube) and an image receptor, such as an image intensifier 3 (as shown) or a film cassette or the like, moveably mounted on opposite ends thereof by means of slides 5, 6 respectively, and connected with an actuating means 50 (FIG. 3) for varying the distance therebetween as brought out more fully hereinafter;

(2) an arc-in-the arc structure being an arc member 8 moveably mounted on a second arc member 9 and having C-arm structure 1 moveably mounted thereon for the orbital displacement of the C-arm with respect to the curvature of the C-arm between slides 5 and 6, and also said arc member 8 (and hence the C-arm) being orbitally displaceable with respect to the curvature of said arc member 8 to increase the range of the orbital displacement of the C-arm;

(3) a horizontal structure 10, which structure has a downwardly extending portion 11, which portion has a second arc member 9 rotatably mounted thereon for the rotation of said second member around the predetermined horizontal axis;

(4) a pantograph structure 12 being a pair of two rods 13 and 14 pivotably joined at opposite ends by means of pairs of plates 15 and 16 to form a parallelogram for vertical displacement of the C-arm; horizontal structure 10 being moveably mounted on plate 15;

(5) a counterbalancing means comprising a lengthwise elongated member 17 being an extension of the lower rod 13 and having a counterweight 18 mounted thereon and a compression spring 19 affixed to member 17 at one end and to plates 16 at the opposite end;

(6) a rotating disc 20 having pair of plates 16 mounted thereon and said disc being mounted on a first frame means 21, which means is moveably mounted on rails 22, which rails are moveably mounted on a second frame means 23, which second frame means is moveably mounted on longitudinal rails 24, which rails are rigidly mounted on a ceiling in the direction generally perpendicular to rails 22 and generally parallel to the lengthwise axis of the examination table.

To counterbalance the weight of the C-arm 1 and the weight of arc member 8 for manual control of the orbital displacement, the outer curvature of arc structure 2 is drawn from a center O.sub.1, and the outer curvature of arc member 8 drawn from a center O.sub.2 so that the ratio of the distance between these two centers and the radius of the outer curvature of arc structure 2 is equal to the ratio of the weight of arc member 8 and the weight of C-arm 1.

Actuating means 50 for varying the distance between X-ray tube 4 and image intensifier 3 is shown in FIG. 3. Image intensifier 3 is attached to plate 24, which plate is moveably mounted on slide 6 and also connected with a cable 29; X-ray tube 4 is affixed to a rack 26, which rack is moveably mounted on slide 5 and driven by a pinion 25. Pinion 25 is mounted on one end of shaft 27, which shaft has a drum 28 mounted on the opposite end thereof. Cable 29 is affixed to and wound over drum 28 for the length of the displacement of X-ray tube 4 (and hence image intensifier 3), and further, said cable extends over various pulleys 30 so that image intensifier 3 and X-ray tube 4 move in unison toward and away from one another. To counterbalance this movement, a ratio of the pitch diameter of the drum 28 to the pitch diameter of pinion 25 is selected to equal the ratio of the weight of X-ray tube 4 (with collimator 7) to the weight of image intensifier 3 (with plate 24).

FIG. 4 shows rotating disc 20 and first frame means 21, which frame means comprises a frame 33 with a cross member 34 connecting two opposite sides of frame 33 and having four struts 35 (shown two). Frame 33 (and hence the C-arm) moves on four bearings 31 along rails 22. Rotating disc 20 comprises a larger diameter, thinner lower disc 36 (made of hard material) and a smaller diameter upper disc 37 (made of lighter material), which discs are bound together by an adhesive. Disc 37 includes a hub for a bearing 32 which bearing is secured by a pin 38 placed in cross member 34. Disc 20 (and hence the C-arm) rotates between four pairs of bearings 39.

FIG. 5 is a cross section taken through line A--A of FIG. 2 illustrating arc-in-the arc structure (8,9) and arc structure 2 (which structure is discussed in detail in another co-current patent application). Arc member 8 is moveably mounted on arc member 9 by means of inserts 40 and 43 made of a hard material and imbedded in member 8 and member 9 to form channels in the shape of an arc, in which channels balls 41 roll to facilitate orbital displacement of member 8 with respect to member 9.