Overhead Isocentric Couch For Therapy Equipment

Abstract

There is disclosed a patient positioning apparatus, particularly for use with therapy wherein an associated couch is suspended from above rather than forming an integral part of therapy equipment. Also provided is a isocentric facility and the ability to move the patient in rectilinear coordinates and also in r - relationship to a datum which may be the access of emission of an X-ray device or a source line of a piece of radio therapy equipment.

Description

This invention relates generally to overhead supported couches used for the positioning of patients. More particularly the invention relates to a patient positioning system which is supported from above and which is of particular utility in teletherapy for example, radio therapy treatment of cancer etc.

There is described, in copending Canadian Pat. application No. 069,250, filed Dec. 8th, 1969, and U.S. Pat. application No. 008,351 filed Feb. 2nd, 1970, each entitled "Patient Positioning Systems" by Pegrum and Whitfield, each application being assigned to Atomic Energy of Canada Limited, a patient positioning system for sole support by the main frame of the equipment. The type of equipment contemplated in these prior applications is exemplified by the Theratron R 60 and 80 units and the Eldorado R 6 and 8 units, the registered trademarks owned by Atomic Energy of Canada Limited. The foregoing units, well known to those skilled in the art, are Cobalt 60 teletherapy units.

In the aforementioned two copending applications there is disclosed and claimed a therapy couch which is solely supported by the body of the unit frame. The applications also teach the provision of r - and rectilinear movements to the couch relative to the source-head and, more importantly, isocentric movement when required.

While the advantages of existing Theratron R and Eldorado R units continue to be enjoyed and that the frame-mounted underslung therapy couches, described in the aforementioned copending applications, have found quick acceptance among radiotherapists, the latter required yet another type of couch support.

It has been found that in certain installations the couch and its associated supporting structure require to be accessible from all horizontal directions. Such a requirement exists, for example, the therapy equipment is mobile and may be withdrawn away from the patient in order to permit space for other equipment, such as X-ray or Fluroscopic equipment.

Further it has been found necessary to move a therapy couch to one side to permit therapy of a patient in bed and the manipulation of a therapy unit around the bed. Again, in order to allow the mounting or dismounting of a patient from the couch from either side of a therapy unit without moving the latter, even more degrees of freedom become necessary. In providing all the desired accessibility, it was required to not only preserve the r - and rectilinear movements but also the isocentric movement capability.

It is an object of one feature of the invention to provide an overhead supported patient positioning having r -, rectilinear and isocentric movements and enhanced accessibility.

In accordance with the foregoing object, the invention comprises: an overhead suspension member the upper end of which is attached to the said ceiling or overhead structure, a mount plate having at one end pivotally attached the lower end of said suspension member and having the other cantilevered outwardly from said one end, a longitudinal guide member pivotally attached at a point intermediate its length, to the other end of said mount plate, said longitudinal guide member having slide-block engaging means thereon, a longitudinal slide-block slidably received in the slide-block engaging means on the longitudinal guide member, a transverse guide member attached, at a point intermediate its length, to the said longitudinal slide-block, said longitudinal guide member having slide-block engaging means thereon, a transverse slide-block slidably received in the slide-block engaging means on the transverse guide member, and, a lower suspension member pivotally attached to and extending downwardly from said transverse slide-block.

A preferred embodiment of the invention will now be described with reference to the accompanying drawing which shows, in isometric, patient positioning apparatus.

In the drawing, a column 1 is rigidly fastened to the ceiling or other overhead structure by means not shown. A mount plate 4 is cantilevered horizontally from the lower end of the column 1 and is provided with bearing means therebetween to permit rotation of the mount about the column 1. At the remote end of the mount plate 4 there is a pivot 42 which supports a longitudinal guide 6 disposed for rotation, about the pivot 42 beneath the mount plate 4. The underside of the longitudinal guide 6 is provided with a channel, flanges and a slide-block, not shown, to which is attached a transverse guide 66 which likewise is provided with a channel 67 and flanges 69. A transverse slide-block 68 is slidably received in the channel 67.

Thus, the transverse guide 66 may be moved longitudinally under the longitudinal guide 6 while the slideb-block 68 may be moved transversely relative to the guide 66. A column 70, having an adjustable length facility, not shown, extends downwardly from the transverse slide-block 68. A detachable stretcher 5 is removably attached to the lower end of the column 70 forms no part of the present invention.

If the longitudinal guide 6 is rotated, about pivot 42, so that the guide 6 and the mount plate 4 are substantially coextensive, then rotation of the mount plate 4 about column 1 provides the "-" function in an r - movement. The `r` function is then set by the movement of longitudinal block within the longitudinal guide 6. It will be obvious that r - movements may be effected without the prior coextensiveness of the longitudinal guide 6 and the plate 4. However, for any angular position of the guide 6 and the plate 4, having first fixed the r - functions, the stretcher may be given pure rectilinear translations. Pure linear translations are, of course, entirely simple.

To assist in summarizing the above movements, the directions of X-X, Y--Y and Z--Z are marked on the drawing together with the direction of `r` and horizontal plane of `-.`

Thus, the following movements are provided.

Vertical Z--Z

Longitudinal X--X

Transverse Y--Y

Isocentric r - (relative to column 1)

Rotational Facility r' - (relative to pivot 42) (This movement is rotational but is not isocentric)

In the second rotational facility the - function is in the same plane as the first mentioned -. The direction of r' is shown on the drawing.

It will be obvious to those skilled in the art that the source-head must be located coaxially with respect to the particular axis chosen for r - movement. Thus the drawing shown, in phantom, a source-head disposed on the axis of the column 1. All movements may, however, be individually locked to give the associated elements desired fixed positions. As with couch column 7, the overhead column 1 may be of adjustable length. Generally, the two columns will be parallel to each other.

The invention just described provides for a wider range of heights for associated therapy or diagnostic equipment. Theoretically, the maximum range of vertical movement is about one-half of the ceiling height. The five distinct movements may be individually or collectively power assisted by means well known in the art. The overhead mount provides much greater access to and manoeuvrability around the couch. From the latter feature stems the possibility of using less expensive couches, more importantly, the invention provides isocentric properties combined with the ability to execute rectilinear movements or composite isocentric and rectilinear movements using either of the isocentric axes. Further, all the advantages of the invention may be enjoyed by radio therapy installations already having fixed or moveable source heads and associated counter weight and support frame. These and other advantages and further embodiments falling within the terms of the appended claims will occur to those skilled in the art.

Claims

I claim:

1. A patient positioning apparatus for suspension from a ceiling or other overhead structure, said apparatus comprising:

i. an overhead suspension member the upper end of which is attached to the said ceiling or overhead structure,

ii. A mount plate having at one end pivotally attached the lower end of said suspension member and having the other cantilevered outwardly from said one end,

iii. a longitudinal guide member pivotally attached to a point intermediate its length, to the other end of said mount plate, said longitudinal guide member having slide-block engaging means thereon,

iv. a longitudinal slide-block slidably received in the slide-block engaging means on the longitudinal guide member,

v. a transverse guide member attached, at a point intermediate its length, to the said longitudinal slide-block, said longitudinal guide member having slide-block engaging means thereon,

vi. a transverse slide-block slidably received in the slide-block engaging means on the transverse guide member, and,

vii. a lower suspension member pivotally attached to and extending downwardly from said transverse slide-block.

2. Apparatus as defined in claim 1 wherein in axis of pivot of the mount about the overhead suspension member defines a first isocenter.

3. Apparatus as defined in claim 2 wherein the axis of pivot of the longitudinal guide member about the other end of the mount plate defines a second isocenter.

4. Apparatus as defined in claims 1, wherein the longitudinal and transverse movements in the associated slides may be locked in selected positions whereby the said lower suspension member may move in a r - relationship to either of said isocenters.

5. Apparatus as defined in claim 1, wherein the defined pivotal facilities may be locked whereby the said lower suspension member may be moved rectilinearly with respect to either of said isocenters.

6. Apparatus as defined in claim 1 wherein the vertical length of said overhead suspension unit is adjustable.

7. Apparatus as defined in claim 1 wherein the vertical length of said lower suspension member is adjustable.