Abstract:
A patient transfer system including a patient support panel, a first base member mounted on a first support structure, e.g., a gurney, and a second base member mounted on a second support structure, e.g., a patient treatment table. The patient support panel has a pair of longitudinally extending side rails. Each base member has at least one clamp arranged to engage a rail of the patient support panel to hold it in place thereon. The clamps are releasable to enable the patient support panel to be slid off of one base member and onto the other base member. If the support structures are spaced apart at least one bridging member is provided to bridge the gap therebetween and allow the patient support member to be slid thereacross.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority from Provisional Application Ser. No. 61/073,201, filed on Jun. 17, 2008, entitled Patient Transfer System For Use In Stereotactic Radiation Therapy, which application is assigned to the same assignee as this application and whose disclosure is incorporated by reference herein. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    “Not Applicable” 
       INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISK 
       [0003]    “Not Applicable” 
       FIELD OF THE INVENTION 
       [0004]    This invention relates generally to holding devices and more particularly for devices for transferring patients from a gurney or other movable support structure to a radiation treatment couch or other patient support structure. 
       BACKGROUND OF THE INVENTION 
       [0005]    Patients undergoing radiation therapy for cancer treatment or some other procedure have to be transferred from a gurney on which they have been placed to transport them to the room in which a linear accelerator (LINAC) or other radiation therapy apparatus is located and then onto the treatment couch or table of that apparatus. One common practice to achieve that end is to roll the patient slightly on his/her side on the gurney to provide a space between the sheet on which the patient is disposed and the top pad of the gurney. An elongated patient transfer board formed of a strong low friction material, such as polyethylene, and which is at least as long and wide as the patient is then inserted between the gurney and the sheet on which the patient is disposed. The patient with his/her sheet is then rolled back down onto the board. The board with the patient and the underlying sheet on it is then lifted and/or slid to a position wherein the transfer board bridges the space between the gurney and the treatment couch. Once that has been accomplished the sheet with the patient on it is lifted up and slid from the board to a position fully on the treatment couch. 
         [0006]    While the foregoing technique is generally suitable for its intended purpose, it involves “brute force” to overcome friction between the various sheets/coverings of the gurney and treatment couch/table. In particular, when the transfer board has been located in the position bridging the space between the gurney and the treatment couch it leaves a considerable portion of the sheet on the treatment couch exposed and a considerable portion of the sheet or covering of the gurney&#39;s pad exposed. Thus, there is considerable friction when sliding the patient and his/her sheet onto the bridging board and then off of the bridging board and fully onto the treatment couch. In a similar manner, there is considerable friction that has to be overcome when using the bridging board to transfer the patient back from the treatment couch to the gurney when the patient&#39;s treatment has been completed. 
         [0007]    There are some roller systems which are designed to effect the transfer of the patient from the gurney to the treatment table and vice versa, but those systems are somewhat complex and still leave much to be desired. 
         [0008]    With the forgoing in mind it should be clear to those skilled in the art that a system and technique for effectively and efficiently transferring the patient from a gurney or other movable table onto a stationary treatment couch or table and vice versa, with ease, with minimum personnel and with minimal disturbance of the patient is desirable. The subject invention addresses that need. 
         [0009]    All references cited and/or identified herein are specifically incorporated by reference herein. 
       SUMMARY OF THE INVENTION 
       [0010]    In accordance with one aspect of the invention there is provided a system for transferring a patient from a first support structure, e.g., a movable gurney, to a second support structure, e.g., a treatment table of a radiation therapy machine. The system basically comprises a patient support panel, a first base member and a second base member. The patient support panel itself comprises a pair of longitudinally extending side rail portions. The first base member comprises at least one clamp and is arranged to be mounted on the first support structure. The second base member also comprises at least one clamp and is arranged to be mounted on the second support structure. 
         [0011]    The patient support panel is arranged to be disposed on the first support structure. The first support structure is arranged to be moved to an operative position adjacent the second support structure. The first and second base members each have a respective planar surface over which the patient support panel can be readily slid when the first support structure is in the operative position with respect to the second support structure. 
         [0012]    The at least one clamp of the first base member is arranged to releasably secure the patient support panel on the first base member via the at least one clamp of the first base member engaging one of the longitudinal extending side rail portions of the patient support panel. In a similar manner the at least one clamp of the second base member is arranged to releasably secure the patient support panel on the second base member via the at least one clamp of the second base member engaging the other of the longitudinal extending side rail portions of the patient support panel. 
         [0013]    In accordance with another aspect of this invention the system additionally comprises at least one bridging member and wherein the first base member comprises at least one first recess therein and the second base member comprises at least one second recess therein. The at least one bridging member is arranged to be located within the at least one first and second recess to bridge any space between the first and second support structures so that the patient support panel can be readily slid from the first base member to the second base member and vice versa via the at least one bridging member. 
         [0014]    In accordance with another preferred aspect of this invention each of the support structures and the patient support panel has a longitudinal axis. The system includes a lever device arranged to cooperate with either of the base members to effect the orientation of the patient support panel so that the longitudinal axis of the patient support panel is generally aligned with the longitudinal axis of the support structure on which the patient support panel is disposed so that the clamp of the base member can releasably engage a portion of a side rail of the patient support panel. 
     
    
     
       DESCRIPTION OF THE DRAWING 
         [0015]      FIG. 1  is an isometric view of one exemplary patient transfer system constructed in accordance with this invention and shown ready for use in transferring a patient from a movable gurney onto a stationary treatment table or couch; 
           [0016]      FIG. 2  is an isometric view showing an initial step in the transfer of the patient from the gurney to the treatment table; 
           [0017]      FIG. 3  is an isometric view showing a subsequent step in the transfer of the patient from the gurney to the treatment table; 
           [0018]      FIG. 4  is an isometric view showing the completed transfer of the patient from the gurney to the treatment table; 
           [0019]      FIG. 5  is an isometric view, similar to  FIG. 1 , showing the system of  FIG. 1 , but without the patient support panel on which the patient is located; 
           [0020]      FIG. 6  is a top plan view of the system shown in  FIG. 5 ; 
           [0021]      FIG. 7  is a bottom plan view of the system shown in  FIG. 5 ; 
           [0022]      FIG. 8  is a somewhat enlarged isometric view showing the system without the patient support panel; 
           [0023]      FIG. 9  is a somewhat enlarged isometric view showing the system with the patient support panel and with an orientation adjusting level also forming a part of the system of this invention; 
           [0024]      FIG. 10  is an enlarged isometric view of a clamp structure forming a portion of the system shown in  FIG. 1 ; 
           [0025]      FIG. 11  is an enlarged isometric view of a portion of the system shown in  FIG. 1  during the process of transferring the patient from the gurney to the treatment table; 
           [0026]      FIG. 12  is an enlarged isometric view of a wrench device that can be used to effect precise alignment of the patient support panel on either the gurney or the treatment couch; 
           [0027]      FIG. 13  is an enlarged isometric view of a portion of one of the transfer bars or slides of the system shown in  FIG. 1 ; and 
           [0028]      FIG. 14  is an enlarged end view of a portion of the system shown in  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0029]    Referring now to the various figures of the drawing wherein like reference characters refer to like parts, there is shown in  FIG. 1  a patient transfer system  20  and method of use that provides an effective and simple means to smoothly and with minimal jostling transfer a patient, such as patient  10  shown in  FIG. 1 , positioned on a conventional gurney  12  to treatment couch (e.g., a scanning or LINAC table)  14  and back again without lifting. The patient transfer system  20  will be described in detail later. Suffice it for now to state that it includes a patient support panel  22  and a pair of modular transfer members or base units  24  and  26  which cooperate with the patient support panel to accurately and repeatably register the patient  10  longitudinally and transversely utilizing existing couch tops (treatment tables) and the universal two pin registration system commonly used today for mounting various components to the couch top. 
         [0030]    As shown in  FIG. 1  the patient  10  is disposed on the patient support panel  22 . The patient support panel  22  not only constitutes a portion of this invention, but of another invention of ours which is disclosed in a U.S. Provisional Patent application filed contemporaneously herewith entitled Stereotactic Radiotherapy System, which is assigned to the same assignee as this invention and whose disclosure is incorporated by reference herein. 
         [0031]    The details of the patient support panel  22  will be described in detail later. Suffice it for now to state that the patient support panel is a generally planar member which is of sufficient size to support an adult patient in a prone position like shown in  FIG. 1 . The patient support panel  22  is arranged to have various components (not shown) for use with the radiation therapy releasably mounted on it via its side rails. Examples of such components are positioning masks, positioning cushions, fiducial marker frames, etc. The patient support panel  22  is arranged to be secured in place, via releasable rail clamps (to be described later) on the base unit portion  24  of the patient transfer system  20  that is located on the gurney  12 . The gurney can then be moved to a position beside the treatment couch  14 , whereupon the clamps can be released and the patient support panel  22  with the patient  10  thereon slid onto the base portion  26  of the patient transfer system that is located on the treatment couch/table  14 . The portion  26  of the patient transfer system also includes releasable clamps to releasably secure the patient support panel  22  with the patient  10  thereon to the top of the treatment couch/table so that the radiation procedure can be effected. Once that has been accomplished the patient can be transferred back to the gurney in a similar manner to the transfer of the patient to the treatment table. 
         [0032]    As best seen in  FIGS. 3 ,  6  and  7  the two modular base members  24  and  26  are identical in construction. In particular, the module  24 , which shall be referred to hereinafter as the gurney base module, in the exemplary embodiment shown basically comprises three transfer plates  24 A,  24 B and  24 C that are disposed on the top surface of the gurney. The transfer plates are connected to one another by two pairs of planar legs  24 D. If desired the gurney base module can be secured in place by any suitable means. 
         [0033]    The base module  26 , which shall be referred to hereinafter as the treatment couch module, is mounted on the top of the treatment couch/table  14  of the LINAC or other radiation therapy device (not shown) via a conventional two pin registration system (or any other suitable means). As is known such registration systems make use of elongated bars each having two upwardly projecting pins arranged to be received within correspondingly shaped and located apertures in the bottom surface of a device to be mounted on the treatment table or couch. Each bar of the registration system includes means, e.g., a respective ball, located on a respective end of the bar for securing the bar at various locations along the length of the treatment couch via respective sockets provided along the sides of the couch. The balls and sockets may be reversed, i.e., the bars may include the sockets and the couch top may include the cooperating balls. Alternatively, the two pin registration bar may include clamping members at it respective ends in lieu of balls or sockets to secure it in its desired position on the treatment table. 
         [0034]    The treatment couch module  26  includes three base panels (also called transfer plates)  26 A,  26 B and  26 C, each of which is mounted onto the top of the treatment couch  14  by a respective two pin registration bar (not shown). The transfer plates  26 A,  26 B and  26 C are connected to one another by two pairs of planar legs  26 D. 
         [0035]    Each of the transfer plates of each of the base modules  24  and  26  is a generally planar member having a smooth top surface across which the patient support panel can be readily slid to effect the transfer of the patient support panel from the gurney to the treatment couch and vice versa. For those patient transfer applications wherein the gurney  12  can be brought into lateral abutment with the treatment couch  14 , i.e., be brought into side-by-side abutment with it, the patient support panel  22  with the patient  10  thereon can be readily slid from the gurney module  24  directly onto the treatment couch module  26  and vice versa. If however, the gurney cannot be brought into such close lateral proximity to the treatment couch, a plurality of slide members forming an optional portion of the patient transfer system  20  can be employed to bridge the gap between the gurney and the treatment couch. In the exemplary embodiment shown, wherein each module includes three transfer plates, if the gurney  14  has to be located at some distance laterally of the treatment table, such as shown in  FIG. 2 , three bridging slide members  28 A,  28 B and  28 C are utilized to bridge the gap between the gurney and the treatment couch. 
         [0036]    The slide members  28 A,  28 B and  28 C are arranged to be disposed in respective channels or slots  30 A,  30 B and  30 C (to be described later) in the three transfer plates  24 A,  24 B, and  24 C, respectively, making up the gurney module  24 . In the exemplary embodiment shown in  FIG. 1  only two transfer bars  28 A and  28 B are shown in place in the plates  24 A and  24 B. The third bar  28 C is shown located in space over one of the transfer plates making up the treatment couch module  26  to illustratively represent that the bars  28 A,  28 B and  28 C are identical separate members that are each arranged to be located (placed) in a respective slot in a respective plate of a respective module of the system. 
         [0037]    Thus, each slide member  28 A,  28 B and  28 C is an elongated planar bar formed of any strong, yet light weight material, e.g., aluminum. A stop plate  34  is mounted on the underside of each slide bar at the midpoint thereof. The purpose of the stop plate  34  will be described later. In order to facilitate the sliding of the patient support panel across the slide members, each of the slide members includes means forming a low friction slide surface. To that end, as best seen in  FIGS. 13 and 14  a plurality of glide buttons  36  are located at the mid-portion of each slide bar. Each glide button  36  includes a head portion which extends upward from the top surface of the slide bar by a short distance (height), e.g.,  50  thousandth&#39;s of an inch, to serve as a low friction slide surface across which the patient support panel  22  can be freely slid. Each button is formed of a low friction material, e.g., Teflon®. 
         [0038]    To transfer a patient on a patient support panel  22  located on a gurney that can&#39;t be brought into abutment with a treatment couch, the three slide bars  28 A,  28 B and  28 C are inserted into respective slots  30 A,  30 B and  30 C of the transfer plates  24 A,  24 B and  24 C, respectively, after the patient support panel with the patient thereon has been disposed on the gurney&#39;s transfer plates. The thickness (depth) of each of the slots  30 A,  30 B and  30 C is approximately equal to the combined thickness of the slide bar and the head portion of the buttons mounted thereon so that when a slide bar is located within its associated slot of the associated transfer plate the top surface of that transfer plate will be flush or coplanar with the top or glide surface of the buttons. The proximal end of each of slide bars is located within a respective slot in the transfer plates on the gurney. The gurney can then be moved into position with respect to the treatment couch wherein the distal end of the respective slide bars  28 A,  28 B and  28 C are aligned with the slots  30 A,  30 B and  30 C of the transfer plates  26 A,  26 B and  26 C, respectively, on the treatment couch. The gurney is then lowered slightly (or the treatment platform raised) until the transfer bars  28 A,  28 B and  28 C just touch the bottom of the slots  30 A,  30 B and  30 C, respectively, in the transfer plates  26 A,  26 B and  26 C, respectively. The gurney can then be moved closer to the treatment couch whereupon the distal end of each of the transfer bars enters deeper into the associated slot of the associated transfer plate of the treatment couch module. There is plenty of side play in the fit between the bars and the slots, reducing the demand on precise longitudinal alignment. The vertical alignment of the gurney and treatment couch need not be perfect, but the closer the two are to the same height the better. 
         [0039]    The stop plates  34  that are mounted on the undersurface of the midsection of each of the slide bars help to set the separation distance between the gurney and treatment couch and also keeps the transfer bars in place during sliding of the patient support table thereacross. 
         [0040]    Once the gurney and treatment couch are at their desired spacing with the transfer bars bridging the gap between them, the rail clamps  40  of the system  20  can be released, thereby freeing the patient support panel from its fixed position on top of the gurney module. Before beginning to move (slide) the patient support panel off of the gurney module and onto the bridging bars and from there to the treatment table module, the clamps  40  of the treatment table module are opened. The clamps forming a portion of the gurney module and the treatment table module are identical in construction and will be described later with respect to  FIGS. 10 and 11 . Suffice it for now to state that each clamp includes a mouth portion  42  that is arranged to grasp a rail portion  22 A of the patient support panel  22 . There are two rail portions  22 A extending along respective longitudinal sides of the patient support panel. Each rail portion is bulbous in cross section. The patient support panel also includes two pairs of handles  22 B and  22 C located adjacent the respective ends of the panel. 
         [0041]    After the two sets of clamps  40  on the gurney module  24  are open, all that is required is to grasp the patient support panel  22  and slide it off of the gurney module and onto the bridging bars and from there to the treatment table module  26 . As mentioned earlier the slightly projecting buttons  36  provide a low friction glide surface across which the patient support panel can be readily slid. Moreover, the materials making up of other components of the system  20  are specifically chosen for their low coefficient of friction, e.g., the transfer plates are formed of UHMW expanded polyethylene and the patient support panel is formed of carbon fiber with a foam core. 
         [0042]    As will be appreciated by those skilled in the art, with the system constructed as just described while it may take a little more force to get the patient support panel  22  moving from its initial position on the gurney module  24 , once static friction is broken it slides easily with little force. Thus, once the patient support panel begins to move it is rather easy to position it so that its longitudinal side edge rail  22 A is brought into engagement with the rail clamps  40  on the treatment table module  26 . 
         [0043]    If any fine adjustment of the patient support panel  22  is needed to complete positioning it against the rail clamps  40 , a special wrench  44  can be used. The wrench is shown best in  FIG. 12  and basically comprises an elongated lever member having one end portion including a pair of rounded projections  44 A and  44 B and an upstanding boss  46  located adjacent those projections. Each of said transfer plates  24 A,  24 C,  26 A and  26 C includes a pair of complementary shaped recesses  48  for receiving one of the projections  44 A or  44 B of the wrench  44  to enable said wrench to be pivoted in the complementary shaped recess so that its boss  46  gently engages a portion of the peripheral rail  22 A of the patient support panel  22  to adjust its orientation and position. Thus, one can insert the special wrench into the recess of the module to gently slide the patient support panel in place against the rail clamps. The positioning of the patient support panel&#39;s distal side rail against the rail clamps at the foot and head end ensures that the patient support panel is parallel and repeatedly positioned in relation to the treatment couch. It is also desirable to make sure during final placement of the patient support panel that it is correctly positioned longitudinally (i.e., to achieve longitudinal registration). To that end, each of the end transfer plates  24 A and  26 A also includes a transversely extending stop  50  against which the foot end of the patient support panel  22  can be brought during the fine adjustment of the orientation of the patient support panel to bring its longitudinally extending distal side rail into engagement with the clamps  40  and its foot end into engagement with the stop  50 . 
         [0044]    Once the patient support panel and patient are in place on the treatment couch, the gurney is lowered slightly (or the treatment table is raised) to eliminate any possible remaining tension on the transfer bars and they are removed. If desired the gurney can then be moved away from the treatment couch. 
         [0045]    Referring now to  FIGS. 10 and 11 , the details of an exemplary one of the various rail clamps  40  of the system  20  will now be described. As can be seen the clamp  40  basically comprises a body portion having a T-shaped base  52  which is arranged to be received within a correspondingly shaped slot  54  in the associated transfer plate. The slots in transfer plates  24 A,  24 C,  26 A and  26 C receive a correspondingly shaped base of a respective rail clamp  40  therein to releasably mount the clamp to the transfer plate. The remainder of the body portion of each clamp  40  is designated by the reference number  56  and projects upward from the T-shaped base to form a concave lower jaw portion of the clamp. Each clamp  40  also includes a movable upper jaw  58  which includes an arcuate concave surface located adjacent the arcuate concave surface forming the lower jaw. The arcuate surfaces of the upper and lower jaws conjoin to form the socket/throat  42  into which the portion of the peripheral edge of the longitudinally extending side rail  22 A of the patient support panel  22  can be located. The upper jaw is arranged to be moved relative to the lower jaw by means of an adjustable thumbscrew  60  to close the socket/throat of the clamp and thereby releasably secure the patient support panel to the clamp. 
         [0046]    After the patient has received his/her treatment he/she can be transferred back onto the gurney in a reciprocal manner than that described above for transferring the patient from the gurney to the treatment table. Thus, in the interest of brevity the procedure for transferring the patient back to the gurney will not be described herein. 
         [0047]    As will be appreciated by those skilled in the art from the foregoing the system of the subject invention makes use of a support surface on which the patient is initially placed and the patient remains on that surface at all times, with the support surface being moved from a position fully in place on the Gurney to a position fully in place on the treatment couch/table and vice versa. This is extremely important from the standpoints of safety, not disturbing the patient and reproducibility of patient positioning. Moreover, it should be appreciated that the subject invention is not limited for use with gurneys and treatment couches of radiation therapy machines, but can be used in any application wherein it is desired to transfer a patient from a movable support structure to a fixed or stationary support structure and/or vice versa. Further still, while each of the base units or modules  24  and  26  was shown and described as including three transfer plates, that arrangement is merely exemplary so that each module can have one, two, three or any number of transfer plates, if desired. 
         [0048]    Without further elaboration the foregoing will so fully illustrate our invention that others may, by applying current or future knowledge, adopt the same for use under various conditions of service.