Abstract:
A multi-use examination table provides x-ray imaging thereby conserving examination room space and to speed patient examination while retaining standard examination table features such as table extensions, foot end drawers, trays and stirrups, and a step for access to the high examination table surface. A repositionable imaging boom allows the table to remain unobstructed when x-ray imaging is not required.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application is a continuation-in-part of U.S. application Ser. No. 10/411,584 filed Apr. 10, 2003 hereby incorporated by reference. 
     
    
     
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
       BACKGROUND OF THE INVENTION  
         [0002]    The present invention relates generally to examination tables for doctor&#39;s offices and in particular to an examination table providing in-office x-ray imaging.  
           [0003]    Office space of physicians and other medical practitioners can be limited or expensive so that if an examination function or test is added in-office, an existing faction or text may have to be eliminated from in-office availability. This is particularly true for functions, such as x-ray imaging which normally require equipment that takes up a large portion of floor space of a typical examination room or physician&#39;s office. The result is that patients requiring x-rays must be referred to off-site locations or at a minimum different specialized x-ray facilities within the same building, increasing the time required for the patient examination and the inconvenience to the patient.  
         BRIEF SUMMARY OF THE INVENTION  
         [0004]    The present invention provides an x-ray machine that is incorporated into a standard patient examination table to provide either x-ray imaging or unobstructed use of the examination table for normal examination.  
           [0005]    By eliminating the need for separate tables, the space required for the x-ray machine is significantly reduced, allowing the x-ray imaging to be instantly accessible in the patient examination room for routine use. Important examination table features: including low cost, small foot print, drawers, stirrups, and table extenders at the foot of the table, and the like, are preserved by limiting the scan area to several compact regions of interest.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]    [0006]FIG. 1 is a perspective view of an examination table equipped for x-ray imaging showing a C-arm positioned within the pedestal of the examination table providing a pivoting upper arm such as allows unobstructed access to the examination table when x-ray imaging is not required;  
         [0007]    [0007]FIG. 2 is a fragmentary perspective view the foot of the table of FIG. 1 showing the upholstered top, the table extension, heated tray, and stirrup in retracted positions;  
         [0008]    [0008]FIG. 3 is a fragmentary view of the stirrup of FIG. 2 in extended position;  
         [0009]    [0009]FIG. 4 is a fragmentary view of a paper roll supported at the head of the examination table of FIG. 1;  
         [0010]    [0010]FIG. 5 is a perspective phantom view of the C-arm of FIG. 1 showing an internal mechanism for transverse scanning of the x-ray tube and detector, and an external mechanism for longitudinal scanning of the entire C-arm to obtain a raster pattern;  
         [0011]    [0011]FIG. 6 is an exploded view of a pivot allowing a swinging of the upper arm of the C-arm between a scanning and into a stowed position about a vertical axis;  
         [0012]    [0012]FIG. 7 is a fragmentary side elevation view of an alternative embodiment of the invention in which the upper arm of the C-arm pivots vertically rather than horizontally;  
         [0013]    [0013]FIG. 8 is a fragmetary perspective view of an alternative embodiment of the examination table using area x-ray detectors;  
         [0014]    [0014]FIG. 9 is a perspective phantom view of an alternative embodiment of the upper arm of the C-arm providing an enlarged housing wholly enclosing the x-ray detector during the longitudinal and transverse scanning; and  
         [0015]    [0015]FIG. 10 is a plan view of the top of the table of FIG. 1 showing the x-ray scanning area and relative portions of the patient&#39;s skeletal anatomy in phantom.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0016]    Referring now to FIG. 1, a multi-use examination table  10  providing x-ray imaging includes a modified examination table  12  and an imaging arm assembly  14 .  
         [0017]    The examination table  12  includes a pedestal  16  being a generally rectangular cabinet constructed of sheet metal and having legs  18  for supporting the pedestal  16  on an office floor.  
         [0018]    Fitted to the upper surface of the pedestal  16  is a table top  20  extending in a longitudinal direction  22  to receive a patient (not shown) lying on top of the table top  20  also along the longitudinal direction. A head end  24  of the table top  20  may be hinged at transverse hinge line  26  with respect to the foot end  28  of the table top  20  so that the head end  24  may angle upward to support the patient&#39;s head and torso at a range of positions between lying down and sitting up. The position of the head end  24  is locked by a release handle  30  according to methods well known in the art. The foot end  28  of the table top  20  remains generally horizontal.  
         [0019]    Referring also to FIG. 4, the head end  24  of the table top  20  may support beneath its upper surface a paper roll dispenser  32 . The paper roll dispenser  32  provides an axle  34  fitting within standard hollow-core paper roll  36  so that a sheet of paper  38  may be pulled up over the top of the head end  24  of the table top  20 . The paper  38  may be drawn along the surface of the table top  20  in a longitudinal direction to be retained under bands  39  providing a clean surface for each patient.  
         [0020]    The length of the table top  20  is less than the maximum expected patient height to provide more space within the examination room. The shortened length of the table top  20  also facilitates the patient&#39;s sitting up with his or her legs dangling over the foot end  28  toward the floor and allows the physician to easily maintain eye contact with the patient during the examination. As shown in FIG. 2, if the patient must subsequently lie down, a table extension  40  may be drawn from the foot end  28  of the table top  20  allowing full support of the patient&#39;s feet without a great amount of movement of the patient. When retracted, the table extension  40  fits within the foot end  28  of the tabletop.  
         [0021]    A head end  42  of the pedestal  16 , which in a conventional examination table normally contains drawers, is left empty to support a lower arm of a C-arm  46  being part of the imaging arm assembly  14  as will be described. In contrast, the foot end  48  of the pedestal  16 , shown also in FIG. 1, includes a number of longitudinally sliding drawers  50  including, for example, a heated drawer  52  for holding instruments at a temperature near that of body temperature as are well known in the art of examination tables. The drawers  50  may also have liners making them fluid tight.  
         [0022]    A step  51  may slide in and out of the pedestal  16 , longitudinally in drawer fashion, to allow the patient to climb up onto the table top  20  which unlike radiographic tables is more highly elevated, normally 31 inches above the floor, to facilitate examination.  
         [0023]    Stirrups  54 , as also shown in FIG. 3, may extend longitudinally on either side of an upper drawer  50  by means of stirrup extension rods  56  to provide stirrup loops  60  that pivot about pivot axis  58  to receive a patient&#39;s feet, also according to methods well known in the art.  
         [0024]    The side of the pedestal may support a convenience electrical outlet  49  attached via internal wiring to a source of line voltage.  
         [0025]    Fitted to the upper surface of the table top  20 , as shown in FIG. 2, and extending its full length between the head end  24  and foot end  28 , is upholstery  62  comprised of an internal cushion layer  64 , typically of a polyurethane foam, covered by a water-resistant and x-ray transparent outer covering  66 . The upholstery  62  is supported by an underlying radio translucent foam-cored, fiber composite, a portion of which is shown in FIG. 2.  
         [0026]    Referring now to FIGS. 1 and 5, as mentioned above, a lower extension  44  of a C-arm  46  of the imaging arm assembly  14  may fit within the pedestal  16  beneath the head end  24  of the table top  20 . A corresponding upper extension  68  of the C-arm  46  may then pivot between a longitudinal stowed position, as shown in FIG. 1, or to a transverse scanning position, as shown in FIG. 5, the latter with upper and lower extensions of the C-arm  46  in aligned opposition about a vertical axis.  
         [0027]    The lower extension  44  supports a movable carriage  70  holding an x-ray tube  72  directing a pencil, fan or cone beam  74  of x-rays vertically so as to pass through the head end  24  of the table top  20 . Desirably, the end of the lower extension  44  is positioned significantly below the top of the table top  20  when a fan beam is used in order to provide sufficient fan beam width.  
         [0028]    The x-ray beam  74  is then intercepted by a corresponding detector  76  on a movable carriage  78  within the upper extension  68  of the C-arm  46 . When the C-arm  46  is in the scanning position, carriages  70  and  78  may move in tandem under the influence of servo or stepper motors  80  so that the x-ray beam  74  may scan transversely as indicated by arrow  82  in a lateral direction across a patient supine on table top  20 .  
         [0029]    An additional stepper motor  86  positioned in the head end  42  of the pedestal  16  allows motion of the entire C-arm  46  on tracks  88  in a longitudinal direction  22 . According to conventions in the art, the motion of carriages  78  and  70  and C-arm  46  is coordinated so as to trace out a raster scan  90  having a pitch sufficient to provide continuous coverage of the patient with the x-ray beam  74  over a patient scan area  140 . At regular points within the patient scan area  140 , dual energy measurements indicating attenuation of the x-ray beam  74  through the patient at two energies.  
         [0030]    Referring now the FIGS. 5 and 6, a vertical column  92  of the C-arm  46  joining the upper extension  68  and the lower extension  44  may include at its top end, a pivot joint  94  having a hinge plate  104  from which vertically extends a hinge pin  96 . The hinge pin  96  includes a hollow center  98  for passage of electrical cables and the like and is received within a corresponding bore  100  of a hinge plate  110 . The hinge plate  110  is thus free to swivel about a vertical axis with respect to the column  92 .  
         [0031]    The hinge plates  104  and  110  include a number of mounting holes  105  for attaching each to the lower extension  44  and upper extension  68 , respectively. Hinge plate  110  may be retained on the hinge pin  96  by cap screws  106  fastening a retainer disk  108  to the hinge pin  96  to sandwich the hinge plate  110  between the hinge plate  104  and the retainer disk  108 .  
         [0032]    The hinge plate  110  includes a guide hole  112  aligning with a corresponding first guide hole  114  in hinge plate  104 , when the upper extension  68  is extending transversely across the patient in a scanning position, and aligning with a corresponding second guide hole  116  spaced 90 degrees from first guide hole  114  when the upper extension  68  is extending longitudinally in a stowed position as shown in FIG. 1.  
         [0033]    A locking pin  118  may pass through guide hole  112  and one of guide holes  114  and  116  to hold the arm in the respective positions. In this manner, the C-arm may be configured as shown in FIG. 5 for imaging and, as shown in FIG. 1, to provide unobstructed access to the examination table for other purposes.  
         [0034]    Referring now to FIG. 7, in an alternative embodiment, the upper extension  68  and column  92  of the C-arm  46  may be hinged about a horizontal axis so that the upper extension  68  may move between a horizontal scanning position A and a vertical stowed position B as indicated by arrow  120 . A mechanical assist through spring loaded cable  122  may be provided so that the arm is stable in either position A or B, according to methods well known in the mechanical arts.  
         [0035]    Referring now to FIG. 1, the imaging arm assembly  14  provides a control terminal  124  and a controller  126  to provide an interface for a doctor to initiate and control the scanning and to receive processed signals derived from the dual energy measurements and relevant to bone health. The control terminal may provide for the execution of a program to provide for simple pre-set techniques (of x-ray current and voltage) for a set of standard imaging situations.  
         [0036]    Referring generally to FIG. 8, in an alternative embodiment, the scanning fan or pencil beam may be replaced with a more conventional area beam x-ray tube  72  positioned as before beneath the table top  20  to project an area beam  160  upward through the upper surface of the table top  20  collimated to the patient scan area  140 . The x-ray tube  72  may be a conventional stationary anode or rotating anode tube.  
         [0037]    An x-ray cassette  162  either supporting a conventional grid or screen and film or a stimulable phosphor plate may be received in or removed through a slot  164  in the side of a tray held above the table top  20  by upper extension  68 . The cassette  162  may employ a Bucky system using a stationary or moving x-ray grid and may open to remove film for processing or for use with a plate reader for a stimulable-phosphor plate.  
         [0038]    Alternatively, electronic area detectors, such as an image intensifier/camera system  166  may be used to detect the area beam  160  or a solid state detector array using photo diodes or other detector materials such as cadmium telluride or cadmium zinc telluride (CZT) may be used to detect the area beam  160  and contained in a housing attached to the upper extension  68  and communicating with the control terminal  124  for the output of data for real-time imaging.  
         [0039]    Alternatively, the detector  162  or  166  may be placed beneath the top of the table top  20  and the x-ray tube  72  on the upper extension  68  of the C-arm  46 . In this case, for these areal detectors, movement of the upper extension  68  of the C-arm  46  is not required.  
         [0040]    Hybrid areal systems using an areal detector and pencil beam or fan beam of x-ray are also contemplated by the present invention.  
         [0041]    Referring now to FIG. 9, a housing of the upper extension  68  may be widened along the longitudinal direction  22  so as to enclose the detector  76  and its carriage mechanism  78  throughout an entire raster scan of the patient scan area  140 . In this way, mechanical interference between the patient and the detector  76  during the raster scan may be eliminated as well as motion of the C-arm  46 . A similar mechanism may support the x-ray tube  72  within the pedestal  16  and coordination of movement of the detector  76  and x-ray tube  72  provided electronically.  
         [0042]    Specifically, the upper extension  68  may enclose an x-y track including transverse track  142  allowing for transverse motion of the detector  76  and carriage  78  and longitudinal track  148  providing for longitudinal motion of the track  142  and thus of the detector  76  and carriage  78 . Stepper or servo motors  150  may be used to electrically synchronize motion of the x-ray detector  76  with corresponding motion of the x-ray tube  72  in the pedestal  16 . In this case, a horizontal axis per FIG. 7 is most conveniently employed to move the upper extension between the scanning and stowed positions.  
         [0043]    Referring now to FIG. 10, convenient implementation of the combination of the modified examination table  12  and imaging arm assembly  14  while providing important examination table features is possible by locating and restricting the patient scan area  140  to the head end  24  of the table top  20  above the head end  42  of the pedestal  16 . This scanning area may be marked by a visible indication  152  so as to allow a positioning of the patient appropriately for imaging and in particular for scanning of the lower spine  154  and femur scanning  156 .  
         [0044]    Generally, the patient need not be lying on the table but the table may be used for a patient support, for example, for the patient&#39;s arm, during an x-ray procedure.  
         [0045]    It is specifically intended that the present invention not be limited to the embodiments and illustrations contained herein, but include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims.