Abstract:
A digital radiography system for imaging a subject. A support structure, coupled to an X-ray source and an X-ray imaging detector, is rotatable about a first axis and is linearly moveable. The X-ray source and the X-ray imaging detector are also rotatable about second and third axes, respectively, to provide an operator with a number of degrees of freedom to move the X-ray source and the X-ray imaging detector to different positions relative to a subject. Further, the system has means for coupling an operator control interface and a display to the X-ray source for permitting an operator to rotate them about a fourth axis so that the operator control interface and display are accessible to the operator such that the position of the operator does not have to change when the positions of the X-ray source and the X-ray detector are changed.

Description:
FIELD OF THE INVENTION 
     The invention relates generally to digital radiography imaging systems having an X-ray source and an X-ray imaging detector that are moveable among various positions to accommodate a variety of physical characteristics of a subject, and more particularly to an operator control interface for such an imaging system. 
     BACKGROUND OF THE INVENTION 
     Some digital radiography imaging systems have an X-ray source and an X-ray imaging detector that are coupled together and supported in a manner that provides for a plurality of degrees of freedom of movement so that the imaging system can be properly positioned relative to a subject. Often, an operator control interface having a display screen is integrated into the system. A problem occurs when an operator needs to access the control interface and it has been shifted out of a convenient position for maintaining control of the apparatus by the movement of the imaging system. 
     There are prior systems that are adapted to maintain a correct viewing orientation of the image on the operator control interface with respect to the operator by adjusting the image on the display screen to compensate for the tilting movement of the X-ray source and an X-ray imaging detector. That is, the image to be displayed is modified in accordance with the tilting movement. The image data stored in memory is remapped from memory locations to positions on the display screen in order to display the image on the screen in a desired orientation. Such systems require re-computation, resizing, and redrawing of the image on the display screen in conjunction with the movement of the patient table. The readability and legibility of the display suffer due to angularities of the screen text in relationship to the operator. See, for example, U.S. Pat. No. 4,674,107 wherein orientation of an image on a display is maintained constant with respect to a main support during pivotal motion of the X-ray system by rotating the displayed image as a function of the direction and extent of the pivotal motion. PCT Application WO 2004/064039 discloses an imaging device with means for rendering the detector orientation and the display orientation essentially equal, but does not disclose maintaining a particular orientation of the display relative to an observer. 
     Other digital radiography imaging systems will “flip” and redraw the image on the display screen after the display and X-ray source have been subject to a given amount of angular rotation (e.g., a 45 degree angle in either direction) by an operator in positioning the source. 
     In other digital radiography imaging systems such as shown in U.S. Pat. No. 3,702,035, the display screen is mounted on an independent support arm that does not move in conjunction with the movement of X-ray source. Rather, it maintains a fixed position. Such systems have limited ability to handle different orientations of individuals for imaging, and must include additional support structure for the display monitor. Furthermore, such systems occupy significant floor space, which is disadvantageous in emergency room situations. 
     There exists a need for a digital radiography system that has a display and controls that are always in the same orientation for an operator. Additionally, there exists a need for ergonomic features for controlling the operation of an imaging system with an X-ray source and detector in a variety of positions. 
     SUMMARY OF THE INVENTION 
     The present invention provides a digital radiography system with an operator control interface and display that can be moved with degrees of freedom so as to maintain the same orientation with respect to an operator when the X-ray source and X-ray imaging detector are positioned to capture an image of a subject. 
     The present invention is intended for use in radiography systems having an X-ray source, an X-ray imaging detector, and a support structure coupling the X-ray source and the X-ray detector, wherein the support structure is rotatable about a predetermined axis such as to position the X-ray source and the X-ray imaging detector at various rotational positions about a subject. In accordance with a feature of the invention, an operator control interface is mounted on the radiography system for rotation about an axis that is substantially parallel to the predetermined axis such that relative orientation between the operator control interface and the operator can remain constant when the support structure rotates about said predetermined axis. 
     In a preferred embodiment of the invention, the predetermined axis is substantially horizontal when the radiography system is in use. The operator control interface includes a first display having a scene orientation with a top and a bottom, the scene orientation remaining constant when the support structure rotates about said predetermined axis. A second display having a scene orientation with a top and a bottom may be provided such that the scene orientation of the second display remains constant when the support structure rotates about the predetermined axis. 
     One advantage of the present invention is that it is a compact, adjustable digital radiography imaging system where the X-ray source and X-ray imaging detector are capable of being positioned in at least the same positions achievable with conventional floor mounted systems, with the additional feature of providing a display and controls which have a given orientation with respect to the operator. Typical imaging systems are generally much larger, or have separate pieces of equipment that work together. These systems are more mechanically complex, and have disadvantages in usability, cost and reliability. The adjustability of the present invention allows an operator to position the X-ray source and X-ray imaging detector to achieve suitable positioning to accommodate subjects for imaging (including ambulatory and non-ambulatory patients standing, reclining or in seated position), and provides a display and controls which retain the same orientation with respect to the operator. Thus, the operator control interface and display of the present invention is accessible to the operator so that the position of the operator does not have to change when the position of the X-ray source and X-ray imaging detector are changed. The position of the operating control interface and its display relative to the operator is important for critical environments, such as emergency or trauma rooms. The advantages of the operator control interface include, but are not limited to, greater legibility and readability of the display, less errors made by an operator in orienting the system to procure images, and other related advantages. By virtue of its size and placement of the operator control interface relative to the operator, this invention minimizes the potential for injury to an operator or patient by accidental contact with the hardware. Moreover, this invention can minimize the potential for collision between with obstructions in the installation environment by providing the operator with familiar controls. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing and other objects, features, and advantages of the invention will be apparent from the following more particular description of the embodiments of the invention, as illustrated in the accompanying drawings. 
         FIG. 1  shows a digital radiography system in accordance with the present invention. 
         FIG. 2  is a series of views of the digital radiography system of  FIG. 1  in various positions in accordance with present invention. 
         FIGS. 3A and 3B  show the coupling between the X-ray source and operator controls of the digital radiography system of  FIG. 1 . 
         FIG. 4  shows a diagrammatic view of the digital radiography system of  FIG. 1  and it&#39;s labeled X, Y, Z, A, B, C and D axes with a subject to be imaged in a standing position. 
         FIG. 5  shows a diagrammatic view of the digital radiography system of  FIG. 1  with a subject to be imaged in a reclined position. 
         FIG. 6  shows another diagrammatic view of the digital radiography system of  FIG. 1  with a subject to be imaged in a reclined position. 
         FIG. 7  shows another diagrammatic view of the support structure, X-ray source and X-ray imaging detector of the digital radiography system of  FIG. 1 . 
         FIG. 8  shows a diagrammatic view of a display and operator control interface for a digital radiography system of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following is a detailed description of the preferred embodiments of the invention, reference being made to the drawings in which the same reference numerals identify the same elements of structure in each of the several figures. 
     Referring to  FIG. 1 , a digital radiography system  100  has an X-ray source  110 , a first display  120 , an operator control interface  130 , a support structure  140 , and an X-ray imaging detector  160  with a coupling  170 . X-ray source  110  is connected to a support structure  140  by a coupling  112  (see  FIGS. 6-7 ) that allows X-ray source  110  to rotate in the C and C′ directions (shown in  FIG. 4 ). Coupling  170  permits X-ray imaging detector  160  to move in the D and D′ directions (illustrated in  FIG. 4 ), and to rotate so as to orient X-ray imaging detector  160  into a portrait or landscape position. Support structure  140  is pivotally mounted for rotation about an axis  145  as illustrated in  FIG. 4 . Support structure  140  is linearly adjustable (e.g., in the E and E′ directions shown in  FIG. 7 ) so as to allow an operator to set the source-to-image distance between X-ray source  110  and X-ray imaging detector  160 . X-ray source  110  is linearly moveable in directions F and F′ (shown in  FIG. 7 ) along support structure  140  so as to adjust the source-to-image distance before capturing an image of a subject as shown in  FIGS. 4-6 . Support structure  140  is further rotatable about axis an  145  in the A and A′ directions illustrated in  FIG. 4  by an operator in preparation for capturing an image of subject  195 . 
     Operator control interface  130  and first display  120  are mounted for movement about an axis  152  in the G and G′ directions (see  FIGS. 3A and 3B ). Axis  152  is substantially parallel to axis  145 . As used herein, the phrase “substantially parallel” is intended to mean that axis  145  and axis  152  are close enough to parallel so as to maintain the information presented on first display  120  close enough to the same orientation relative to an operator so that the position of the operator does not have to change when the positions of the X-ray source and the X-ray imaging detector are changed, regardless of the direction and extent that support structure  140  is rotated. Operator control interface  130  has grip points incorporated into its handle to maximize grasp by an operator. These grip points can be optimized to allow for left-handed or right-handed use. 
     As illustrated in  FIGS. 4-6 , support structure  140  is connected to telescoping support member  180  by a coupling  155  (see  FIG. 6 ). The telescoping support member is designed to be suspended from a ceiling of a room by a moveable base  190  (illustrated in  FIG. 5 ). Moveable base  190  can be attached to a typical ceiling-mounted X-Y rail structure using a carriage system with a plurality of wheels or other suitable movement system. Thus, with such an X-Y rail structure, moveable base  190  is selectably moveable in the X, X′, Y and Y′ directions illustrated in  FIGS. 4 and 5 . Moveable base  190  or coupling  155  can include a rotational mechanism, which is used in rotating telescoping support member  180  or support structure  140  about an axis  147  in the B and B′ directions illustrated in  FIG. 4 . 
     Telescoping support member  180  is adjustable in the Z and Z′ directions shown in  FIGS. 4 and 5  to varying positions between a collapsed position and an extended position. That is, telescoping support member  180  is configured to slide inward and outward in overlapping sections. In a collapsed position, telescoping support member  180  is moved in the Z′ direction and disposed towards moveable base  190  close to the ceiling. In an extended position, telescoping support member  180  is moved in the Z direction and is disposed away from moveable base  190  close to the floor. Telescoping support member  180  can move in Z and Z′ directions to discrete positions intermediate of the collapsed and extended positions. This motion allows for the imaging of objects of various heights and orientations between the collapsed and extended positions. 
     Support structure  140  allows digital radiography system  100  to image a variety of subjects (e.g., subject  195  illustrated in  FIGS. 4-6 ), which can be an individual or a body part of the individual), whether the subject is standing (e.g., see subject  195  of  FIG. 4 ), reclining on a table (e.g., see subject  195  of  FIGS. 5 and 6 ), or sitting. Support structure  140  is configured to slide inward and outward in overlapping sections in directions E and E′ (shown in  FIG. 7 ), so as to move the location of X-ray imaging detector  160 . X-ray source  110  is moveable linearly to discreet positions in the F and F′ directions (illustrated in  FIG. 7 ) along support structure  140  to provide further adjustment of digital radiography system  100  for imaging. The positioning of X-ray source  110  and X-ray imaging detector  160  by an operator can achieve an appropriate source-to-image distance for imaging of the subject to occur. As indicated in  FIG. 4 , the source-to-image distance is the linear distance between X-ray source  110  and X-ray imaging detector  160 . 
       FIG. 8  illustrates an exemplary display screen for first display  120  and control setup for operator control interface  130 . As shown, operator control interface  130  has X-direction control  210 , Y-direction control  220 , Z-direction control  230 , B-direction control  240 , detent skip control  245 , source-to-image distance release control  250 , X-ray source tilt control  260 , A-direction control  270 , X-ray imaging detector release control (not shown), or any suitable combination thereof. 
     X-direction control  210  permits moveable base  190  to move in the X and X′ directions (see  FIG. 4 ). Similarly, Y-direction control  220  permits control the movement of moveable base  190  in the Y and Y′ directions (see  FIG. 4 ), and Z-direction control  230  permits adjustment of telescoping support member  180  in the Z and Z′ directions. In other words, controls  210 ,  220 , and  230  allow an operator to control the forward, back, left, right, up, or down movements of support structure  140 . As described above, movement of base  190  in the X, X′, Y, and Y′ directions can be achieved through use of the rails on the ceiling, and movement in the Z and Z′ directions is permitted by the sliding inward and outward of the overlapping sections of telescoping support member  180 . B-direction control  240  allows an operator or technician to control the rotational motion of support structure  140  in a plane parallel to the ground (e.g., movement in the B and B′ directions illustrated in  FIG. 4  as illustrated in  FIGS. 2 and 4 ). 
     Detent skip control  245  allows an operator to bypass detents (e.g., detents fixed by manufacturing or detents added through software configuration) that represent predefined amounts of movement of a structure about an axis or in a particular direction. Movement from detent to detent in a particular direction represents a predefined amount of movement in a direction or about an axis. The detents can be set by operators at particular locations that are expected to be common stoppage points of motion along an axis or direction. The detents permit the operator to reach these predefined points without overshooting, or the need of additional fine positioning adjustments. For example, detents can be used to define discrete amounts of movement for support structure  140  in the A, A′, B, and B′ directions illustrated in  FIG. 4 . Detents can also be used to define discrete amounts of movement of moveable base  190  in the X, X′, Y, and Y′ directions (see  FIGS. 4 and 5 ). In another example, detents can be predefined for movement of X-ray source  110  in the C and C′ directions, or detents can be predefined for X-ray imaging detector  160  in the D and D′ directions. The detent will normally stop the motion of the structure at the detent point along a given direction or about an axis. By using detent skip control  245 , the operator can move the device or structure without interruption. 
     A-direction control  270  allows an operator or technician to rotate direct radiography system  100  in a plane perpendicular to the ground (e.g., movement about the A-axis as shown in  FIG. 2 ). Source-to-image distance release control  250  can control movement of support structure  140  (for movement of X-ray imaging detector  160  in the E and E′ directions indicated in  FIG. 7 ). Using source-to-image distance release control  250 , an operator can also move X-ray source  110  in the F and F′ directions indicated in  FIG. 7  on support structure  140  so as to change the source-to-image distance (as illustrated in  FIG. 4 ) between X-ray source  110  and X-ray imaging detector  160 . X-ray source tilt control  260  allows an operator or technician to adjust the angular movement of X-ray source  110  in the C and C′ directions (as illustrated in  FIG. 4 ). 
     Turning again to  FIG. 7 , digital radiography system  100  includes a second display  280  and second controls  290 . Second display  280  is coupled to support structure  140  to provide an alternative display to an operator of the same information provided on first display  120 . Second display  280  is fixed in a position on support structure  140  (in contrast to first display  120 , where coupling  150  allows rotational movement of first display  120  and operator control interface  130  so as to maintain a consistent position relative to an operator). Second controls  290  or third controls  292  can provide duplicate controls for X-direction control  210 , Y-direction control  220 , Z-direction control  230 , B-direction control  240 , detent skip control  245 , SID release control  250 , X-ray source tilt control  260 , A-direction control  270 , D-direction control, or any suitable combination thereof (in addition to these controls being located on operator control interface  130  or on first display  120 ). These controls can have any suitable arrangement. These additional controls are advantageous, for example, if an operator or technician is located adjacent to second controls  290  or third controls  292 , and he or she controls the operation and positioning of X-ray source  110  and X-ray imaging detector  160  of digital radiography system  100 . 
     The invention has been described in detail with particular reference to a presently preferred embodiment, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the appended claims, and all changes that come within the meaning and range of equivalents thereof are intended to be embraced therein. 
     PARTS LIST 
     
         
           100  Digital radiography system 
           110  X-ray source 
           112  Coupling 
           120  First Display 
           130  Operator control interface 
           140  Support structure 
           145  Axis 
           147  Axis 
           150  Coupling 
           152  Axis 
           170  Coupling 
           180  X-ray imaging detector 
           170  Coupling 
           180  Telescoping support member 
           190  Moveable base 
           195  Subject 
           210  X-direction control 
           220  Y-direction control 
           230  Z-direction control 
           240  B-direction control 
           245  Detent skip control 
           250  SID release control 
           260  X-ray source tilt control 
           270  A-direction control 
           280  Second display 
           290  Second controls 
           292  Third controls