Abstract:
A urological device include a patient table with longitudinal and broad sides, and an X-ray imaging system containing an X-ray source and an X-ray detector for detecting the X-ray radiation emitted by the X-ray source towards the patient on the patient table. A first linear drive is provided for moving the X-ray source parallel to the broad side and a second linear drive is provided for moving the X-ray detector parallel to the broad side, but in an opposite direction. A dedicated pivoting mechanism is configured to pivot the X-ray source around a first pivot axis.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority from pending European Application No. 16173033.8, filed on Jun. 6, 2016. The disclosure of the priority application is incorporated by reference herein in its entirety. 
       BACKGROUND 
     1. Field of the Invention 
       [0002]    The invention relates to a device including a urology table for Percutaneous Nephrolithotomy (PCNL) surgery of the human or animal body. Such a device includes a radiologic system, which allows to survey the surgery. Percutaneous Nephrolithotomy (PCNL) is the preferred technique for treating large stones (over 2 cm in diameter) in the kidney. It involves keyhole surgery performed through a small incision in the skin overlying the kidney. During the surgery, X-ray images are made in order to locate the position of the operating instruments in relation to the kidney stones. 
       2. Description of Relevant Art 
       [0003]    A commonality shared by the surgical systems in the field of urology is that the X-ray source and the X-ray detector have to be pivoted around the patient in a common orbit. This is necessary to make X-ray images of a subject in different orientations, for example to allow to survey a surgery and to detect the exact position(s) of operating instruments. 
         [0004]    The state of the art describes two different types of X-ray systems. The first type includes C-arm systems. Here, the X-ray source is located at one end of a C-arm, and the X-ray detector is at the other side opposed to the X-ray source. Both may be rotated around a virtual center axis. The movement of the whole X-ray system is necessary in order to prevent image distortions and to allow pictures from different angles and positions. The surgeon and the operating room personal are limited in their freedom of movement by the C-arm of the X-ray system. 
         [0005]    The second type includes systems with a focus on ergonomic concentrated, fatigue-free work. These systems have an X-ray detector located in a position within or under the patient table. The X-ray source is located on a support, which is normally configured as an arm above the patient table and opposite to the X-ray detector. An electromechanical system in the surgery system allows pivoting and tilting the patient table into multiple positions in order to provide optimal working conditions for the doctor and his/her assistants, as well as a comfortable access position for the patient by changing the height of the table. The X-ray source and the X-ray detector are configured to be tilted synchronously, so that they are facing each other in every state or position. 
         [0006]    U.S. Pat. No. 7,942,575 B2 discloses a urological X-ray workstation with an X-ray source and an X-ray detector. The X-ray workstation as well as the X-ray source are supported on device retainers of a device carrier, which is located at the longitudinal side of a patient positioning table such that the X-ray source and the X-ray detector can be positioned opposite one another and independently from one another in various orientations on an orbit that proceeds around a common center in a working plane (the working plane is oriented orthogonally to the longitudinal axis of the patient positioning table). The disadvantage of this contraption stems from a complex, large, and heavy X-ray tube mount and a complex and expensive X-ray receiver positioning system. 
       SUMMARY 
       [0007]    The embodiments of the inventions are aimed at the goal of providing an improved urological X-ray system and/or urology table with X-ray system, which allows an improved treatment procedure without the spatial restrictions of a mobile C-arm system and which simultaneously allows for an ergonomic concentrated, fatigue-free work. The disclosed X-ray system and/or urology table with X-ray system should has a simple and light-weight mechanical design, which consumes less space and offers the surgeon an expanded freedom of movement. Furthermore, manufacturing costs associated with the production of an embodiment of the invention are decreased in comparison with those of related art. 
         [0008]    A first embodiment relates to a urological radiology device. The device includes a patient table, an X-ray source and an X-ray detector. It may additionally include at least one X-ray source support configured to hold the device. 
         [0009]    For easier reference in the following description, a Cartesian coordinate system is defined. The point of origin of such Cartesian coordinate system preferably is arranged in the center of the upper surface of the patient table. X-axis and y-axis are in a plane defined by the patient table. The x-axis is parallel to a longitudinal side of the patient table. The y-axis is parallel to a broad side of the patient table. The longitudinal side is longer than the broad side. The z-axis points upwards and is orthogonal to the x-y plane. 
         [0010]    The X-ray source, which preferably is an X-ray tube and which may include a high voltage power supply, is held above the patient table by an X-ray source support. The X-ray source support is preferably configured to allow movement of the X-ray source in a first plane parallel to and above the x-y plane with the use of at least one X-ray source linear drive. Most preferably, such linear drive is additionally configured to provide for a translational movement parallel to the y-axis, in y direction. 
         [0011]    The X-ray source may be aligned to emit an X-ray beam of X-ray radiation in the direction of a patient table and, when the patient is on the table, through the patient. For improved alignment, the X-ray source may be appropriately equipped with a pivoting means (such as a rotatable shaft) to be pivotable around a first pivot axis. This configuration allows for keeping the X-ray beam aligned with respect to the patient (patient table) and/or the X-ray detector, even when the X-ray tube is being translated. Therefore, it is possible to orient the X-ray source to direct the X-ray beam from different angles and positions to the patient (patient table) at any time. The X-ray source preferably has an X-ray beam collimator. 
         [0012]    The X-ray radiation, once emitted, can be detected with an X-ray detector unit, which preferably includes a planar detector within or under the patient table. The X-ray detector may be appropriately equipped with a repositioner to be moveable in a second plane that is parallel to the patient table. At least one X-ray detector linear drive is provided to move the X-ray detector and to align the X-ray detector with respect to the X-ray source to receive the emitted X-ray beam. 
         [0013]    Alternatively, the X-ray source and the X-ray detector may be moved such that a desired region or section of the patient positioned on the table is projected onto the detector. Most preferably, the same region of the patient on the patient table may be projected from different angles to the X-ray detector. Therefore, the X-ray source must be aligned with the X-ray detector in each position. This structural configuration allows taking X-ray images of the patient at different angles. Furthermore, it allows using a much simpler and cheaper mechanical mounting and bearing of the detector and the X-ray source. 
         [0014]    To coordinate the movement of at least two linear movement mechanisms of the X-ray source and the X-ray detector and the pivot mechanism of the X-ray source, a control unit may be additionally provided. The control unit may be in practice connected to the X-ray source linear drive, the pivot mechanism, and the detector linear drive—preferably by at least one control cable. The control unit may be configured to coordinate the X-ray source linear drive, the pivot mechanism, and the detector linear drive as explained above. Alternatively, it may assert control signals, such that at least 50 percent of radiation contained in the X-ray beam be collected by the X-ray detector. In a situation when not all of the X-ray beam hits the detector, the beam&#39;s dimension has to be appropriately reduced by the collimator in such a way as to be fully received by the detector. 
         [0015]    Preferably, the alignment of the X-ray source and the X-rays detector is carried out such that the center of the X-ray beam is aligned to the center of the X-ray detector and with a certain region of the patient to be imaged. It may be desirable to have a plurality of X-ray images of the same region from different directions. 
         [0016]    There may be further included a means for adaptation or change of an X-ray dose, to compensate for variation of the distance between the X-ray source and the X-ray detector with position. Therefore, in one implementation, the X-ray dose may be adapted or varied depending on the mutual positioning of the X-ray source and the detector to ensure a constant level of X-ray energy at the detector. Furthermore, the adaptation may be appropriately coordinated to be made dependent on the patient characteristics. 
         [0017]    As the X-ray detector is not tilted, there may be a keystone distortion present in images generated by the X-ray detector in a lateral state of the X-ray source, when the X-ray source is not directly above the X-ray detector but is laterally shifted in a plane parallel to the plane of the table. If present, such keystone distortion may be corrected digitally, with an image-processing unit (such as a programmable processor or computer). 
         [0018]    A basic unit may provide housing for a power supply, the image processing computer, a master control system, and mechanical systems configured to adjust position of at least one attachment part (such as, for example, the X-ray source support). 
         [0019]    A patient table may be attached to the basic unit via an X-ray source support. In one implementation, the patient table is designed to receive a patient thereon preferably in a treatment position. The patient table may be made of carbon composite, glass fiber composite material, or any other kind of X-ray transmissive material. In a related embodiment, the patient table may be positioned on an independent stand or foot. The device carrier and the patient table may be configured to be height-adjustable and pivotable around an axis of rotation to allow for an ergonomic positioning of the patient and for the surgeon, and to allow for easy handling of the patient during the surgery. 
         [0020]    The X-ray detector preferably is a flat panel detector. The detector may work based on GDO2 (Gadolinium dioxide) or CsJ (Cesiumjodide). The X-ray image data generated by the X-ray detector is further transferred to an image-processing computer. The X-ray detector may be configured to be part of the patient table or may be part of a separate unit that is disposed below the patient table and that may be attached to the X-ray source support or to an extra stand or foot of the patient table. The patient table may be structured to be moveable, independently from the X-ray detector, in parallel to the x and/or y-axes. 
         [0021]    In one case, the X-ray source is supported by the X-ray source support, which may be a stand-alone, independent support standing at or attached to the ground. In a preferred embodiment, the X-ray source support comprises a first support section, a second support section, and a third support section. Preferably, the second support section is attached orthogonally to a first support section in z-direction. Alternatively, the second support section may be attached to the patient table in z-direction. The third support section may be attached at one end to the second support section parallel to the first support section (y-direction). The third support section may be structured to be height adjustable in the direction of the z-axis. Preferably, this section may be moveable by a linear moving means, in parallel to the y-axis. The other end of the third support section, holding the X-ray tube may be located above the patient table preferably opposite to the X-ray detector. Most preferably, the second and/or third support sections are moveable in a plane parallel to that of the patient table. 
         [0022]    Another embodiment of the invention relates to a method for recording a plurality of X-ray images of the target (such as same area of the patient&#39;s body) at or from different angles. The method includes at least one of the following steps:
       Positioning an X-ray source in a first position above a patient table to face an X-ray detector that is disposed within or under the patient table (such that, in operation, the X-ray source emits the X-rays towards or in the direction of the X-ray detector).   Generating an X-ray beam with the X-ray source and generating a first X-ray image of a section of a target (for example, a patient) on the patient table with the X-ray detector.   Moving/displacing the X-ray source parallel to a y-axis (that is preferably in a plane of the patient table and parallel to a broad side of the patient table) with an X-ray source linear drive to a second position and pivoting the X-ray source with a pivoting means to align the X-ray beam with the contours or bounds of the target (the patient body).   Moving the X-ray detector parallel to the y-axis in a direction opposite to the direction of displacement of the X-ray source to align the X-ray detector with the X-ray beam.   Generating another X-ray beam with the X-ray source and generating a second X-ray image of a section of a patient on the patient table (and, in a specific case, the second image of the same section) with the X-ray detector.       
 
         [0028]    Furthermore, a multi-view image or a 3-D image may be generated from the first X-ray image and the second X-ray image and/or further X-ray images as a result of image data processing with a programmable processor. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0029]    In the following, the invention will be described by way of example, without limitation of the general inventive concept, on examples of embodiment and with reference to the drawings. 
           [0030]      FIG. 1  shows a first embodiment of a urological device. 
           [0031]      FIG. 2  shows a related embodiment. 
           [0032]      FIG. 3  shows the device with displaced and tilted X-ray tube. 
           [0033]      FIG. 4  shows the device from a top view. 
           [0034]      FIG. 5  shows a keystone distorted picture and a corrected one. 
           [0035]      FIG. 6  shows a block diagram of the movement control. 
       
    
    
       [0036]    While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the appended claims. 
       DETAILED DESCRIPTION 
       [0037]      FIG. 1  shows a first embodiment of a urological device. The device includes a patient table  110 , an X-ray source  120 , and an X-ray detector  130 . In a preferred embodiment, it may further include at least one X-ray source support  150  for holding the whole device, as well as a basic unit  140  configured to provide housing for a power supply, the image processing computer, a master control system and mechanical systems for adjusting the position of at least one attachment part for example the X-ray source support  150 . 
         [0038]    For easier reference of the following, a Cartesian coordinate system is defined. The point of origin of the Cartesian coordinate system preferably is arranged in the center of the upper surface of the patient table. (For a better clarity of the drawings, the axes of the coordinate system in the drawings is shown below the patient table.) X-axis  410  and y-axis  420  are in a plane defined by the patient table. The x-axis  410  is parallel to a longitudinal side of the patient  110  table and the y-axis  420  is parallel to a broad side of the patient table. The z-axis  430  points upwards and is orthogonal to the x-y plane. 
         [0039]    The X-ray source  120  is held above the patient table  110  by an X-ray source support  150  and is translatable in a plane  441  parallel to the x-y plane and along the z-axis by an X-ray source linear drive  154 . 
         [0040]    Additionally the X-ray source  120  may be structured to be pivotable about a pivot axis  161  such as to align the X-ray source to emit an X-ray beam  121  in the direction of patient  200  on the patient table  110 . The X-ray source preferably has a collimator  122  for beam forming. 
         [0041]    An X-ray detector  130  within, or under, the patient table  110  is disposed to detect the X-ray radiation. The X-ray detector may be moveable in a second plane parallel to the x-y plane and the patient table  110 . At least one X-ray detector linear drive  155  allows for the X-ray detector  130  to be aligned with respect to the X-ray beam  121  and, preferably, with respect to the center of the X-ray beam. Thus, X-ray images from different angles of the same region of the patient  200  can be recorded (for example, to survey the surgery procedure). 
         [0042]    The patient table  110  may be attached to the basic unit  140  via an X-ray source support  150  (as shown—to a part  151  of the X-ray source support), which, in turn, may be attached to the basic unit  140 . The patient table  110  may be moveable independent from the X-ray detector  130  parallel to the x  410  and y-axis  420 . The X-ray source support  150  comprises a first support section  151 , a second support section  152 , and a third support section  153 . The second support section  152  is attached orthogonally to a first support section  151 , along the z-axis. The third support section  153  may be attached with one end to the second support section  152 , parallel to the first support section  151  (which extends in y-direction,  420 ). The third support section  153  may be configured to be height adjustable (in the direction of the z-axis  430 ). Preferably, it may be moveable by the X-ray source linear drive  154  parallel to the y-axis  420 . Another end of the third support section  153 , holding the X-ray  120  tube, may be located above the patient table  200  preferably opposite to and above the X-ray detector  130 . Most preferably, the second  152  and/or third support  153  sections are configured to be moveable in a plane parallel to the plane of the patient table  200 . 
         [0043]    The X-ray detector preferably is a flat panel detector  130 . The detector may be based on GDO 2  (Gadolinium dioxide) or CsJ (Cesiumjodide). The X-ray image data generated by the X-ray detector  130  may be transferred to an image-processing computer (not shown). 
         [0044]      FIG. 2  shows a related embodiment. Here, the X-ray source  120  and the X-ray detector  130  are shown moved in the same direction and by the same distance from the first centerline  165 . As a result, a desired region or section of the patient  200  that is different from the center of the patient  201 , is projected to the X-ray detector  130 . Therefore, as shown, the center line  166  representing the center/axis of the X-ray beam  122 , does not run through the center  201  of the patient  200 . Instead, there is a lateral offset  168  between the first centerline  165 , which runs through the center  201  of the patient  200  and the third centerline  166 . As shown, the X-ray source  120  and the X-ray detector  130  may be in a position facing each other. This movability/repositioning of the X-ray source  120  and the X-ray detector  130  allows to irradiate and image various parts of the patient  200  without the necessity of moving the patient  200  or changing the position of the patient table  110 . 
         [0045]      FIG. 3  shows the same urology device  100  as that of  FIG. 1 , but with a laterally displaced and tilted X-ray tube. The X-ray source  120  is displaced parallel to the y-axis  420  with respect to the center  201  of the target (patient)  200  and therefore is laterally offset from the center  201  of the patient  200 . The X-ray source  120  is tilted around the first pivot axis  161 . 
         [0046]    The X-ray detector  130  has been moved in a direction opposite to the direction of displacement of the X-ray source  120 , and parallel to the y-axis  420 . By doing so, X-ray images of the center  201  of the patient  200  or of other target portions of the patient  200  may be procured from different perspectives or angles  164 . Therefore, multiple images can be composed into a 3-D image. 
         [0047]    To obtain a good alignment of the X-ray source  120  and the X-ray detector  130 , preferably the X-ray source  120  is moved in the first plane  441  parallel to the patient table  110 , while the X-ray detector  130  is moved in the second plane  442  parallel to the patient table  110  in an opposite direction. The distances of movement of the X-ray tube  120  and the X-ray detector  130  may be adjusted as required to preferably align the X-ray beam, emitted by the X-ray source, at the center of the X-ray detector  130 . 
         [0048]    The center of the X-ray beam  121  in a center position of the X-ray source  120  and the X-ray detector  130  is defined by a first centerline  165 . In a lateral position of the X-ray source, the center of the X-ray beam  121  is defined by a second centerline  167 . The angle  164  between the first centerline  165  and the second centerline  167  may be up to 40 degrees, and preferably 30 degrees. The patient table  110  may be moveable independently from the X-ray detector  130  in directions of the x-axis  410  and y-axis  420 . The patient  110  table may also be pivotable or rotatable about a second pivot axis  162 . 
         [0049]    In addition, a number of different images may be made from different angles  164  as shown above in  FIG. 3  by moving the X-ray source  120  and the X-ray detector  130  in opposite directions. 
         [0050]      FIG. 4  presents a top view of the urology device  100  from  FIG. 1 . The urology device  100  comprises a patient table  110 , a basic unit  140 , an X-ray source  120  and an X-ray detector  130 . 
         [0051]      FIG. 5  presents two illustrations  300 ,  301 . The first illustration  300  depicts an image of a scene in a state where the X-ray source  120  and the X-ray detector  130  are facing each other. In this state, there is no keystone distortion. In the other operational state of the device (which corresponds to, for example,  FIG. 3 ) there is a keystone distortion of the X-ray image of the scene, as shown. The keystone distortion has to be corrected by digital post processing. 
         [0052]      FIG. 6  illustrates a control unit  500  for the at least two linear movement mechanisms  154 ,  155  of the X-ray source  154  and the X-ray detector  155 , and the pivot mechanism  156  of the X-ray source  120 . The control unit may be connected to the X-ray source linear drive  154 , the pivot mechanism  156 , and the detector linear drive  154  preferably by at least one control cable  510 . The control unit  500  may be configured to coordinate the operation(s) of the X-ray source linear drive  154 , the pivot mechanism  156 , and the detector linear drive  155  as explained above. Preferably, the X-ray beam is aligned to, or preferably centered on the X-ray detector. Alternatively, it may provide control signals, such that the X-ray detector may collect at least 50 percent of the X-ray beam. Nevertheless, if not the complete X-ray beam hits the detector is has be reduced in size by the collimator in such a way, that now x-ray can pass next the detector. Additionally an external control  520  can be connected to the control unit  500 . The external control can be a manual control and/or a master computer. The control unit  500  may be part of the basic unit  140  or the master computer. The communication between the different parts can be a unidirectional communication or bidirectional communication. 
         [0053]    It will be appreciated to those skilled in the art having the benefit of this disclosure that this invention is believed to provide a device including a urology table for Percutaneous Nephrolithotomy (PCNL) surgery. Modifications and alternative embodiments of various aspects of the invention can be made without deviation from the scope of the invention. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the general manner of carrying out the invention. It is to be understood that the forms of the invention shown and described herein are to be taken as the presently preferred embodiments. Elements and materials may be substituted for those illustrated and described herein, parts and processes may be reversed, and certain features of the invention may be utilized independently, all as would be apparent to one skilled in the art after having the benefit of this description of the invention. Changes may be made in the elements described herein without departing from the spirit and scope of the invention as described in the following claims. 
       LIST OF REFERENCE NUMERALS 
       [0000]    
       
           100  Urology device 
           110  Patient table 
           120  X-ray source 
           121  X-ray beam 
           122  Collimator 
           130  X-ray detector 
           140  Basic unit 
           150  X-ray source support 
           151  First support section 
           152  Second support section 
           153  Third support section 
           154  X-ray source linear drive 
           155  X-ray detector linear drive 
           156  Pivot mechanism 
           161  First pivot axis 
           162  Second pivot axis 
           164  Interior angle 
           165  First centerline 
           166  Third centerline 
           167  Second centerline 
           168  Offset 
           200  Patient 
           201  Center 
           300  Image 
           301  Image with keystone distortion 
           410  x-axis, direction 
           420  Y-axis, direction 
           430  z-axis, direction 
           441  First plane (X-ray tube) 
           442  Second plane (X-ray detector) 
           500  Control unit 
           510  Control cable 
           520  External control