Abstract:
A stand, especially a floor stand, with a movable arm with an attachment section provided at the end of the arm for an object to be held by means of the stand, especially an imaging device in the form of an ultrasound head, with the attachment section being supported movably on the arm via a ball-and-socket joint comprising a ball head carrying the attachment section and a head holder supporting the ball head on the arm side, with a locking device being provided for releasable locking of the ball head ( 32 ) in its adopted position in the head holder.

Description:
This application claims the benefit of DE 10 2008 059 344.3 filed Nov. 27, 2008, which is hereby incorporated by reference. 
     BACKGROUND 
     The present embodiments relate to a stand with a movable arm and an attachment section provided on the end of the arm for an object to be held by the stand. 
     Stands are frequently used with a medical imaging apparatus, such as an ultrasound head, and have a movable arm arranged on a vertical pillar on which the imaging apparatus is arranged. The movement capability for the ultrasound head is provided by the movability of the arm and also by a ball-and-socket joint support of the imaging apparatus on the arm. In practice, the imaging apparatus, for example the ultrasound head (the imaging apparatus is to be taken as including larger systems or components, for example, including a frame or the like), is applied and positioned by the doctor on a patient, for example, to record an image of a breast in a mammography. The doctor aligns the ultrasound head depending on the position of the breast in order to position the ultrasound head correctly relative to the breast or relative to a specific point (e.g., the nipple). The doctor records images of the entire desired area under investigation from which, for example, 3D images will subsequently be reconstructed. The ability to move the ultrasound head into a given position depending on the position or the size of the breast is made possible by the movability of the arm and especially the ball-and-socket joint support of the imaging apparatus. 
     During mammography, the doctor may apply considerable pressure and maintain this pressure on the ultrasound head while recording the images. Considerable pressure is applied to the breast during this process. When an ultrasound image recording apparatus including a stand is used, the patient is lying so that the ultrasound head can be applied and pushed on by the doctor from above and slightly inclined to the side. The doctor may press the ultrasound head during the entire imaging process with considerable pressure against the breast; this requires great effort on the part of the doctor and results in the problem that the ultrasound head moves around the ball-and-socket joint support, either as a result of the breathing movement of the patient or the movement of the doctor. Such a change in the relative position of the ultrasound head to the imaging area has a negative effect on the quality of the images recorded. 
     SUMMARY AND DESCRIPTION 
     The present embodiments may obviate one or more of the drawbacks or limitations in the related art. For example, in one embodiment, a stand may improve image recording. 
     In one embodiment, the stand may include a locking device for releasably locking a ball joint head once the ball joint head has adopted a specific position in a head support. 
     In one embodiment, the stand may allow, as a result of the ball-and-socket joint support of the imaging device, an accurate and precise alignment of the ultrasound head relative to the imaging area, and provide, as a result of the ability to lock any given position of the ultrasound head adopted relative to the arm, a system for fixing this optimum position for the subsequent imaging. Accordingly, the doctor merely needs to exert the required pressure against the body under investigation. There is no longer any danger of the relative position of the ultrasound head being changed by a movement of the ball joint, since this movable link is fixed or locked using the locking device of one of the present embodiments. Accordingly, the alignment during imaging is no longer changeable. 
     The locking device may include or is a clamping device, which clamps the ball head into the head support. Once a user (e.g., the doctor) has made the alignment, the user merely actuates the locking device, which directly results in the clamping of the movable parts in relation to each other, thereby fixing the alignment. For clamp locking, the locking device may include a clamping element able to be moved linearly via a motorized positioning element that, on actuation of the positioning element, is able to be moved against the ball head, pressing the ball head against the head support. The use of a motorized adjustment element for moving the clamping element allows an automated locking. The doctor only has to give a corresponding electrical actuation signal to the locking device or to the motorized adjustment element (e.g., through a suitable control key that the user holds, or the like in the area of the imaging device), in order to control an adjusting motor, which then moves the clamping element into the clamping position. The clamping element may be a clamping sleeve and may include a pressure surface adapted to the shape of the ball head, which presses against and clamps the ball head. This enables a large clamping surface to be realized, which makes clamping that is secure, by virtue of being a high-force and a form-fit clamping, possible. 
     The motorized adjustment element may be an electric motor with a downstream transmission. The transmission may be coupled directly or indirectly to the clamping element via a shaft. A suitable gearing can be set by the transmission so that the clamping can be realized accurately and precisely and with high clamping pressure. The shaft may include an outer thread, on which runs a sleeve or nut provided with an inner thread. The sleeve or nut is moved along as the shaft turns and is supported on or connected to the clamping element. The inner thread and the outer thread may be trapezoidal threads with a small pitch. Thus, clamping involves actuating the electric motor to turn the shaft via the transmission, which moves the sleeve or nut that runs on the outer thread of the shaft quasi axially, moving the clamping element, to which the sleeve or nut is connected or coupled, against the ball head and clamping the ball head. For fixing or supporting the sleeve or nut, a recess is provided on the clamping element, in which the sleeve or nut is preferably loosely located. A loose location is sufficient since when the strain is relieved on the sleeve or on the nut (e.g., when the shaft is turned back via the electric motor), the clamping connection is automatically removed and the ability to rotate is re-established. 
     In one embodiment, the clamping element may be held pre-tensioned via at least one tensioning element (e.g., a coil spring) against the ball head. In other words, even when the strain on the clamping element is removed and there is no clamping, the clamping element may be in slight contact with the ball head, allowing the ball head to move but preventing movement of the clamping element that could lead to noises. In one embodiment, the sleeve or nut may loosely engage the clamping element or the clamping sleeve, respectively. 
     In one embodiment, for secure guidance of the clamping element, which is to be guided axially on the arm or the arm section respectively in which the components for movement and clamping are contained, the clamping element may be guided linearly on one or more guide pins, which extend between a fixed-position holder and the clamping element. The coil spring may be arranged around the guide pin to provide guidance and pre-tensioning as well. 
     The ball-and-socket joint support allows any given rotation or pivoting of the imaging device relative to the arm. Since various connecting lines are routed via the arm to the imaging device, one embodiment may include a limiting stop to limit the rotational movement of the ball head in the head support so that the ball head cannot simply be rotated through 360° any number of times. Such a limiting stop may, for example, be set at an angle of rotation of approximately 290°. Any other maximum angles of rotation (e.g., 320°) may be realized via the limiting stop. 
     In one embodiment, the limiting stop may include a stop element provided on a propeller shaft joint or a propeller shaft arranged on the ball head, which is supported with a second end on the clamping element. The propeller shaft joint or the propeller shaft may include one or more stops limiting the rotational movement. The propeller shaft joint or the propeller shaft is linked to the clamp element to allow free movement. In one embodiment, the stop element located on the propeller shaft joint or the propeller shaft may be a laterally-protruding pin that comes into contact, on sufficient pivoting, with one or more stops limiting the rotary movement, which may be arranged on the clamping element. 
     In addition to such a rotational movement limiting stop, one embodiment may include a limiting stop of the pivoting movement of the ball head in the head support. The limiting stop of the pivoting movement may limit a pivot angle, (e.g., a maximum of 90° or larger or smaller maximum pivot angles). This pivot limiting may be formed by a free edge of the head support (i.e. the free edge of the head support forms the limiting stop of the pivoting movement), with which an extension provided on the ball head comes into contact. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows one embodiment of a stand, and 
         FIG. 2  shows an enlarged sectional view of one embodiment of a stand. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows an embodiment of a stand  1  with a floor plate  2 , on which a vertical pillar  3  with a casing  4  is arranged. Guided vertically on the vertical pillar  3  via a linear guide (e.g., rail and guide carriage) to allow a vertical movement is an arm  6  comprising two arm sections  7 ,  8 . The arm  6  is pivotable via a first pivot  9  relative to the linear guide  5 . A second pivot point  10  between the arm sections  7  and  8  allows the two arm sections  7  and  8  to pivot relative to one another. An adapter  11 , on which an attachment section shown in  FIG. 2  is provided, is located at an end of the arm section  8 . An imaging device  13 , (e.g., an ultrasound head  14  for recording ultrasound images during the course of a mammography) can be detachably fastened to the adapter  11 . The imaging device  13  may include a frame-type housing  15 , on which a section  16  with diverse operating devices (e.g., pivot motor, control system) is provided, and the pivotable ultrasound head  14 . The imaging device  13  can be attached to the attachment section  12  of the arm  6 , which allows the imaging device  13  to be rotated and pivoted in order to enable the imaging device  13  to be aligned in relation to the breast to be imaged during the mammography. During a mammography, the alignment is usually undertaken such that the ultrasound head is aligned relative to a fixed point on the breast, usually the nipple, so that the ultrasound head lies above the fixed point. For imaging, the ultrasound head is then moved via an imaging device-side movement system, starting from the fixed point, to the respective sides, to record an ultrasound image of the breast. 
       FIG. 2  shows an enlarged sectional view through the adapter  11 . The adapter  11  includes a housing  17 , which may include a motorized control element in the form of an electric motor  18  with a downstream transmission  19 . The transmission  19  is supported on a housing-side holder  20 , which includes a central breakthrough  21  into which a take-off shaft  22  engages a shaft  23 , which is rotationally supported via a suitable bearing  24  in the holder  20 . The shaft  23  features an outer thread  25  (e.g., a trapezoidal thread), on which a sleeve  26  with an inner thread runs. The sleeve  26  is loosely located in a recess  27  of a clamping element  28 . The clamping element may be a clamping sleeve  29 . The clamping sleeve  29  is able to be moved axially in the housing  17 . In other words, the clamping sleeve can be displaced in the direction of the housing longitudinal axis, for which purpose the electric motor  18  and the downstream transmission  19  is used. For guidance of this linear movement two guide pins  30  (of which only one is shown), which extend between the holder  20  and the clamping sleeve  29 , are provided. 
     The clamping sleeve  29  has a curved clamping surface  31  on a lower free annular edge, the shape of which corresponds to an outer side of a ball head  32  that is arranged movably in a head support  33  of the housing  17 . In other words, the ball head  32  and the head support  33  form a ball-and-socket joint. The attachment section  12  is located on the ball head  32  and may be attached to the imaging device  13 . The ball head  32  is loosely connected, via a propeller shaft  34 , to the clamping sleeve  29  with a retaining pin  35 . In other words, the clamping sleeve  29  is movable relative to the propeller shaft  34 . 
     As shown in  FIG. 2 , as indicated by the double-headed arrow, the attachment section  12  can be turned in the head support  33  via the ball head  32 . The ball head  32  can also be pivoted in the head support, as is shown by the arrow P2. To limit the angle of torsion (P1), a stop element  36  is provided on the propeller shaft and a stop  37  is provided on the clamping sleeve  29  in the form of a stop screw, which delimits the rotational movement. As a result of the use of the propeller shaft  34 , since the horizontal relative position of the stop element  36  in relation to the vertical axis and of the stop  37  does not change even if the ball head  32  is pivoted in the direction P2, there is always a movement limitation independent of the ball head position. The rotational movement may be limited to 290° as the maximum angle of rotation. The pivoting movement may be limited to 90° as the maximum pivot angle. 
     To limit the pivoting (P2), a lower edge  38  of the head support  33  forms the stop for a corresponding stop projection  39  of the ball head. 
     To record an image, the user now initially positions the imaging device  13 , by grasping the imaging device  13  with his hand by the two bars  40  shown in  FIG. 1 , whereby the arm  6  can be moved vertically and can be pivoted around the corresponding ball joint  9 ,  10 , and the imaging device  13  can also be pivoted around the ball-and-socket joint connection (i.e., ball head  32 , ball support  33 ). In order to now be able to lock this pivot position, one embodiment of the locking system described above is used, including the electric motor  18 , the downstream transmission  19 , the movement mechanism connected to the downstream transmission, as well as the clamping sleeve  29 . The clamping sleeve  29  is located in the initial position if the ball head  32  can thus be moved relative to the head support  33 , in a position released from the ball head  32  (i.e., not clamped rigidly against the head  32 ). The clamping sleeve  29  is pre-tensioned, via coil springs  41 , which are arranged around the guide pins  30 , against the ball head  32 , and rest in the released position lightly against the ball head  32  without restricting the movement of the ball head  32 . 
     If a pivoting or rotational position adopted is now to be locked, the user may issue an electrical signal to the electric motor  18  via a button, which may be a bar  40 , provided on the imaging device  13 . The control motor  18  turns the shaft  23  via the transmission  19 . As a result of the shaft transmission, the sleeve  26  moves downwards on the shaft  23 , as can be seen in  FIG. 2 . Thus, the sleeve  26  is moved against the clamping sleeve  29 , which is pressed downwards with a rounded clamping surface  31  against an outer surface of the ball head  32 . The ball head  32  will be pressed against the head support  33  and clamped in position as a result. The pressing-on process is movement-controlled (e.g., by recording the rotation of the output shaft  22 ) or force controlled (e.g., via a sensor measuring the press-on force), so that there is no resulting overload. 
     If the locking is to be released again via the head clamping, the electric motor  18  is activated again and operates in the other direction. In other words, the shaft  23  will be moved via the transmission  19  in the opposite direction. This leads to the sleeve  26  moving in the other direction on the outer thread  25  of the shaft  23 , and the sleeve  26  is “pulled out” of the recess  27 . This relieves the strain on the clamping sleeve  29 . The clamping sleeve  29  is simultaneously slightly pre-tensioned against the ball head  32  via the two or more coil springs  41 . The ball head  32  is thus released again. 
     The sleeve  26  and the propeller shaft  34  are both loosely supported on the clamping sleeve  29 , the sleeve in the recess  27  and the propeller shaft  34  on the retaining pin  35 . This loose support ensures the axial movability of the clamping sleeve  29 . 
     The relative position of the imaging facility  13  can be fixed in any number of given rotational or pivot positions with the embodiments described above. 
     While the present invention has been described above by reference to various embodiments, it should be understood that many changes and modifications can be made to the described embodiments. It is therefore intended that the foregoing description be regarded as illustrative rather than limiting, and that it be understood that all equivalents and/or combinations of embodiments are intended to be included in this description.