Abstract:
A mobile digital fluoroscopy system comprises either a G-arm ( 18 ) stand ( 1 ) having two X-ray beam transmitter ( 21,23 )/receiver ( 22,24 ) pairs arranged at right angles to each other or a C-arm having a single transmitter/receiver pair. Protective collimator shutter plates ( 1060 ) at each transmitter limit the X-ray irradiation area. These collimator plates are properly adjusted via servo motors prior to or during the operation, by fingertip movements, touching collimator representations on a touchscreen for each transmitter/receiver pair, to provide both protection to the surgeon and patient and sufficient fluoroscopic view to the surgeon of the operation site of interest in the body.

Description:
FIELD OF THE INVENTION 
     The present invention relates in general to a preferably mobile digital fluoroscopy system for medical applications operating with an X-ray device mounted to generate X-ray images. 
     More specifically, the present invention relates to a fluoroscopy system having one or more X-ray devices each provided with a digital X-ray detector, and oriented on different axes to provide different views of the location of interest in the patient with the ability to narrow or widen the area of the patient exposed to the X-ray beam via a graphical user interface (GUI), such as a touch screen. 
     BACKGROUND 
     In orthopedic surgery environment, there is a need for allowing full access to the operating area with total control at each step. Therefore, X-ray imaging using C-stands or G-stands comprising imaging systems is commonly used, wherein a C-stand only has one X-ray imaging device while a so-called G-stand comprises two such imaging devices, with their axes oriented at an angle to each other. 
     A symmetrical G-stand may in some circumstances be preferable to a C-stand, since it comprises two perpendicularly mounted X-ray imaging devices, and is thereby able to provide both frontal and lateral X-ray imaging with fixed settings. The ability to simultaneously see the surgical area in both a frontal and lateral view reduces the need to move and adjust the equipment during surgery, thus reducing both surgery time and radiation dose. When the need to move the equipment is reduced, better sterility is also achieved. 
     X-ray imaging devices may be used for accurate positioning of implants thereby creating a safer and more reliable method of surgery. The X-ray devices are fixed in perpendicular relation to each other and may be tilted somewhat for better access and views. 
     A general problem in the technical field of X-ray imaging is to protect personnel involved in surgery as well as parts of the patient&#39;s body, not part of an area of interest, from unnecessary exposure to X-ray radiation. A common way to achieve this is that the X-ray beam is narrowed by protective lead collimator shutters. 
     A problem with conventional systems is to easily and accurately narrow or widen the X-ray beam, used for imaging, to the area of interest as the area of interest may change, e.g. during surgery. There is a need to improve the user&#39;s or surgeon&#39;s understanding of what the selected area of interest is and to improve the method of changing the area of interest during use of the X-ray imaging device, e.g. as surgery proceeds. 
     In presently used systems, keyed in numerical values are often used to adjust the physical positions of the collimators. This is very indirect, difficult and non-intuitive. These difficulties will result in non-optimal setting of the collimators, and most likely overexposure X-ray radiation. 
     RELATED ART 
     An example of such a mobile digital fluoroscopy system is described in patent application WO 03/077762. 
     One example of a G-stand X-ray system is shown and described in WO 96/11633 Further examples of related art are shown in the following publications:
     US 2005/0116878 A1   U.S. Pat. No. 6,789,941   U.S. Pat. No. 7,231,014   U.S. Pat. No. 6,431,751   US2C212308A1   US2C213338A1   US20070255292   U.S. Pat. No. 7,403,591   

     SUMMARY OF THE INVENTION 
     The general object of the invention is to provide improvements in a digital fluoroscopy system for medical applications operating with first and optionally a second X-ray imaging device mounted on a C-stand or G-stand to generate X-ray images along two mutually intersecting axes. 
     A problem with conventional systems is to easily and accurately narrow or widen the x-ray beam, used for imaging prior to surgery in compliance with safety policies and regulations. The area of interest may change during surgery. There is a need to improve the user&#39;s or surgeon&#39;s understanding of what the selected area of interest is and to improve the method of changing the area of interest as surgery proceeds. There is also a need to facilitate rapid, accurate and intuitive setting of the protective collimators, to avoid overexposure to X-rays and to provide optimal viewing of the area of interest. 
     One embodiment of the invention effects this narrowing or widening of the irradiated area by the use of collimator plates disposed in front of a beam transmitter in each X-ray imaging device together with servo motors controlled by user input on a touchscreen, thereby narrowing the exposed area of the patient irradiated with X-rays and imaged on a display. 
     One embodiment of the invention effects this narrowing or widening of the irradiated area by the use of a dilatable collimator iris disposed in front of a beam transmitter in each X-ray imaging device together with servo motors controlled by user input on a touchscreen, thereby narrowing or widening the irradiated area of the patient and imaged on a display. 
     One embodiment of the invention solves this narrowing or widening the irradiated area by the use of a dilatable collimator iris and collimator plates disposed in front of a beam transmitter in each X-ray imaging device together with servo motors controlled by user input on a touchscreen, thereby narrowing or widening the irradiated area of the patient and imaged on a display. 
     In one embodiment of the invention a stored unnarrowed still image is shown on a touch screen and a user can narrow or widen the irradiated area via user touchscreen input data that is received by a control unit. The control unit is configured to process user input data to control data indicative of a desired servo motor position, to send said control data as control signals to a servo motor unit adapted to receive control data as control signals from said control unit, to control servo motors to a predetermined position based on said control data by sending servo motor signals, thereby causing the dilatable collimator iris or collimator plates to narrow or widen the irradiated area. 
     In one embodiment of the invention the actual current movement of the collimators in response to touchscreen input data is indicated on the touchscreen by obtaining in a servo motor unit servo motor status data indicative of the status of a servo motor, by sending servo motor status data as status control signals from said servo motor unit to said control unit, by receiving servo motor status data as status control signals by a control unit from a servo motor unit, processing servo motor status data to a visual representation of said servo motor status data and to send said visual representation to said touch screen as a display signal, wherein said touch screen is configured to display said visual representation to a user. 
     For safety reasons it is important that these collimator plates be adjusted properly and accurately before the operation. 
     One specific object of the present invention is to provide improvements in the apparatus for setting the protective collimators in a mobile digital fluoroscopy system. It has hitherto been difficult to see to it that the collimators are precisely and easily positioned prior to irradiation with X-rays. 
     Embodiments of the invention provide such improvements, as described herein. 
     The digital fluoroscopy system comprising a G-arm may also be referred to as a G-arm system, or a G-stand. 
     The digital fluoroscopy system comprising a C-arm may also be referred to as a C-arm system, or a C-stand. 
     The object is fulfilled and the problem is solved by embodiments of the invention as described below and in the accompanying claims. 
     Embodiments of the invention comprise a mobile C-arm or G-arm fluoroscopy system provided with digital X-ray detectors. 
     According to one embodiment, there is provided a mobile digital fluoroscopy system, comprising a mobile unit  1  having a stand having a G-arm  18  suspended on a chassis frame  7 ; a first X-ray device  19  mounted on the G-arm  18  to transmit an X-ray beam along a first axis P 1 , the first X-ray device  19  having a first receiver  22  mounted on the G-arm  18  and a first transmitter  21  mounted on the G-arm  18  opposite said first receiver  22 ; a second X-ray device  20  mounted on the G-arm  18  to transmit an X-ray beam along a second axis P 2  intersecting the first axis P 1  of the first X-ray device, the second X-ray device  20  having a second receiver  24  mounted on the G-arm  18  and a second transmitter  23  mounted on the arm  18  opposite said second receiver  24 , wherein said first and second receivers  22  and  24  are flat digital X-ray detectors mounted at respective ends of the G-arm. 
     According to another embodiment of the invention, the mobile unit  1 , has a stand with a so-called C-arm, with X-ray beams transmitted only along one axis P 1  between a single transmitter and receiver pair. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will be further explained below with reference to the accompanying drawings, in which: 
         FIG. 1-FIG .  8  show a schematic overview of one embodiment of the invention in a digital fluoroscopy system configured on a G-arm, wherein 
         FIG. 1  shows a perspective view of the G-stand of the system as seen from a first direction. 
         FIG. 2  shows a perspective view as seen from a second direction. 
         FIG. 3  shows the G-stand of the system in a first side elevation. 
         FIG. 4  shows the G-stand of the system from a second side elevation. 
         FIG. 5  shows another form of G-stand used in a system according to the invention, showing a patient with her neck at the intersection of the two X-ray axes. 
         FIG. 6  shows one embodiment of a fluoroscope system comprising a mobile unit and a control console. 
         FIG. 7  shows a control console to be used in the system according to the invention. 
         FIG. 8   a  shows a console view along one axis showing a collimator iris and two collimator plates represented overlaid on an X-ray image of a hip joint. 
         FIG. 8   b  shows a console view along one axis showing four collimator plates in a rectangle represented overlaid on an X-ray image of a hip joint. 
         FIG. 9  shows a schematic view of a control unit in a console, with dedicated halves for the two axes of a G-stands, in a system according to the invention. 
         FIGS. 10 and 11  show schematic views of a control unit in a console with other configurations of the touchscreen. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     System Overview 
     The present invention concerns an X-ray apparatus configured as a system of components illustrated in  FIG. 1  to  FIG. 5 , adapted for use in connection with surgical orthopedic operations. 
     One embodiment of the apparatus shown in  FIG. 1  to  FIG. 5  comprises a mobile unit  1  provided with two X-ray systems  19 ,  20  mounted to operate and transmit X-ray beams along mutually intersecting axes P 1 , P 2 . The arm  18  of the embodiment illustrated in  FIG. 1  is referred to as a G-arm. 
     An object, typically the body of a patient undergoing surgery, is placed inside the mobile unit  1  so that beam axis P 1  and beam axis P 2  of the two X-ray systems cross within the object. The first X-ray device  19  includes a first transmitter  21  (an X-ray tube or x-tube) for emitting X-rays and a first receiver  22  (e.g. image intensifier or flat screen semiconductor sensors) for receiving X-rays emitted by the first transmitter  21  and having passed through the object. The first transmitter  21  may be located down below on the arm  18  and the first receiver  22  at the top of the arm  18 . The second X-ray device  20  includes a second transmitter  23  (an X-ray tube or x-tube) for emitting X-rays and a second receiver  24  (e.g. image intensifier or semiconductor sensors) for receiving X-rays emitted by the second transmitter  23  and having passed through said object. The receivers  22 ,  24  may each comprise image intensifying means and an image capturing device, typically a CCD camera, for converting X-rays into a visible image. 
       FIG. 5  shows the placement of an exemplary patient PA in a mobile fluoroscopy system. In this G-arm system shown in  FIG. 5 , the receivers  24   a  and  22   a  are traditional receivers and not flat screen receivers  22 ,  24  as shown in the G-arms of  FIGS. 1-4 . 
       FIG. 6  shows a G-arm of the type shown in  FIG. 5 , to be placed around the patient as shown in  FIG. 5  together with a separate console  2   a  which can be operated by the surgeon prior to the operation or during the operation by an assistant who does not have sterility restraints. High definition monitors  4   a  face the surgeon displaying the X-ray images in two different orthogonal planes either in real time or in so called “cine” replay to review exactly how and precisely where a prosthetic joint component has been placed without the necessity of exposing the patient and surgeon to more X-ray radiation. 
       FIG. 7  shows another console  2   b  to be used in an X-ray system according to the invention. The HD display monitors  4   b  are shown here facing the operator of the console. During an operation, the high definition monitors will typically be turned around to present the fluoroscopic images to the surgeon. The cables connecting the G-stand to the console can be wound up and stored in the slot  5  when the console and the G-stand are close to each other. The console shown in  FIG. 7  has a touch screen graphic user interface (GUI)  3   b , comprising in this case two fields which can be configured in various ways as shown in  FIGS. 9-11 .  FIG. 9  for example shows horizontal and vertical x-ray views  5  of a prosthesis mounted in a patient&#39;s hip, each view being surrounded by touch screen button  101  or slide  102  controls as well as numerical or analogue read-outs.  FIG. 11  shows a configuration in which the left half of the touchscreen has a keyboard  6   c  for inputting and recording information to identify patient or operation information for example and “cine” recordings. 
     Each x-ray transmitter  21  and  23  is provided with a servo motor unit and servo motors moving collimator plates which must be adjusted to limit the exposed area of the patient to only the area of interest required to adequately perform the operation. Each transmitter is typically equipped with two pairs of collimator plates arranged perpendicularly to each other to form a rectangular exposure area  6  which must be adjusted to limit X-ray exposure. It is also possible to provide the mobile X-ray apparatus with servo motors moving a circular collimator iris. 
     Such a system may also comprise high resolution monitors or touch screens for presenting images to a surgeon for example and a user input unit, such as a foot switch (not shown) or touch screen functionality of the monitor to enable the surgeon with sterile hands to display X-ray images and control the area of interest. The system further comprises a control unit ( 2   a ,  2   b ) comprising at least one touch screen display for displaying image data, a control panel, and a data processor comprising image processing means adapted to receive images transmitted from said image capturing devices comprised in said receivers  22 ,  24 . This is illustrated in  FIG. 6 , wherein a system comprises a mobile unit  1   a  and a control unit  2   a . The mobile unit  1   a  and the control unit  2   a  are communicatively coupled to each other, for instance by means of a cable or through wireless signal transmission, which is indicated by the dashed arrow in  FIG. 6 . 
     The control unit is further configured to receive user indications via said touch screen as user input data in the form of user input data signals, to process user input data to control data indicative of a desired servo motor position, to send said control data as control signals to a servo motor unit, to receive servo motor status data as status control signals from a servo motor unit, to process servo motor status data to a visual representation of said servo motor status data and to send said visual representation to said touch screen as a display signal, wherein said touch screen is configured to display said visual representation to a user. 
     The control unit further comprises a processor/processing unit provided with specifically designed programming or program code portions configured to control the processing unit to perform the steps and functions of embodiments of the inventive method described herein. The control unit further comprises at least one memory configured to store data values or parameters received from a processor or to retrieve and send data values or parameters to a processor. The control unit further comprises a communications interface configured to send or receive data values or parameters to/from a processor to/from external units via the communications interface. 
     In one or more embodiments the processor/processing unit may be a processor such as a general or specific purpose processor/processing unit for example a microprocessor, microcontroller or other control logic that comprises sections of code or code portions, stored on a computer readable storage medium, such as a memory, that are fixed to perform certain tasks but also other alterable sections of code, stored on a computer readable storage medium, that can be altered during use. Such alterable sections of code can comprise parameters that are to be used as input for the various tasks, such as receiving user indications. 
     In one or more embodiments the control unit further comprises a display configured to receive a display signal from a processor and to display the received signal as a displayed image, e.g. to a user control. 
     In one or more embodiments the control unit further comprises an input device, e.g. integrated in the touch screen, configured to receive input or indications from a user as user input data. 
     In one or more embodiments, wherein communications interface may include at least one of a Local Area Network (LAN), Metropolitan Area Network (MAN), Global System for Mobile Network (GSM), Enhanced Data GSM Environment (EDGE), High Speed Downlink Packet Access (HSDPA), Wideband Code Division Multiple Access (W-CDMA), Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Bluetooth®, Zigbee®, Wi-Fi, Voice over Internet Protocol (VoIP), LTE Advanced, IEEE802.16m, WirelessMAN-Advanced, Evolved High-Speed Packet Access (HSPA+), 3GPP Long Term Evolution (LTE), Mobile WiMAX (IEEE 802.16e), Ultra Mobile Broadband (UMB) (formerly Evolution-Data Optimized (EV-DO) Rev. C), Fast Low-latency Access with Seamless Handoff Orthogonal Frequency Division Multiplexing (Flash-OFDM), High Capacity Spatial Division Multiple Access (iBurst®) and Mobile Broadband Wireless Access (MBWA) (IEEE 802.20) systems, High Performance Radio Metropolitan Area Network (HIPERMAN), Beam-Division Multiple Access (BDMA), World Interoperability for Microwave Access (Wi-MAX), infrared communications and ultrasonic communication, etc., but is not limited thereto. 
     In one or more embodiments, the processor/processing unit is communicatively coupled and communicates with a memory where data and parameters are kept ready for use by the processing unit. The one or more memories may comprise a selection of a hard RAM, disk drive, a floppy disk drive, a magnetic tape drive, an optical disk drive, a CD or DVD drive (R or RW), or other removable or fixed media drive. 
     The system further comprise a servo motor unit configured or adapted to receive control data as control signals from said control unit, to control servo motors to a predetermined position based on said control data by sending servo motor signals, to obtain servo motor status data indicative of the status of a servo motor by receiving servo motor signals and to send servo motor status data as status control signals to said control unit. The servo motor unit and the servo motors are communicatively coupled to each other, for instance by means of a cable or through wireless signal transmission. The servo motor unit and the control unit  2   a  are communicatively coupled to each other, for instance by means of a cable or through wireless signal transmission. 
     In one embodiment a transmitter comprise a dedicated servo motor unit controlling servo motors moving collimator plates and/or a collimator iris narrowing the area of interest. 
     In one embodiment a common servo motor unit is shared by a first transmitter and a second transmitter, wherein the servo motor unit is controlling servo motors moving collimator plates and/or a collimator iris narrowing the area of interest for both the first and the second transmitter. 
     In non-limiting example, the servo motor status data is indicative of the position and/or if the servo motor is stationary or moving, i.e. has not yet reached a position corresponding to the a new irradiation area so that the transmitter can radiate the new irradiation area of interest. 
     The servo motor unit further comprises a processor/processing unit provided with specifically designed programming or program code portions configured to control the processing unit to perform the steps and functions of embodiments of the inventive method described herein. The servo motor unit further comprises at least one memory configured to store data values or parameters received from a processor or to retrieve and send data values or parameters to a processor. The servo motor unit further comprises a communications interface configured to send or receive data values or parameters to/from a processor to/from external units via the communications interface. 
     In one or more embodiments the processor/processing unit may be a processor such as a general or specific purpose processor/processing unit for example a microprocessor, microcontroller or other control logic that comprises sections of code or code portions, stored on a computer readable storage medium, such as a memory, that are fixed to perform certain tasks but also other alterable sections of code, stored on a computer readable storage medium, that can be altered during use. Such alterable sections of code can comprise parameters that are to be used as input for the various tasks, such as controlling servo motors. 
     In one or more embodiments, the servo motors control four straight collimator shutters forming a rectangle represented on the GUI touchscreen. 
     In one or more embodiments, the servo motors control the collimator iris and the two collimator shutters  1360  on either side of the iris. 
     In one or more embodiments, the servo motor unit further comprises one or a plurality of servo motors configured to receive servo motor signals from said processor and to move to a predetermined position, thereby moving a connected collimator or iris, and to indicate the status of said servo motor, such as the position or if the servo motor is stationary or moving, by sending servo motor signals to said processor. 
     In one or more embodiments, wherein communications interface may include at least one of a Local Area Network (LAN), Metropolitan Area Network (MAN), Global System for Mobile Network (GSM), Enhanced Data GSM Environment (EDGE), High Speed Downlink Packet Access (HSDPA), Wideband Code Division Multiple Access (W-CDMA), Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Bluetooth®, Zigbee®, Wi-Fi, Voice over Internet Protocol (VoIP), LTE Advanced, IEEE802.16m, WirelessMAN-Advanced, Evolved High-Speed Packet Access (HSPA+), 3GPP Long Term Evolution (LTE), Mobile WiMAX (IEEE 802.16e), Ultra Mobile Broadband (UMB) (formerly Evolution-Data Optimized (EV-DO) Rev. C), Fast Low-latency Access with Seamless Handoff Orthogonal Frequency Division Multiplexing (Flash-OFDM), High Capacity Spatial Division Multiple Access (iBurst®) and Mobile Broadband Wireless Access (MBWA) (IEEE 802.20) systems, High Performance Radio Metropolitan Area Network (HIPERMAN), Beam-Division Multiple Access (BDMA), World Interoperability for Microwave Access (Wi-MAX), infrared communications and ultrasonic communication, etc., but is not limited thereto. 
     In one or more embodiments, the processor/processing unit is communicatively coupled and communicates with a memory where data and parameters are kept ready for use by the processing unit. The one or more memories may comprise a selection of a hard RAM, disk drive, a floppy disk drive, a magnetic tape drive, an optical disk drive, a CD or DVD drive (R or RW), or other removable or fixed media drive. 
     In one or more embodiments, the servo motor unit is comprised in a first transmitter and/or a second transmitter. 
     In one or more embodiments, the servo motor unit is comprised in the mobile unit separately from the first transmitter and/or the second transmitter. 
     Generally, in  FIGS. 1-11  the following reference numbers refer to the listed parts of the fluoroscopy system, wherein any or all of the listed parts may be included according to different embodiments described herein:
       1 ,  1   a  Mobile unit     2 ,  2   a  Control unit     7  Chassis frame     8 ,  9  Wheel units     10  Wheels     11 ,  12  Vertical columns, allowing vertical adjustments     13  Midpoint of collimator irradiation rectangle     14  Rotation corner     15  Mid-side movement point     16  Iris side collimator     17  Iris side collimator     25  Iris side collimator touch point     26  Iris side collimator rotation point     18  G-arm     19  First X-ray device  2       20  Second X-ray device     21  First transmitter     22  First receiver     23  Second transmitter     24  Second receiver   P 1 , P 2  Intersecting axes     91  Handle     100  Fluoroscope system, or fluoroscopy system     120  Foot pedal unit holder     160  Cable holder   

     EMBODIMENTS AND FEATURES OF THE INVENTION 
     In one embodiment, four protective lead collimators or shutters, disposed at each transmitter, are arranged to form an area of interest or a rectangular space around the area to be irradiated. These four collimators for each transmitter can be moved, through servo motor mechanisms, by user indications, such as fingertip movement, on the touch screen of the control unit, wherein the current irradiated area is indicated as a rectangle. Usually this adjustment is performed when there is a previously acquired an x-ray still image on the screen. Such a rectangle is labeled  6  in  FIG. 8 . The rectangle appears as an overlay on the still image. The midpoint of the rectangle is indicated at  13 . By touching this rectangle midpoint  6  with the fingertip, it is possible to move the rectangle translationally (resolution 1 mm), that is in any direction but preserving its orientation. While the midpoint  13  is used for translational movement of the rectangle, the corner point  14 , is used to rotate (resolution 1°) the triangle about the corner point  14 . To do this, the user merely touches the corner point  14  with his or her fingertip and twists it in the desired direction of rotation. Thus the rectangle can be turned to any orientation and placed at any location in the field of view. 
     The size of the rectangular exposed space can be adjusted by placing ones fingertip on one of the four circles  15  halfway along each side of the rectangle and moving it perpendicularly to the side. This perpendicular movement of the fingertip will narrow or broaden the rectangle  6  around the midpoint  13 . 
     In one or more embodiments, an x-ray image and a user indicated irradiated area is displayed simultaneously on the touchscreen. 
     In one or more embodiments, user input is determined based on predetermined control points associated to the displayed irradiated area, wherein the control points are located on the perimeter or in the center of the overlaid irradiated area. 
     In one or more embodiments, the control points are one or more of:
         An upper vertical control point configured to adjust the size of the irradiated area in the vertical direction   An lower vertical control point configured to adjust the size of the irradiated area of interest in the vertical direction   an upper horizontal control point configured to adjust the size of the irradiated area in the horizontal direction   an lower horizontal control point configured to adjust the size of the irradiated area in the horizontal direction   an offset control point configured to adjust the offset of the area of interest       

     The control unit then receives a user indication of the rectangle as user input data, processes the user input data to control data, sends the control data to a servo motor unit configured or adapted to receive control data as control signals from said control unit, to control servo motors to a predetermined position. 
     Since each transmitter  21 ,  23  has its individual set of four collimators, the console is divided into two halves (see  FIG. 9 ) each showing the area of interest from a vertical or horizontal perspective. Each collimator set of four shutters can be adjusted with ones fingertips, as a user indication, on its side of the screen as described above. 
     As an alternative, particularly when the system is equipped with one or more round image intensifiers instead of one or more flat screen detectors, the X-ray system according to the invention can have an IRIS collimator  7  instead. By touching the center point of the circle, which is fixed, the diameter of the circle can be changed. It is also provided with two parallel straight collimators,  16  and  17 . It is possible to rotate the two straight collimators in parallel to each other by touching ones fingertip to the rotational point  14  and twisting, in the manner of manipulating the rectangle via corner point  14  as described above. The two straight side collimators  16  and  17  can be moved perpendicularly by touching the point  25  and moving it to one side or the other. 
     The control unit then receives a user indication of the diameter or rectangular area as user input data, processes the user input data to control data, sends said control data to a servo motor unit configured or adapted to receive control data as control signals from said control unit, to control servo motors to a predetermined position. 
     In one or more embodiments, the new irradiation area e.g. a rectangle or a diameter, is displayed on the touchscreen together with information indicative of whether the servo motors have completed their movement to the positions ordered by the control signals or are still it motion there. 
     In these two alternative touch screen collimator embodiments, there is always a slight delay after the user gives a user indication by moving the bars representing the collimator shutters on the touch screen until the servo motors controlling the physical collimator shutters have reached the positions corresponding to those indicated by a user on the touchscreen. During this delay time, the new area and/or current area of interest of interest is presented on the touchscreen together with information indicative of whether the servo motor is stationary or moving. 
     In one or more embodiments, the information indicative of if the servo motor is stationary or moving is indicated by the representational bars on the screen flash flashing and they then stop flashing when the actual physical collimator shutter reaches the position of the bar shown on the screen. 
     In one non-limiting example, a rectangle indicating the new irradiation area and or a rectangle indicating the current irradiation area of interest is/are presented as flashing objects on the touchscreen. 
     In one or more embodiments, a servo motor unit is configured to obtain servo motor status data indicative of the status of a servo motor by receiving servo motor signals and to send servo motor status data as status control signals to said control unit. 
     In one or more embodiments, a control unit is configured to receive servo motor status data as status control signals from a servo motor unit, to process servo motor status data to a visual representation of said servo motor status data and to send said visual representation to said touch screen as a display signal, wherein said touch screen is configured to display said visual representation to a user. 
     In one or more embodiments, the servo motor unit and the servo motors are communicatively coupled to each other, for instance by means of a cable or through wireless signal transmission. 
     In one or more embodiments, the servo motor unit and the control unit  2   a  are communicatively coupled to each other, for instance by means of a cable or through wireless signal transmission. 
     In one or more embodiments, a computer program product comprising computer readable code configured to, when executed in a processor, perform any or all of the method steps described herein. 
     In one or more embodiments, a non-transitory computer readable memory on which is stored computer readable code configured to, when executed in a processor, perform any or all of the method steps described herein. 
     A tangibly embodied computer-readable medium including executable code that, when executed, causes a control unit to perform any or all of the method steps described herein. A tangibly embodied computer-readable medium including executable code that, when executed, causes a servo motor unit to perform any or all of the method steps described herein.