Method and device for X-ray diagnosis of an examination object

Abstract

Device (10) for X-ray diagnosis of an examination object, which has a component (30, 31) designed as an X-ray emitter (30) and / or X-ray detector (31), which is movable relative to a couch (23) for the examination object, wherein at least one predeterminable stop position (80) for the component (30, 31) and a spatial stop area (81) predetermined around the stop position are set, wherein - a position measuring device (40, 41) designed as a sensor system for determining a position of the component (30, 31), - a braking device (70) for braking the manually moved component (30, 31), - a control device (60) operatively connected to the position measuring device (40, 41) and the braking device (70) is provided, by means of which control device the braking device (70) can be activated as a function of the position of the component (30, 31) when the stop range is reached, characterized in that a drive unit (90) is provided for driving the component (30, 31), which drive unit is operatively connected to the control device (60) in such a way that the component (30, 31) can be moved from a braked position to the stop position (80) within the stop range.

Description

[0001] The invention relates to a device for X-ray diagnosis of an examination subject, comprising a component configured as an X-ray emitter and / or X-ray detector, which is movable relative to a couch for the examination subject, wherein at least one predeterminable stop position is set for the component. The invention further relates to a method for performing an X-ray diagnosis on an examination subject, wherein a component configured as an X-ray emitter and / or X-ray detector is moved to a set stop position.

[0002] The present invention relates generally to improving the positioning of components of an X-ray device. Despite developments in the field of medical technology, particularly imaging techniques such as computed tomography and magnetic resonance imaging, X-ray systems remain an important tool for medical diagnosis and patient monitoring. X-ray examinations are also used to investigate bone fractures, tumors, cysts, calcifications, and air pockets, as well as for angiographic examinations to assess a patient's vascular system. X-ray examinations during interventional procedures can also be used to locate inserted medical instruments. By reducing the radiation dose used for X-ray examinations on patients, particularly through technical advances, further areas of application for X-ray diagnostics are being opened up.

[0003] The flexible positioning of components in an X-ray system, particularly X-ray sources and X-ray detectors, is of great importance in the field of medical diagnostics. This type of flexibility in the use of components is desirable for users, as it opens up a wider range of applications for an X-ray machine. Frequently performed X-ray examinations generally require the same positions or stop positions of components, such as the X-ray detector and the X-ray source. One possible stop position for X-ray examinations could be the arrangement of an X-ray source above a patient bed, so that the X-ray radiation strikes the thorax of a patient positioned on the bed essentially vertically, for example, and is detected by an X-ray detector below the patient.Another possible position could involve an arrangement of the X-ray source and X-ray detector rotated by 90 degrees. Furthermore, certain angle combinations of the X-ray radiation and the surface of the X-ray detector are advantageous.

[0004] The operating instructions for the 3D-TOP ceiling mount describe a stand for an X-ray device that specifies a stop position (referred to in the operating instructions as the exposure position) of an over-table X-ray tube using locking positions along a longitudinal and transverse path. The movement of the over-table X-ray tube is performed manually by medical personnel. The locking positions are specified by tactile detents or electromechanical locking latches. This has the disadvantage that mechanical adjustment of the tactile detents or electromechanical detents is required to adjust a fixed stop position.

[0005] Further systems with moving components are described as examples in the following publications: DE 103 47 738 A1 DE 103 47 740 A1 US 6 282 264 B1 US 4 964 152 A WO 2003 / 071 948 A1 US 2006 / 0 126 795 A1 WO 2004 / 052 207 A1.

[0006] The invention is based on the object of providing an apparatus and a method as mentioned above for carrying out an X-ray diagnosis, in which the positioning of components in a stop position is improved.

[0007] The subtask to be solved by the device is achieved in a generic device in that a device for determining a position of the component, a device for braking the movable component, and a control device operatively connected to the position-determining device and the braking device are provided, by means of which the braking device can be activated depending on the position of the component relative to the stop position. This enables rapid movement of the component, e.g., the X-ray tube and / or the X-ray detector, to a specific stop position, of which several can exist. The movement of the component to the stop position, which includes displacements and / or rotations of the component, is automatically detected by the controller via the position-measuring device.

[0008] The position measuring device can, for example, be designed as a sensor system. At least one sensor is attached to each moving component of an X-ray device. The position of the sensor can be detected and, if necessary, determined by a sensor query system via a wireless connection. Alternatively, absolute encoders or rotary encoders can be used to detect the position of a component. Linear measuring systems – such as magnetorestrictive sensors or magnetoresistive sensors – can also be used. The determined position of the component is recorded in a coordinate system in which the stop positions for the respective components are also recorded. The stop positions can be set via a human-machine interface, e.g., on a display or control switch on the X-ray machine or on a personal computer connected to the control system.A spatial stop area is predetermined around the stop position, which can also be adjusted via the human-machine interface.

[0009] If the component enters a predetermined stop area around the stop position, the braking device is activated. The stop positions and the predetermined stop area around the stop position can be preset by the device manufacturer or adapted to the user's requirements during or after commissioning of the device. Once activated, the braking device slows the movement of the component until it comes to a standstill. The braking device can be activated by the user and / or the control device. For example, a user can move the X-ray tube unit into a stop area and activate the brake, e.g. by releasing an operating button. The X-ray tube unit can then be moved to the stop position via the control device and the position detection device using a drive device.

[0010] Alternatively, in addition to determining the position of the component, its speed can also be recorded. If necessary, the speed can also be used as a criterion for activating the braking device. For example, by exceeding a specified limit speed - for example, in an area outside the predetermined stop range of the stop position - a stop position can be passed without the braking device being triggered. If, on the other hand, the specified limit speed is not exceeded in an area outside the predetermined stop range of the stop position and the component reaches the predetermined stop range of the stop position, braking is triggered. The value for a limit speed can be stored in the control system.To measure the speed, for example, sensors can be provided to detect the quantitative change in position of a moving component.

[0011] With such a device for positioning components in stop positions, additional and / or modified stop positions can be provided without any structural changes to the device.

[0012] In an advantageous embodiment of the invention, a device for driving the component is provided which is operatively connected to the control device such that the component can be moved to the stop position. This makes it possible to set the stop position entirely without manual drive, i.e. drive of the component generated by the user. However, a combination of different drives can also be used, e.g. manual and motor drive. For example, the component can be roughly adjusted to the stop position using a manual drive, while the motor drive can finely adjust the stop position for the component. Particularly for fine adjustments of the stop position of the component, it is advantageous if the drive device moves the component in a small step size and the position is determined by the control system in real time.This ensures that the stop position can be reached with high accuracy.

[0013] In an advantageous embodiment of the invention, a coupling device is provided between the drive device and the movable component. This allows the propulsion to be transmitted to the component to be metered and adapted to the position of the components. This also increases positioning accuracy.

[0014] In an advantageous embodiment of the invention, the X-ray tube is mounted for rotation, and a first and second stop position can be set, in which X-rays can be emitted in a vertical and horizontal direction, respectively. The vertical direction is parallel to the direction of gravity, the horizontal direction perpendicular to it. The horizontal and vertical stop positions of the X-ray tube are frequently used for X-ray examinations and should therefore be easy to adjust. However, other stop positions can also be easily adjusted by operating the control system. This can, for example, also include setting specific angles of the X-ray radiation relative to the detection surface of the X-ray detector. Such angles are difficult for the user to adjust manually. Therefore, support for component adjustment by a device according to the invention is helpful.

[0015] In a preferred embodiment of the invention, the drive unit is designed as an electric motor and / or the braking device is designed as a permanent magnet brake. An electric motor can be easily dimensioned in terms of size and power and positioned on the device. Furthermore, an electric motor has the advantage of being easy to control. An X-ray device can contain multiple electric motors to drive rotations and displacements of various components, such as the displacement of stand carriages or the rotation of components attached to the stand.

[0016] Electromagnetic braking devices are preferably used as the braking device, as they offer low wear and good controllability. The electromagnetic braking device can therefore be designed as a permanent magnet brake. This not only decelerates the movement but also fixes the component in a stop position after it has come to a standstill. Therefore, no additional fixation device for the component is required after it has come to a standstill. In addition, a power supply to the X-ray diagnostic device is not a prerequisite for the function of the permanent magnet brake, which increases the safety of the X-ray diagnostic device. A friction brake can also be used, which is released magnetically and applied by spring force. This braking device also has the advantages of the permanent magnet brake, but is subject to greater wear due to the load on mechanical braking components - such as a spring.A magnetic brake can also be used as a braking device, where a magnetic field and thus the braking effect can be controlled, for example, via a coil current. A magnetic brake offers the advantage of easily controllable braking effect. A power supply is required for its operation.

[0017] Alternatively, a fixing device—i.e., a device designed solely for fixing, i.e., for holding a component in a specific position—and a device for braking moving components can be provided separately. For example, in addition to a fixing device, which may be configured as a permanent magnet brake, a wear-free eddy current brake may be provided to brake component movements.

[0018] The subtask to be solved by the method is achieved in a generic method by moving the component manually and / or by motor toward the stop position, whereby the position of the component is detected, and by braking the moving component as soon as the position of the component reaches a predetermined stop range around the stop position. This method enables wear-free, rapid positioning of movable components. Furthermore, existing stop positions can be easily changed and new stop positions defined by feeding the changed or new stop positions to the controller.

[0019] Further advantages of the device according to the invention and the method according to the invention will become apparent from an embodiment which will be explained in more detail below with reference to the drawings, in which Fig. 1 a side view of a device according to the invention Fig. 2 a flow chart for illustrating the method according to the invention is schematically illustrated.

[0020] In Fig. 1 shows an X-ray diagnostic device 10 for examining an examination subject. To increase its flexibility of use, the X-ray diagnostic device 10 has a ceiling guide rail system 22. Two carriages 20 are movably mounted on this ceiling guide rail system 22 such that they can be moved freely and independently of one another in a plane parallel to the ceiling. A couch 23 for holding an examination subject is positioned below the ceiling guide rail system 22. In order to be able to examine an examination subject in different positions and from different directions, extendable telescopic stands 21 are attached to the carriages 20 in order to adapt the length of the stand to the requirements of the medical examination. An X-ray source 30, mounted for rotation about two axes, and an X-ray detector 31 are attached to the ends of each of the two telescopic stands 21.

[0021] For frequently performed examinations, stop positions for the X-ray tube 30 and the X-ray detector 31 are preset. Fig. 1, two stop positions are defined for the X-ray source 30 and for the X-ray source 31, namely a vertical stop position of the X-ray source 30 and an associated horizontal stop position 80 of the X-ray detector 31. Furthermore, a horizontal stop position of the X-ray source 30 and an associated vertical stop position of the X-ray detector are possible, which, however, are not shown in Fig. 1. After the X-ray source 30 and the X-ray detector 31 have assumed their respective stop positions, an X-ray examination can be started. An X-ray beam region 32 forms between the X-ray source 30 and the X-ray detector 31, which covers the area to be examined of the object positioned on the couch 23. Depending on the application of the X-ray diagnostic device 10, the stop positions may also differ from the aforementioned stop positions.

[0022] The stop positions can be changed or supplemented with new stop positions via an input / output device 61, which is operatively connected to the control device 60. The change and / or readjustment of stop positions occurs through the user entering setting parameters for the respective components 30 or 31.

[0023] The X-ray tube 30 has Fig. 1 the vertical stop position. However, the X-ray detector 31 is not yet in the corresponding horizontal stop position 80. In order to perform an examination, the X-ray detector 31 must first be moved to its stop position 80. Both the X-ray tube 30 and the X-ray detector 31 are equipped with position sensors 41, which belong to a position determination device. The position determination device further comprises a position data transmitting / receiving unit 40. The position data transmitting / receiving unit 40 communicates wirelessly with the position sensors 41 on the X-ray tube 30 and the X-ray detector 31. With the help of the position sensors 41 and the position data transmitting / receiving unit 40, the position determination device can detect the location and position of the X-ray tube 30 and the X-ray detector 31 and, if applicable, any changes in their position. The recorded position data are fed to a control device 60.Using a coordinate system stored in the control device 60, the position of the X-ray tube 30 and the X-ray source 31 can be determined from the position data supplied to the control device 60. This can optionally be performed in the position determination device.

[0024] In order to be able to carry out the X-ray examination, the X-ray detector 31 should be brought into the corresponding horizontal stop position 80. To fix the X-ray detector 31 and / or the X-ray source 30 in any position, a fixing device is provided, which Fig. 1 is identical to a braking device 70. Alternatively, a fixing device and a braking device 70 can be implemented in different, possibly spatially separated devices. In order to position the X-ray detector 31 in the Fig. 1, a user of the X-ray diagnostic device 10, e.g., on-site medical service personnel or a doctor, must first release the braking device 70 by operating an operating switch 50. The user then rotates the X-ray detector 31 in the direction of the desired horizontal stop position 80 of the X-ray detector 31. The movement of the X-ray device 31 driven by the user is detected by the position detection device and fed to the control device 60. A stop region 81 that encloses the stop position 80 is stored in the control device 60. If the X-ray detector 31 enters the stop region 81 of the stop position 80, the control device 60 activates a braking device 70, which is designed here as a permanent magnet brake. The permanent magnet brake 70 completely brakes the rotation of the X-ray detector 31.The X-ray detector 31 therefore comes to a standstill in the predetermined stop position 80.

[0025] To increase the accuracy of the braking process, it may be advantageous to use a larger stop range 81 than that shown in Fig. 1. This allows the braking force of the permanent magnet brake 70 to be controlled during deceleration, taking into account the determined position of the X-ray detector 31 within the stop range 81, such that the X-ray detector 31 comes to a stop precisely in the stop position 80.

[0026] The movement of a component 30 or 31 into a preset stop position, e.g., the stop position 80 of the X-ray detector 31, and also the selection of various stop positions can be accomplished, for example, via a human-machine interface. For example, if a thorax examination is to be performed, the stop positions for a thorax examination generally differ from an X-ray examination in which, for example, a foot fracture is to be visualized—for example, by the position of the tripod carriage 20, the length of the telescopic tripods 21, and the stop position of the X-ray tube 30 and X-ray source 31. Such examination scenarios can be stored in a data processing system (not shown) and fed to the control device 60 after a user has selected an examination scenario.The examination scenario is selected by the user pressing a button—for example, on a touchscreen or a display 51 with an associated control switch 50. This allows new stop positions to be defined quickly and easily. If necessary, the entire movement of the component 30 or 31 can also be driven by a drive device 90, which is designed here as an electric motor. The control device 60 can control the electric motor 90 such that the components 30 or 31 move to the specified stop positions. Stop positions can also include the position of one or more tripod carriages 20, the length of the telescopic tripod 21, etc.

[0027] The following procedure steps are described in accordance with Fig. 2 in conjunction with the Fig. 1, wherein reference numerals of device components refer to Fig. 1.

[0028] In the described exemplary embodiment, the method assumes that an existing braking device 70 is activated in order to fix the X-ray detector 31 in its position. If the user wishes to move and / or rotate the X-ray detector 31, the method is started by releasing the brake in a method step 101. The brake can be released, for example, by pressing an operating button 50 - e.g. mechanically or by means of a touchscreen. The operating button 50 is arranged here on the X-ray tube 30. Alternatively, the brake is only released as long as the button 50 is pressed by the user. In this case, it is advantageous to attach the button 50 releasing the brake to the component 30 or 31 to be moved.

[0029] By releasing the brake, the X-ray detector 31 is now freely movable and can be moved by the user towards a stop position 80. In a next method step 102, the position of the X-ray detector 31 is detected. The position of the X-ray detector 31 can be determined, for example, continuously or at periodic time intervals. After each position determination, a movement step 103 is performed in which a comparison is made as to whether the detected position of the X-ray detector 31 lies within the predeterminable stop range 81. If the detected position of the X-ray detector 31 lies outside the stop range 81, the X-ray detector 31 can continue to be moved as before. If, on the other hand, the detected position of the X-ray detector 31 lies within the predeterminable stop range 81, the X-ray detector 31 is braked and fixed in a further method step 104.Braking and locking are performed here by means of the braking device 70, which is designed as a permanent magnet brake. During the deceleration of the X-ray detector 31 until it comes to a standstill, the position of the X-ray detector 31 continues to be detected according to method step 102. After the moving X-ray detector 31 has been decelerated, the position of the X-ray detector 31 is compared with the predetermined stop position 80 in a method step 105. If the position of the decelerated X-ray detector 31 matches the predetermined stop position 80, the method for the X-ray detector 31 is terminated.

[0030] If there is a significant deviation of the position of the braked X-ray detector 31 from the preset stop position 80, which is detected by a control device 60, the fixation of the X-ray detector 31 is released again by the control device 60 in a method step 101. A drive device 90 designed as an electric motor is then started by the control device 60, which drive device 90 moves the X-ray detector 31 in the direction of the preset stop position 80 in a method step 106. In this case, the position of the X-ray detector 31 is further detected according to method step 102 and compared with the preset stop position 80 according to method step 105. As long as the position of the X-ray detector 31 does not correspond to the preset stop position 80, the X-ray detector 31 is moved further in the direction of the stop position 80 by the electric motor 90.As soon as the position of the X-ray detector 31 coincides with the predetermined stop position 80, the drive device 90 is switched off, and in a method step 104, the braking device 70 is activated and the X-ray detector 31 is braked. The propulsion to reach the stop position 80 is selected so high that an almost immediate stop of the X-ray detector 31 is possible upon activation of the brake. The method is terminated by applying the brake for the X-ray detector 31 in the stop position 80. The method can be repeated for another component, e.g., the X-ray tube 30, until all components required for the X-ray diagnosis are positioned in their designated stop positions. The X-ray examination can then be started.

[0031] Alternatively, a method can be selected in which no constant position detection of moving components 30 or 31 is required. This will be explained using the X-ray tube 30 as an example. If the user wishes to change the stop position of the X-ray tube 30 from the vertical to the horizontal stop position, the brake for the X-ray tube 30 is released according to method step 101. This is done here by the user pressing a button that releases the brake, e.g., the operating button 50 for the X-ray tube 30. As long as the operating button 50 is pressed, the brake of the X-ray tube 30 is released. The user moves the X-ray tube 30 in the direction of a predetermined Fig.1 not shown, horizontal stop position. If the X-ray tube 30 enters the stop area around the horizontal stop position (not shown), the user receives an output on the display 51 indicating that the X-ray tube 30 is now in the stop area. The user then releases the brake-releasing button 50, and the X-ray tube 30 is braked. Position detection can be activated after the X-ray tube 30 has come to a standstill or as soon as the X-ray tube 30 enters the stop area. The current position of the X-ray tube 30 is then compared with the predetermined stop position, e.g., in the control device 60. The control device activates an electric motor 90, releases the brake of the X-ray tube 30, and moves the X-ray tube 30 to the designated stop position by means of the electric motor 90 and continuous position detection.Such a method reduces the data processing effort, since position data of the components 30 and 31 are only determined when they are already positioned close to the respective, predetermined stop position.

Claims

[1] Device (10) for X-ray diagnosis of an examination object, which has a component (30, 31) designed as an X-ray emitter (30) and / or X-ray detector (31), which is movable relative to a couch (23) for the examination object, wherein at least one predeterminable stop position (80) for the component (30, 31) and a spatial stop area (81) predetermined around the stop position are set, wherein - a position measuring device (40, 41) designed as a sensor system for determining a position of the component (30, 31), - a braking device (70) for braking the manually moved component (30, 31), - a control device (60) is provided which is operatively connected to the position measuring device (40, 41) and the braking device (70), by means of which the braking device (70) can be activated as a function of the position of the component (30, 31) when the stop range is reached, characterized bythat a drive unit (90) is provided for driving the component (30, 31), which is operatively connected to the control device (60) in such a way that the component (30, 31) can be moved within the stop range from a braked position to the stop position (80). [2] Device according to claim 1, characterized by that a coupling device is provided between the drive unit (90) and the movable component (30, 31). [3] Device according to claim 1 or 2, characterized by that the X-ray emitter (30) is mounted for rotation, and a first or second stop position is adjustable, in which X-ray radiation can be emitted in the vertical or horizontal direction. [4] Device according to one of claims 1 to 3, characterized by that the drive unit (90) is designed as an electric motor and / or the braking device (70) is designed as a permanent magnet brake. [5] Method for carrying out an X-ray diagnosis on an examination object, wherein a component (30, 31) designed as an X-ray emitter (30) and / or X-ray detector (31) is moved into a set stop position (80), wherein the component (30, 31) - is first moved manually in the direction of the stop position (80), whereby the position of the component (30, 31) is detected (102), - the manually moved component (30, 31) is braked (104) as soon as the position of the component (30, 31) reaches a predetermined stop range (81) around the stop position (80) (103), characterized by that the component (30, 31) is moved within the stop range from the braked position of the component (30, 31) to the stop position (80) by an electric motor.

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