Abstract
An apparatus and a method are provided for positioning an x-ray machine having an x-ray source and a detector. A second X-ray image is recorded once an x-ray apparatus has been positioned by using information of an alignment point in a first x-ray image.
Claims
1-10 (canceled)
11. An apparatus for positioning an x-ray machine including an x-ray source and a detector, the apparatus comprising: an aligning module for positioning the x-ray machine by matching a first x-ray image in a 3D data record created preoperatively or intraoperatively and noting at least one alignment point or a trajectory in the 3D data record for forming at least one second x-ray image.
12. The apparatus according to claim 11, which further comprises a controller for coordinated control of the x-ray machine by ascertaining control signals for motorized alignment of the x-ray machine based on actual position data and predetermined coordinates of the at least one alignment point in the preoperative or intraoperative 3D data record.
13. The apparatus according to claim 11, which further comprises: at least one of a positioning module or a repositioning module carrying out a comparison of target and actual values between a current alignment and a desired alignment of the x-ray source; and a single motorizable positioning device being actuated or a plurality of motorizable positioning devices being included for positioning the x-ray source.
14. The apparatus according to claim 11, wherein the x-ray machine has a mobile platform, and a C-arm disposed on the mobile platform, the x-ray source being disposed at the C-arm.
15. The apparatus according to claim 11, which further comprises a visualization unit for displaying at least one x-ray image by noting the at least one alignment point in the preoperative or intraoperative 3D data record.
16. The apparatus according to claim 12, wherein said controller is configured to capture the at least one alignment point being predeterminable in the preoperative or intraoperative 3D data record for ascertaining control signals for a motorizable positioning device for aligning the mobile x-ray machine and forming corresponding control signals.
17. A method for positioning an x-ray machine including an x-ray source and a detector, the method comprising the following steps: aligning the x-ray source according to a prescription of at least one alignment point or a trajectory being matched in a preoperative or intraoperative 3D data record and noted in a first x-ray image; and creating at least one second x-ray image.
18. The method according to claim 17, which further comprises ascertaining control signals for motorized alignment of the x-ray machine based on actual position data and predetermined coordinates of the at least one alignment point in the preoperative or intraoperative 3D data record.
19. The method according to claim 17, which further comprises: carrying out a comparison of target and actual values between a current alignment and a desired alignment of the x-ray source; and positioning the x-ray source by a singular actuation of motorizable elements or by an inclusion of a plurality of motorizable elements.
20. The method according to claim 17, which further comprises aligning the x-ray source according to the prescription of at least one alignment point noted in the preoperative or intraoperative 3D data record and creating the second x-ray image for an alignment point in each case.
Description
[0017] In the figures:
[0018] FIG. 1 shows a schematic illustration of a mobile x-ray machine,
[0019] FIG. 2 shows a first x-ray image and a second x-ray image, and
[0020] FIG. 3 shows a detailed view for controlling the mobile x-ray machine.
[0021] In the subject matter of the apparatus and the associated method, a second x-ray image is made after positioning an x-ray machine on the basis of the prescription of an alignment point in a first x-ray image.
[0022] FIG. 1 schematically reproduces an x-ray machine, in particular a mobile x-ray machine comprising a C-arm CB. An x-ray source R and a detector D are arranged at the open ends of the C-arm CB. This mobile C-arm CB comprises a displaceable platform PF provided with movement elements BE. By way of example, the movement elements BE may be controllable wheels such as spherical wheels, rotatable running wheels or omni wheels. A chassis CH is arranged on the platform PF. Firstly, the attachment of the movable C-arm and, secondly, the computing unit RE required for controlling the movable C-arm are integrated into this chassis CH. Inter alia, a positioning module PM, a repositioning module RPM and an aligning module ASM comprising a controller SE are integrated into the computing unit RE. The holding elements, which are arranged between chassis CH and C-arm CB and which may also be referred to as connecting elements, are subdivided into a lifting column HS and a horizontal connecting element HV comprising a guiding unit FE for the semicircular C-arm CB. The horizontal connecting element HV and the lifting column HS are movably mounted in each case over the axes plotted in this sketch. Lifting column HS and horizontal connecting element HV are each embodied with positioning means. The entire C-arm can be lifted and lowered by means of the lifting column HS. The cross bracing arranged on the lifting column HS serves for the horizontal alignment of the C-arm CB. Likewise, the lifting column HS and the horizontal connecting element HV are respectively embodied in such a way that a rotation of the lifting column HS or a rotation of the connecting element HV about the axes extending therein is possible. The rotation about the horizontally extending axis in the connecting element HV causes an angular rotation AD of the C-arm. A displacement of the C-arm along the curved guiding unit FE results in an orbital rotation OD of the C-arm CB. Below, the individual motorizable elements such as movement elements BE, lifting column HS, horizontal connecting element HV or guiding unit FE are also referred to as positioning means. Stored in the computing unit RE are, firstly, the coordinates of a first coordinate system KC assigned to the C-arm CB, a second coordinate system KD assigned to the detector D, and a third coordinate system KO assigned to an object 0 placed on a couch L between the x-ray source R and the detector D. Moreover, the computing unit RE even has access to a fourth coordinate system KR. The fourth coordinate system KR is in each case assigned to a room in which the mobile C-arm CB is situated. These coordinates of the first to fourth coordinate systems KC, KD, KO, KR may be assigned, respectively, to determine a first x-ray image RB1 and a second x-ray image RB2 such that, by means of arbitrary coordinate transforms between the individual coordinate systems KC, KD, KO and KR, it is possible to calculate a positioning and/or an alignment and a repositioning of the C-arm CB. By means of an input means, such as a keyboard EE or an electronic marking pen EM, the alignment of the C-arm CB or of the x-ray source R may be predetermined, for example, on a monitor BS on the basis of at least one marking in the form of an alignment point AP in a first x-ray image RB1 which, for example, is also imaged on the monitor BS. If a plurality of alignment points APn are noted in the first x-ray image RB1, the individual alignment points APn are worked through in succession in accordance with their input sequence and a second x-ray image RB2 is in each case produced in this respect.
[0023] FIG. 2 reproduces a first x-ray image RB1 and a second x-ray image RB2. The first x-ray image RB1 may likewise be referred to as an overview x-ray image. By specifying a region of interest, an alignment of the x-ray system is prepared from the overview x-ray image in such a way that, by means of an input means EM or a keyboard EE, an alignment point AP in the form of a cursor point is predetermined in a first x-ray image RB1 visualized on a visualization unit BS. By way of example, the visualization unit may be a tablet or a monitor. The control pulses required for controlling the positioning means in order to bring the x-ray source R into the desired alignment are converted on the basis of the alignment point AP in the first x-ray image RB1 and the assignable coordinate systems KC, KD, KO, KR. The alignment point AP predetermined in the first x-ray image RB1, which may also be referred to as a center of a region of interest ZROI, forms the location of the principal ray ZSR, which is situated in the image center thereof, in the second x-ray image RB2. When the alignment point AP is set in the first x-ray image RB1, there also may be, at the same time, a tilt of the image plane about an x-ray focal point to be set. In the described example, the x-ray focal point lies in the alignment point AP in the image plane. In a further embodiment variant, there is also a local change of the x-ray focal point along a straight line passing through the alignment point AP. An orbital rotation OD and/or an angular rotation AD of the C-arm CB may be carried out for the purposes of tilting the image plane. Using this configuration, the surgeon may additionally make the direction of view onto the center of the region of interest ROI more precise.
[0024] In a further embodiment variant, a first x-ray image RB1 may be created by reconstruction from a created 3D data record. The 3D data record may be created by a multiplicity of x-ray recordings of an object made preoperatively or intraoperatively, for example during a circular-arc-shaped trajectory. Using this 3D data record, the treating medical practitioner may set a slice plane for creating a first x-ray image RB1 through the object 0. This created first x-ray image RB1 is then imaged on the monitor BS. Then, a more precise alignment for a region of interest ROI in a second x-ray recording RB2 may be predetermined on this first x-ray image RB1. This prescription may be carried out either manually or electronically. In the case of an electronic prescription, a specific landmark, such as the spinal column, may be identified and one or more alignment points may be set on the vertebrae for the purposes of aligning the x-ray source for e.g. a series of second x-ray images RB2n. In a further embodiment variant, the first x-ray image RB1 may be matched in a preoperative or intraoperative 3D data record and at least one alignment point AP or a trajectory may be noted in the 3D data record. This is accompanied by the advantage that the image data, the coordinates thereof or the alignment of the 2D x-ray image RB1 may be retrieved in the 3D data record and an alignment of the x-ray machine C may be determined for a second x-ray image RB2 within the 3D data record.
[0025] FIG. 3 reproduces a schematic illustration of an apparatus for aligning an x-ray source R and/or a detector D. Inter alia, a positioning module PM, the repositioning module RPM and the controller SE are arranged in the computing unit RE, in which the aligning module ASM is integrated. In the shown apparatus, the positioning data for positioning the x-ray source R arranged at an x-ray machine and/or for positioning a detector D are ascertained by means of an aligning module ASM. For a second x-ray image RB2, the x-ray source R is aligned according to the prescription of an alignment point AP marked in a first x-ray image RB1. The x-ray image denoted by the first x-ray image RB1 may be either an x-ray image or an x-ray image reconstructed from a 3D data field. By way of example, the alignment point AP which is entered in a first x-ray image RB1 on a visualization unit BS, and marked, is read by the controller SE. The control signals for coordinated control of the x-ray machine C are generated in the controller SE for the positioning module PM and repositioning module RPM. These control signals bring about motorized alignment of the x-ray machine C, in particular of the x-ray source R and/or the detector D, on the basis of actual position data and the predetermined coordinates of an alignment point AP deliberately predetermined in a first x-ray image RB1, see also FIG. 2. A comparison of target and actual values is carried out in each case in the positioning module PM between the current alignment and a desired alignment of the x-ray source R, and the x-ray source R brings about by a singular actuation of the motorizable positioning means BE, HS, HV, FE, CB or by inclusion of a multiplicity of motorizable positioning means BE, HS, HV, FE, CB. The x-ray source R is aligned in such a way that an alignment point AP in the region of interest ROI, deliberately selected in a first x-ray image RB1, lies approximately centrally in a second x-ray image RB2. The alignment point AP may also lie on the principal ray ZSR of the x-ray source R. Control signals for the individual elements or units are ascertained in the controller SE. The controllable elements or units are listed below. For the purposes of controlling the x-ray source R, the control signals are ascertained for actuating the elements such as lifting column HS, horizontal connecting element HV or for a further guiding unit FE, in each case by a comparison between actual coordinates and target coordinates. Individual motor controllers of positioning means, such as a motor controller MHS of the lifting column HS, a motor controller MHV of the horizontal connecting elements HV, a motor controller MFE for the guiding unit FE, a motor controller MOD for the orbital rotation, a motor controller MAD for the angular rotation and the motor controller MBE for the movement elements BE, may be actuated. The necessary control signals are calculated in the controller SE. The sensor data required for the motor control are queried by way of sensor elements arranged at and/or in the corresponding positioning means. Thus, first sensor elements SHS are integrated in the lifting column HS and there is integration of second sensor elements SOD for the orbital movement of the C-arm CB, third sensor elements SAD for the angular movement of the C-arm CB and fourth sensor elements SFE for guiding elements FE of the C-arm CB arranged between chassis and C-arm CB. The movement of the wheels, for example omni wheels BE, is captured separately by fifth sensor elements SBE. All positioning data for a first x-ray image RB1 and a second x-ray image RB2 are, inter alia, also stored in the repositioning module RPM for the purposes of repositioning the mobile C-arm CB. Controlling the mobile C-arm CB is also triggered by the spatial coordinates for an alignment point AP marked in the first x-ray image RB1, said spatial coordinates being stored in the controller SE. By way of example, the alignment point AP may be entered and imaged in the first x-ray image RB1 by way of a monitor BS embodied with touchscreen elements. The coordinates for the second x-ray image or images RB2 are stored in the repositioning module RPM and positioning module PM arranged in the aligning module ASM. Proceeding from the coordinates of the alignment point AP and the coordinates of the principal ray ZSR of the x-ray source R in respect of a first x-ray image RB1, the position of the x-ray source R is derived for a second x-ray image RB2. The x-ray source R may be aligned for the second x-ray image RB2 by either a singular or a combined actuation of motorizable positioning means BE, HS, HV, FE, CB.
LIST OF REFERENCE SIGNS
[0026] R X-ray source
[0027] D Detector
[0028] C Mobile C-arm
[0029] KC First, C-arm coordinate system
[0030] KD Second, detector D coordinate system
[0031] KO Third, object coordinate system
[0032] KR Fourth, room coordinate system
[0033] CH Chassis
[0034] PF Displaceable platform
[0035] BE Movement elements (rotatable running wheels, spherical wheel, omni wheels...)
[0036] RB1 First x-ray image
[0037] RB2 Second x-ray image
[0038] RE Computing unit
[0039] BS Monitor
[0040] EM Input means
[0041] AP Alignment point
[0042] ASM Aligning module
[0043] SE Controller
[0044] PM Positioning module
[0045] RPM Repositioning module
[0046] ZSR Principal ray of the x-ray source
[0047] ROI Region of interest
[0048] ZROI Center of the region of interest
[0049] OD Orbital rotation
[0050] AD Angular rotation
[0051] HS Lifting column
[0052] HV Horizontal connecting element
[0053] FE Curved guiding unit
[0054] CB C-arm
[0055] MHS Motor controller for lifting column HS
[0056] SHS First sensor elements for lifting column movement
[0057] MHV Motor controller for horizontal connecting element HV
[0058] MOD Motor controller for orbital rotation OD
[0059] SOD Second sensor elements for orbital rotational movement
[0060] MAD Motor controller for angular rotation AD
[0061] SAD Third sensor elements for angular rotational movement
[0062] MFE Motor controller for guiding elements FE
[0063] SFE Fourth sensor elements for guiding elements
[0064] MBE Motor controller for movement elements BE
[0065] SBE Fifth sensor elements for movement elements
