DE202005021106U1 - X-ray diagnostics device, for generating projection images of e.g. patient, has axis controller adjusting sequence of axis with projection geometries, transmits release signal to computing unit for releasing X-rays, and adjusts geometries - Google Patents

Abstract

The device has a motor adjustable holder with a position sensor for determining a relative position of a C-bend with respect to the holder. An axis controller (50) includes a control output (53) for controlling a servomotor of the holder and the relative position of the C-bend. The controller adjusts a sequence of axes with given projection geometries, where the sequence of axes are selected by an operating person and are stored in a computing unit. The controller transmits a release signal to the computing unit for releasing X-rays, and adjusts the projection geometries.

Description

The The invention relates to a mobile X-ray diagnostic device with a C-arm for the automatic generation of projection shots for one Volume reconstruction.

X-ray diagnostic equipment, with which a sequence of X-ray projection images are generated, which is associated with a specific X-ray imaging geometry, are known from the patent literature.

The German Offenlegungsschrift DE3526850A1 relates to a mobile X-ray diagnostic device with a C-arm, a motorized and angle-coded orbital motion and a plant controller and an image processing system. The X-ray diagnostic facility allows the recording and correction of an x-ray sequence from the one Volume can be reconstructed.

From the patent DE10153787B4 The applicant is a mobile X-ray diagnostic device with a manually along its circumference displaceable C-arm and a motor-driven C-arm holder known to be recorded with the projection recordings of a predetermined projection geometry.

The known X-ray diagnostic equipment, which make it possible a series of x-ray projection images with a respective predetermined projection geometry automatically have the disadvantage that the central beam of the X-ray diagnostic device in the orbital motion of the C-arm always through a target point (POI, Point of interest) runs within the object under investigation and the distance of the target point to the image intensifier input window for each projection shot nearly is equal to.

task The invention is an X-ray diagnostic device to create, which automatically allows a series of X-ray projection images for one To generate volume reconstruction, so that every projection shot the distance between a study area (ROI, Region of Interest) within the examination object and the entrance window of the X-ray image as possible is small without that Entrance window of the X-ray image recorder with the surface of the examination object in contact comes.

• • eine in mehreren Achsen motorisch verstellbare und mit Mitteln zur Bestimmung der Position in mehreren Achsen ausgerüstete Halterung für einen C-Bogen mit einer an dessen einem Ende angeordneten Röntgenstrahlenquelle und einem dieser gegenüberliegend angeordneten Röntgenstrahlenempfänger,
• • einen motorischen Orbitalantrieb zur Bewegung des C-Bogens längs seines Umfanges in einer Halterung, ausgerüstet mit einem Wegmeßsystem,
• • Mittel zur Eingabe des von der Bedienperson der Röntgendiagnostikeinrichtung vorgesehenen Bewegungsablaufs während der Aufnahme der Folge von der Röntgenprojektionsaufnahmen
• • eine Achsensteuerung, die die Verstellung der motorisch angetriebenen Achsen in Abhängigkeit eines von der Bedienperson der Röntgendiagnostikeinrichtung gewählten Bewegungsablaufes steuert und die einzelnen Röntgenprojektionsaufnahmen auslöst
• • einen Bildverarbeitungsrechner, der aus den Röntgenprojektionsaufnahmen zusammen mit den Daten für die Prokjektionsgeometrie der jeweiligen Aufnahme ein Volumenmodell errechnet.

The object of the invention is achieved by an X-ray diagnostic device which has the following:

• A multi-axis, motor-adjustable, C-arm mount having means for determining the multi-axis position with an X-ray source disposed at one end thereof and one of the X-ray receivers disposed opposite thereof;
• A motorized orbital drive for moving the C-arm along its circumference in a holder equipped with a position measuring system,
• • means for entering the provided by the operator of the X-ray diagnostic device movement during the recording of the sequence of the X-ray projection recordings
• • An axis control that controls the adjustment of the motor-driven axles in response to a selected by the operator of the X-ray diagnostic device sequence of movements and triggers the individual X-ray projection recordings
• An image processing computer, which computes a volume model from the x-ray projection images together with the data for the projection geometry of the respective image.

• 1. Das Eingangsfenster des Röntgenstrahlenempfängers soll im Automatiklauf genau wie in einer von der Bedienperson in einem Teach-in-Lauf geführten Weise in geringem Abstand über die Oberfläche des Untersuchungsobjektes geführt werden, wobei eine vorgegebene Anzahl von Röntgenprojektionsaufnahmen längs des gesamten Verfahrweges des Bewegungsablaufes erstellt und zur weiteren Verarbeitung an den Bildverarbeitungsrechner übertragen werden. Dabei ist es unerheblich, ob der Zentralstrahl der Röntgendiagnostikeinrichtung stets durch einen Punkt POI verläuft; entscheidend ist, daß der Untersuchungsbereich ROI bei der Mehrzahl der Projektionsaufnahmen vollständig vom Röntgenstrahlenempfänger erfaßt wird. Es ist unerheblich, ob das Eingangsfenster des Röntgenstrahlenempfängers tangential zu der Oberfläche des Untersuchungsobjektes verläuft. Bei Vorhandensein von Hindernissen kann es angebracht sein, den Mittelpunkt des Eingangsfensters des Röntgenstrahlenempfängers nahezu unverändert zu lassen und nur die Richtung des Zentralstrahls im Raum derart zu verändern, daß die ROI noch von dem Röntgenstrahlenempfänger erfaßt wird,
• 2. Die Bedienperson legt fest, daß das Eingangsfenster des Röntgenstrahlenempfängers sich tangential zu einer Mantelfläche eines elliptischen Prismas bewegen soll. Die Festlegung der Ellipse erfolgt beispielsweise durch manuelles Anfahren der beiden Scheitelpositionen der Ellipse und Abspeichern der für diese beiden Scheitelwerte gültigen Koordinaten bzw. Meßwerte der Positionssensoren der einzelnen Verstellachsen des C-Bogens. Nach Festlegung der elliptischen Bahnkurve wird von der Bedienperson ein Probelauf ohne Röntgenstrahlung ausgelöst und bei eventuell drohenden Kollisionen von Teilen des C-Bogens mit Hindernissen im Operationsfeld oder solchen unterhalb der Patientenliege, der Probelauf gestoppt, das Hindernis von der Bedienperson manuell umfahren und der Probelauf nach Umfahren des Hindernisses fortgesetzt. Die Bewegungssteuerung der Röntgendiagnostikeinrichtung fügt die Ausweichmanöver der gewählten Bahnkurve hinzu und steuert die Bewegung des C-Bogens im Röntgenaufnahmelauf mit Röntgenstrahlung derart, daß die Hindernisse umfahren werden. Bei der Eingabe der elliptischen Bahnkurve kann von der Bedienpersion festgelegt werden, daß an den beiden Scheitelpunkten der Ellipse der Zentralstrahl der Röntgendiagnostikeinrichtung durch die Mitte des Untersuchungsbereiches (ROI) verläuft.

The following are examples of movements that can be selected by the operator of the X-ray diagnostic device and / or entered via input means:

• 1. The input window of the X-ray receiver to be performed in automatic mode just as in a run by the operator in a teach-in run manner at a small distance above the surface of the examination subject, with a predetermined number of X-ray projection images along the entire trajectory of the movement created and be transferred to the image processing computer for further processing. It is irrelevant whether the central ray of the X-ray diagnostic device always runs through a point POI; it is crucial that the examination region ROI is completely detected by the X-ray receiver in the majority of the projection images. It does not matter whether the entrance window of the X-ray receiver is tangent to the surface of the examination subject. In the presence of obstacles, it may be appropriate to leave the center of the entrance window of the X-ray receiver almost unchanged and to change only the direction of the central beam in the room so that the ROI is still detected by the X-ray receiver,
• 2. The operator specifies that the entrance window of the X-ray receiver should move tangentially to a lateral surface of an elliptical prism. The definition of the ellipse is done, for example, by manually approaching the two vertex positions of the ellipse and storing the gül for these two peaks Coordinates or measured values of the position sensors of the individual adjustment axes of the C-arm. After determining the elliptical trajectory, a test run is triggered by the operator without X-radiation and stopped in case of imminent collisions of parts of the C-arm with obstacles in the operating field or such below the patient bed, the test run, manually avoid the obstacle of the operator and the test run after Driving around the obstacle continued. The motion control of the X-ray diagnostic device adds the evasive maneuvers to the selected trajectory and controls the movement of the C-arm in the X-ray trajectory with X-radiation such that the obstacles are bypassed. When entering the elliptical trajectory can be determined by the Bedienigungsion that extends at the two vertices of the ellipse of the central beam of the X-ray diagnostic device through the center of the examination area (ROI).

at In the above examples one can distinguish between sequences of movements that factory programmed as an option (elliptical scan) and those controlling the X-ray diagnostic device must be learned in a so-called "teach-in mode". there It does not matter if the tech-in is by manual guidance of the C-arms or by evaluation of others entered into the controller Information such as picture information of a television camera or readings a distance measuring sensor, takes place.

The Invention will be described with reference to the figures.

In 1 a mobile X-ray diagnostic device is shown with a multi-adjustable C-arm. On a trolley 1 that by means of rollers 14 . 15 on the floor 16 is movable, is a multi-adjustable bracket 5 arranged, which has a circular arc C-arm 6 with center 60 wears, with the C-bow 6 along its circumference on the holder 5 is movably mounted. The C-arm 6 has at its ends an X-ray receiver 7 and an X-ray source lying opposite to it 8th on. The middle-point 60 of the C-arm 6 lies in the embodiment of 1 outside the central ray 10 passing through the focus point 9 the X-ray source 8th and the center 12 of the entrance window 11 of the X-ray receiver 7 is determined. The central beam 10 contains a reference point 18 by the distance to the focal point 9 is defined. The car 1 carries a pillar 2 by means of a self-aligning bearing 21 with a horizontal guide 3 connected is. The horizontal guide 3 is height adjustable by means of the column and around the pendulum axis 20 rotatably mounted. The horizontal guide 3 wears on the C-arm 6 facing side a tilting bearing 4 in which the holder 5 around the tilt axis 40 is rotatably mounted. The pendulum axle 20 is preferably vertical and the tilt axis 40 arranged horizontally in the room.

In 2 a known arrangement is shown with a C-arm whose plane is perpendicular to the floor 16 stands and in the example of the 2 lies in the paper plane.

The equipment cart 1 and the mounts from the 1 are in 2 not shown. An examination object 13 that is fixed with respect to the floor 16 is to be arranged, contains a destination point 17 which corresponds, for example, to the point of greatest interest determined by a surgeon or a diagnostician. The central beam 10 contains the destination point 17 , A dashed C-bow 6 ' , which is provided with primed reference numerals, has a central ray 10 ' on, which is also the destination point 17 contains, where the distance of the destination point 17 to the focal point 9 is identical to the distance to the focal point 9 ' , The point fixed on the C-arm on the central ray 10 is the reference point 18 in 1 , This is for the two orientations of the C-arm 6 respectively. 6 ' the imaging geometry of the X-ray optics identical. The with the X-ray receiver 7 images obtained point in particular in the destination 17 the same object magnification due to the location of the reference point 18 on the central ray 10 is determined. To the in 2 To obtain the situation shown, the C-arm must be moved along the circumference and in the plane of the paper perpendicular and parallel to the floor so that the center 60 of the C-arm 6 in the center 60 ' the dashed C-arm 60 ' passes. When shifting the C-arm 6 in the holder, not shown 5 in the counterclockwise direction, the holder 5 by a displacement of the vertical column 2 down and by a shift of the horizontal guide 3 be shifted to the right so that the center 60 of the C-arm 6 in the center 60 ' of the C-arm 6 ' passes. The vertical and horizontal displacement of the C-arm 6 is preferably carried out by motor drives of the column and the horizontal guide, wherein the travel paths in the vertical and in the horizontal direction of an axis control in dependence on the orientation of the C-arm 6 with respect to the holder 5 be specified. For this purpose, the holder 5 preferably a position sensor. The motor drives in the horizontal and in the vertical direction are preferably realized with actuators with position sensors. Another input variable for the control program is the position of the reference point 18 on the central ray 10 , for example, determined by the distance of the reference point 18 from the focal point 9 , This distance can optionally be entered at an input panel of the X-ray diagnostic device or determined by means of an adjustment process described below.

An x-ray image of a target point 17 within a study object 13 can be treated according to the rules of geometric optics as an X-ray absorption image obtained by means of the X-radiation of an X-ray source 8th on the entrance window 11 an X-ray receiver 7 is projected. In addition to the quality of the X-ray radiation of the X-ray source 8th and the imaging properties of the X-ray beam receiver 7 the imaging geometry is important for the evaluation and / or evaluation of an X-ray image. The mapping geometry for the mapping of a target point 17 should for all further considerations by the distance of the target point 17 containing and on the central ray 10 perpendicular reference plane from the focal point 9 and by the position of the central ray 10 with respect to a floor-fixed coordinate system, with respect to which also the position of the examination object 13 and the destination point 17 are defined. The intersection of the reference plane with the central ray 10 is used as a reference point 18 designated. If a reconstruction of the examination subject is to take place from a large number of x-ray images, then the respective imaging geometries of the individual x-ray images are required for the arithmetic operations known from computer tomography.

If you leave that in the 2 the clarity of the presentation serving to define the plane of the C-arm fall on a plane perpendicular to the floor, so it can to achieve a predetermined magnification of a positioned on the central beam target point / / object to be examined 13 be necessary, in addition to the vertical movement in the column 2 and the horizontal movement in the horizontal guide 3 also the rotational movements in the self-aligning bearing 21 around the pendulum axis 20 , the tilting movement in the tilting bearing 4 around the tilt axis 40 and possibly a movement of the equipment cart with a component perpendicular to the C-arm plane by motorized rollers 14 . 15 to control.

• 1. Orbitalbewegung (elektromotorische Bewegung des C-Bogens 6 längs seines Umfanges in der Halterung 5, Vorhandensein eines Positionssensors)
• 2. Horizontalbewegung (motorisierte Bewegung der Halterung 5 in der Horizontalführung 3 mit Positionssensor)
• 3. Vertikalbewegung (motorische Bewegung der Horizontalführung 3 in vertikaler Richtung längs der Säule 2, mit Positionssensor)
• 4. Kippbewegung (Rotation der Halterung 5 und damit der C-Bogen-Ebene um die Kippachse 40; vorzugsweise motorisch bewegt mit Positionssensor, andernfalls in einer definierten Position während des Bewegungsablaufes arretiert)
• 5. Pendelbewegung (Rotation der Horizontalführung 3 um die Pendelachse 20 im Pendellager 21; vorzugsweise motorisch bewegt mit Positionssensor, andernfalls in einer definierten Position während des Bewegungsablaufes arretiert)
• 6. Lenkbewegung (Rotation der Lenkachsen der Rollen 14, 15, wobei die Lenkrichtungen aller Rollen 14, 15 parallel ausgerichtet sind;; wahlweise motorisch bewegt mit Positionssensor, andernfalls in einer definierten Position während des Bewegungsablaufes arretiert
• 7. Rollbewegung (Abhängig von der Stellung der Lenkachsen der Rollen 14, 15 sind Bewegungen des Gerätewagens 1 in jeder Richtung parallel zum Fußboden 16 möglich;; wahlweise motorisch bewegt mit Positionssensor, andernfalls in einer definierten Position während des Bewegungsablaufes arretiert

The known mobile X-ray diagnostic devices generally have the following adjustment options, which are referred to below as "axes" and are described below:

• 1. Orbital movement (electromotive movement of the C-arm 6 along its circumference in the holder 5 Presence of a position sensor)
• 2. Horizontal movement (motorized movement of the bracket 5 in the horizontal guide 3 with position sensor)
• 3. Vertical movement (motor movement of the horizontal guide 3 in the vertical direction along the column 2 , with position sensor)
• 4. tilting movement (rotation of the holder 5 and thus the C-arm plane around the tilt axis 40 ; preferably motor-driven with position sensor, otherwise locked in a defined position during the course of motion)
• 5. Oscillation (rotation of the horizontal guide 3 around the pendulum axis 20 in the pendulum bearing 21 ; preferably motor-driven with position sensor, otherwise locked in a defined position during the course of motion)
• 6. Steering movement (rotation of the steering axles of the rollers 14 . 15 , where the steering directions of all roles 14 . 15 aligned in parallel; optionally motor-driven with position sensor, otherwise locked in a defined position during the movement sequence
• 7. Rolling (Depending on the position of the steering axles of the rollers 14 . 15 are movements of the equipment cart 1 in every direction parallel to the floor 16 possible;; optionally motor-driven with position sensor, otherwise locked in a defined position during the movement sequence

In 3 is a sequence of movements of a C-arm 6 with an x-ray receiver 7 and a Röngtenstrahlenquelle 6 one on a patient bed 70 positioned examination object 13 with a study ROI 71 shown schematically. For four different positions, the respective receiving geometry is shown; for these positions are the respective centers 12 . 12 ' . 12 '' . 12 ''' of the input window of the X-ray receiver. In this example, below the patient bed is an obstacle 72 which requires that in order to avoid the collision of the X-ray source 8th with the obstacle 72 the distance of the point 12 '' must be increased to the surface of the examination object.

In 4 is a block diagram of the X-ray diagnostic device according to the invention shown schematically. An unspecified arithmetic unit 52 has control outputs 53 and inputs 54 controls all processes for generating X-rays and for obtaining, storing and displaying image data. The arithmetic unit 52 also has a data interface 56 on, via the X-ray diagnostic device can be connected to an external evaluation computer. To the arithmetic unit 52 is a display unit 55 and an axis control 50 connected. the axis control 50 has an input for an input panel 51 on and outputs for controlling the motors 101 . 201 . 301 and inputs that position sensors 102 . 202 . 302 zugeord are net, which detect the relative position of the respective axis with respect to a zero point. For each of the three axes shown schematically 100 . 200 . 300 In each case a motor and a position sensor is provided. However, it is irrelevant for the invention if no motor is provided for one or more axes and this respective axis is manually movable; however, a position sensor may be provided for such a non-motorized axle.

In a program memory, not shown, the axis control 50 preferably user-specific control programs are stored, which correlate with certain examination programs or diagnostic standard situations. It may be provided that certain parameters of the control programs from the user by means of the input panel 51 or other, not shown input means are adapted to the desired examination situation. By means of said input means, the control programs desired by the user are also selected, started or stopped from the totality of the stored control programs.

Even if in the example of the 2 The movement of the C-arm is done in a plane, the movement restriction, the restriction to a level is not required. For example, the X-ray diagnostic device may be moved around the skull, knee, shoulder, hand, or other peripheral body portion such that the center of the X-ray receiver entrance window may, for example, move approximately on a hemisphere.

It is for the invention irrelevant whether the C-arm has a circular shape or the shape of a U or a conic or a free selected has flat or non-planar curve. During a movement of the C-arms in the holder along its scope would the central jet is moving back and forth within the ROI, which is compensated accordingly by the axis control.

List of pictures:

1 : Mobile X-ray diagnostic device with C-arm

2 : Orientation of the C-arm perpendicular to the floor

3 : Schematic representation of the sequence of movements

4 : Block diagram of the X-ray diagnostic device

1

trolley

2

pillar

3

horizontal guide

4

rocker bearing

5

bracket

6 6 '

C-arm

7, 7 '

X-ray receiver

8th, 8th'

X-ray source

9 9 '

focus point

10 10 '

central beam

11

entrance window

12 12 ', 12' ', 12' ''

Focus of the entrance window

13

object of investigation

14

role

15

role

16

floor

17

Endpoint

18

reference point

20

swing axle

21

aligning bearing

40

tilt axis

50

axis control

51

input panel

52

computer unit

53

control outputs

54

inputs

55

display unit

56

Data Interface

60 60 '

Focus of the C-arm

70

patient support

71

Examination volume, ROI (Region of Interest)

72

obstacle

100

axis 1

101

engine

102

position sensor

200

axis 2

201

engine

202

position sensor

300

axis 3

301

engine

302

position sensor

Claims (2)

X-ray diagnostic device with one on a trolley ( 1 ), multiple motorized adjustable bracket ( 5 ), on which a C-arm ( 6 ) with an X-ray source ( 8th ) and one of these oppositely disposed X-ray receiver ( 7 ) is mounted so as to be motor-displaceable along its circumference, wherein the holder ( 5 ) Means for determining the relative position of the C-arm ( 6 ) with respect to the holder ( 5 ), with - an axis control ( 50 ), which outputs for controlling the servomotors of the motor adjustable ba retainer ( 5 ) and the relative position of the C-arm ( 6 ) with respect to the holder, - a computing unit ( 52 ) for controlling the X-ray diagnostic device, - input means for inputting a movement sequence desired by an operator into the arithmetic unit ( 52 ) - an image processing computer, characterized in that the axis control ( 50 ) selected by the operator and in the arithmetic unit ( 52 ) automatically stores successively stored sequence of axis settings with predetermined projection geometries, after each successful setting, a release signal to the arithmetic unit ( 52 ) sets off to trigger an X-ray and sets the setting of the next projection geometry of the sequence after X-ray exposure. X-ray diagnostic device according to Claim 1, characterized in that the sequence of projection geometries selected by the operator is determined in a teach-in run without X-radiation, wherein the desired projection geometries are set manually one after the other and stored in the arithmetic unit ( 52 ) are stored.