Determining calibration information for an x-ray apparatus
AssigneeBrainlab AG
InventorsRobert Essenreiter, Michael Bertram, Martin Ringholz
Life of this patent
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Abstract
A device and method are provided that enable calibration information to be determined for an x-ray apparatus that performs a three-dimensional x-ray scan. The calibration information is determined using an adapting method, wherein the adapting method is based on a position of an x-ray source relative to an x-ray unit marker device during image acquisition, an x-ray unit data set that describes the position of the x-ray unit marker device during image acquisition, and a two-dimensional calibration data set that describes at least one and preferably two actual two-dimensional x-ray images produced by irradiating a calibration object.
Claims15
A method for determining calibration information which includes information on a spatial relationship between an x-ray apparatus reference frame and a three-dimensional scan reference frame, comprising:
- obtaining a three-dimensional calibration data set representing a three-dimensional calibration model of a calibration object in the three-dimensional scan reference frame, wherein the calibration model is determined from scan data generated by a three-dimensional calibration x-ray scan of the calibration object, wherein during the three-dimensional calibration x-ray scan an x-ray unit is moved along a three-dimensional scanning path relative to the calibration object, and at least a portion of the three-dimensional scanning path lies in the x-ray apparatus reference frame;
- obtaining x-ray source relative position data that includes information on the position of an x-ray source of the x-ray unit relative to an x-ray unit marker device attached to the x-ray unit when actual two-dimensional x-ray images are produced;
- obtaining a two-dimensional calibration data set that describes a first of the actual two-dimensional x-ray images produced by irradiating at least the calibration object in a first position of the x-ray source in the x-ray apparatus reference frame, and which also describes at least one of:
- a) a second of the actual two-dimensional x-ray images produced by irradiating at least the calibration object, which is spatially fixed as compared to the first two-dimensional x-ray image, in a second position of the x-ray source in the x-ray apparatus reference frame different from the first position;
- or
- b) the dimensions of the calibration object;
- obtaining an x-ray unit data set that describes the position of the x-ray unit marker device when the at least one actual two-dimensional x-ray image is generated;
- and
- determining the calibration information using an adapting method based on the x-ray source relative position data, the x-ray unit data set and the two-dimensional calibration data set, said calibration information including information on the spatial relationship between the x-ray apparatus reference frame and the three-dimensional scan reference frame.
A data processing device for determining the position of a calibration object, which is subject to a three-dimensional x-ray scan, in a navigation reference frame, the data processing device comprising:
- logic that obtains a three-dimensional calibration data set representing a three-dimensional calibration model of the calibration object in the navigation reference frame, wherein the calibration model is determined from scan data generated by a three-dimensional calibration x-ray scan of the calibration object, wherein during the three-dimensional calibration x-ray scan an x-ray unit is moved along a three-dimensional scanning path relative to the calibration object, and at least a portion of the three-dimensional scanning path lies in the x-ray apparatus reference frame;
- logic that obtains x-ray source relative position data that includes information on the position of an x-ray source of the x-ray unit relative to an x-ray unit marker device attached to the x-ray unit when two-dimensional x-ray images are produced;
- logic that obtains a two-dimensional calibration data set that describes a first of the actual two-dimensional x-ray images produced by irradiating at least the calibration object in a first position of the x-ray source in the x-ray apparatus reference frame, and which also describes at least one of:
- a) a second of the actual two-dimensional x-ray images produced by irradiating at least the calibration object, which is spatially fixed as compared to the first two-dimensional x-ray image, in a second position of the x-ray source in the x-ray apparatus reference frame different from the first position;
- or
- b) the dimensions of the calibration object;
- logic that obtains an x-ray unit data set that describes the position of the x-ray unit marker device when the at least one actual two-dimensional x-ray image is generated;
- and
- logic that determines the position of the object based on calibration information obtained using an adapting method, said adapting method using the x-ray source relative position data, the x-ray unit data set and the two-dimensional calibration data set, said calibration information including information on the spatial relationship between the x-ray apparatus reference frame and the three-dimensional scan reference frame.
Dependencies are inferred from the claim text.