Moiré marker for x-ray imaging

A computer-implemented method of determining a rotational position of an object in a coordinate system of an associated x-ray imaging device, the method comprising:

• providing an x-ray image of an object to which a Moiré marker for x-ray imaging is attached during generation of the x-ray image, the x-ray image having been generated when the object to which the Moiré marker for x-ray imaging is attached is imaged together with the Moiré marker for x-ray imaging by the associated x-ray imaging device, wherein a Moiré pattern of x-ray signal intensities is generated on the x-ray image by the Moiré marker for x-ray imaging when the object to which the Moiré marker for x-ray imaging is attached is imaged together with the Moiré marker for x-ray imaging by the associated x-ray imaging device, wherein the Moiré pattern of x-ray signal intensities generated when the object to which the Moiré marker for x-ray imaging is attached is imaged together with the Moiré marker for x-ray imaging by the associated x-ray imaging device is indicative of an angle between the Moiré marker for x-ray imaging and an x-ray propagation direction of the associated x-ray imaging device in the coordinate system of the associated x-ray imaging device, wherein the object comprises one or more of:
• a medical robot, a medical instrument, a medical device, a patient support device, and/or a patient, wherein, in the provided x-ray image, the Moiré marker and a further marker are attached to the object as marker array;
• determining, based on the Moiré pattern of x-ray signal intensities generated when the object to which the Moiré marker for x-ray imaging is attached is imaged together with the Moiré marker for x-ray imaging by the associated x-ray imaging device, the rotational position of the object in the coordinate system of the associated x-ray imaging device;
• and
• automatically identifying the further marker in the provided x-ray image.

A computer-implemented method of

• determining a rotational position of an object in a coordinate system of an associated x-ray imaging device, the method comprising:
• providing an x-ray image of an object to which a Moiré marker for x-ray imaging is attached during generation of the x-ray image, the x-ray image having been generated when the object to which the Moiré marker for x-ray imaging is attached is imaged together with the Moiré marker for x-ray imaging by the associated x-ray imaging device, wherein a Moiré pattern of x-ray signal intensities is generated on the x-ray image by the Moiré marker for x-ray imaging when the object to which the Moiré marker for x-ray imaging is attached is imaged together with the Moiré marker for x-ray imaging by the associated x-ray imaging device, wherein the Moiré pattern of x-ray signal intensities generated when the object to which the Moiré marker for x-ray imaging is attached is imaged together with the Moiré marker for x-ray imaging by the associated x-ray imaging device is indicative of an angle between the Moiré marker for x-ray imaging and an x-ray propagation direction of the associated x-ray imaging device in the coordinate system of the associated x-ray imaging device, wherein the object comprises one or more of:
• a medical robot, a medical instrument, a medical device, a patient support device, and/or a patient;
• and
• determining, based on the Moiré pattern of x-ray signal intensities generated when the object to which the Moiré marker for x-ray imaging is attached is imaged together with the Moiré marker for x-ray imaging by the associated x-ray imaging device, the rotational position of the object in the coordinate system of the associated x-ray imaging device, wherein the determining the rotational position further comprises comparing at least the Moiré pattern of the x-ray signal intensities generated by the Moiré marker in the x-ray image with a target pattern of x-ray intensities to be generated by the Moiré marker.

A Moiré marker for x-ray imaging, the Moiré marker for x-ray imaging comprising:

• a layered pattern structure of a plurality of layers comprising at least a first material and a second material,
• wherein the first material has a higher x-ray opacity than an x-ray opacity of the second material,
• wherein pattern structures of the first and second materials are configured for generating a Moiré pattern of x-ray signal intensities in an x-ray image when being imaged by an associated x-ray imaging device,
• wherein the layered pattern structure further comprises:
• a first layer with a first pattern of the first material and the second material;
• and
• a second layer with a second pattern of the first material and the second material.