Apparatus for fiducial-association as part of extracting projection parameters relative to a 3D coordinate system

Patent metadata

Field	Value
Publication number	US-11564769-B2
Application number	US-201916393535-A
Country	US
Kind code	B2
Filing date	Apr 24, 2019
Priority date	Apr 27, 2018
Publication date	Jan 31, 2023
Grant date	Jan 31, 2023

Abstract

A registration fixture or plate is configured for use with a medical imaging system. The registration fixture may be an optical magnetic registration plate including a plurality of fiducial markers in arranged in a predefined unique pattern. The pattern can be unambiguously detected on 2D image of the plate produced by the medical imaging system. Association of the 2D imaged pattern of fiducial markers with the actual 3D pattern on the optical magnetic registration plate allows for accurate calculation of projection matrices and co-registration of the 3D and 2D coordinate systems.

First claim

What is claimed:

1. A registration fixture configured for use with a medical imaging system, the registration fixture comprising:
a first plurality of fiducial markers arranged in a first predefined pattern within the fixture;
a second plurality of fiducial markers arranged in a second predefined pattern within the fixture; and
a plurality of magnetic transmitters coupled to the registration fixture,
wherein the first and second predefined patterns are unique such that they are distinguishably detectable, with respect to each other, on a two-dimensional (2D) image of the fixture produced by the medical imaging system, wherein the registration fixture is configured to fixedly couple to a patient table to secure the registration fixture under a patient throughout a procedure, wherein the first and second pluralities of fiducial markers define a three-dimensional (3D) coordinate system, wherein the 2D image defines a 2D coordinate system, and wherein the 3D coordinate system and the 2D coordinate system are co-registered by associating a first position of at least one of the first or second pluralities of fiducial markers detected on the 2D image with a second position of the at least one of the first or second pluralities of fiducial markers within the fixture, wherein the first or second predefined patterns comprise a plurality of sub-patterns, and wherein each of the plurality of sub-patterns comprises a unique and unambiguous arrangement of fiducial markers such that each of the plurality of sub-patterns is distinctly identifiable, with respect to each other, on the 2D image, wherein each of the plurality of sub-patterns comprises a symmetric grid, and wherein the first and second predefined patterns are configured to allow the medical imaging system to determine a majority of possible projections from the medical imaging system.

2. The fixture of claim 1 , wherein the medical imaging system is an x-ray imaging system, and wherein the first and second pluralities of fiducial markers are radiolucent or radiopaque.

3. The fixture of claim 2 , wherein the x-ray imaging system includes a c-arm.

4. The fixture of claim 2 , wherein at least a portion of the fixture is located within a path of an x-ray beam.

5. The fixture of claim 1 , wherein the first and second pluralities of fiducial markers comprise balls or line elements.

6. The fixture of claim 5 , wherein the first and second pluralities of fiducial markers comprise identically-sized metal balls.

7. The fixture of claim 1 , wherein the first and second predefined patterns of fiducial markers are configured to allow viewing of a majority of a field of view of the medical imaging system.

8. The fixture of claim 1 , wherein the fixture is fixed with respect to at least one of the plurality of magnetic field transmitters.

9. The fixture of claim 1 , wherein at least one magnetic tracking element is embedded within the fixture.

10. The fixture of claim 1 , wherein the medical imaging system includes the patient table, and wherein the fixture is configured to be placed on top of the patient table.

11. The fixture of claim 1 , wherein at least one of the first and second predefined patterns are multi-layered, such that at least one of the first or second plurality of fiducial markers are dispersed in a plurality of layers within the fixture.

12. The fixture of claim 1 , wherein the first or second predefined patterns are distinguishably detectable on the 2D image.

13. A registration system configured for use with a medical imaging system, the registration system comprising:
a registration fixture including a plurality of fiducial markers arranged in a plurality of unique subsets of fiducial markers, each of the subsets being arranged in a predefined pattern within the fixture;
a plurality of magnetic tracking elements;
a plurality of magnetic transmitters coupled to the registration fixture; and
a processor configured to calculate a plurality of projection matrices from a three-dimensional (3D) coordinate system of the fixture to a two-dimensional (2D) coordinate system of an image of the fixture produced by the medical imaging system;
wherein each of the subsets is unique such that they are distinguishably detectable, with respect to one another, on the image of the fixture, wherein the registration fixture is configured to fixedly couple to a patient table to secure the registration fixture under a patient throughout a procedure, wherein a first subset and a second subset of the plurality of unique subsets define the three-dimensional (3D) coordinate system, wherein the image defines the 2D coordinate system, wherein each of the subsets comprises a symmetric grid, and wherein the plurality of fiducial markers are configured to allow the medical imaging system to determine a majority of possible projections from the medical imaging system.

14. The system of claim 13 , and wherein the processor is configured to associate each subset of the subsets of fiducial markers detected on the image with the corresponding subset of fiducial markers in the fixture.

15. The system of claim 13 , wherein the plurality of fiducial markers comprise radiopaque balls or line elements.

16. The system of claim 13 , wherein the plurality of magnetic tracking elements comprises magnetic sensors.

17. The system of claim 16 , wherein at least one magnetic sensor of the magnetic sensors is embedded within the fixture.

18. The system of claim 13 , wherein at least some of the fiducial markers cannot be distinguished individually.

19. The system of claim 13 , wherein the predefined pattern of each of the subsets is unambiguously detectable on the image.

20. The system of claim 13 , wherein each and every of the plurality of subsets is unique such that they are distinguishably detectable with respect to one another, on the image of the fixture.

Assignees

• St Jude Medical Int Holding Sarl
• St Jude Medical Int Holdings Sarl

Inventors

• Izmirli Alon
• Hoory Shlomo
• Levi Shay
• Winkler Itai

Classifications

• A61B2090/3966

  Radiopaque markers visible in an X-ray image · CPC title

• A61B90/39 Primary

  Markers, e.g. radio-opaque or breast lesions markers · CPC title

• A61B6/0407

  Supports, e.g. tables or beds, for the body or parts of the body · CPC title

• A61B2090/3937

  Visible markers · CPC title

• A61B6/4441

  the rigid structure being a C-arm or U-arm · CPC title