Claims
- 1. A method for relative calibration of a mobile X-ray C-arm system including an X-ray source and an external pose system, comprising:
coupling a set of marker or tool plates rigidly to an X-ray source; measuring the 6-dimensional (6D) pose (position and orientation) of said tool plates relative to a sensor system; utilizing data derived from said sensor system for calculating a transformation from a coordinate system attached to said tool plates to a coordinate system attached to said X-ray source; utilizing data derived from said sensor system for calculating a transformation from a coordinate system attached to said sensor system to a coordinate system attached to a predefined world coordinate system; and utilizing results obtained in the preceding two steps for calculating the projection parameters of said X-ray C-arm system.
- 2. A method for relative calibration of a mobile X-ray C-arm system in accordance with claim 1 wherein said step for calculating a transformation from a coordinate system attached to said tool plates to a coordinate system attached to said X-ray source utilizes data based on CAD drawings and a calibration of the focal point of said X-ray system.
- 3. A method for relative calibration of a mobile X-ray C-arm system in accordance with claim 2 including the step of:
calculating the transformation, denoted by Ei, for an arbitrary image frame, from said world coordinate system (Ow) to said X-ray coordinate system (Ox) utilizing data for a tracking system, including pose information of tracking system Li derived from said sensor system, in accordance with the equationEi=Q·Li·V−1 (1)
- 4. A method for relative calibration of a mobile X-ray C-arm system in accordance with claim 3 including, following said step of calculating the transformation from said world coordinate system (Ow) to said X-ray coordinate system (Ox), the step of:
projecting said arbitrary image frame onto an image plane IX, defined by intrinsic parameters Ai-As.
- 5. A method for relative calibration of a mobile X-ray C-arm system in accordance with claim 3 wherein said step of calculating the transformation, denoted by E1 comprises a step of calculating a transformation S in accordance with the equation
- 6. A method for relative calibration of a mobile X-ray C-arm system in accordance with claim 5 including a step for calculating said X-ray projection geometry in accordance with the equations:
- 7. An external tracking system for use three dimensional (3D) reconstruction with an X-ray C-arm system, including an X-ray source, comprises:
a set of marker or tool plates rigidly coupled to an X-ray source; a sensor system for measuring the 6-dimensional (6D) pose (position and orientation) of said tool plates relative to said sensor system; means utilizing data derived from said sensor system for calculating a transformation from a coordinate system attached to said tool plates to a coordinate system attached to said X-ray source; means utilizing data derived from said sensor system for calculating a transformation from a coordinate system attached to said sensor system to a coordinate system attached to a predefined world coordinate system; and means utilizing results obtained in the preceding two steps for calculating the projection parameters of said X-ray C-arm system.
- 8. An external tracking system in accordance with claim 7 wherein said means for calculating a transformation from a coordinate system attached to said tool plates to a coordinate system attached to said X-ray source utilizes data based on CAD drawings and a calibration of the focal point of said X-ray system.
Parent Case Info
[0001] Reference is hereby made to co-pending Provisional U.S. patent application Ser. No. 60/181,481 entitled “Relative calibration of a mobile X-RAY C-ARM and an external pose tracking system”, filed in the names of Navab and Mitschke on Feb. 10, 2000 and whereof the disclosure is hereby incorporated herein by reference.
Provisional Applications (1)
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Number |
Date |
Country |
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60181481 |
Feb 2000 |
US |