Methods and apparatus for registering CT-scan data to multiple fluoroscopic images

A robotically-assisted surgical system, comprising:

• a robot having an effector that is controllably positioned within a robot coordinate system;
• a first imaging device for obtaining two dimensional radiographic images a tissue of interest, the images containing markers obtained from a calibration device that is located within a field of view of the first imaging device and that is separate from the tissue of interest the markers being used for associating an image coordinate system with the robot coordinate system;
• a second imaging device for obtaining images of slices through the tissue of interest;
• a data processor having an input coupled to an output of the first and second imaging devices and an output coupled to the robot, said data processor generating a three dimensional model of the tissue of interest from the output of the second imaging device, said data processor further detecting a presence of two dimensional contours of the tissue of interest in each of at least two views of the tissue and deriving bundles of lines in three dimensional space that pass through the detected two dimensional contours;
• said data processor operating to iteratively match points in three dimensional space, that are located on three dimensional apparent contours that are associated with a surface of the three dimensional model, with the bundles of lines in three dimensional space until the three dimensional model is registered with the robot coordinate system to a predetermined level of accuracy, wherein said surface apparent contours are boundaries between visible and invisible surface triangles.

A system for registering two dimensional fluoroscopic images with a three dimensional model of a tissue of interest, comprising:

• a model processor for generating a three dimensional model of a tissue of interest using as input a plurality of images taken through the tissue of interest;
• an imaging system for obtaining, in cooperation with a calibration device, at least two, two dimensional images representing at least two views of the tissue of interest, the images containing calibration markers for associating an image coordinate system with a second coordinate system;
• and
• an image processor having inputs coupled to outputs of said model processor and said imaging system for detecting the presence of first contours of the tissue of interest in each of the at least two views, said image processor operating to derive bundles of lines in three dimensional space that pass through the detected first contours, and further operating to match points on second contours obtained from the three dimensional model with the bundles of lines in three dimensional space until the three dimensional model is registered within the second coordinate system to a predetermined degree of accuracy.

A method for generating a three dimensional model of a tissue of interest and for aligning the three dimensional model with two dimensional images of the tissue of interest, comprising steps of:

• performing a plurality of imaging scans through the tissue of interest to generate a plurality of two dimensional image slices;
• processing the image slices to generate a three dimensional model of a surface of the tissue of interest;
• obtaining a plurality of two dimensional images representing at least two views of the tissue of interest, the at least two views also comprising images of calibration markers for associating an image coordinate system with a second coordinate system;
• detecting first contours of the tissue of interest in each of the at least two views;
• deriving bundles of lines in three dimensional space that pass through the detected first contours;
• and
• matching points on second contours obtained from the surface of the three dimensional model with the bundles of lines until the three dimensional model is aligned within the second coordinate system to a predetermined level of accuracy.