Image guidance system for detecting and tracking an image pose
First Claim
Patent Images
1. A system for tracking the pose of an object displaceable in a coordinate reference frame, the system comprising:
- an optically-visible target pattern on an object being tracked, the pattern containing a plurality of 2D contrasting shapes located on a tile, the contrasting shapes being in an arrangement so as to uniquely differentiate the pattern from other patterns;
a storage media containing stored data for a plurality of distinct patterns of contrasting shapes including, for each distinct pattern, the arrangement of contrasting shapes and locations of defined points in the pattern;
an optical sensor assembly spaced apart from the object, the optical sensor assembly located and configured to capture images of at least a portion of the pattern, the sensor assembly including at least two cameras, each camera configured to capture a 2D image of the portion of the pattern, each 2D image being at a different viewing angle of the portion of the pattern than the other 2D image(s); and
a processor configured to (i) retrieve the stored data for the plurality of distinct patterns of contrasting shapes, (ii) receive the 2D images from the sensor assembly, (iii) locate a plurality of defined points in each 2D image and determine a pair of basis vectors between each defined point and two of its adjacent defined points, (iv) determine a rectifying affine transform applicable to contrasting shapes in the pattern in each 2D image and predict grid locations in each 2D image, (v) determine a set of descriptors for each 2D image, each descriptor being determined based on coloring or shading of the contrasting shapes adjacent to each predicted grid location, and (vi) compare the descriptors to a library of descriptors in the stored data to select a specific pattern in the stored data that is closest to the pattern in each 2D image, and the processor configured to (vii) match defined points in one of the 2D images with corresponding defined points in the other 2D image and perform stereo triangulation with a location of the cameras to determine an estimate of a 3D location of each matched defined point, and (viii) calculate a second transform to convert the matched defined points to a target coordinate system to determine the pose of the object;
wherein the processor is configured to use the rectifying affine transform to provide 2D translation, rotation, and scaling of the located defined points in the 2D images for correlating with 3D coordinates in the stored data for the identified distinct pattern.
2 Assignments
0 Petitions
Accused Products
Abstract
An image guidance system for tracking a surgical instrument during a surgical procedure. The image guidance system includes a plurality of cameras adapted to be located external to a surgical area for capturing images of optically visible patterns. A processing system receives and processes the images to recognize the patterns and triangulate the locations and orientations of each pattern relative to a camera. The processing system uses a reference dataset to recognize the patterns.
-
Citations
31 Claims
-
1. A system for tracking the pose of an object displaceable in a coordinate reference frame, the system comprising:
-
an optically-visible target pattern on an object being tracked, the pattern containing a plurality of 2D contrasting shapes located on a tile, the contrasting shapes being in an arrangement so as to uniquely differentiate the pattern from other patterns; a storage media containing stored data for a plurality of distinct patterns of contrasting shapes including, for each distinct pattern, the arrangement of contrasting shapes and locations of defined points in the pattern; an optical sensor assembly spaced apart from the object, the optical sensor assembly located and configured to capture images of at least a portion of the pattern, the sensor assembly including at least two cameras, each camera configured to capture a 2D image of the portion of the pattern, each 2D image being at a different viewing angle of the portion of the pattern than the other 2D image(s); and a processor configured to (i) retrieve the stored data for the plurality of distinct patterns of contrasting shapes, (ii) receive the 2D images from the sensor assembly, (iii) locate a plurality of defined points in each 2D image and determine a pair of basis vectors between each defined point and two of its adjacent defined points, (iv) determine a rectifying affine transform applicable to contrasting shapes in the pattern in each 2D image and predict grid locations in each 2D image, (v) determine a set of descriptors for each 2D image, each descriptor being determined based on coloring or shading of the contrasting shapes adjacent to each predicted grid location, and (vi) compare the descriptors to a library of descriptors in the stored data to select a specific pattern in the stored data that is closest to the pattern in each 2D image, and the processor configured to (vii) match defined points in one of the 2D images with corresponding defined points in the other 2D image and perform stereo triangulation with a location of the cameras to determine an estimate of a 3D location of each matched defined point, and (viii) calculate a second transform to convert the matched defined points to a target coordinate system to determine the pose of the object; wherein the processor is configured to use the rectifying affine transform to provide 2D translation, rotation, and scaling of the located defined points in the 2D images for correlating with 3D coordinates in the stored data for the identified distinct pattern. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A system for tracking the pose of an object displaceable in a coordinate reference frame, the system comprising:
-
an optically-visible target pattern on an object being tracked, the pattern containing a plurality of 2D contrasting shapes located on a tile, the contrasting shapes being in an arrangement so as to uniquely differentiate the pattern from other patterns; a storage media containing stored data for a plurality of distinct patterns of contrasting shapes including, for each distinct pattern, the arrangement of contrasting shapes and locations of defined points in the pattern; an optical sensor assembly spaced apart from the object, the optical sensor assembly located and configured to capture images of at least a portion of the pattern, the sensor assembly including at least a first and second camera, each of the first and second cameras arranged to capture a 2D image of the portion of the pattern, each 2D image being at a different viewing angle of the portion of the pattern than the other 2D image; and a processor configured to (i) retrieve the stored data for the plurality of distinct patterns of contrasting shapes, (ii) receive the 2D images from the cameras in the sensor assembly, (iii) locate a plurality of defined points in each 2D image and determine a pair of basis vectors between each defined point and two of its adjacent defined points, (iv) determine a rectifying affine transform applicable to contrasting shapes in the pattern in each 2D image and predict grid locations in each 2D image, (v) determine a set of descriptors for each 2D image, each descriptor being determined based on coloring or shading of the contrasting shapes adjacent to each predicted grid location, and (vi) compare the descriptors associated with each 2D image to a library of descriptors in the stored data to select a specific pattern in the stored data that is closest to the pattern in the 2D image, and the processor configured to (vii) match defined points in one of the 2D images with corresponding defined points in the other 2D image and perform stereo triangulation with a location of the cameras to determine an estimate of a 3D location of each matched defined point, and (viii) calculate a second transform to convert the matched defined points to a target coordinate system to determine the pose of the object; wherein the processor uses the rectifying affine transform to provide 2D translation, rotation, and scaling of the located defined points in the 2D images for correlating with 3D coordinates in the stored data for the identified distinct pattern. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
-
-
23. A system for tracking the pose of an object displaceable in a coordinate reference frame, the system comprising:
-
an optically-visible target pattern on an object being tracked, the pattern containing a plurality of 2D contrasting shapes, the contrasting shapes defining a grid having a plurality of boxes, each box having a color selected from at least two optically distinguishable colors, the boxes arranged based on their color so as to uniquely differentiate the pattern from other patterns; a storage media containing stored data for a plurality of distinct patterns of contrasting shapes including, for each distinct pattern, the arrangement of contrasting shapes and locations of defined points in the pattern; an optical sensor assembly spaced apart from the object, the optical sensor assembly located and configured to capture images of at least a portion of the pattern, the sensor assembly including at least a first and second camera, each of the first and second cameras arranged to capture a 2D image of the portion of the pattern, each 2D image being at a different viewing angle of the portion of the pattern than the other 2D image; and a processing system including a camera processor associated with each camera and a main processor, the processing system configured to (i) receive the 2D images from the cameras, (ii) retrieve the stored data for the plurality of distinct patterns of contrasting shapes, (iii) for each 2D image, detect defined points between adjacent contrasting colored boxes and determine basis vectors between a defined point and two of its adjacent defined points, (iv) for each 2D image, determine a rectifying affine transform based on the basis vectors that transforms a rhombohedral image patch into a square image patch, three of whose corners are the defined point and its two adjacent defined points, wherein the affine transform is used to predict where each grid location should be in the image, (v) analyze each 2D image at each predicted grid location to calculate a descriptor which describes the grid location based on locations of adjacent distinct color boxes, and (vi) compare the descriptors to a library of descriptors in the stored data to select a specific pattern in the stored data that is closest to the pattern in the 2D image, and use the selected pattern in the stored data to determine the pose of the object in a camera-centric frame of reference of each camera, and configured to (vii) match defined points in one of the 2D images with corresponding defined points in the other 2D image and perform stereo triangulation with a location of the cameras to determine an estimate of a 3D location of each matched defined point, and (viii) calculate a second transform to convert the matched defined points to a target coordinate system to determine the pose of the object. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31)
-
Specification