Method for navigating a virtual camera along a biological object with a lumen
First Claim
1. A computer-implemented method of navigating along a hollow tubular object bounded by a wall and represented by a three-dimensional volume data set, the data set comprising a plurality of voxels arranged in a three-dimensional array, the method comprising:
- generating a plurality of navigation segments connectable in a sequence, each segment having a start point within the object, a direction and a length;
the direction of each segment being determined by;
calculating an average ray length for each of two or more groups of rays cast from the start point of the segment and that have a different direction, each group comprising a plurality of rays arranged about a central axis, and each ray extending from the start point to the wall;
selecting the group with the largest average ray length; and
setting the direction of the segment to the direction of the central axis of the selected group.
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Accused Products
Abstract
A method of navigating along a biological object with a lumen represented by a three-dimensional volume data set comprises generating a plurality of navigation segments connectable in a sequence, each segment having a start point within the lumen, a direction and a length. The navigation may be used for a camera in a virtual endoscopic examination, for example. The direction of each segment is determined by casting groups of rays outwards from the start point of the segment to the object wall, and calculating an average ray length for each group. The group having the largest average ray length is selected, and the axial direction of this group is used as the direction for the segment. The average ray lengths of the groups may be weighted using the direction of the previous segments to bias the navigation generally forward, or may be weighted using a view direction of the camera to allow a user to turn the camera into a chosen branch in the object.
31 Citations
35 Claims
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1. A computer-implemented method of navigating along a hollow tubular object bounded by a wall and represented by a three-dimensional volume data set, the data set comprising a plurality of voxels arranged in a three-dimensional array, the method comprising:
generating a plurality of navigation segments connectable in a sequence, each segment having a start point within the object, a direction and a length;
the direction of each segment being determined by;calculating an average ray length for each of two or more groups of rays cast from the start point of the segment and that have a different direction, each group comprising a plurality of rays arranged about a central axis, and each ray extending from the start point to the wall; selecting the group with the largest average ray length; and setting the direction of the segment to the direction of the central axis of the selected group. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32)
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33. A computer program product comprising machine-readable instructions for implementing a computer-implemented method of navigating along a hollow tubular object bounded by a wall and represented by a three-dimensional volume data set, the data set comprising a plurality of voxels arranged in a three-dimensional array, the instructions being operable to instruct a machine to:
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store a three-dimensional volume data set; and generate a plurality of navigation segments connectable in a sequence, each segment having a start point within the object, a direction and a length;
the direction of each segment being determined by;calculating an average ray length for each of two or more groups of rays cast from the start point of the segment and that have a different direction , each group comprising a plurality of rays arranged about a central axis, and each ray extending from the start point to the wall; selecting the group with the largest average ray length; and setting the direction of the segment to the direction of the central axis of the selected group. - View Dependent Claims (34)
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35. A computer system for implementing a computer-implemented method of navigating along a hollow tubular object bounded by a wall and represented by a three-dimensional volume data set, the data set comprising a plurality of voxels arranged in a three-dimensional array, the computer system comprising:
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memory for storing a three-dimensional volume data set; and a processor programmed to; generate a plurality of navigation segments connectable in a sequence, each segment having a start point within the object, a direction and a length;
the direction of each segment being determined by;calculating an average ray length for each of two or more groups of rays cast from the start point of the segment and that have a different direction , each group comprising a plurality of rays arranged about a central axis, and each ray extending from the start point to the wall; selecting the group with the largest average ray length; and setting the direction of the segment to the direction of the central axis of the selected group.
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Specification