Method of registering surfaces using curvature
AssigneeGeneral Electric Company
InventorsHarvey Ellis Cline, William Edward Lorensen
Life of this patent
Estimating the term…
Abstract
A patient surface is registered with a model surface based on curvature by acquiring patient range data and determining the curvature of the patient surface based on the range data. The patient surface is generated and shaded based on the curvature. A model surface is generated from image data and processed to determine the curvature of the model surface. The model surface is shaded to represent the curvature. The shaded patient surface and the shaded model surface are aligned in registration with each other by manipulating the patient surface and/or the model surface until the curvature features coincide.
Claims12
A method for registering surfaces comprising:
- acquiring a first surface from a body to be imaged, said first surface having a curvature;
- acquiring a second surface from said body;
- determining a first curvature of said first surface, wherein the step of determining a first curvature comprises determining a mean curvature, wherein, in a Cartesian coordinate system, said mean curvature is represented as
- Km=(kxx+kyy)/2,
- where
- kxx=[nx(x+a, y, z)−nx(x=a, y, z)]/2a;
- and
- kyy=[ny(x, y+b, z)−ny(x, y−b, z)]/2b,
- and where nx and ny represent vectors in the x and y directions, respectively, when the direction normal to each of said first and second curvatures is in the z direction, and a, b, and c are the spacings between sampled points;
- determining a second curvature of said second surface;
- shading said first surface in response to said first curvature;
- shading said second surface in response to said second curvature;
- and
- varying orientation of at least one of said first surface and said second surface to align said first surface and said second surface in registration with each other.
A method for registering surfaces comprising:
- acquiring a first surface from a body to be imaged, said first surface having a curvature;
- acquiring a second surface from said body;
- determining a first curvature of said first surface, wherein the step of determining a first curvature comprises determining a Gaussian curvature, wherein said Gaussian curvature is represented as:
- Kg=kxxkyy−kxykyx,
- where
- kxx=[nx(x+a, y, z)−nx(x−a, y, z)]/2a;
- kyy=[ny(x, y+b, z)−ny(x, y−b, z)]/2b;
- kxy=[nx(x, y+b, z)−nx(x, y−b, z)]/2b;
- and
- kyx=[ny(x+a, y, z)−ny(x−a, y, z)]/2a,
- and wherein nx and ny represent vectors in the x and y directions, respectively, when the direction normal to each of said first and second curvatures is in the z direction, and a, b, and c are the spacing between sampled points;
- determining a second curvature of said second surface;
- shading said first surface in response to said first curvature;
- shading said second surface in response to said second curvature;
- and
- varying orientation of at least one of said first surface and said second surface to align said first surface and said second surface in registration with each other.
A storage medium encoded with machine-readable computer program code for registering surfaces comprising instructions for causing a computer to implement a method of:
- acquiring a first surface from a body to be imaged, said first surface having a mean curvature wherein, in a Cartesian coordinate system, said mean curvature is represented as
- Km=(kxx+Kyy)/2
- where
- kxx=[nx(x+a, y, z)−nx(x−a, y, z)]/2a,
- and;
- kyy=[ny(x, y+b, z)−ny(x, y−b, z)]/2b,
- and wherein nx and ny represent vectors in the x and y directions, respectively, where the direction normal to each of said first and second curvatures is in the z direction, and a, b, and c are the spacing between samples points;
- acquiring a second surface from said body;
- determining a first curvature of said first surface;
- determining a second curvature of said second surface;
- shading said first surface in response to said first curvature;
- shading said second surface in response to said second curvature;
- and
- varying orientation of at least one of said first surface and said second surface so as to align said first and second surface in registration with each other.
A storage medium encoded with machine-readable computer program code for registering surfaces comprising instructions for causing a computer to implement a method of:
- acquiring a first surface from a body to be imaged, said first surface having a Gaussian curvature, wherein said Gaussian curvature is represented as
- Kg=kxxkyy−kxykyx,
- where
- kxx=[nx(x+a, y, z)−nx(x−a, y, z)]/2a;
- kyy=[ny(x, y+b, z)−ny(x, y−b, z)]/2b;
- kxy=[nx(x, y+b, z)−nx(x, y−b, z)]/2b;
- and
- kxy=[ny(x+a, y, z)−ny(x−a, y, z)]/2a,
- and wherein nx and ny represent vectors in the x and y directions, respectively, when the direction normal to each of said first and second curvatures is in the z direction, and a, b, and c are spacings between sampled points;
- acquiring a second surface from said body;
- determining a first curvature of said first surface,
- determining a second curvature of said second surface;
- shading said first surface in response to said first curvature;
- shading said second surface in response to said second curvature;
- and
- varying orientation of at least one of said first surface and said second surface so as to align said first and second surface in registration with each other.
Dependencies are inferred from the claim text.