Method and system of depth determination with closed form solution in model fusion for laparoscopic surgical guidance

Machine readable medium having information recorded thereon for estimating a three-dimensional (3D) coordinate of a 3D virtual model, wherein the information, when read by the machine, causes the machine to perform the following steps:

• accessing a 3D virtual model constructed for an organ of a patient based on a plurality of images of the organ prior to a medical procedure;
• obtaining a first pair of corresponding feature points, with a first two-dimensional (2D) feature point on the organ observed in a 2D image acquired during the medical procedure and a first corresponding 3D feature point from the 3D virtual model;
• obtaining a second pair of corresponding feature points, with a second 2D feature point on the organ observed in the 2D image and a second corresponding 3D feature point from the 3D virtual model, wherein the depths of the first and the second 3D feature points are substantially the same;
• and
• automatically determining a first 3D coordinate of the first 3D feature point and a second 3D coordinate of the second 3D feature point based on the first and the second pairs of corresponding feature points so that a first distance between the determined first 3D coordinate and the determined second 3D coordinate equals to a second distance between a first actual 3D coordinate of the first 3D feature point and a second actual 3D coordinate of the second 3D feature point in the 3D virtual model.

A system for estimating a three-dimensional (3D) coordinate of a 3D virtual model, comprising:

• an anatomical structure mesh generation unit configured for constructing a 3D virtual model for an organ of a patient based on a plurality of images of the organ prior to a medical procedure;
• and
• a one-mark based model-to-video alignment unit configured for
• obtaining a first pair of corresponding feature points, with a first two-dimensional (2D) feature point on the organ observed in a 2D image acquired during the medical procedure and a first corresponding 3D feature point from the 3D virtual model,
• obtaining a second pair of corresponding feature points, with a second 2D feature point on the organ observed in the 2D image and a second corresponding 3D feature point from the 3D virtual model, wherein the depths of the first and the second 3D feature points are substantially the same, and
• automatically determining a first 3D coordinate of the first 3D feature point and a second 3D coordinate of the second 3D feature point based on the first and the second pairs of corresponding feature points so that a first distance between the determined first 3D coordinate and the determined second 3D coordinate equals to a second distance between a first actual 3D coordinate of the first 3D feature point and a second actual 3D coordinate of the second 3D feature point in the 3D virtual model.