Method of catheter tracking using image information

• US 8,311,614 B2
• Filed: 07/21/2008
• Issued: 11/13/2012
• Est. Priority Date: 03/01/2004
• Status: Active Grant

• Current Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: Sathyanarayana, Shashidhar
• Primary Examiner(s): Chao, Elmer
• Application Number:
  US12/176,990
• Publication Number:
  US 20080281191A1
• Time in Patent Office: 1,576 Days
• Field of Search: 606/159, 606/169, 606/130, 600423-424, 600/443, 600/447, 600/454, 600/455, 600/916
• US Class Current: 600/424
• CPC Class Codes: G06T 2207/10068 Endoscopic image
• CPC Class Codes: G06T 2207/30101 Blood vessel; Artery; Vein; Vascular
• CPC Class Codes: G06T 7/20 Analysis of motion motion estimation for coding, decoding, compressing or decompressing digital video signals H04N19/43, H04N19/51
• CPC Class Codes: G06T 7/55 from multiple images
• CPC Class Codes: G06T 7/74 involving reference images or patches

Abstract

An improved method of tracking a catheter'"'"'s position within a human body does not rely on x-rays, but instead calculates the position of the catheter'"'"'s imaging head by analyzing image data. Such an analysis is able to determine the position of the imaging head in 3 dimensional space, relative to an arbitrarily selected reference image. An image is compared with the reference image, correlation data between corresponding points on the two images are gathered, and a correlation loss rate in a particular direction is determined. This correlation loss rate is modeled to an exponential function, which is evaluated to estimate an angle of separation between the image and the reference image. One or more angles of separation are used to determine a position in three dimensional space of the image, relative to the reference image. By repeating this process for a series of images being gathered by a catheter, the position of the catheter can be determined. Additionally, a 3 dimensional map of lumens in the human body can be created.

Claims

1. A method of tracking a position of an imaging head of a catheter in three-dimensional space within a human body, the method comprising:

receiving a first image captured by the catheter, wherein the first image is in a first image plane;

receiving a second image captured by the catheter, wherein the second image is in a second image plane, wherein the first and second image planes are non-parallel to each other;

for each of a plurality of first data locations situated along a first line in the first image and a plurality of corresponding second data locations situated along a corresponding second line in the second image, determining differences in an image property between the first data locations in the first image and the corresponding second data locations in the second image along a first direction along the first and second lines, wherein the corresponding second line is a projection of the first line onto the second image;

determining first correlation loss data from the determined differences in the image property between the first image and the second image along the first direction;

determining a first angle of separation, along the first direction, between the first image plane and the second image plane using the first correlation loss data; and

outputting the first angle of separation.

2. The method of claim 1, wherein determining first correlation loss data comprises determining a first rate of correlation loss from the determined differences in the image property between the first image and the second image.

3. The method of claim 2, wherein determining the first angle of separation comprises determining the first angle of separation, along the first direction, between the first image plane and the second image plane using the first rate of correlation loss.

4. The method of claim 1, wherein determining the first correlation loss data comprises determining an initial value of the first correlation loss data.

5. The method of claim 4, wherein determining the first angle of separation comprises determining the angle of separation, along the first direction, using the initial value of the first correlation loss data.

6. The method of claim 1, wherein the image property comprises one or more of density, color, hue, saturation, or reflectivity.

7. The method of claim 1, further comprising

for each of a plurality of third data locations situated along a third line in the first image and a plurality of corresponding fourth data locations situated along a corresponding fourth line in the second image, determining differences in an image property between the third data locations in the first image and the corresponding fourth data locations in the second image along a second direction along the third and fourth lines, wherein the corresponding fourth line is a projection of the third line onto the second image;

determining second correlation loss data from the determined differences in the image property between the first image and the second image along the second direction;

determining a second angle of separation, along the second direction, between the first image plane and the second image plane using the second correlation loss data; and

outputting the second angle of separation.

8. A method of tracking a position of an imaging head of a catheter in three-dimensional space within a human body, the method comprising:

receiving a first image captured by the catheter, wherein the first image is in a first image plane;

receiving a second image captured by the catheter, wherein the second image is in a second image plane, wherein the first and second image planes are non-parallel to each other;

determining, for each of a plurality of first data locations in the first image, differences in an image property between the first data locations in the first image and the corresponding second data locations in the second image along a first direction, wherein the plurality of first data locations are situated along a first line in the first image and the corresponding second data locations are situated along a corresponding second line in the second image, wherein the corresponding second line is a projection of the first line onto the second image;

determining a first rate of correlation loss between the first and second images along the first direction using the determined differences in the image property between the first image and the second image;

determining a first angle of separation, along the first direction, between the first image plane and the second image plane using the first rate of correlation loss;

determining first position data for the second image, relative to the first image, using the first angle of separation; and

outputting the first position data.

9. The method of claim 8, further comprising

for each of a plurality of third data locations situated along a third line in the first image and a plurality of corresponding fourth data locations situated along a corresponding fourth line in the second image, determining differences in an image property between the third data locations in the first image and the corresponding fourth data locations in the second image along a second direction along the third and fourth lines, wherein the corresponding fourth line is a projection of the third line onto the second image;

determining a second rate of correlation loss between the first and second images along the second direction using the determined differences in the image property between the first image and the second image;

determining a second angle of separation, along the second direction, between the first image plane and the second image plane using the second rate of correlation loss;

determining second position data for the second image, relative to the first image, using the second angle of separation; and

outputting the second position data.

10. The method of claim 8, wherein the image property comprises one or more of density, color, hue, saturation, or reflectivity.

11. A non-transitory computer readable storage medium having processor-executable instructions, the processor-executable instructions when installed onto a system enable the system to perform actions, the actions comprising:

receiving a first image captured by a catheter, wherein the first image is in a first image plane;

receiving a second image captured by the catheter, wherein the second image is in a second image plane, wherein the first and second image planes are non-parallel to each other;

for each of a plurality of first data locations situated along a first line in the first image and a plurality of corresponding second data locations situated along a corresponding second line in the second image, determining differences in an image property between the first data locations in the first image and the corresponding second data locations in the second image along a first direction along the first and second lines, wherein the corresponding second line is a projection of the first line onto the second image;

determining first correlation loss data from the determined differences in the image property between the first image and the second image along the first direction;

determining a first angle of separation, along the first direction, between the first image plane and the second image plane using the first correlation loss data; and

outputting the first angle of separation.