System and method for image based sensor calibration

• US 8,320,653 B2
• Filed: 11/08/2010
• Issued: 11/27/2012
• Est. Priority Date: 06/14/2000
• Status: Expired due to Term

• Current Assignee: Medtronic Navigation Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Navigation Incorporated (Medtronic Plc)
• Inventors: Holsing, Troy, Goodchild, Gordon
• Primary Examiner(s): TUCKER, WESLEY J
• Application Number:
  US12/941,537
• Publication Number:
  US 20110052008A1
• Time in Patent Office: 750 Days
• Field of Search: 382128-133
• US Class Current: 382/131
• CPC Class Codes: A61B 2017/00725 Calibration or performance testing
• CPC Class Codes: A61B 2090/378 using ultrasound
• CPC Class Codes: A61B 34/20 Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• CPC Class Codes: A61B 90/36 Image-producing devices or illumination devices not otherwise provided for
• CPC Class Codes: G06T 2207/30004 Biomedical image processing
• CPC Class Codes: G06T 7/70 Determining position or orientation of objects or cameras camera calibration G06T7/80
• CPC Class Codes: G06T 7/80 Analysis of captured images to determine intrinsic or extrinsic camera parameters, i.e. camera calibration

Abstract

Apparatus and methods are disclosed for the calibration of a tracked imaging probe for use in image-guided surgical systems. The invention uses actual image data collected from an easily constructed calibration jig to provide data for the calibration algorithm. The calibration algorithm analytically develops a geometric relationship between the probe and the image so objects appearing in the collected image can be accurately described with reference to the probe. The invention can be used with either two or three dimensional image data-sets. The invention also has the ability to automatically determine the image scale factor when two dimensional data-sets are used.

Claims

1. A method of determining a position of a detection plane relative to a detectable structure, the detectable structure including a first member that is parallel to a second member and a third member connected between the first member and the second member, all of the first member, the second member, and the third member having predefined locations in a first coordinate system defined by the detectable structure, wherein the third member is non-perpendicular to the first member and the second member, the method comprising:

generating the detection plane with an ultrasound probe;

determining positions of the third member relative to the first member and second member in a second coordinate system for each of a plurality of locations by executing instructions with a processor to evaluate collected position information of intersections through the detection plane of the first, second, and third members at each of the plurality of locations by impinging the detection plane that is in the second coordinate system on the detectable structure at each of the plurality of locations; and

determining, for the determined positions of the third member, a position of the third member in the first coordinate system at the intersection at each of the plurality of locations.

3. The method of claim 1, further comprising:

providing the first member, the second member, and the third member formed of a nylon and submerged in a medium that approximates ultrasound wave propagation in a selected volume.

5. The method of claim 1, further comprising:

providing the first member, the second member, and the third member formed of a material imageable by the ultrasound probe when impinged by the detection plane, wherein at least the third member is formed as a member that extends a length that is configured to be impinged at each of the plurality of locations.

6. The method of claim 1, wherein determining positions of the third member relative to the first member and second member in the second coordinate system for each of a plurality of locations further, includes:

determining a middle center of a middle image portion, wherein the middle center is a center of an image of the third member;

determining a first center of a first image portion, wherein the first center is a center of an image of the first member;

determining a second center of a second image portion, wherein the second center is a center of an image of the second member; and

by executing instructions with the processor, calculating a ratio of distance of the middle center between the first center and the second center;

wherein determining, for the determined positions of the third member, the position of the third member in the first coordinate system at the intersection at each of the plurality of locations includes, with the processor;

determining a Z-axis location of the middle center based on the calculated ratio; and

recalling the predefined locations of the first member, the second member, and the third member in the first coordinate system defined by the detectable structure; and

comparing the determined Z-axis location and the recalled predefined location.

7. The method of claim 6, wherein at least one of determining the middle center of a middle image portion, determining the first center of a first image portion, or determining the second center of a second image portion is performed automatically by executing instructions with the processor.

8. The method of claim 6, further comprising:

overcoming an elevation effect error of determining a location of an imaged member by the determining the middle center of a middle image portion, determining the first center of a first image portion, or determining the second center of a second image portion.

2. A method of determining a position of a detection plane relative to a detectable structure, the detectable structure including a first member that is parallel to a second member and a third member connected between the first member and the second member, all of the first member, the second member, and the third member having predefined locations in a first coordinate system defined by the detectable structure, wherein the third member is non-perpendicular to the first member and the second member, the method comprising:

determining positions of the third member relative to the first member and second member in a second coordinate system for each of a plurality of locations by executing instructions with a processor to evaluate collected position information of intersections through the detection plane of the first, second, and third members at each of the plurality of locations by impinging the detection plane that is in the second coordinate system on the detectable structure at each of the plurality of locations;

determining, for the determined positions of the third member, a position of the third member in the first coordinate system at the intersection at each of the plurality of locations;

transforming the determined positions of the third member from the first coordinate system for each of the plurality of locations into a third coordinate system;

calculating a relationship, for each of the plurality of locations, between the determined positions of the third member relative to the second coordinate system and the same third member relative to the third coordinate system; and

utilizing the relationship to describe the origin of the second coordinate system in terms of the third coordinate system.

4. A method of determining a position of a detection plane relative to a detectable structure, the detectable structure including a first member that is parallel to a second member and a third member connected between the first member and the second member, all of the first member, the second member, and the third member having predefined locations in a first coordinate system defined by the detectable structure, wherein the third member is non-perpendicular to the first member and the second member, the method comprising:

determining positions of the third member relative to the first member and second member in a second coordinate system for each of a plurality of locations by executing instructions with a processor to evaluate collected position information of intersections through the detection plane of the first, second, and third members at each of the plurality of locations by impinging the detection plane that is in the second coordinate system on the detectable structure at each of the plurality of locations;

determining, for the determined positions of the third member, a position of the third member in the first coordinate system at the intersection at each of the plurality of locations;

tracking the detectable structure with a tracking sensor; and

tracking the detection plane generated by an ultrasound probe with the tracking sensor;

wherein determining positions of the third member relative to the first member and second member in the second coordinate system includes the tracking the detectable structure and tracking the detection plane with the tracking sensor.

9. A method of determining a position of a detection plane relative to a detectable structure, the detectable structure including a first member that is parallel to a second member and a third member connected between the first member and the second member, all of the first member, the second member, and the third member having predefined locations in a detectable structure coordinate system defined by the detectable structure, wherein the third member is non-perpendicular to the first member and the second member, the method comprising:

storing the predefined locations of the first member, the second member, and the third member in a storage system;

tracking the detectable structure with a tracking system;

tracking a probe generating the detection plane with the tracking system;

determining a position of the third member relative to the first member and second member in an image coordinate system of a plurality of locations of the detection plane by executing instructions with a processor to evaluate collected position information of intersections through the detection plane of the first, second, and third members at each location of the plurality of locations;

determining, for the determined positions of the third member, a position of the third member in the detectable structure coordinate system at the intersection at each of the plurality of locations; and

transforming the detectable structure coordinate system to a probe coordinate system based on a determined probe calibration point and a determined detectable structure calibration point and on the tracking the detectable structure, recalling the stored predefined locations of the first member, the second member, and the third member, and tracking the probe with the tracking system.

10. The method of claim 9, further comprising:

generating the detection plane; and

moving the detection plane relative to the detectable structure to the plurality of locations to impinge the detection plane on the first member, the second member, and the third member;

wherein the position information is collected by impinging the detection plane that is in the image coordinate system on the detectable structure at each of the plurality of locations.

11. The method of claim 9, further comprising:

determining the probe calibration point; and

determining the detectable structure calibration point.

12. The method of claim 9, further comprising:

acquiring an image of at least the third member at the detection plane with the probe; and

determining an image calibration point in the image by determining at least a middle center of an image portion of the third member.

13. The method of claim 9, further comprising:

calibrating the probe coordinate system to the image coordinate system by;

determining an image calibration point identical to the probe calibration point; and

executing instructions with the processor to translate the probe calibration point to the image calibration point.

14. The method of claim 13, wherein executing instructions with the processor to translate the probe calibration point to the image calibration point further includes translating image space points in the image coordinate system to probe space points in the probe coordinate system.

15. A method of determining a position of a detection plane relative to a detectable structure, the detectable structure including a first member that is parallel to a second member and a third member connected between the first member and the second member, all of the first member, the second member, and the third member having predefined locations in a detectable structure coordinate system defined by the detectable structure, wherein the third member is non-perpendicular to the first member and the second member, the method comprising:

storing the predefined locations of the first member, the second member, and the third member in a storage system;

accessing a plurality of images, wherein each image of the plurality of images is acquired with a probe at least at one location of a plurality of locations of the detection plane relative to the detectable structure, wherein at least each of the plurality of images defines an image coordinate system;

collecting position information of intersections through the detection plane of the first member, the second, and the third member at each location of the plurality of locations of the detection plane;

determining a position of the third member relative to the first member and second member in a probe coordinate system for each location of the plurality of locations of the detection plane by executing instructions with a processor to evaluate the collected position information of intersections through the detection plane; and

determining, for the determined positions of the third member, a position of the third member in the detectable structure coordinate system at the intersection at each of the plurality of locations.

16. The method of claim 15, further comprising:

tracking a location of the probe with a tracking system; and

tracking a location of the detectable structure with the tracking system.

17. The method of claim 16, further comprising:

determining a first center of a first image portion in each image of the plurality of images, wherein the first center is a center in each image of the first member;

determining a second center of a second image portion in each image of the plurality of images, wherein the second center is a center in each image of the second member; and

determining a third center of a third image portion in each image of the plurality of images, wherein the third center is a center in each image of the third member.

18. The method of claim 17, further comprising:

transforming the probe coordinate system and the detectable structure coordinated system based on the tracked location of the probe and the tracked location of the detectable structure and the determined position of the third member in both the probe coordinate system and the detectable structure coordinate system;

wherein determining the position of the third member relative to the first member and second member in a probe coordinate system for each location of the plurality of locations the detection plane by executing instructions with a processor to evaluate the collected position information of intersections through the detection plane includes determining a distance ratio of the determined third center between the determined first center and the determined second center; and

wherein determining, for the determined positions of the third members, the position of the third member in the detectable structure coordinate system at the intersection at each of the plurality of locations includes recalling the stored predefined locations of the first member, the second member, and the third member from the storage system.