Verification of positions in camera images

• US 6,724,922 B1
• Filed: 10/21/1999
• Issued: 04/20/2004
• Est. Priority Date: 10/22/1998
• Status: Expired due to Term

• Current Assignee: Brainlab AG
• Original Assignee: Brainlab AG
• Inventors: Vilsmeier, Stefan
• Primary Examiner(s): Ahmed, Samir
• Assistant Examiner(s): BHATNAGAR, ANAND P
• Application Number:
  US09/422,590
• Time in Patent Office: 1,643 Days
• Field of Search: 382/131, 382/154, 382/291, 348/47, 348/48, 378/41, 378/63, 600/310, 600/426
• US Class Current: 382/128
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/5247 combining images from an ionising-radiation diagnostic technique and a non-ionising radiation diagnostic technique, e.g. X-ray and ultrasound
• CPC Class Codes: A61N 2005/1059 using cameras imaging the patient
• CPC Class Codes: A61N 5/1049 for verifying the position of the patient with respect to the radiation beam
• CPC Class Codes: G01B 11/002 for measuring two or more coordinates

Abstract

The invention concerns a method for showing three-dimensionally defined fiducial points in a video camera image involving monitoring of a spatial region by at least two cameras which can map invisible light, especially infrared light, and by at least one video camera, computer-assisted analysis of the image data of the cameras, using the three-dimensional data obtained by means of the invisible-light cameras to compute the spatial location of objects located in the monitored spatial region as mapped by the invisible-light cameras, and displaying the fiducial points assigned to the objects together with the video image; the invention also relating to an apparatus for implementing the method or for visually verifying the correct position of an object.

Claims

1. A method for providing visual verification of mapped fiducial points on an object with the actual position of the fiducial points in a video image of the object, comprising:

monitoring a spatial region including the object by at least two cameras which can map invisible light;

monitoring the spatial region by at least one video camera that produces a video image of the spatial region including the object and in which the fiducial points on the object are visible;

computing the spatial location of the fiducial points on the object in said monitored spatial region as mapped by said invisible-light cameras; and

showing in overlapping relationship on a display the video image in which the fiducial points on the object are visible and also the fiducial points at their computed spatial locations in the same frame of reference as the video image shown on the display, thereby to enable visual verification of the computed spatial locations of the fiducial points with the positions of the fiducial points in the video image shown on the display.

2. The method of claim 1, comprising

introducing a calibration tool comprising landmarks, capable of being mapped by both said invisible-light cameras and by said video camera, into the spatial region monitored by said cameras;

computer-assisted assignment, by means of the three-dimensional data obtained by said invisible-light cameras, of the spatial location of said landmarks on said calibration tool in said video camera image relative to said position of landmarks on said calibration tool, thereby to establish a means by which fiducial points on the object can be related to spatial locations in the same frame of reference as the video image shown on the display; and

computing, on the basis of the computer-assisted assignment, the spatial coordinates of the fiducial points mapped by said invisible-light cameras in the said frame of reference and outputting said coordinates as fiducial points together with said video image on a display.

3. The method as set forth in claim 2, wherein two infrared cameras are used as the invisible-light cameras.

4. The method as set forth in claim 2, wherein said calibration tool, whose landmark array is memorized in said computer, is moved in said monitored spatial region until an output occurs computer-assisted indicating conclusion of calibration.

5. The method as set forth in claim 1, wherein said monitored spatial region is within an operating room.

6. The method as set forth in claim 1, wherein said fiducial points are patient landmarks.

7. The method as set forth in claim 1, wherein further object data is shown on the display along with said video image and the fiducial points at their computed spatial locations.

8. The method as set forth in claim 7, wherein said further object data includes parts of the body of a patient and/or contours and/or target volume of the patient for radiotherapy/surgery.

9. The method as set forth in claim 1, comprising applying the landmarks to the object.

10. The method as set forth in claim 1, further comprising the landmarks.

11. The method as set forth in claim 1, wherein said monitored spatial region is within a radiotherapeutical or radiosurgical operating room.

12. An apparatus for visually verifying mapped fiducial points on an object with the actual position of the fiducial points in a video image of the object, comprising:

at least two cameras which map invisible light, for monitoring a spatial region in which said object is located; and

at least one video camera monitoring the spatial region, for producing a video image of the spatial region including the object and in which the fiducial points on the object are visible;

a computer for computer-assisted mapping, by use of the invisible-light cameras, of the spatial location of the fiducial points on the object in said monitored spatial region into the same frame of reference as the video image when shown on a display; and

a display for showing in overlapping relationship the image of the video camera in which the fiducial points are visible and also the fiducial points at their computed spatial locations in the same frame of reference as the video image shown on the display, thereby to enable visual verification of the computed spatial locations of the fiducial points with the positions for the fiducial points in the video image shown on the display.

13. The apparatus as set forth in claim 12, further comprising the landmarks and a source of invisible light for illuminating said landmarks, and wherein said landmarks are reflectors that reflect the invisible light.

14. The apparatus as set forth in claim 12, wherein the invisible light cameras are infrared cameras.