SYSTEM AND METHOD FOR AUTOMATICALLY DETERMINING CALIBRATION PARAMETERS OF A FLUOROSCOPE

• US 20140221824A1
• Filed: 07/23/2012
• Published: 08/07/2014
• Est. Priority Date: 07/23/2011
• Status: Active Grant

• Current Assignee: Broncus Medical Incorporated
• Original Assignee: Broncus Medical Incorporated
• Inventors: Rai, Lav, Wibowo, Henky
• Granted Patent: US 9,693,748 B2
• Time in Patent Office: Days
• US Class Current: 600/424
• CPC Class Codes: A61B 2017/00725 Calibration or performance testing
• CPC Class Codes: A61B 2034/2055 Optical tracking systems
• CPC Class Codes: A61B 2090/363 Use of fiducial points
• CPC Class Codes: A61B 2090/376 using X-rays, e.g. fluoroscopy
• CPC Class Codes: A61B 2090/3966 Radiopaque markers visible in an X-ray image
• CPC Class Codes: A61B 2090/3983 Reference marker arrangements for use with image guided surgery
• 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 6/12 Arrangements for detecting or locating foreign bodies
• CPC Class Codes: A61B 6/485 involving fluorescence X-ray imaging
• CPC Class Codes: A61B 6/487 involving fluoroscopy
• CPC Class Codes: A61B 6/582 Calibration
• CPC Class Codes: A61B 6/584 determining position of components of the apparatus or device using images of the phantom
• CPC Class Codes: A61B 90/39 Markers, e.g. radio-opaque or breast lesions markers

Abstract

A method and system for estimating calibration parameters of a medical fluoroscope and more particularly a method and system which automatically determines intrinsic and distortion correction parameters of a fluoroscopy device.

Claims

1. A method for determining calibration parameters of a medical fluoroscopic device, said method comprising the steps of:

a) providing a calibration device comprising at least one reference marker visible under fluoroscopy;

b) determining the pose of the calibration device with a tracking device and a plate tool rigidly connected to the calibration device, said plate tool being sensed by said tracking device;

c) calculating pose of said reference marker based on said pose of the calibration device and the pose of the fluoroscopic device;

d) receiving a 2D image of calibration device using the fluoroscopic device; and

e) calculating at least one calibration parameter of the fluoroscopic device based on image information from said 2D image and said pose of said reference marker.

2. The method of claim 1 wherein said pose of the fluoroscopic device is based on sensing a pose of the fluoroscopic device with said tracking device.

3. The method of claim 1 wherein the at least on calibration parameters are selected from the group consisting of dx, dy, theta, tx, ty, focal length, and distortion.

4. The method of claim 1 wherein the plate tool comprises a plurality of arms each having a different length.

5. The method of claim 1 wherein the calibration device is a planar circular shaped plastic plate.

6. The method of claim 5 wherein the reference markers of the calibration plate are a plurality of metal beads.

7. A system for calibrating a medical fluoroscopic device comprises:

a computer workstation comprising a processor, memory, and a input device;

a tracking device;

a calibration plate having at least one reference marker visible under the fluoroscopic device; and

a plate tool in fixed engagement with the calibration device and comprising a plurality of locators visible with said tracking device, and wherein the processor being operable to calculate a pose of said reference marker based on said position of the calibration device and the pose of the fluoroscopic device;

to receive a 2D image of the calibration device using the fluoroscopic device; and

to calculate at least one calibration parameter of fluoroscopic device based on image information from said 2D image and said pose of said reference marker.

8. The system of claim 7 wherein the processor is operable to calculate at least on calibration parameters selected from the group consisting of dx, dy, theta, tx, ty, focal length, and distortion.

9. The system of claim 7 wherein the plate tool comprises a plurality of arms each having a different length.

10. The system of claim 7 wherein the calibration device is a planar circular shape

11. The system of claim 10 wherein the calibration device comprises a plastic plate.

12. The system of claim 11 wherein the reference markers of the calibration plate are a plurality of metal beads.

13. A calibration assembly comprising a calibration plate, a plurality of fixed reference markers visible under a fluoroscope or x-ray device, and a plate tool in a known rigidly fixed engagement to said calibration plate wherein said plate tool includes a plurality of infrared visible locators.

14. The calibration assembly of claim 13 wherein said plate is comprised of polymer and said reference markers include at least three metal beads.

15. The calibration assembly of claim 13 wherein said plate tool is in the shape of a cross comprising at least four arms, each having a different length.