Multi-sensor distortion mapping method and system

• US 20080079421A1
• Filed: 08/15/2006
• Published: 04/03/2008
• Est. Priority Date: 08/15/2006
• Status: Active Grant

• Current Assignee: Northern Digital Inc. (Roper Technologies, Inc.)
• Original Assignee: General Electric Company
• Inventors: Jensen, Vernon Thomas
• Granted Patent: US 8,040,127 B2
• Time in Patent Office: Days
• US Class Current: 324/207.17
• CPC Class Codes: A61B 2017/00725 Calibration or performance testing
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• CPC Class Codes: A61B 2090/376 using X-rays, e.g. fluoroscopy
• 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 6/4441 the rigid structure being a C-arm or U-arm
• CPC Class Codes: A61B 6/487 involving fluoroscopy
• CPC Class Codes: A61B 6/582 Calibration
• CPC Class Codes: A61B 90/36 Image-producing devices or illumination devices not otherwise provided for

Abstract

In one aspect of the present technique, an array of electromagnetic sensors is positioned within a volume of interest. In the presence of an electromagnetic field, the array of electromagnetic sensors is sampled to acquire signals representative of the location of the electromagnetic sensors in the array. The electromagnetic field distortion within the volume of interest is determined based on the acquired signals. In another aspect of the present technique, a system for detecting electromagnetic field distortions includes an electromagnetic sensor assembly for positioning within a volume of interest, a plurality of electromagnetic sensors for transmitting or receiving signals representative of the location of the electromagnetic sensors on the sensor assembly; and a tracker. In another aspect of the present technique, an electromagnetic sensor assembly for detecting electromagnetic field distortion includes a body, and an array of electromagnetic sensors positioned on the body.

Claims

1. A method for determining electromagnetic field distortion, comprising:

positioning an array of electromagnetic sensors in a volume of interest;

sampling the array of electromagnetic sensors, in the presence of an electromagnetic field, to acquire signals representative of locations of the electromagnetic sensors in the array; and

determining an electromagnetic field distortion within the volume of interest based on the acquired signals.

2. The method of claim 1, comprising determining a measured location for each of the electromagnetic sensors in the array based on the acquired signals.

3. The method of claim 2, comprising evaluating the measured locations of the electromagnetic sensors to determine established locations of a portion of the electromagnetic sensors.

4. The method of claim 3, comprising determining established locations of the remaining electromagnetic sensors based on the established locations of the portion of the electromagnetic sensors.

5. The method of claim 4, comprising comparing the measured locations of the remaining sensors to the established locations of the remaining sensors.

6. The method of claim 5, wherein determining the electromagnetic field distortion is based on the comparison of the measured locations of the remaining sensors to the established locations of the remaining sensors.

7. The method of claim 1, wherein the array of electromagnetic sensors is repeatedly sampled as the sensor assembly is continuously moved through the volume of interest.

8. The method of claim 1, comprising moving one or more field distorting objects away from the volume of interest based on the determined electromagnetic field distortion.

9. The method of claim 1, comprising creating a distortion map of the volume of interest based on the determined electromagnetic field distortion.

10. The method of claim 1, comprising calibrating a tracking system based on the determined electromagnetic field distortion so the tracking system can account for the determined electromagnetic field distortion.

11. A system for detecting electromagnetic field distortions, comprising:

an electromagnetic sensor assembly for positioning within a volume of interest, the electromagnetic sensor assembly comprising a body, and an array of electromagnetic sensors positioned on one or more surfaces of the body;

a plurality of electromagnetic sensors for transmitting or receiving signals representative of the location of the electromagnetic sensors in the array; and

a tracker configured to acquire the signals representative of the location of the electromagnetic sensors in the array, and determine electromagnetic field distortion within the volume of interest based on the signals.

12. The system of claim 11, wherein the electromagnetic sensors in the array are configured to transmit electromagnetic signals.

13. The system of claim 11, wherein the plurality of electromagnetic sensors are fixed in relation to an X-ray fluoroscopy system.

14. An electromagnetic sensor assembly for detecting electromagnetic field distortion, comprising a body, and an array of electromagnetic sensors positioned on one or more surfaces of the body.

15. The electromagnetic sensor assembly of claim 14, wherein the array of electromagnetic sensors comprises a linear array, a two-dimensional array, or a three-dimensional array.

16. The electromagnetic sensor assembly of claim 14, wherein the body has a generally rod-like shape, and the array comprises a linear array of electromagnetic sensors positioned on the body.

17. The electromagnetic sensor assembly of claim 14, wherein the array of electromagnetic sensors comprises a plurality of two-dimensional arrays of electromagnetic sensors positioned on a plurality of sides of the body.

18. The electromagnetic sensor assembly of claim 14, wherein the electromagnetic sensors in the array are configured to transmit electromagnetic signals.

19. The electromagnetic sensor assembly of claim 14, comprising a multiplexer coupled to the body.

20. The electromagnetic sensor assembly of claim 14, comprising a handle assembly coupled to the body for enabling handling of the electromagnetic sensor assembly.