Position tracking and imaging system for use in medical applications

• US 6,341,231 B1
• Filed: 10/11/2000
• Issued: 01/22/2002
• Est. Priority Date: 09/15/1994
• Status: Expired due to Fees

• Current Assignee: GE Medical Systems Global Technology Company LLC (GE Healthcare Technologies, Inc.)
• Original Assignee: Visualization Technology, Inc.
• Inventors: Ferre, Maurice R., Tieman, James S., Jakab, Peter D.
• Primary Examiner(s): Casler, Brian L.
• Application Number:
  US09/686,188
• Time in Patent Office: 468 Days
• Field of Search: 600/424, 600/407, 600/415, 600/417, 606/130, 128/897, 128/898
• US Class Current: 600/424
• CPC Class Codes: A61B 2017/00022 Sensing or detecting at the treatment site
• CPC Class Codes: A61B 2017/00464 for use with different instruments with hole for different instruments A61B2017/22072
• CPC Class Codes: A61B 2017/00477 Coupling A61B2017/0046 takes precedence
• CPC Class Codes: A61B 2017/00482 with a code
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• CPC Class Codes: A61B 2034/2055 Optical tracking systems
• CPC Class Codes: A61B 2034/2068 using pointers, e.g. pointers having reference marks for determining coordinates of body points
• CPC Class Codes: A61B 2034/2072 Reference field transducer attached to an instrument or patient
• CPC Class Codes: A61B 2090/0818 Redundant systems, e.g. using two independent measuring systems and comparing the signals
• CPC Class Codes: A61B 2090/363 Use of fiducial points
• CPC Class Codes: A61B 2090/3937 Visible markers
• 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 5/06 Devices, other than using radiation, for detecting or locating foreign bodies for removing same A61B17/50 ; determining position of probes within or on the body of the patient
• CPC Class Codes: A61B 5/062 using magnetic field
• CPC Class Codes: A61B 5/064 using markers A61B5/062 takes precedence
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/037 Emission tomography
• CPC Class Codes: A61B 90/10 for stereotaxic surgery, e.g. frame-based stereotaxis
• CPC Class Codes: A61B 90/14 Fixators for body parts, e.g. skull clamps; Constructional details of fixators, e.g. pins
• CPC Class Codes: A61B 90/36 : Image-producing devices or illumination devices not otherwise provided for
• CPC Class Codes: A61B 90/361 : Image-producing devices, e.g. surgical cameras
• CPC Class Codes: A61B 90/39 : Markers, e.g. radio-opaque or breast lesions markers
• CPC Class Codes: A61B 90/98 : using electromagnetic means, e.g. transponders
• CPC Class Codes: G01B 7/004 : for measuring coordinates of points
• CPC Class Codes: G06T 3/14 : Transformations for image registration, e.g. adjusting or mapping for alignment of images

Abstract

A system is disclosed for monitoring the position of a medical instrument with respect to a patient'"'"'s body and for displaying at least one of a plurality of prerecorded images of said body responsive to the position of said medical instrument. In one embodiment the system includes a reference unit secured from movement with respect to the patient'"'"'s body such that said reference unit is substantially immobile with respect to a target operation site. The system also includes a remote unit for attachment to the medical instrument. A field generator may be associated with one of the units for generating a position characteristic field in an area including the target operation site. One or more field sensors may be associated with either of the units responsive to the presence of the position characteristic field for producing one or more sensor output signals representative of said sensed field. A position detector in communication with the sensor output signal produces position data representative of the position of the remote unit with respect to the reference unit. An output display in communication with the position detector displays at least one of the prerecorded images responsive to the position data.

Claims

1. A computerized method for registering the orientation of a patient in a surgical environment with the orientation of scan images of said patient, said method comprising:

securing a body attachment unit including a plurality of fiducial elements to said patient'"'"'s body;

locating positions of said fiducial elements on said scan images;

evaluating relative distances between each of said fiducial elements on said scan images, and producing a matrix of said distances;

determining an optimal correlation between a matrix of prerecorded distances between said fiducial elements on said body attachment unit and said matrix of said distances; and

generating an equation that transforms position data with respect to said patient into position data with respect to said scan images.

2. A method as claimed in claim 1, further comprising producing said scan images using computerized tomography.

3. A method as claimed in claim 1, further comprising prerecording said scan images prior to surgery.

4. A method as claimed in claim 1, wherein the step of securing includes securing a body attachment unit including a plurality of fiducial elements comprising radiopaque elements.

5. A method as claimed in claim 1, wherein the step of locating positions comprises filtering image picture elements representing said fiducial elements from image picture elements not representing said fiducial elements.

6. A computerized method for registering the orientation of a patient in a surgical environment with the orientation of scan images of said patient, said method comprising:

securing a body attachment unit including a plurality of fiducial elements to said patient'"'"'s body, said plurality of fiducial elements being mutually spaced from one another by prearranged known distances;

locating positions of said fiducial elements on said scan images;

determining relative distances between each of said fiducial elements on said scan images;

correlating said relative distances with said prearranged known distances between said fiducial elements; and

producing an output signal that is representative of the correlation of said relative distances and said known distances.

7. A method as claimed in claim 6, further comprising producing said scan images using computerized tomography.

8. A method as claimed in claim 6, further comprising prerecording said scan images prior to surgery.

9. A method as claimed in claim 6, wherein the step of securing includes securing a body attachment unit including a plurality of fiducial elements comprising radiopaque elements.

10. A method as claimed in claim 6, wherein the step of producing an output signal includes comparing a correlation value with a threshold value.

11. A method as claimed in claim 10, wherein said step of comparing includes producing an error signal if said correlation value exceeds said threshold value.

12. A method as claimed in claim 6, wherein said step of locating positions includes evaluating image brightness of various areas of the scan images.

13. A computerized method for registering the orientation of a patient in a surgical environment with the orientation of scan images of said patient, said method comprising:

securing a body attachment unit to said patient'"'"'s body;

locating a plurality of fiducial locations on said body attachment unit that appear on said scan images;

determining a relative geometry defined by said plurality of fiducial locations on said scan images;

correlating said relative geometry with a known geometry of said plurality of fiducial locations; and

producing an output signal that is representative of the correlation of said relative geometry and said known geometry.

14. A method as claimed in claim 13, further comprising producing said scan images using computerized tomography.

15. A method as claimed in claim 13, further comprising prerecording said scan images prior to surgery.

16. A method as claimed in claim 13, wherein said step of producing an output signal includes comparing a correlation value with a threshold value.

17. A method as claimed in claim 16, wherein said step of comparing includes producing an error signal if said correlation value exceeds said threshold value.

18. A method as claimed in claim 13, further comprising generating an equation that transforms position data with respect to said patient into position data with respect to said scan images.