Navigational guidance via computer-assisted fluoroscopic imaging

• US 6,470,207 B1
• Filed: 03/23/1999
• Issued: 10/22/2002
• Est. Priority Date: 03/23/1999
• Status: Expired due to Term

• Current Assignee: Medtronic Navigation Incorporated (Medtronic Plc)
• Original Assignee: Surgical Navigation Technologies, Inc. (Medtronic Plc)
• Inventors: Foley, Kevin T., Simon, David A., Smith, Kurt R.
• Primary Examiner(s): Smith, Ruth S.
• Application Number:
  US09/274,972
• Time in Patent Office: 1,309 Days
• Field of Search: 600/425, 600/426, 600/427, 600/428, 378/16, 378/19, 378/20, 378/62, 378/96, 378/97, 378/108, 378/114, 378/117, 378/145, 378/205, 378/207, 250/370.08, 250/370.09, 250/370.1
• US Class Current: 600/426
• CPC Class Codes: A61B 2034/104 Modelling the effect of the tool, e.g. the effect of an implanted prosthesis or for predicting the effect of ablation or burring
• CPC Class Codes: A61B 2034/105 Modelling of the patient, e.g. for ligaments or bones
• CPC Class Codes: A61B 2034/107 Visualisation of planned trajectories or target regions
• CPC Class Codes: A61B 2034/108 Computer aided selection or customisation of medical implants or cutting guides
• CPC Class Codes: A61B 2034/2055 Optical tracking systems
• CPC Class Codes: A61B 2034/2072 Reference field transducer attached to an instrument or patient
• CPC Class Codes: A61B 2034/256 having a database of accessory information, e.g. including context sensitive help or scientific articles
• 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 6/12 Arrangements for detecting or locating foreign bodies
• CPC Class Codes: A61B 6/463 characterised by displaying multiple images or images and diagnostic data on one display
• CPC Class Codes: A61B 6/547 involving tracking of position of the device or parts of the device
• CPC Class Codes: A61M 2025/0166 Sensors, electrodes or the like for guiding the catheter to a target zone, e.g. image guided or magnetically guided
• CPC Class Codes: A61M 25/0105 Steering means as part of the catheter or advancing means; Markers for positioning systems for detection of markers A61B
• CPC Class Codes: G16H 40/63 for local operation
• CPC Class Codes: G16Z 99/00 Subject matter not provided for in other main groups of this subclass

Abstract

Digital x-ray images taken before a surgical procedure by a fluoroscopic C-arm imager are displayed by a computer and overlaid with graphical representations of instruments be used in the operating room. The graphical representations are updated in real-time to correspond to movement of the instruments in the operating room. A number of different techniques are described that aid the physician in planning and carrying out the surgical procedure.

Claims

1. An x-ray imaging device comprising:

an x-ray source for generating cycles of x-ray radiation corresponding to an image acquisition cycle;

an x-ray receiving section positioned so that x-rays emanating from the x-ray source enter the x-ray receiving section, the x-ray receiving section generating an image representing intensities of the x-rays entering the x-ray receiving section;

a computer coupled to the x-ray receiving section;

radiation sensors located in a path of x-rays emitted from the x-ray source, the radiation sensors detecting a beginning and an end of a radiation cycle and transmitting the detected beginning and end of the radiation cycle to the computer;

a dynamic reference frame marker attached in a fixed position relative to a patient;

a calibration and tracking target; and

a tracking sensor for detecting a position, in three-dimensional space, of the dynamic reference frame marker and the calibration and tracking target;

wherein

the computer determines that an image acquisition cycle is erroneous when the, position of the calibration and tracking target moves relative to the position of the dynamic reference frame during an image acquisition cycle.

2. The device of claim 1, wherein the computer further comprises a display for displaying the image generated by the x-ray receiving section.

3. The device of claim 1, wherein the calibration and tracking target includes calibration markers and the calibration and tracking target is attached to the imaging device.

4. The device of claim 1, wherein the calibration and tracking target is physically separated from the x-ray source and the x-ray receiving section and calibration markers included in the calibration and tracking target are in the path of x-rays of the generated cycles of x-ray radiation.

5. An x-ray imaging device comprising:

an x-ray source for generating cycles of x-ray radiation corresponding to an image acquisition cycle;

an x-ray receiving section positioned so that x-rays emanating from the x-ray source enter the x-ray receiving section, the x-ray receiving section generating an image representing intensities of the x-rays entering the x-ray receiving section;

a computer coupled to the x-ray receiving section;

radiation sensors located in a path of x-rays emitted from the x-ray source, the radiation sensors detecting a beginning and an end of a radiation cycle and transmitting the detected beginning and end of the radiation cycle to the computer; and

calibration markers for determining a projective transformation of the image.

6. The device of claim 5, wherein the calibration markers are used to correct image distortion.

7. An x-ray imaging device comprising:

a rotatable C-arm support having first and second ends,

an x-ray source positioned at the first end for initiating an imaging cycle by generating x-ray radiation;

an x-ray receiving section positioned at the second end so that x-rays emanating from the x-ray source enter the x-ray receiving section, the x-ray receiving section generating an image representing the intensities of the x-rays entering the x-ray receiving section;

a calibration and tracking target;

a tracking sensor for detecting a position, in three-dimensional space, of the calibration and tracking target;

a computer communicating with the x-ray receiving section and the tracking sensor, the computer detecting motion of the C-arm based on changes in the position detected by the tracking sensor;

a dynamic reference frame marker attached in a fixed position relative to a patient, the tracking sensor detecting the position, in three-dimensional space, of the dynamic reference frame marker; and

means for detecting a beginning and an end of an imaging cycle and transmitting indications of the detected beginning and end of the radiation cycle to the computer, and the computer determining that an image acquisition cycle is erroneous when the position of the tracking target moves with respect to the dynamic reference frame marker during the imaging cycle.

8. A surgical instrument navigation system comprising;

a computer processor;

a tracking sensor for sensing three-dimensional position information of a surgical instrument and transmitting the position information to the computer processor;

a memory coupled to the computer processor, the memory including computer instructions that when executed by the computer processor cause the processor to generate an icon representing the surgical instrument and to overlay the icon on a pre-acquired x-ray image, the icon of the surgical instrument representing the real-time position of the surgical instrument projected into the pre-acquired x-ray image and the icon being generated as a first representation when the surgical instrument is positioned such that it is substantially viewable in the plane of the pre-acquired image and the icon being automatically generated as a second representation when a distance in the pre-acquired image between a tip and tail of the surgical instrument becomes smaller than a pre-determined distance such that the surgical instrument is substantially perpendicular to the plane of the pre-acquired image; and

a display coupled to the processor for displaying the generated icon as one of either the first and second representations superimposed on the pre-acquired image.

9. The computer system of claim 8, wherein the icon is superimposed on multiple pre-acquired images.

10. The computer system of claim 8, wherein the second representation includes first and second cross-hair icons, the center of the first icon representing one end of the surgical instrument and the center of the second icon representing an opposite end of the surgical instrument.

11. A surgical instrument navigation system comprising:

a computer processor;

a tracking sensor for sensing three-dimensional position information of a surgical instrument and transmitting the position information to the computer processor;

a memory coupled to the computer processor, the memory including computer instructions that when executed by the computer processor cause the processor to generate an icon representing the surgical instrument positioned in a pre-acquired image of a patient'"'"'s anatomy, the icon of the surgical instrument including a first portion corresponding to an actual position of the surgical instrument and a second portion corresponding to a current projection of the surgical Instrument along a line given by a current trajectory of the surgical instrument where a length of the second portion is selectable by a user of the surgical instrument navigation system; and

a display coupled to the processor for displaying the generated icon superimposed on the pre-acquired image.

12. The computer system of claim 11, wherein the icon is superimposed on multiple pre-acquired images.

13. A surgical instrument navigation system comprising,

a rotatable C-arm including an x-ray source and an x-ray receiving section for acquiring x-ray images of a patient, the C-arm being rotatable about one of a plurality of mechanical axes;

a computer processor coupled to the rotatable C-arm;

a memory coupled to the computer processor, the memory storing the x-ray images acquired by the rotatable C-arm and computer instructions that when executed by the computer processor cause the computer processor to generate a line representing a projection of a plane substantially parallel to one of the plurality of the mechanical axes of the C-arm into the x-ray image, the line enabling visual alignment of the one of the plurality of mechanical axes of the C-arm with an axis relating complimentary x-ray images; and

a display coupled to the processor for displaying at least a portion of the generated line superimposed on the x-ray image, wherein the line displayed on the display enables visual alignment of the C-arm with the complimentary axis before the complimentary x-ray image is acquired.

14. The system of claim 13, further comprising:

a tracking target attached to the rotatable C-arm; and

a tracking sensor for detecting a position, in three-dimensional space, of the tracking target, wherein

the computer calculates an amount of rotation of the C-arm based on changes in the position detected by the tracking sensor.

15. A system for defining a surgical plan comprising:

an x-ray imaging device;

a surgical instrument;

a tracking sensor for detecting a position, in three-dimensional space, of the surgical Instrument;

a computer processor in communication with the tracking sensor for calculating a projection of a trajectory of the surgical instrument a distance ahead of an actual location of the surgical instrument; and

a display coupled to the processor for displaying a pre-acquired x-ray image overlaid with an iconic representation of the surgical instrument and a calculated projection of the trajectory of the surgical instrument, wherein a length of the projection of the surgical instrument changes based upon an input received by a user.

16. A method of defining a surgical plan comprising:

acquiring an image of a patient'"'"'s anatomy;

sensing three-dimensional position information of a surgical instrument;

generating a graphical icon representing the surgical instrument positioned in a pre-acquired image of the patient'"'"'s anatomy, the icon of the surgical instrument including a first portion corresponding to a position of the surgical instrument in space and a second portion corresponding to a current projection of the surgical instrument along a line given by a current trajectory of the surgical instrument;

selecting a length of the second portion corresponding to the current trajectory of the surgical instrument; and

displaying the generated icon superimposed on the pre-acquired image.

17. The method of claim 16, further comprising freezing at least the first or second portion of the iconic representation of the surgical instrument in the x-ray image.

18. The method of claim 16, wherein the icon is superimposed on multiple pre-acquired images.

19. A method of representing a real-time position of a surgical instrument in a pre-acquired x-ray image comprising:

generating an icon of a surgical instrument and overlaying the icon on the pre-acquired x-ray image, the icon of the surgical instrument representing the real-time position of the surgical instrument projected into the pre-acquired x-ray image;

representing the icon as a first representation when the surgical instrument is positioned such that it is substantially viewable in a plane of the pre-acquired image; and

automatically representing the icon as a second representation when a distance in the pre-acquired image between a tip and a tail of the surgical instrument becomes smaller than a pre-determined distance such that it is substantially perpendicular to, the plane of the pre-acquired image.

20. A method of detecting an error in an x-ray process comprising:

generating cycles of x-ray radiation corresponding to an image acquisition cycle, the cycles being generated by an x-ray imager and passing through calibration markers of a calibration and tracking target;

generating an image of a patient'"'"'s anatomy defined by intensities of the x-rays in the cycle of the x-ray radiation;

detecting a beginning and an end of a radiation cycle;

detecting a position of the calibration and tracking target and the patient; and

determining that the image acquisition cycle is erroneous when the position of the tracking target relative to the position of the patient moves between the beginning and the end of the radiation cycle.

21. A system of defining a surgical plan comprising:

means for sensing three-dimensional position information of a surgical instrument;

means for generating a graphical icon representing the surgical instrument positioned in a pre-acquired image of a patient'"'"'s anatomy, the icon of the surgical instrument including a first portion corresponding to a position of the surgical instrument in space and a second portion corresponding to a projection of the surgical instrument along a line given by a current trajectory of the surgical instrument;

means for selecting a length of the second portion corresponding to the current trajectory of the surgical instrument; and

means for displaying the generated icon superimposed on the pre-acquired image.

22. A system for representing a real-time position of a surgical instrument in a pre-acquired x-ray image comprising:

means for generating an icon of a surgical instrument and overlaying the icon on the pre-acquired x-ray image, the icon of the surgical instrument representing the real-time position of the surgical instrument projected into the pre-acquired x-ray image;

means for representing the icon as a first representation when the surgical instrument is positioned such that it is substantially viewable in a plane of the pre-acquired image; and

means for representing the icon as a second representation when a distance in the pre-acquired image between a tip and a tail of the surgical instrument becomes smaller than a predetermined distance such that it is substantially perpendicular to the plane of the pre-acquired image.

23. An x-ray imaging device comprising:

means for generating cycles of x-ray radiation corresponding to an image acquisition cycle;

means for generating an image representing intensities of the x-rays entering an x-ray receiving section;

means for detecting a beginning and an end of a radiation cycle and transmitting the detected beginning and end of the radiation cycle to a computer;

a dynamic reference frame marker attached in a fixed position relative to a patient;

a calibration and tracking target; and

a tracking sensor for detecting a position, in three-dimensional space, of the dynamic reference frame marker and the calibration and tracking target;

wherein

the computer determines that an image acquisition cycle is erroneous when the position of the calibration and tracking target moves relative to the position of the dynamic reference frame during an image acquisition cycle.