Methods of adjusting a virtual implant and related surgical navigation systems

1. A method of operating an image-guided surgical system using imaging information for a 3-dimensional anatomical volume, the method comprising:

detecting a pose of a probe based on information received from a tracking system, wherein the probe defines a longitudinal axis;

upon receiving an initial placement instruction from a user, determining an initial placement and a linear trajectory of a virtual implant for the 3-dimensional anatomical volume based on the pose of the probe and based on a non-zero offset from an end of the probe along the longitudinal axis, such that the linear trajectory of the virtual implant is in a geometric relationship with the longitudinal axis of the probe in the pose; and

after determining the initial placement of the virtual implant, adjusting the position of the virtual implant along the linear trajectory and only along the linear trajectory responsive to movement of the probe while proportionally maintaining the offset regardless of the movement of the probe.

2. The method of claim 1 further comprising:

providing first reformatted image data to be rendered on a display based on the imaging information and based on the placement of the virtual implant, the imaging information including 3-dimensional anatomical imaging information for the 3-dimensional anatomical volume; and

after providing the first reformatted image data, providing second reformatted image data to be rendered on the display based on adjusting the virtual implant.

3. The method of claim 2 , wherein adjusting comprises adjusting the virtual implant responsive to movement of the probe and responsive to user input separate from the movement of the probe while maintaining the trajectory of the virtual implant.

4. The method of claim 3 , wherein the user input is first user input, the method further comprising:

responsive to second user input separate from the movement of the probe, storing information regarding the virtual implant based on the trajectory of the virtual implant and based on the adjusting.

5. The method of claim 4 , further comprising:

controlling a robotic actuator to position an end-effector based on the information regarding the virtual implant.

6. The method of claim 1 , wherein adjusting the virtual implant comprises moving the placement of the virtual implant along the trajectory responsive to movement of the probe.

7. The method of claim 6 , wherein moving the virtual implant comprises moving the virtual implant along the trajectory responsive to detecting rotation of the probe about the longitudinal axis of the probe.

8. The method of claim 7 , wherein moving the virtual implant comprising moving the virtual implant in a first direction along the trajectory responsive to detecting rotation of the probe in a first rotational direction and moving the virtual implant in a second direction along the trajectory responsive to detecting rotation of the probe in a second rotational direction.

9. The method of claim 7 , wherein moving the virtual implant comprises moving the virtual implant along the trajectory responsive to detecting rotation of the probe about the longitudinal axis of the probe in a first direction and maintaining a position of the virtual implant responsive to detecting rotation of the probe about the longitudinal axis of the probe in a second direction different than the first direction.

10. The method of claim 6 , wherein moving the virtual implant comprises moving the virtual implant along the trajectory responsive to detecting movement of a tip of the probe in a direction that is nonparallel with respect to the trajectory of the virtual implant.

11. The method of claim 10 , wherein moving the virtual implant comprises moving the virtual implant in a first direction along the trajectory responsive to detecting movement of the tip of the probe away from the trajectory of the virtual implant and moving the virtual implant in a second direction along the trajectory responsive to detecting movement of the tip of the probe toward the trajectory.

12. The method of claim 6 , wherein moving the virtual implant comprises moving the virtual implant along the trajectory responsive to detecting movement of a tip of the probe around the trajectory of the virtual implant.

13. The method of claim 12 wherein moving the virtual implant comprises moving the virtual implant in a first direction along the trajectory responsive to detecting movement of the tip of the probe in a clockwise direction around the trajectory and moving the virtual implant in a second direction along the trajectory responsive to detecting movement of the tip of the probe in a counter clockwise direction around the trajectory.

14. The method of claim 12 , wherein a scale of movement of the virtual implant along the trajectory relative to movement of the tip is based on a distance of the tip from the trajectory.

15. The method of claim 1 , where adjusting the virtual implant comprises changing a size of the virtual implant responsive to movement of the probe while maintaining the trajectory of the virtual implant.

16. The method of claim 15 , wherein the virtual implant comprises a virtual screw and wherein adjusting the size comprises at least one of changing a length and/or changing a width of the virtual screw responsive to movement of the probe.

17. The method of claim 1 , wherein the probe comprises a plurality of spaced apart tracking markers, and wherein detecting the pose of the probe comprises detecting the pose based on the tracking system detecting the tracking markers.

18. A surgical navigation system using imaging information for a 3-dimensional anatomical volume, the surgical navigation system comprising:

a processor; and

memory coupled with the processor, wherein the memory comprises instructions stored therein, and wherein the instructions are executable by the processor to cause the processor to:

detect a pose of a probe based on information received from a tracking system, wherein the probe defines a longitudinal axis;

upon receipt of an initial placement instruction from a user, determine an initial placement and a linear trajectory of a virtual implant for the 3-dimensional anatomical volume based on the pose of the probe and based on a non-zero offset from an end of the probe along the longitudinal axis, such that the linear trajectory of the virtual implant is in alignment with the longitudinal axis of the probe in the pose; and

after determining the initial placement of the virtual implant, adjust the position of the virtual implant along the linear trajectory and only along the linear trajectory responsive to movement of the probe while proportionally maintaining the offset regardless of the movement of the probe.

19. The surgical navigation system of claim 18 , wherein the surgical navigation system is an image-guided surgical system and the imaging information is 3-dimensional anatomical imaging information, wherein the instructions are further executable by the processor for causing the processor to:

provide first reformatted image data to be rendered on a display based on the 3-dimensional anatomical imaging information and based on the placement of the virtual implant; and

after providing the first reformatted image data, provide second reformatted image data to be rendered on the display based on adjusting the virtual implant.

20. The surgical navigation system of claim 19 , wherein the instructions for causing the processor to adjust the virtual implant comprises causing the processor to adjust the virtual implant responsive to movement of the probe and responsive to user input separate from the movement of the probe while maintaining the trajectory of the virtual implant.