Surgical cannulas and related systems and methods of identifying surgical cannulas

1. A method comprising:

sensing magnet presence information and magnet orientation information for each magnet position of a plurality of magnet positions on a cannula mounted to a manipulator arm of a surgical system, the manipulator arm configured to manipulate movement of a surgical instrument mounted at the manipulator arm and the cannula configured to receive the surgical instrument in a mounted state at the manipulator arm,

the magnet presence information indicating a presence or absence of a magnet at the magnet position, and

the magnet orientation information indicating an orientation of a magnet present at the magnet position; and

automatically determining identification information about the cannula based on a combination of the magnet presence information and the magnet orientation information for all magnet positions of the plurality of magnet positions.

2. The method of claim 1 , wherein:

each magnet position of the plurality of magnet positions has a corresponding dedicated sensor of a plurality of sensors; and

sensing magnet presence information for each magnet position of the plurality of magnet positions comprises using each corresponding dedicated sensor of the plurality of sensors to sense magnetic field strength.

3. The method of claim 2 , wherein:

sensing magnet presence information indicating presence of a magnet comprises sensing the magnetic field strength exceeding a threshold; and

sensing magnet presence information indicating absence of a magnet comprises sensing magnetic field strength not exceeding a threshold.

4. The method of claim 2 , wherein:

each magnet position of the plurality of magnet positions has a corresponding dedicated sensor of a second plurality of sensors; and

sensing magnet orientation information for each magnet position of the plurality of magnet positions comprises using each corresponding dedicated sensor of the second plurality of sensors to sense magnetic field orientation.

5. The method of claim 2 , wherein:

sensing magnet orientation information comprises using the plurality of sensors to sense magnetic field orientation.

6. The method of claim 2 , wherein:

the plurality of sensors and the plurality of magnet positions are arranged such that in a state of the cannula mounted to the surgical system each magnet position of the plurality of magnet positions is in sensing proximity to its corresponding dedicated sensor.

7. The method of claim 6 , wherein:

the plurality of magnet positions is arranged in a first planar array at the cannula;

the plurality of sensors is arranged in a second planar array at the surgical system; and

the second planar array is complementary to the first planar array.

8. The method of claim 2 , wherein:

the plurality of sensors comprises one or more omni-polar magnetic sensors.

9. The method of claim 1 , wherein:

all magnet positions of the plurality of magnet positions have a corresponding dedicated sensor group of a plurality of sensor groups; and

sensing magnet presence information for each magnet position of the plurality of magnet positions comprises using each corresponding dedicated sensor group of the plurality of sensor groups to sense magnetic field strength.

10. The method of claim 9 , wherein:

sensing magnet orientation information comprises using the plurality of sensor groups to sense magnetic field orientation.

11. The method of claim 10 , wherein:

each sensor group of the plurality of sensor groups comprises one or more presence sensors to detect magnetic field strength and one or more orientation sensors to detect magnetic field orientation.

12. The method of claim 10 , wherein:

each sensor group of the plurality of sensor groups comprises a first orientation sensor to sense a first magnetic field having a first orientation and a second orientation sensor to sense a second magnetic field having a second orientation.

13. The method of claim 10 , wherein:

one or more sensor groups of the plurality of sensor groups comprises a single sensor to detect both magnetic field strength and magnetic field orientation.

14. The method of claim 9 , wherein:

the plurality of sensor groups and the plurality of magnet positions are arranged on the surgical system such that in a state of the cannula mounted to the surgical system each magnet position of the plurality of magnet positions is in sensing proximity to its corresponding dedicated sensor group.

15. The method of claim 14 , wherein:

the plurality of magnet positions is arranged in a first planar array at the cannula;

the plurality of sensor groups is arranged in a second planar array at the surgical system; and

the second planar array is complementary to the first planar array.

16. The method of claim 9 , wherein:

one or more sensor groups of the plurality of sensor groups comprises an omni-polar magnetic sensor.

17. The method of claim 1 , wherein:

the method further comprises automatically assigning a first value, a second value, or a third value for each magnet position of the plurality of magnet positions based on the sensing;

the first value corresponds to a magnet with a first orientation being present at the magnet position;

the second value corresponds to a magnet with a second orientation being present at the magnet position; and

the third value corresponds to absence of a magnet at the magnet position.

18. The method of claim 17 , wherein:

a combination of the first, second, and third values assigned for all magnet positions of the plurality of magnet positions encodes an identifier of the cannula; and

automatically determining the identification information about the cannula comprises determining the identifier.

19. The method of claim 18 , wherein:

automatically determining the identification information about the cannula further comprises searching a storage medium for property information associated with a plurality of types of cannula based on the identifier.

20. The method of claim 19 , wherein:

the property information comprises one or more of cannula type, cannula shape, cannula length, cannula diameter, and cannula material.

21. The method of claim 1 , wherein:

the identification information about the cannula comprises at least one of a cannula type, a cannula shape, a cannula length, a cannula diameter, and a cannula material.

22. The method of claim 1 , wherein:

the method further comprises automatically determining a mismatch in response to the identification information not matching expected identification information.

23. The method of claim 22 , wherein:

the method further comprises providing feedback to a user of the surgical system in response to the mismatch.

24. The method of claim 23 , wherein:

the method further comprises preventing use of the manipulator arm of the surgical system in response to determining the mismatch.

25. A method comprising:

sensing magnet presence information and magnet orientation information for each magnet position of a plurality of magnet positions on a cannula mounted to a surgical system,

the magnet presence information indicating a presence or absence of a magnet at the magnet position, and

the magnet orientation information indicating an orientation of a magnet present at the magnet position; and

automatically determining identification information about the cannula based on a combination of the magnet presence information and the magnet orientation information for all magnet positions of the plurality of magnet positions;

wherein each magnet position of the plurality of magnet positions has a corresponding dedicated sensor of a plurality of sensors; and

sensing magnet orientation information for each magnet position of the plurality of magnet positions comprises using each corresponding dedicated sensor of the plurality of sensors to sense an angle between a predetermined reference direction and a magnetic field orientation.