Curette with navigation sensor

1. An apparatus, comprising:

(a) a shaft assembly, wherein the shaft assembly defines a longitudinal axis;

(b) a rigid end effector defining a central axis perpendicular to the end effector statically coupled at a distal end of the shaft assembly, wherein the central axis of the end effector is oriented obliquely relative to the longitudinal axis of the shaft assembly; and

(c) a sensor having a position coaxially about the longitudinal axis of the shaft assembly, the position being a known distance from the end effector and having a known orientation relative to the end effector, wherein the sensor is configured to generate a signal in response to a magnetic field, wherein the signal is configured to indicate a position of the end effector within three-dimensional space based on the known distance and known orientation.

2. The apparatus of claim 1 , wherein the shaft assembly is straight.

3. The apparatus of claim 1 , wherein the shaft assembly is rigid.

4. The apparatus of claim 1 , wherein the shaft assembly defines a lumen.

5. The apparatus of claim 4 , wherein the lumen extends coaxially along the longitudinal axis.

6. The apparatus of claim 4 , further comprising a fluid source coupled with the lumen.

7. The apparatus of claim 6 , wherein the fluid source comprises one or both of a source of saline or a source of suction.

8. The apparatus of claim 4 , wherein the end effector defines an opening in communication with the lumen.

9. The apparatus of claim 8 , wherein the opening is positioned on the longitudinal axis.

10. The apparatus of claim 1 , wherein the central axis is oriented obliquely relative to the longitudinal axis.

11. The apparatus of claim 1 , further comprising a grip, wherein the shaft assembly extends distally from the grip.

12. The apparatus of claim 11 , wherein the shaft assembly defines a lumen, wherein the grip defines a lateral opening in fluid communication with the lumen.

13. The apparatus of claim 11 , further comprising a storage device.

14. The apparatus of claim 13 , wherein the storage device is located in the grip.

15. The apparatus of claim 13 , wherein the storage device stores calibration information associated with the sensor.

16. The apparatus of claim 1 , further comprising an insulating cuff captured between the sensor and a distal portion of the shaft assembly.

17. An apparatus, comprising:

(a) a grip;

(b) a shaft assembly extending distally from the grip, wherein the shaft assembly defines a longitudinal axis;

(c) a rigid end effector statically coupled at a distal end of the shaft assembly, wherein the end effector comprises a loop blade defining an opening having a central axis, wherein the central axis is obliquely offset from the longitudinal axis of the shaft assembly; and

(d) a sensor having a position coaxially about the longitudinal axis of the shaft assembly, the position being a known distance from the end effector and having a known orientation relative to the end effector, wherein the sensor is configured to generate a signal in response to a magnetic field, wherein the signal is configured to indicate a position of the loop blade within three-dimensional space based on the known distance and known orientation.

18. A method, comprising:

(a) inserting a rigid end effector of an instrument into a patient, the instrument including a shaft assembly defining a longitudinal axis, the rigid end effector being statically coupled at a distal end of the shaft assembly, the rigid end effector defining a central axis perpendicular to the end effector, the central axis being oriented obliquely relative to the longitudinal axis of the shaft assembly;

(b) observing a display showing a location of the rigid end effector of the instrument in the patient in real-time, wherein the display is driven by a processor processing signals generated from a sensor in the rigid end effector at a position coaxially about the longitudinal axis of the shaft assembly of the instrument, the position being a known distance from the rigid end effector and having a known orientation relative to the rigid end effector, wherein the sensor generates the signals in response to a magnetic field, and wherein the location is based on the known distance and known orientation; and

(c) engaging a transversely extending portion of the rigid end effector of the instrument with tissue in the patient based on the location, wherein the transversely extending portion of the rigid end effector is offset from the longitudinal axis.

19. The apparatus of claim 17 , wherein the shaft assembly defines a lumen.

20. The method of claim 18 , wherein the shaft assembly defines a lumen.