Articulating surgical instruments

1. A surgical instrument comprising:

a handle;

an elongated shaft assembly extending distally from the handle, the elongated shaft assembly including an articulable portion movable between a non-articulated configuration and an articulated configuration, the elongated shaft assembly comprising:

a first shaft including an articulable portion having a first plurality of cuts spaced along a first length of at least a distal portion of the first shaft, wherein each cut of the first plurality of cuts extends partially around a circumference of the first shaft to define a first spine extending along the first length of the first shaft, the first spine having a first width at a distal end of the first spine and a second width greater than the first width at a proximal end of the first spine; and

a second shaft coaxially arranged relative to the first shaft, the second shaft including an articulable portion having a second plurality of cuts spaced along a second length of at least a distal portion of the second shaft, wherein each cut of the second plurality of cuts extends partially around a circumference of the second shaft to define a second spine extending along the second length of the second shaft, the second spine having a third width at a distal end of the second spine and a fourth width greater than the third width at a proximal end of the second spine, wherein the first shaft and the second shaft are axially fixed at a location located distally from the articulable portion of the elongated shaft assembly, wherein the first spine is located on a first side of the elongated shaft assembly, wherein the second spine is located on a second opposing side of the elongated shaft assembly and opposite from the first spine, and wherein proximal portions of the first and second shafts are displaceable in opposing directions to articulate the elongated shaft assembly; and

a driveshaft disposed within the first and second shafts, the driveshaft including a third plurality of cuts formed on the driveshaft, the third plurality of cuts spaced along at least a portion of a length of the driveshaft.

2. The surgical instrument of claim 1 , wherein the first and second spines are parallel to a longitudinal axis of the elongated shaft assembly.

3. The surgical instrument of claim 1 , wherein the first and second spines are curved along a length of the first and second shafts.

4. The surgical instrument of claim 1 , wherein a width of each cut of the second plurality of cuts is selected such that opposing edges of each cut of the second plurality of cuts come into contact when the elongated shaft assembly is in the articulated configuration.

5. The surgical instrument of claim 1 , wherein each cut of the third plurality of cuts forms at most one contact point with a cut of the first or second pluralities of cuts.

6. The surgical instrument of claim 5 , wherein a width of each cut of the third plurality of cuts is selected such that opposing edges of each cut of the third plurality of cuts do not come into contact when the elongated shaft assembly is in the articulated configuration.

7. The surgical instrument of claim 1 , wherein each cut of the first and second plurality of cuts has a width of between about 0.007 mm and about 0.018 mm.

8. The surgical instrument of claim 1 , wherein a spacing between each cut of the first and second plurality of cuts is between about 0.6 mm and about 1.4 mm.

9. The surgical instrument of claim 1 , wherein the first width is between 1.5 mm and about 2.2 mm and the second width is between about 3.5 mm and about 4.0 mm.

10. The surgical instrument of claim 1 , wherein the third width is between about 2.6 mm and about 3.0 mm and the fourth width is between about 4.3 mm and about 4.8 mm.

11. A method of operating a surgical instrument, the method comprising:

articulating an articulable portion of an elongated shaft assembly between a non-articulated configuration and an articulated configuration, the elongated shaft assembly comprising:

a first shaft including an articulable portion with a first spine, the first spine having a first width at a distal end of the first spine and a second width greater than the first width at a proximal end of the first spine; and

a second shaft coaxially arranged relative to the first shaft, the second shaft including an articulable portion having a second spine, the second spine having a third width at a distal end of the second spine and a fourth width greater than the third width at a proximal end of the second spine, wherein the first spine is located on a first side of the elongated shaft assembly, wherein the first shaft and the second shaft are axially fixed at a location located distally from the articulable portion of the elongated shaft assembly, wherein the second spine is located on a second opposing side of the elongated shaft assembly and opposite from the first spine, and wherein proximal portions of the first and second shafts are displaceable in opposing directions to articulate the elongated shaft assembly, and

actuating a driveshaft disposed within the first and second shafts, the driveshaft including a plurality of driveshaft cuts formed on the driveshaft, the plurality of driveshaft cuts spaced along at least a portion of a length of the driveshaft.

12. The method of claim 11 , wherein the first and second spines are parallel to a longitudinal axis of the elongated shaft assembly.

13. The method of claim 11 , wherein the first and second spines are curved along a length of the first and second shafts.

14. The method of claim 11 , wherein the first shaft includes a first plurality of cuts spaced along at least a distal portion of the first shaft, wherein each cut of the first plurality of cuts extends partially around a circumference of the first shaft to define the first spine, and wherein the second shaft includes a second plurality of cuts spaced along at least a distal portion of the second shaft, wherein each cut of the second plurality of cuts extends partially around a circumference of the second shaft to define the second spine.

15. The method of claim 14 , further comprising contacting opposing edges of the second plurality of cuts when the elongated shaft assembly is in the articulated configuration.

16. The method of claim 14 , further comprising: making at most one contact point between each cut of the plurality of driveshaft cuts and a cut of the first or second pluralities of cuts.

17. The method of claim 16 , further comprising preventing contact between opposing edges of each cut of the plurality of driveshaft cuts when the elongated shaft assembly is in the articulated configuration.

18. A surgical instrument comprising:

a handle;

an elongated shaft assembly extending distally from the handle, the elongated shaft assembly including an articulable portion movable between a non-articulated configuration and an articulated configuration, the elongated shaft assembly comprising:

a first shaft including an articulable portion with a first spine, wherein a width of the first spine increases in a proximal direction; and

a second shaft coaxially arranged relative to the first shaft, the second shaft including an articulable portion having a second spine, wherein a width of the second spine increases in the proximal direction, wherein the first spine is located on a first side of the elongated shaft assembly, wherein the first shaft and the second shaft are axially fixed at a location located distally from the articulable portion of the elongated shaft assembly, wherein the second spine is located on a second opposing side of the elongated shaft assembly and opposite from the first spine, and wherein proximal portions of the first and second shafts are displaceable in opposing directions to articulate the elongated shaft assembly; and

a driveshaft disposed within the first and second shafts, the driveshaft including a plurality of driveshaft cuts formed on the driveshaft, the plurality of driveshaft cuts spaced along at least a portion of a length of the driveshaft.

19. The surgical instrument of claim 18 , wherein the first and second spines are parallel to a longitudinal axis of the elongated shaft assembly.

20. The surgical instrument of claim 18 , wherein the first and second spines are curved along a length of the first and second shafts.

21. The surgical instrument of claim 18 , wherein the first shaft includes a first plurality of cuts spaced along at least a distal portion of the first shaft, wherein each cut of the first plurality of cuts extends partially around a circumference of the first shaft to define the first spine, and wherein the second shaft includes a second plurality of cuts spaced along at least a distal portion of the second shaft, wherein each cut of the second plurality of cuts extends partially around a circumference of the second shaft to define the second spine.

22. The surgical instrument of claim 21 , wherein a width of each cut of the second plurality of cuts is selected such that opposing edges of each cut of the second plurality of cuts come into contact when the elongated shaft assembly is in the articulated configuration.

23. The surgical instrument of claim 21 , wherein each cut of the plurality of driveshaft cuts forms at most one contact point with a cut of the first or second pluralities of cuts.

24. The surgical instrument of claim 23 , wherein a width of each cut of the plurality of driveshaft cuts is selected such that opposing edges of each cut of the plurality of driveshaft cuts do not come into contact when the elongated shaft assembly is in the articulated configuration.

25. The surgical instrument of claim 21 , wherein each cut of the first and second plurality of cuts has a width of between about 0.007 mm and about 0.018 mm.

26. The surgical instrument of claim 21 , wherein a spacing between each cut of the first and second plurality of cuts is between about 0.6 mm and about 1.4 mm.