Instrument for endoscopic applications

1. A bendable instrument comprising:

an inner cylindrical element, an outer cylindrical element and an intermediate cylindrical element in between said inner and outer cylindrical elements;

the intermediate cylindrical element having a handling end portion and an actuating end portion opposite the handling end portion, the handling end portion having a first cylindrical part and a first flexible portion, and the intermediate cylindrical element having a plurality of strips connected to said first cylindrical part such that longitudinal movement of said strips relative to one another results in bending of the handling end portion at said first flexible portion, the strips being separated by longitudinal slits in said intermediate cylindrical element;

the inner cylindrical element having a first inner cylindrical element flexible portion aligned with said first flexible portion of said intermediate cylindrical element;

the outer cylindrical element having a first outer cylindrical element flexible portion aligned with said first flexible portion of said intermediate cylindrical element,

wherein the instrument is configured in at least one of the following ways:

said first inner cylindrical element flexible portion comprises at least one first slit in said inner cylindrical element, and

said first outer cylindrical element flexible portion comprises at least one second slit in said outer cylindrical element.

2. The instrument according to claim 1 , wherein the at least one first or second slit extends in helical manner.

3. The instrument according to claim 1 , wherein the at least one first or second slit comprises a plurality of groups of slits, each group located on a tangential line perpendicular to an axis of the instrument, with slits in neighbouring groups being offset to each other.

4. The instrument according to claim 1 , wherein the at least one first or second slit comprises a plurality of slits shaped and spaced to produce a number of swallow's tails fitting into each other.

5. The instrument according to claim 1 , wherein the strips in a first zone adjacent the handling end portion are located in a first cylindrical plane with a first diameter, and in a second zone adjacent to the actuating end portion are located in a second cylindrical plane with a second different diameter.

6. The instrument according to claim 5 , wherein the first diameter is smaller than the second diameter.

7. The instrument according to claim 1 , wherein the instrument has an intermediate portion between the handling end portion and the actuating end portion, said intermediate portion comprising at least one additional flexible portion.

8. The instrument according to claim 1 , wherein said inner cylindrical element flexible portion and outer cylindrical element flexible portion are made by one or more of laser cutting, photochemical etching, deep pressing, chipping, and high pressure water jet cutting.

9. The instrument according to claim 1 , wherein said longitudinal slits in said intermediate cylindrical element are made by one or more of laser cutting, photochemical etching, deep pressing, chipping, and high pressure water jet cutting.

10. The instrument according to claim 1 , wherein said actuating end portion has a second cylindrical portion, said strips also being connected to said second cylindrical portion.

11. The instrument according to claim 10 , wherein the actuating end portion has a second flexible portion, the inner cylindrical element having a second inner cylindrical element flexible portion aligned with said second flexible portion of said intermediate cylindrical element, and the outer cylindrical element having a second outer cylindrical element flexible portion aligned with said second flexible portion of said intermediate cylindrical element,

wherein the instrument is configured in at least one of the following ways:

said second inner cylindrical element flexible portion comprises at least one third slit in said inner cylindrical element, and

said second outer cylindrical element flexible portion comprises at least one fourth slit in said outer cylindrical element.

12. The instrument according to claim 1 , wherein the intermediate cylindrical element comprises at least three strips.

13. A bendable instrument comprising:

an inner cylindrical element, an outer cylindrical element and an intermediate cylindrical element in between said inner and outer cylindrical elements;

the intermediate cylindrical element having a handling end portion and an actuating end portion opposite the handling end portion, the handling end portion having a first cylindrical part and a first flexible portion, and the intermediate cylindrical element having a number of strips connected to said first cylindrical part such that longitudinal movement of said strips relative to one another results in bending of the handling end portion at said first flexible portion, the strips being separated by longitudinal slits in said intermediate cylindrical element; and

at least one of a pair of neighbouring strips is provided with spacer elements located in said slit and extending from one of the neighbouring strips at least partially in a circumferential direction toward the other one of the pair of neighbouring strips.

14. The instrument according to claim 13 , wherein the spacer elements almost bridge completely said slit or contact the other one of the pair of neighbouring strips.

15. The instrument according to claim 13 , wherein the spacer elements are at least one of cam shaped and trapezium shaped.

16. The instrument according to claim 13 , wherein said one of said pair of neighbouring strips is provided with spacer elements extending in a first circumferential direction and with spacer elements extending in a second circumferential direction opposite to said first circumferential direction.

17. The instrument according to claim 13 , wherein the spacer elements are only present in parts of the strips which are coinciding with the flexible portions of the instrument.

18. The instrument according to claim 13 , wherein the inner cylindrical element has a first inner cylindrical element flexible portion aligned with said first flexible portion of said intermediate cylindrical element.

19. The instrument according to claim 13 , wherein the outer cylindrical element has a first outer cylindrical element flexible portion aligned with said first flexible portion of said intermediate cylindrical element.

20. The instrument according to claim 13 , wherein the inner cylindrical element has a first inner cylindrical element flexible portion aligned with said first flexible portion of said intermediate cylindrical element; and

the outer cylindrical element has a first outer cylindrical element flexible portion aligned with said first flexible portion of said intermediate cylindrical element; and

wherein the first inner cylindrical element flexible portion and/or the first outer cylindrical element flexible portion comprises at least one slit.

21. The instrument according to claim 20 , wherein the at least one slit extends in a helical manner.

22. The instrument according to claim 20 , wherein the at least one slit comprises a plurality of groups of slits, each group located on a single tangential line perpendicular to an axis of the instrument, with slits in neighbouring groups being offset to each other.

23. The instrument according to claim 20 , wherein the at least one slit comprises a plurality of slits shaped and spaced to produce a number of swallow's tails fitting into each other.

24. The instrument according to claim 13 , wherein the strips in a first zone adjacent the handling end portion are located in a first cylindrical plane with a first diameter, and in a second zone adjacent to the actuating end portion are located in a second cylindrical plane with a second different diameter.

25. The instrument according to claim 24 , wherein the first diameter is smaller than the second diameter.

26. The instrument according to claim 13 , wherein the instrument has an intermediate portion between the handling end portion and the actuating end portion, said intermediate portion comprising at least one additional flexible portion.

27. The instrument according to claim 13 , wherein said inner cylindrical element flexible portion and outer cylindrical element flexible portion are made by at least one of laser cutting, photochemical etching, deep pressing, chipping, and high pressure water jet cutting.

28. The instrument according to claim 13 , wherein said longitudinal slits in said intermediate cylindrical element are made by at least one of laser cutting, photochemical etching, deep pressing, chipping, and high pressure water jet cutting.

29. The instrument according to claim 13 , wherein said actuating end portion has a second cylindrical portion, said strips also being connected to said second cylindrical portion.

30. The instrument according to claim 13 , wherein the actuating end portion has a second flexible portion, the inner cylindrical element having a second inner cylindrical element flexible portion aligned with said second flexible portion of said intermediate cylindrical element, and the outer cylindrical element having a second outer cylindrical element flexible portion aligned with said second flexible portion of said intermediate cylindrical element,

wherein said second inner cylindrical element flexible portion, and/or

said second outer cylindrical element flexible portion comprises at least one slit.

31. The instrument according to claim 13 , wherein the intermediate cylindrical element comprises at least three strips.