Deflectable insertion tool

1. An insertion instrument, comprising:

a tube having a proximal end, and a distal end adapted for insertion;

a tip control actuator located at the proximal end;

the distal end of the tube including a flexible portion and comprising

a spine,

a plurality of circumferentially extending ribs extending from the spine and being axially spaced apart from a distal tip toward the proximal end, the ribs being spaced apart by wedge shaped partial circumferential openings,

the ribs have first and second axial sides defined by the wedge-shaped openings, with the first axial side of one of the ribs facing the second axial side of an adjacent one of the ribs,

for each of the ribs, at least one of the first or second axial sides including at least one of an axially extending projection or a recess and facing one of the at least one of the first or second axial sides of an adjacent one of the ribs including at least one of a complementary mating recess or a corresponding axial projection, wherein at least one of the recesses and/or complementary mating recesses in the plurality of ribs includes a curved path, and at least one of the axially extending projections and/or corresponding axial projections in the plurality of ribs includes a curved shape complementary to the curved path, wherein said curved path and said curved shape approximate a bend radius of the flexible portion of the tube when flexed;

at least one tension wire extending from the tip control actuator to the distal tip

wherein upon application of a tension force on the tension wire, the distal tip being deflectable from an unbent state in which the distal tip remains aligned with an axis of the insertion instrument, to an intermediate state in which the distal tip is aligned at an angle to the axis and at least some spaces remain between at least some of the first and second axial sides of the ribs, to a fully deflected state in which the first and second axial sides of the ribs contact one another; and

wherein in each of the intermediate state and the fully deflected state, at least some of the axial projections are circumferentially braced against sides of the corresponding complementary mating recesses and/or the corresponding axial projections are circumferentially braced against sides of the recesses to maintain a rigidity of the distal tip relative to a normally applied force on the distal tip.

2. The insertion instrument of claim 1 , wherein the tip control actuator comprises a rotatable grip.

3. The insertion instrument of claim 1 , wherein the tube comprises a guide tube connected to an end tube, with the end tube forming the distal end of the tube and including the flexible portion.

4. The insertion instrument of claim 3 , wherein the end tube is formed of a super elastic material.

5. The insertion instrument of claim 1 , wherein the end tube is made of Nitinol and has a wall thickness of about 0.4-0.6 mm, and a diameter of about 3.2-3.6 mm.

6. The insertion instrument of claim 1 , wherein the axially extending projections and corresponding complementary mating recesses and/or the recesses and the corresponding axial projections in the plurality of ribs are arranged in at least one axially extending row.

7. The insertion instrument of claim 6 , wherein there are at least two rows of the axially extending projections and corresponding complementary mating recesses and/or the recesses and the corresponding axial projections.

8. The insertion instrument of claim 6 , wherein there are three of the axially extending rows of the axially extending projections and corresponding complementary mating recesses and/or the recesses and the corresponding axial projections on the distal end of the tube, with a first one of the rows being located approximately 80-100 degrees from the spine, a second one of the rows being located approximately 170-190 degrees from the spine, and a third one of the rows being located approximately 260-280 degrees from the spine.

9. The insertion instrument of claim 8 , wherein the recesses and/or corresponding complementary mating recesses of the second row extend along a straight axial path and the respective projections or the corresponding axial projections have a complementary shape.

10. The insertion instrument of claim 1 , wherein a clearance in a circumferential direction between axial projections and corresponding complementary mating recesses and/or the recesses and the corresponding axial projections is 0.1-0.4 mm.

11. The insertion instrument of claim 1 , further comprising at least one opening in the distal tip to connect the tension wire.

12. The insertion instrument of claim 1 , further comprising at least one of a complementary projection or a mating recess located in the distal tip facing the first axial side of an adjacent one of the ribs.

13. The insertion instrument of claim 1 , wherein at least some of the axial projections are at least partially located in the corresponding complementary mating recesses or the corresponding axial projections are at least partially located in the recesses, or both, in an unbent state of the distal end of the tube.

14. The insertion instrument of claim 1 , wherein a widest part of the wedge-shaped openings is located circumferentially opposite to the spine.

15. The insertion instrument of claim 1 , wherein at least some of the wedge-shaped openings have different shapes to provide a variable bend profile.

16. The insertion instrument of claim 1 , further comprising at least one of a complementary projection or recess in a part of the tube facing the second axial side of a proximal-most one of the ribs.

17. The insertion instrument of claim 1 , wherein the tip control actuator comprises a rotatable grip having an internal thread, the rotatable grip being axially fixed but rotatable on the tube, a sleeve with an external thread, the sleeve is slideable on the tube and the external thread is engaged with the internal thread of the rotatable grip, the sleeve further including an axially extending slot, and a projection connected to the tube that extends into the slot that prevents rotation of the sleeve, and the at least one tension wire is connected to the sleeve.

18. The insertion instrument of claim 1 , wherein at least some of the ribs have different axial widths.

19. The insertion instrument of claim 1 , wherein in each of the intermediate state and the fully deflected state, at least some of the axial projections are circumferentially braced against sides of the corresponding complementary mating recesses and the corresponding axial projections are circumferentially braced against sides of the recesses to maintain a rigidity of the distal tip relative to a normally applied force on the distal tip.