Controlled steering functionality for implant-delivery tool

1. Apparatus for percutaneous access to a body of a patient, comprising:

a first steerable tube shaped to define a first lumen, and a first coupling at a longitudinal site of the first steerable tube;

a second steerable tube, shaped to define a second lumen and a second coupling, the second coupling being intracorporeally couplable to the first coupling;

a first handle, coupled to a proximal portion of the first steerable tube;

a second handle, coupled to a proximal portion of the second steerable tube; and

an extracorporeal locking system comprising:

a third coupling coupled to a handle selected from the group consisting of: the first handle and the second handle, and defining a locking location, and

a fourth coupling coupled to another handle selected from the group consisting of: the first handle and the second handle, the fourth coupling being:

configured to engage the third coupling,

movable toward the locking location while engaged to the third coupling,

coupled to the other handle such that movement of the other handle that moves the fourth coupling toward the locking location also brings the second coupling closer to the first coupling, and

configured to lock to the third coupling,

the apparatus having:

an unlocked state in which at least the second coupling is disposed within the first lumen, and the second steerable tube is rotatable within the first lumen, and

a locked state in which the second coupling is locked to the first coupling, the locking of the second coupling to the first coupling inhibiting rotation of the second steerable tube within the first lumen, and

the apparatus being configured such that:

the second coupling is advanceable through the first lumen until at least the longitudinal site,

the apparatus remains in the unlocked state when the second coupling is disposed within the first lumen, proximal to the longitudinal site, and

when (i) the second coupling is disposed at the longitudinal site and (ii) the second steerable tube is in a given rotational orientation within the first lumen, the apparatus moves into the locked state by the second coupling automatically coupling to the first coupling.

2. The apparatus according to claim 1 , wherein the fourth coupling defines an extracorporeal indicator, and is coupled to the second steerable tube such that the extracorporeal indicator (i) moves, both longitudinally and rotationally, in correspondence with the second coupling, and (ii) provides an indication of an intracorporeal position of the second coupling with respect to the first steerable tube.

3. The apparatus according to claim 1 , wherein the third coupling defines the locking location, such that when the third coupling enters the locking location, the fourth coupling automatically locks to the third coupling.

4. The apparatus according to claim 3 , wherein the third coupling comprises a locking element, configured to inhibit movement of the fourth coupling out of the locking location.

5. The apparatus according to claim 1 , wherein the third coupling defines an access location, and the fourth coupling is:

configured to initially engage the third coupling via the access location, and

movable toward the locking location while engaged to the third coupling, by moving away from the access location.

6. The apparatus according to claim 5 , wherein the fourth coupling is coupled to the other handle such that introduction of the fourth coupling into the access location places the second coupling at the longitudinal site.

7. The apparatus according to claim 6 , wherein the fourth coupling is coupled to the other handle such that introduction of the fourth coupling into the access location places the second coupling at the longitudinal site, rotationally-offset with respect to the first coupling.

8. The apparatus according to claim 5 , wherein the fourth coupling is shaped to define a protrusion, and the third coupling comprises a housing that is shaped to define the access location, the locking location, and a groove therebetween, and wherein the first and second handles and the third and fourth couplings are arranged such that the protrusion moves along the groove away from the access location and toward the locking location in response to movement of the second handle with respect to the first handle.

9. The apparatus according to claim 8 , wherein the groove is curved.

10. The apparatus according to claim 5 , wherein the first and second handles and the third and fourth couplings are arranged such that the fourth coupling is:

introducible into the access location of the third coupling, by moving the second handle distally toward the first handle, and

subsequently, movable toward the locking location while engaged with the third coupling, by rotating the second handle with respect to the first handle.

11. The apparatus according to claim 1 , wherein the apparatus is configured such that, while the second coupling is disposed at the longitudinal site, movement of the second steerable tube into a given rotational orientation within the first lumen moves the apparatus into the locked state by the second coupling automatically coupling to the first coupling.

12. The apparatus according to claim 1 , wherein the fourth coupling is coupled to the other handle such that while (i) the apparatus is not in the locked state, and (ii) the fourth coupling is engaged with the third coupling, movement of the second handle that moves the fourth coupling into the locking location causes locking of the second coupling to the first coupling.

13. The apparatus according to claim 1 , wherein, when the apparatus is in the locked state, the second coupling is longitudinally slidable with respect to the first coupling.

14. The apparatus according to claim 13 , wherein the first steerable tube is shaped to define the first coupling as a slit having a length along a longitudinal axis of the first steerable tube, and the second coupling comprises a depressible engager, configured to protrude within the slit, and having a length along a longitudinal axis of the second steerable tube that is shorter than the length of the slit.

15. The apparatus according to claim 13 , wherein the second steerable tube has a distal steering portion, and when the apparatus is in the locked state, at least part of the distal steering portion is exposed from a distal end of the first steerable tube, the exposed part having an exposed length, and the slidability of the second coupling with respect to the first coupling facilitating the exposed length being variable.

16. The apparatus according to claim 13 , wherein the first steerable tube is shaped to define the first coupling as a slit having a length along a longitudinal axis of the first steerable tube, and the second coupling comprises a depressible engager, configured to protrude within the slit, and having a length along a longitudinal axis of the second steerable tube that is shorter than the length of the slit.

17. The apparatus according to claim 13 , wherein the second steerable tube has a distal steering portion, and when the apparatus is in the locked state, at least part of the distal steering portion is exposed from a distal end of the first steerable tube, the exposed part having an exposed length, and the slidability of the second coupling with respect to the first coupling facilitating the exposed length being variable.

18. A method for percutaneous access to a body of a patient, the method comprising:

providing:

a first steerable tube having a proximal end and a distal end, and defining a first lumen therebetween and a first coupling at a longitudinal site of the first steerable tube,

a second steerable tube having a proximal end and a distal end, and defining a second lumen therebetween and a second coupling;

a third coupling, coupled to the first steerable tube proximal from the first coupling; and

a fourth coupling, coupled to the second steerable tube proximal from the second coupling,

transluminally advancing the first steerable tube into the body such that at least the first coupling is disposed inside the body;

subsequently, advancing the second steerable tube through the first steerable tube such that (i) the second coupling becomes disposed at the longitudinal site while rotationally offset with respect to the first coupling, and (ii) the third coupling becomes engaged with the fourth coupling; and

subsequently, coupling the second coupling to the first coupling by rotating the second steerable tube with respect to the first steerable tube until the second coupling becomes rotationally aligned with respect to the first coupling.

19. The method according to claim 18 , wherein advancing the second steerable tube such that the third coupling becomes engaged with the fourth coupling comprises advancing the second steerable tube such that the third coupling becomes engaged with the fourth coupling extracorporeally.

20. The method according to claim 19 , wherein coupling the second coupling to the first coupling comprises coupling the second coupling to the first coupling by locking the fourth coupling to the third coupling.

21. The method according to claim 20 , wherein the third coupling defines an access location and a locking location, engaging the third coupling with the fourth coupling comprises introducing the fourth coupling into the access location, and locking the fourth coupling to the third coupling comprises moving the fourth coupling from the access location into the locking location.

22. The method according to claim 18 , wherein advancing the second steerable tube comprises exposing the distal end of the second steerable tube out of the distal end of the first steerable tube, and wherein coupling the second coupling to the first coupling comprises coupling the second coupling to the first coupling subsequently to the distal end of the second steerable tube becoming exposed from the distal end of the first steerable tube.

23. Apparatus for percutaneous access to a body of a patient, comprising:

a first steerable tube, having a proximal end and a distal end, and shaped to define:

a first lumen between the proximal end and the distal end, and

a first coupling at a longitudinal site of the first steerable tube;

a second steerable tube, shaped to define a second lumen and a second coupling, the second coupling being intracorporeally couplable to the first coupling;

a first handle, coupled to the first steerable tube;

a second handle, coupled to the second steerable tube; and

an extracorporeal locking system comprising:

a third coupling couplable to a handle selected from the group consisting of: the first handle and the second handle, and

a fourth coupling couplable to another handle selected from the group consisting of: the first handle and the second handle, and configured to be locked to the third coupling,

the apparatus having:

an unlocked state in which at least the second coupling is disposed within the first lumen, and the second steerable tube is rotatable within the first lumen, and

a locked state in which the second coupling is coupled to the first coupling, the coupling of the second coupling to the first coupling inhibiting rotation of the second steerable tube within the first lumen, and the apparatus being configured such that:

the second coupling is advanceable through the first lumen until at least the longitudinal site,

the apparatus remains in the unlocked state when the second coupling is disposed within the first lumen, proximal to the longitudinal site,

when the second coupling becomes disposed at the longitudinal site in a given rotational orientation of the second steerable tube within the first lumen, the apparatus moves into the locked state by the second coupling automatically coupling to the first coupling, and

while the apparatus is not in the locked state, locking of the fourth coupling to the third coupling automatically places the second coupling in the given rotational orientation.

24. The apparatus according to claim 23 , wherein the fourth coupling defines an extracorporeal indicator, and is coupled to the second steerable tube such that the extracorporeal indicator (i) moves, both longitudinally and rotationally, in correspondence with the second coupling, and (ii) provides an indication of an intracorporeal position of the second coupling with respect to the first steerable tube.

25. The apparatus according to claim 23 , wherein, when the apparatus is in the locked state, the second coupling is longitudinally slidable with respect to the first coupling.