Controlled steering functionality for implant-delivery tool
An apparatus can include: (1) a steerable tube, having a proximal section, a distal section, and a central longitudinal axis, the tube defining a primary lumen and two secondary lumens; (2) two wires, each extending from the distal section proximally through a respective secondary lumen; (3) a handle, coupled to the proximal section, and including a steering knob that is coupled to the wires such that rotation of the knob adjusts a degree of tension in the wires; (4) a pull ring coupled to the distal section of the tube such that the pull ring circumscribes the longitudinal axis at the distal section of the tube, and defining two recesses, a distal end portion of each wire being disposed in a respective one of the recesses; and (5) at least one cap, bridging the recesses and the distal end portion of the wires. Other embodiments are also described.
1. Apparatus for percutaneous access to a body of a patient, comprising:
a steerable tube, having a proximal section including a proximal end, a distal section including a distal end, and a central longitudinal axis between the proximal end and the distal end, the tube being shaped to define:
a primary lumen between the proximal end and the distal end, and defining a central axis of the steerable tube, and
two secondary lumens, each of the secondary lumens extending longitudinally from the proximal section to the distal section;
two wires, each of the wires extending from the distal section proximally through a respective one of the secondary lumens;
a handle, coupled to the proximal section of the tube, and comprising a steering knob that is coupled to the wires such that rotation of the knob adjusts a degree of tension in the wires;
a pull ring:
coupled to the distal section of the tube such that the pull ring circumscribes the longitudinal axis at the distal section of the tube, and
defining two recesses, each of the recesses disposed laterally from the central axis and aligned parallel with the central axis, and having a floor, a distal end portion of each wire being disposed in a respective one of the recesses; and
two caps, each of the caps bridging a respective one of the recesses and the distal end portion of a respective one of the wires, wherein the distal end portion of the respective one of the wires is:
aligned parallel with the central axis, and
sandwiched between the respective one of the caps and the floor of the respective one of the recesses.
2. The apparatus according to claim 1 , wherein the pull ring has a length along the longitudinal axis of 2.5-2.6 mm.
3. The apparatus according to claim 1 , wherein the tube has an inner diameter of 6.5-7 mm and an outer diameter of 7-9 mm.
4. The apparatus according to claim 1 , wherein the tube has an inner diameter of 4.7-5.3 mm and an outer diameter of 6.3-6.9 mm.
5. The apparatus according to claim 1 , wherein the tube has a length of 700-1200 mm.
6. The apparatus according to claim 1 , wherein the tube has a length 1000-1500 mm.
7. The apparatus according to claim 1 , wherein the secondary lumens are spaced from each other by 180 degrees around the primary lumen.
8. The apparatus according to claim 1 , wherein the distal end portion of each wire is welded to the pull ring.
9. The apparatus according to claim 1 , wherein each of the caps is welded to the pull ring.
10. The apparatus according to claim 1 , wherein each of the caps is welded to the respective one of the wires.
11. The apparatus according to claim 1 , further comprising an implant, advanceable though the primary lumen of the tube.
12. The apparatus according to claim 1 , wherein the tube comprises a friction-reducing liner that lines the secondary lumens.
13. The apparatus according to claim 12 , wherein the friction-reducing liner comprises polytetrafluoroethylene.
14. The apparatus according to claim 1 , wherein the distal section has a durometer of 45D-63D.
15. The apparatus according to claim 14 , wherein the distal section has a length of 4-5 mm.
16. The apparatus according to claim 14 , wherein the distal section has a length of 3.5-4.5 mm.
17. The apparatus according to claim 14 , wherein the tube has a bending section proximal to the distal section, the bending section having a lower durometer than the distal section.
18. The apparatus according to claim 17 , wherein the bending section has a durometer of 25-45D.
19. The apparatus according to claim 17 , wherein the bending section has a length of 22-27 mm.
20. The apparatus according to claim 17 , wherein the bending section has a length of 60-70 mm.
21. The apparatus according to claim 17 , wherein the tube has a transition section longitudinally between the distal section and the bending section, the transition section having a durometer of 63D-72D.
22. The apparatus according to claim 21 , wherein the transition section has a length of 1-2 mm.
23. The apparatus according to claim 21 , wherein the transition section is immediately proximal to the distal section, and immediately distal to the bending section.
24. The apparatus according to claim 21 , wherein, proximal to the bending section, the tube has a uniform durometer section having a durometer of 63-72D.
25. The apparatus according to claim 24 , wherein the uniform durometer section has a length of 770-860 mm.
26. The apparatus according to claim 24 , wherein the uniform durometer section has a length of 900-1400 mm.
27. The apparatus according to claim 1 , wherein each of the wires has a distal tip that is disposed distally beyond the respective one of the caps.