Manufacture of steerable delivery devices
Steerable delivery devices use one or more pull wires. Described herein are devices and methods for securing a pull wire to an adjustment mechanism of such delivery devices. The disclosed devices facilitate securing the pull wire by using a wrapping set screw that forms a lumen for the pull wire and one or more notches in the side of the wrapping set screw at its proximal end. The notches allow the pull wire to be pulled through a notch so that when the wrapping set screw is driven into a threaded lumen the pull wire lies along the roots of the screw. The pull wire is secured in place due at least in part to friction and/or to being pressed between the screw and the threaded lumen of a wrap housing where the wrap housing can be part of the adjustment mechanism of the delivery device.
1 . An adjustment mechanism comprising:
a wrapping set screw having a threaded portion, the wrapping set screw forming a lumen for a pull wire, a notch at a proximal end of the wrapping set screw through which the pull wire can be pulled, and a socket for a driving tool at the proximal end of the wrapping set screw; and
a wire wrap housing having a wrapping set screw lumen that is at least partially threaded to receive the wrapping set screw, the pull wire secured in place based at least in part on the pull wire lying between threads of the wrapping set screw lumen and roots of the threaded portion of the wrapping set screw with the wrapping set screw at least partially driven into the wire wrap housing such that a portion of the pull wire between the roots of the wrapping set screw and the threads of the wrapping set screw lumen experiences a force from the threads of the wrapping set screw lumen to secure the pull wire in place.
2 . The adjustment mechanism of claim 1 wherein the wrapping set screw forms two or more notches.
3 . The adjustment mechanism of claim 1 wherein the wrapping set screw includes a head portion that forms the socket.
4 . The adjustment mechanism of claim 1 wherein the wire wrap housing further forms a catheter lumen that is larger than the wrapping set screw lumen, the catheter lumen configured to fit over a shaft of a steerable delivery device.
5 . The adjustment mechanism of claim 1 wherein the threaded portion of the wrapping set screw extends from a distal end of the wrapping set screw to the proximal end of the wrapping set screw.
6 . The adjustment mechanism of claim 1 wherein the notch extends distally from the proximal end of the wrapping set screw into the threaded portion of the wrapping set screw.
7 . The adjustment mechanism of claim 1 wherein the wrapping set screw lumen is formed with a first portion that is threaded and a second portion that has an inner radius that is less than an inner radius of the first portion.
8 . The adjustment mechanism of claim 1 wherein the socket comprises a hexagonal socket.
9 . The adjustment mechanism of claim 1 further comprising an alignment guide configured to aid in aligning the pull wire with the wire wrap housing and the wrapping set screw.
10 . The adjustment mechanism of claim 9 wherein the alignment guide comprises a threaded portion abutting the wire wrap housing.
11 . A steerable catheter including a shaft, a handle coupled to the shaft, and the adjustment mechanism of claim 1 coupled to the handle.
12 . A wrapping set screw for securing a pull wire to an adjustment mechanism of a steerable delivery device, the wrapping set screw comprising:
a proximal end and a distal end, with a lumen formed longitudinally between the proximal end and the distal end, the lumen configured to allow a pull wire to be passed therethrough;
a threaded portion extending proximally from the distal end;
a notch portion formed at the proximal end, the notch portion extending distally from the proximal end into the threaded portion; and
a socket portion formed by the proximal end, the socket portion configured to be compatible with a driving tool,
wherein the notch portion is configured to allow a pull wire to be bent out of the notch prior to the proximal end and wrapped within roots of the threaded portion such that driving the wrapping set screw into a threaded lumen compatible with the threaded portion exerts a force on the pull wire from threads of the threaded lumen and roots of the threaded portion to secure the pull wire in place.
13 . The wrapping set screw of claim 12 wherein the notch portion forms two notches.
14 . The wrapping set screw of claim 12 wherein the notch portion forms four notches.
15 . The wrapping set screw of claim 12 further comprising a head portion at the proximal end such that the head portion includes the socket portion.
16 . The wrapping set screw of claim 15 wherein the notch portion extends distally beyond the head portion.
17 . The wrapping set screw of claim 12 wherein the threaded portion extends from the distal end to the proximal end.
18 . The wrapping set screw of claim 12 wherein the threaded portion does not extend to the proximal end and the notch portion forms a notch that extends distally into the threaded portion.
19 . The wrapping set screw of claim 12 wherein the socket portion is configured to be compatible with a hex key.
20 . The wrapping set screw of claim 12 wherein the lumen extends from the distal end to a distal end of the socket portion formed by the proximal end.
21 . A method for anchoring a pull wire to an adjustment mechanism using a wrapping set screw, the method comprising:
guiding the pull wire through a threaded lumen of a wire wrap housing;
guiding the pull wire through a lumen of the wrapping set screw;
bending the pull wire through a notch at a proximal end of the wrapping set screw;
rotating the pull wire to lie along a root of a threaded portion of the wrapping set screw; and
driving the wrapping set screw into a threaded lumen of the wire wrap housing, wherein a portion of the pull wire lying along the root of the wrapping set screw is between the root of the wrapping set screw and a threaded portion of the threaded lumen such that the portion of the pull wire between the root of the wrapping set screw and the threaded portion of the threaded lumen experiences a force from the threaded portion of the threaded lumen to secure the pull wire in place.
22 . The method of claim 21 wherein driving the wrapping set screw includes rotating the wrapping set screw less than one time.
23 . The method of claim 21 wherein driving the wrapping set screw includes using a tool that fits within a socket formed at a proximal end of the wrapping set screw.
24 . The method of claim 23 wherein the tool includes a hex key.
25 . The method of claim 21 wherein the wrapping set screw includes a head portion that is unthreaded.
26 . The method of claim 21 wherein the wrapping set screw is threaded along its entire length.
27 . The method of claim 21 further comprising:
guiding a second pull wire through the threaded lumen of the wire wrap housing; and
guiding the second pull wire through the lumen of the wrapping set screw.
28 . The method of claim 27 further comprising bending the second pull wire through a second notch at the proximal end of the wrapping set screw.
29 . The method of claim 28 further comprising rotating the second pull wire to lie along the root of the wrapping set screw.
30 . The method of claim 29 wherein a portion of the second pull wire lying along the root of the wrapping set screw is within the threaded portion of the threaded lumen with the wrapping set screw driven into the threaded lumen of the wire wrap housing.
31 . The method of claim 27 further comprising bending the second pull wire through the notch at the proximal end of the wrapping set screw.