Introducer with steerable distal tip section

Abstract

An introducer with a steerable distal tip section is disclosed. The steerable distal tip section may comprise an articulation support member comprising a laser-cut pattern of symmetrical elongated apertures in which the shape of each aperture is defined by at least three radii, a central radii being the largest and two end radii being smaller. This pattern of apertures can minimize ovaling of the cross-sectional shape of introducer shaft over the length of the deflectable section. The introducer can articulate in multiple planes. A tension pull wire can allow the introducer to resist directional bias.

What is claimed is: 
     
         1 . A steerable introducer comprising
 a shaft comprising a proximal end portion and a distal end portion; and   a steerable distal tip section attached to the distal end portion of the shaft, the steerable distal tip section comprising an articulation support member comprising a plurality of elongated apertures arranged in a pattern;   wherein each pair of adjacent apertures defines a rib therebetween;   wherein a shape of each aperture of the plurality of apertures comprises a first arc defining a central section of the aperture, a second arc defining an outboard section of the aperture, and a third arc defining an inboard section of the aperture between the first arc and the second arc;   wherein the first arc has a first radius, the second arc has a second radius, and the third arc has a third radius, the first radius being greater than the third radius, and the third radius being greater than the second radius; and   wherein, when the introducer is steered to a maximum angle of deflection, and the steerable distal tip section defines a curve portion comprising an inner surface and an outer surface, contact between the ribs is maximized along the inner surface.   
     
     
         2 . The steerable introducer of  claim 1 , wherein the pattern of one or more elongated apertures comprises a plurality of laser-cuts within the articulation support member. 
     
     
         3 . The steerable introducer of  claim 1 , wherein the articulation support member comprises stainless steel. 
     
     
         4 . The steerable introducer of  claim 1 , wherein the shape of each aperture comprises n number of arcs, wherein n is equal to or greater than 3, and wherein n is an odd number. 
     
     
         5 . The steerable introducer of  claim 1 , wherein the shape of each aperture is symmetrical about at least one axis. 
     
     
         6 . The steerable introducer of  claim 1 , wherein a cross-sectional area of the steerable distal tip section is maintained during deflection. 
     
     
         7 . The steerable introducer of  claim 1 , wherein the first radius is about 1-3 inches, the second radius is about 0.002-0.009 inches, and the third radius is about 0.1-0.5 inches. 
     
     
         8 . The steerable introducer of  claim 1 , wherein when the introducer is fully deflected, the plurality of apertures are closed along a portion of the inner surface. 
     
     
         9 . A steerable introducer comprising
 a shaft with a proximal end portion, a distal end portion , and a shaft longitudinal axis extending between the proximal end portion and the distal end portion;   a steerable distal tip section attached to the distal end portion of the shaft, the steerable distal tip section comprising an articulation support member;   a retroflex pull wire extending from the proximal end portion of the shaft to the distal end portion of the shaft, wherein the retroflex pull wire is anchored at a first anchor position on a distal pull ring portion of the articulation support member, the first anchor position being laterally offset from the shaft longitudinal axis in a first direction;   at least one tension pull wire extending from the proximal end portion of the shaft to the distal end portion of the shaft, wherein the at least one tension pull wire is anchored at a second anchor position on a proximal pull ring portion of the articulation support member, the second anchor position being (i) laterally offset from the shaft longitudinal axis in a second direction and (ii) angularly offset from the distal pull ring portion by a first angle, wherein the first direction is different from the second direction, and wherein the first angle is about 180 degrees;   wherein tension on the retroflex pull wire causes the steerable distal tip section to bend in the first direction; and   wherein the tension on the tension pull wire opposes shaft bending in the first direction.   
     
     
         10 . The steerable introducer of  claim 9 , wherein the retroflex pull wire causes the shaft to bend between about 0-120 degrees in the first direction. 
     
     
         11 . The steerable introducer of  claim 9 , wherein the tension pull wire causes the shaft to bend between about 0-20 degrees in the second direction. 
     
     
         12 . The steerable introducer of  claim 9 , wherein a cross-sectional area of a lumen of the shaft is maintained during bending. 
     
     
         13 . The steerable introducer of  claim 9  comprising a handle assembly operably attached to the shaft, the handle assembly comprising at least one stud;
 wherein one of the retroflex pull wire or the tension pull wire is anchored to a guitar peg connection, the guitar peg connection located within the stud and operably connected to the stud; 
 wherein the one of the retroflex pull wire or the tension pull wire is wrapped around the guitar peg connection at least once; and 
 wherein the guitar peg connection allows maintenance of a full tensile strength of the one of the retroflex pull wire or the tension pull wire. 
 
     
     
         14 . The steerable introducer of  claim 13  wherein the guitar peg connection is tapered to a specific angle; wherein a hole within the stud is tapered to the specific angle; and wherein the guitar peg is configured to lock into the hole. 
     
     
         15 . A steerable introducer comprising
 a shaft with a proximal end portion, a distal end portion, and a shaft longitudinal axis extending between the proximal end portion and the distal end portion;   a steerable distal tip section attached to the distal end portion of the shaft, the steerable distal tip section comprising an articulation support member;   a first pull wire extending from the proximal end portion of the shaft to the distal end portion of the shaft, wherein the first pull wire is anchored at a first anchor position on the articulation support member, the first anchor position being laterally offset from the shaft longitudinal axis in a first direction;   a second pull wire extending from the proximal end portion of the shaft to the distal end portion of the shaft, wherein the second pull wire is anchored at a second anchor position on the articulation support member, the second anchor position being (i) laterally offset from the shaft longitudinal axis in a second direction and (ii) angularly offset from the first anchor position by a specified angle, wherein the first direction is different from the second direction;   wherein tension on the first pull wire causes the shaft to bend in the first direction; and   wherein the tension on the second pull wire causes the shaft to bend in the second direction.   
     
     
         16 . The steerable introducer of  claim 15 , wherein the specified angle is about 90 degrees and wherein the first direction is perpendicular to the second direction. 
     
     
         17 . The steerable introducer of  claim 15 , wherein a cross-sectional area of a lumen of the shaft is maintained during bending. 
     
     
         18 . The steerable introducer of  claim 15 , further comprising a third pull wire and a fourth pull wire;
 wherein the third pull wire extends from the proximal end portion of the shaft to the distal end portion of the shaft and is anchored at a third anchor position on the articulation support member, the third anchor position being (i) laterally offset from the shaft longitudinal axis in a third direction and (ii) angularly offset from the first anchor position by about 90 degrees;   wherein the fourth pull wire extends from the proximal end portion of the shaft to the distal end portion of the shaft and is anchored at a fourth anchor position on the articulation support member, the fourth anchor position being (i) laterally offset from the shaft longitudinal axis in a fourth direction and (ii) angularly offset from the second anchor position by about 90 degrees;
 wherein tension on the third pull wire causes the shaft to bend in the third direction; and 
 wherein the tension on the fourth pull wire causes the shaft to bend in the fourth direction. 
   
     
     
         19 . The steerable introducer of  claim 18 , wherein the third anchor point is longitudinally offset from the fourth anchor point; wherein the first anchor point is longitudinally offset from the third anchor point and the fourth anchor point; and wherein the second anchor point is longitudinally offset from the third anchor point and the fourth anchor point. 
     
     
         20 . The steerable introducer of  claim 18 , wherein the articulation support member comprises a first region and a second region; wherein the first region defines a first bending plane; wherein the second region defines a second bending plane; and wherein the first bending plane is perpendicular to the second bending plane.