Multi-Directional Steerable Catheter

Abstract

A bi-directional steerable catheter adapted for delivery into a patient's vasculature. The pull wires which are used to tension the deflectable segment of the steerable catheter are wound in parallel around the axis of the steerable catheter on opposite sides of the steerable catheter.

1 . A steerable catheter comprising:
 a tube ( 2 ) having a proximal end ( 4 ), a distal end ( 5 ), and a lumen extending therebetween, said tube ( 2 ) having a first segment ( 2   d  ) proximate said distal end and second segment ( 2   w  ) that extends proximally from said first segment ( 2   d  ) toward said proximal end, a first pull wire ( 12 ) and a second pull wire ( 13 ) embedded within a wall of the tube, and extending from the distal end ( 5 ) to the proximal end ( 4 ) of the tube ( 2 ), said first and second pull wires comprising first and second wound segments ( 12   w ,  13   w ) which are wound about a longitudinal axis of the tube, with the first pull wire ( 12 ) wound in a first direction and the second pull wire ( 13 ) wound in the first direction, substantially in parallel with the first pull wire with the first wound segment ( 12   w ) and the second wound segment ( 13   w ) dispersed circumferentially about the longitudinal axis of the tube ( 2 ).   
     
     
         2 . The steerable catheter of  claim 1 , wherein:
 said first and second pull wires comprise first and second straight distally extending segments ( 12   d ,  13   d ) extending distally from the respective wound segments ( 12   w ,  13   w ); and   the first and second straight distally extending segments ( 12   d ,  13   d ) are disposed within the first segment ( 2   d ) of the tube; and   the first and second wound segments ( 12   w ,  13   w ) are disposed in the second segment of the tube.   
     
     
         3 . The steerable catheter of  claim 2 , wherein:
 in the first segment ( 2   d ) of the tube, the tube wall consists of an inner tube ( 11 ), the pull wires ( 12   d ,  13   d ) disposed about the inner tube ( 11 ), a braid ( 14 ) embedded in a low durometer polymer disposed about the inner tube ( 11 ) and pull wires ( 12   d ,  13   d ), and the outer tube ( 10 ) disposed about the braid ( 14 ).   
     
     
         4 . The steerable catheter of  claim 2 , wherein:
 in the second segment ( 2   w ) of the tube, the tube wall consists of an inner tube ( 11 ), the wound segments ( 12   w ,  13   w ) of the pull wires disposed about the inner tube ( 11 ), the braid ( 14 ) embedded in a low durometer polymer disposed about the inner tube and pull wires, an additional braid  16  disposed about the braid ( 14 ), and the outer tube  10  disposed about the additional braid  16 .   
     
     
         5 . The steerable catheter of  claim 2 , wherein:
 in the first segment of the tube, the tube wall consists of a liner ( 15 ), an inner tube ( 11 ) disposed about the liner, the pull wires ( 12   d ,  13   d ) disposed about the inner tube ( 11 ), a braid ( 14 ) embedded in a low durometer polymer disposed about the inner tube and pull wires, and the outer tube  10  disposed about the braid ( 14 ).   
     
     
         6 . The steerable catheter of  claim 2 , wherein:
 in the second segment of the tube, the tube wall consists of a liner ( 15 ), an inner tube ( 11 ) disposed about the liner ( 15 ), the wound segments ( 12   w ,  13   w ) of the pull wires disposed about the inner tube ( 11 ), a braid ( 14 ) embedded in a low durometer polymer disposed about the inner tube and pull wires, and the outer tube  10  disposed about the braid.   
     
     
         7 . The steerable catheter of  claim 1 , wherein:
 first and second wound segments ( 12   w ,  13   w ) each comprise three turns about the longitudinal axis of the tube.   
     
     
         8 . The steerable catheter of  claim 2 , further comprising:
 a third segment ( 2   p  ) of the tube ( 2 ) extending proximally from the second segment ( 2   w  ) to the proximal end of the tube; and   the first pull wire ( 12 ) and a second pull wire ( 13 ) each comprise a straight proximally extending segment ( 12   p  and  13   p  ) extending proximally from the wound segment toward the proximal end ( 4 ) of the tube ( 2 ); and   said straight proximally extending segments ( 12   p  and  13   p  ) of the pull wires are disposed within the third segment ( 2   p  ) of the tube.   
     
     
         9 . The steerable catheter of  claim 1 , further comprising:
 handle ( 3 ) fixed to the steerable catheter tube ( 2 ), said handle comprising:   a steering lever ( 6 ) rotatably secured to the handle at a fulcrum ( 28 ), with the first and second pull wires ( 12 ,  13 ) fixed to the steering lever ( 6 )on opposite sides of the fulcrum ( 28 ); and   a disc ( 24 ) rotationally fixed to the steering lever ( 6 );   a brake ( 7 ) disposed on the handle such that the rotation of the brake prevents rotation of the disc ( 24 ), thereby holding the deflectable segment ( 2   d  ) in a configuration corresponding to the rotational position of the steering lever ( 6 ).   
     
     
         10 . The steerable catheter of  claim 9 , wherein the brake comprises:
 a brake lever ( 27 ) and a cam plate ( 26 ), disposed on the housing such that the rotation of the brake lever ( 27 ) rotates the cam plate ( 26 ) into interfering contact with the disc ( 24 ) and prevents the disc ( 24 ) from rotating.   
     
     
         11 . A method of accessing a target site in the vasculature of a patient, said method comprising the steps of:
 providing a steerable catheter comprising:   a tube ( 2 ) having a proximal end ( 4 ), a distal end ( 5 ), and a lumen extending therebetween, said tube ( 2 ) having a first segment ( 2   d  ) proximate said distal end and second segment ( 2   w  ) that extends proximally from said first segment ( 2   d  ) toward said proximal end,   one or more pull wires embedded within a wall of the tube, and extending from the distal end ( 5 ) to the proximal end ( 4 ) of the tube ( 2 ), said pull wires comprising wound segments ( 12   w ,  13   w ) which are wound about a longitudinal axis of the tube;   inserting the steerable catheter into the vasculature of the patient, and navigating the steerable catheter through the vasculature of the patient until the deflectable segment is disposed proximate the target site and the wound segment is disposed across a curve in the vasculature; and   operating one or both of the pull wires to deflect the deflectable segment.   
     
     
         12 . The method of  claim 11 , wherein the steerable catheter comprises at least two pull wires, and the wound segments are dispersed about the circumference of the steerable catheter. 
     
     
         13 . The method of  claim 11 , wherein the target site is a left atrium and the curve is the curve is a transition from an inferior vena cava to an atrial septum of the patient. 
     
     
         14 . The method of  claim 11 , wherein the target site is an iliac artery of a patient and the curve is an iliac bifurcation of the patient. 
     
     
         15 . The method of claim  21 , wherein the target site is a left ventricle of a patient and the curve is an aortic arch of the patient. 
     
     
         16 . The method of  claim 11 , wherein the target site is a coronary artery of a patient and the curve is an aortic arch of the patient. 
     
     
         17 . The method of  claim 11 , wherein the target site is an aortic valve of a patient and the curve is an aortic arch of the patient. 
     
     
         18 . The method of  claim 11 , wherein the target site is a peripheral blood vessel of a patient and the curve is a tortuosity between the target site and an entry point into the vasculature of the patient. 
     
     
         19 . The method of  claim 11 , wherein the target site is a carotid artery of a patient and the curve is bifurcation of the brachiocephalic trunk or the aorta of the patient. 
     
     
         20 . The steerable catheter of  claim 8 , further comprising:
 handle ( 3 ) fixed to the steerable catheter tube ( 2 ), said handle comprising:   a steering lever ( 6 ) rotatably secured to the handle at a fulcrum ( 28 ), with the first and second pull wires ( 12 ,  13 ) fixed to the steering lever ( 6 )on opposite sides of the fulcrum ( 28 ); and   a disc ( 24 ) rotationally fixed to the steering lever ( 6 );   a brake ( 7 ) disposed on the handle such that the rotation of the brake prevents rotation of the disc ( 24 ), thereby holding the deflectable segment ( 2   d  ) in a configuration corresponding to the rotational position of the steering lever ( 6 ).