Steerable catheter

Abstract

A catheter, which is adapted to be inserted into a body lumen, comprises a symmetrical cylindrical control handle, an elongate tubular catheter body, and a flexible catheter tip having a lumen offset from the axis of the catheter tip. The control handle comprises a housing having a piston chamber at its distal end. A piston is mounted in the piston chamber and is afforded lengthwise movement. The proximal end of the catheter body is fixedly attached to the distal end of the piston. A puller wire is attached to the housing and extends through the piston, through and coaxial with the catheter body and into the offset lumen of the catheter tip where it is attached to the wall of the catheter tip. Lengthwise movement of the piston relative to the housing results in deflection of the catheter tip.

What is claimed is: 
     
       1. A steerable catheter comprising: a flexible elongated catheter body having proximal and distal ends and a first lumen;   a flexible catheter tip fixedly attached to the distal end of the catheter body, said tip comprising a second lumen, the axis of the second lumen being offset from the axis of the tip;   a control handle at the proximal end of the catheter body, said control handle comprising: a housing having proximal and distal ends and a piston chamber at its distal end;   a piston having proximal and distal ends and a longitudinal bore therethrough mounted in the piston chamber of the housing and moveable longitudinally within the piston chamber, wherein the proximal end of the catheter body is fixedly attached to the distal end of the piston; and   means proximal to the piston, for securing the proximal end of a puller wire to the housing;     an elongated puller wire having a proximal end fixedly attached to the securing means at a location proximal to the piston chamber, said puller wire extending through the bore of the piston, the first lumen of the catheter body and into the second lumen of the catheter tip, said puller wire further comprising a distal end fixedly attached to the catheter tip; and   whereby longitudinal movement of the piston relative to the housing results in deflection of the catheter tip.   
     
     
       2. A catheter as claimed in claim 1 wherein the puller wire is generally coaxial with the catheter body. 
     
     
       3. A catheter as claimed in claim 1 wherein the distal end of the piston extends out of the distal end of the housing and comprises a thumbrest to facilitate manual movement of the piston relative to the housing. 
     
     
       4. A catheter as claimed in claim 1 wherein the piston comprises a circumferential notch along its length, and the control handle comprises an O-ring positioned within the notch for forming a generally water-tight seal between the piston and the housing. 
     
     
       5. A catheter as claimed in claim 1 wherein the piston comprises a slot along a portion of its length, and the control handle comprises a pin which extends from the housing into the slot. 
     
     
       6. A catheter as claimed in claim 1 wherein the housing comprises a transversely extending bore proximal to the piston, and the securing means comprises an anchor positioned within the bore, said anchor having a hole through which the puller wire extends, and wherein the anchor is rotatable to thereby wedge and secure the proximal end of the puller wire between the anchor and the housing. 
     
     
       7. A steerable electrode catheter comprising: a flexible, elongated catheter body having proximal and distal ends and a lumen;   a flexible catheter tip fixedly attached to the distal end of the catheter body, said tip comprising at least one electrode and at least one lumen having an axis offset from the axis of the tip;   a control handle at the proximal end of the catheter body, said control handle comprising: a housing having proximal and distal ends and a piston chamber at its distal end and a connector chamber at its proximal end;   a rotary connector attached to the proximal end of the housing, the rotary connector comprising:   a male plug having a terminal for electrical connection with each electrode; and   a contact which extends into the connector chamber electrically connected to each terminal;   a piston having proximal and distal ends and a longitudinal bore therethrough mounted in the piston chamber of the housing and moveable longitudinally within the piston chamber, wherein the proximal end of the catheter body is fixedly attached to the distal end of the piston; and   means proximal to the piston, for securing the proximal end of a puller wire to the housing;   an elongated puller wire having a proximal end secured to the securing means, said puller wire extending through the bore of the piston, through the first lumen of the catheter body in generally coaxial relation to the catheter body and into the offset lumen of the catheter tip, said puller wire further comprising a distal end fixedly attached to the catheter tip whereby longitudinal movement of the piston relative to the housing results in deflection of the catheter tip; and   an electrode lead associated with each electrode, each electrode lead having a distal end attached to an electrode and extending through the catheter tip, catheter body, and piston and into the connector chamber of the housing wherein the electrode lead is attached to a contact of the rotary connecter.     
     
     
       8. A catheter as claimed in claim 7 wherein the distal end of the piston extends out of the distal end of the housing and comprises a thumbrest to facilitate manual movement of the piston relative to the housing. 
     
     
       9. A catheter as claimed in claim 7 wherein the piston comprises a circumferential notch along its length and the control handle comprises an O-ring positioned within the notch for forming a generally water-tight seal between the piston and the housing. 
     
     
       10. A catheter as claimed in claim 7 wherein the piston comprises a slot along a portion of its length and the control handle comprises a pin which extends from the housing into the slot. 
     
     
       11. A catheter as claimed in claim 7 wherein the housing comprises a transversely extending bore proximal to the piston and the securing means comprises an anchor positioned within the bore, said anchor having a hole through which the puller wire extends, and wherein the anchor is rotatable to thereby wedge and secure the proximal end of the puller wire between the anchor and housing. 
     
     
       12. A catheter as claimed in claim 7 wherein the rotary connector comprises a flexible core between the contacts and the male plug. .Iadd. 
     
     
       13.  A steerable catheter comprising: a flexible, elongated catheter body having proximal and distal ends and a first lumen formed therein in coaxial relation with the catheter body;   a flexible catheter tip portion fixedly attached to the distal end of the catheter body, said tip portion having proximal and distal ends and a second lumen wherein the axis of the second lumen is offset from the axis of the tip portion;   an elongated puller wire having a proximal end located at the proximal end of the catheter body and a distal end at the catheter tip portion, the puller wire being disposed in and extending through the first lumen in coaxial relation with the catheter body and into the second lumen, the distal end of the puller wire being secured to the catheter tip portion, wherein the catheter further comprises means for supporting the puller wire in the first lumen in coaxial relation with the catheter body, whereby longitudinal movement of the puller wire results in deflection of the catheter tip portion; and   means located at the proximal end of the catheter body for controlling longitudinal movement of the puller wire. .Iaddend. .Iadd.   
     
     
       14.  A catheter as claimed in claim 13, wherein the means for supporting the puller wire in the first lumen such that the puller wire is coaxial with the catheter body comprises a sheath around the puller wire, said sheath further providing lubricity for the puller wire in the first lumen. .Iaddend.