Electrode assembly having an atraumatic distal tip

Abstract

A catheter including expandable electrode assembly having a distal cap that mechanically engages a locking feature provided on the distal ends of each of two or more flexible splines forming a portion of the expandable electrode assembly is described. The distal cap defines an atraumatic distal tip of the catheter. The catheter may be used in a cardiac mapping and/or ablation procedure.

We claim: 
     
         1 . A catheter comprising:
 an elongate catheter body extending from a proximal end to a distal end;   an expandable electrode assembly disposed at the distal end of the catheter body, the electrode assembly including:   a distal cap including an inner cavity and a plurality of slots disposed about an outer circumference of the distal cap;   a plurality of flexible splines extending from the distal end of the catheter body to the distal cap, the plurality of flexible splines including a first spline including a distal end defining a locking feature secured within one of the plurality of slots provided in the distal cap, the expandable electrode assembly configured to be transitioned between a collapsed configuration suitable for delivery and an expanded configuration;   at least one of a cylindrical tube, a plug, and a gasket disposed with in the inner cavity of the distal cap to occlude a gap in at least the one of the plurality of slots securing the first spline; and   two or more electrodes located on the first spline.   
     
     
         2 . The catheter of  claim 1 , wherein the at least one of the cylindrical tube, the plug, and the gasket includes a gasket extending into the at least the one of the plurality of slots securing the first spline. 
     
     
         3 . The catheter of  claim 1 , wherein a height is greater than a width for each of the slots. 
     
     
         4 . The catheter of  claim 1 , wherein the locking feature defined by the distal end of the first spline comprises a first portion having a first width and a second portion having a second width, the first width greater than the second width. 
     
     
         5 . The catheter of  claim 1 , wherein the locking feature defined by the distal end of the first spline includes an arrowhead shape. 
     
     
         6 . The catheter of  claim 1 , wherein the locking feature defined by the distal end of the first spline includes a hook shape. 
     
     
         7 . The catheter of  claim 1 , wherein the distal cap includes a rounded distal end and defines an atraumatic distal tip of the catheter. 
     
     
         8 . The catheter of  claim 1 , wherein the distal cap serves as a distal tip electrode. 
     
     
         9 . The catheter of  claim 1 , wherein the slots are spaced an equal distance from one another about the outer circumference of the distal cap. 
     
     
         10 . The catheter of  claim 1 , further comprising an actuation member coupled to the expandable electrode assembly. 
     
     
         11 . The catheter of  claim 1 , further comprising an adhesive disposed within the inner cavity of the distal cap. 
     
     
         12 . The catheter of  claim 1 , further comprising a sealing material disposed within the at least the one of the plurality of slots securing the first spline. 
     
     
         13 . The catheter of  claim 1 , wherein each of the plurality of flexible splines includes a distal end defining the locking feature, each locking feature secured within a different one of the plurality of slots. 
     
     
         14 . A method of forming an expandable basket electrode assembly, the method comprising:
 forming a flattened spline array including two or more flexible splines, a distal end of each spline defining a locking feature;   forming a cylindrical spline array from the flattened spline array;   positioning a distal cap including two or more slots disposed about an outer circumference adjacent a distal end of the cylindrical spline array;   separating a first spline from the two or more flexible splines of the cylindrical spline array;   rotating the first spline about its major axis from a first orientation to a second orientation;   bending the first spline along its minor axis while it is in its second orientation and inserting the distal end into a first slot of the distal cap;   returning the first spline to its original first orientation; and   inserting at least one of a cylindrical tube, a plug, and a gasket into the distal cap to occlude the first slot adjacent to the first spline.   
     
     
         15 . The method of  claim 14 , further comprising delivering a potting material into the distal cap. 
     
     
         16 . A catheter comprising:
 an elongate catheter body extending from a proximal end to a distal end;   an expandable electrode assembly disposed at the distal end of the catheter body, the expandable electrode assembly configured to be transitioned between a collapsed configuration suitable for delivery and an expanded configuration, the expandable electrode assembly including:   a distal cap including an inner cavity and a plurality of slots disposed about an outer circumference of the distal cap;   a plurality of flexible splines extending from the distal end of the catheter body to the distal cap, the plurality of flexible splines including a first spline including:   at least two electrodes; and   a distal end defining a locking feature secured within one of the plurality of slots provided in the distal cap; and   at least one gasket disposed with in the inner cavity of the distal cap to occlude a gap in at least the one of the plurality of slots securing the first spline.   
     
     
         17 . The catheter of  claim 16 , further comprising a potting material disposed within the inner cavity of the distal cap. 
     
     
         18 . The catheter of  claim 16 , further comprising a sealing material disposed within the at least the one of the plurality of slots securing the first spline. 
     
     
         19 . The catheter of  claim 16 , wherein the distal cap includes a rounded distal end and defines an atraumatic distal tip of the catheter. 
     
     
         20 . The catheter of  claim 16 , wherein the distal cap serves as a distal tip electrode.