Through-transmission welding of catheter components

Abstract

A process for forming a heat weld between a catheter shaft and a surrounding balloon comprises selecting an elongate catheter shaft formed of thermoplastic polymeric material that is opaque to red and near-infrared light, and selecting a balloon formed of thermoplastic polymeric material that is transparent or translucent to red and near-infrared light. While a neck of the balloon is fitted in close contact around a distal portion of the catheter shaft, a laser beam of red and near-infrared light is applied through the balloon neck to impinge on the underlying opaque distal shaft, which is heated thereby. Heat from the shaft is conducted into the surrounding balloon neck so that adjacent annular portions of both components melt and mix. The molten materials are allowed to cool, forming a secure weld joint between the neck and the shaft. The process yields strong, flexible bonds between balloons and catheter shafts that may be selected from a wide variety of materials.

1 - 9 . (canceled)  
     
     
         10 . A balloon catheter assembly comprising: 
 an elongate catheter shaft having a distal portion formed of thermoplastic polymeric material that is opaque to red and near-infrared light;    a balloon having a generally cylindrical dilating portion with conical ends tapering to shorter, smaller diameter, cylindrical necks wherein at least one neck is formed of thermoplastic polymeric material that is transparent or translucent to red and near-infrared light, said balloon being mounted around the distal shaft portion such that the balloon neck is fitted in close uniform contact with the distal portion of the shaft; and    a weld joint securing the balloon neck to the catheter shaft, wherein the joint comprises a generally cylindrical region including blended materials of the neck and the shaft.    
     
     
         11  (canceled)  
     
     
         12 . The balloon catheter assembly of  claim 10 , wherein the balloon is welded to the catheter shaft by a heat weld between the catheter shaft and the surrounding balloon neck made by a laser source of red and near-infrared light by applying light from the laser source as a laser beam through the balloon neck to the underlying distal shaft portion, such that polymer melting occurs in the cylindrical region including adjacent parts of the neck and distal shaft portion.  
     
     
         13 . A balloon catheter comprising: 
 a shaft having at least a distal portion formed of a polymeric material that is opaque to red and near-infrared light;    a balloon formed of a polymeric material that is transparent to red and near-infrared light, the balloon having a neck portion fitted about the distal portion of the shaft; and    a weld joint between the neck portion and the distal portion of the shaft, wherein the weld joint includes a mix of the materials of the neck portion of the balloon and the distal portion of the shaft.    
     
     
         14 . The balloon catheter of  claim 13 , wherein the material of the balloon is a polyurethane block amide copolymer.  
     
     
         15 . The balloon catheter of  claim 13 , wherein at least the distal portion of the shaft is made from a multilayer coextrusion.  
     
     
         16 . The balloon catheter of  claim 15 , wherein an outer layer of the distal portion of the shaft is made of a polymeric material that is opaque to red and near-infrared light.  
     
     
         17 . The balloon catheter of  claim 13 , wherein only an outer layer of the distal portion of the shaft is made of a polymeric material that is opaque to red and near-infrared light.  
     
     
         18 . The balloon catheter of  claim 13 , wherein the material of the distal portion of the shaft includes nylon 12 polyamide and carbon black.  
     
     
         19 . The balloon catheter of  claim 13  further comprising, a tube surrounding the weld joint made of a material that is transparent to red and near-infrared light.  
     
     
         20 . The balloon catheter of  claim 19 , wherein the tube is shrunk about the weld joint and is made of a polyolefin.  
     
     
         21 . The balloon catheter of  claim 19 , wherein the tube is shrunk about the weld joint and is made of a polyester.  
     
     
         22 . The balloon catheter of  claim 19 , wherein the tube is made of an elastomeric material.  
     
     
         23 . The balloon catheter of  claim 19 , wherein the weld joint includes corrugations.