Endoscope assemblies having working channels with reduced bending and stretching resistance

Abstract

Apparatus and methods for endoscope assemblies having working channels with reduced bending and stretching resistance are disclosed. In one embodiment, an endoscope assembly includes a sheath having a body portion adapted to at least partially encapsulate an endoscopic insertion tube, and a working channel attached to the body portion and extending along at least a portion of the body portion. The working channel includes a component for reducing the resistance of the assembly to bending and stretching. In alternate aspects, the working channel may include a cut, a gap, a sliding portion, or an expansion section. Endoscope assemblies having a working channel in accordance with the invention advantageously reduce the articulation and stretching resistance of the assembly during articulation of the endoscope assembly. Also, because the axial forces (tension and compression) within the working channel are reduced, the working channel can be fabricated out of a relatively hard, inelastic material, thereby reducing the friction within the working channel and improving the physician's ability to perform a medical procedure.

1 - 138 . (canceled)  
   
   
       139 . A method of performing a procedure using an endoscopic insertion tube having a working end adapted to be insertable into a patient, comprising: 
 providing a sheath assembly having a body portion that at least partially encapsulates the endoscopic insertion tube, the body portion having a distal end proximate the working end of the insertion tube;    providing a working channel attached to the body portion proximate the distal end and having a sliding portion extending along at least part of the body portion, the sliding portion being axially slideable along the body portion when the working channel is subjected to an axial force; and    exerting an axial force on the working channel to axially slide the sliding portion of the working channel along the body portion.    
   
   
       140 . The method of  claim 139  wherein providing a working channel attached to the body portion comprises providing a working channel having a sliding portion coupled to the body portion by a sleeve support.  
   
   
       141 . The method of  claim 139  wherein providing a working channel attached to the body portion comprises providing a collapsible channel attached to the body portion.  
   
   
       142 . The method of  claim 139  wherein providing a working channel attached to the body portion comprises providing a working channel having a first end proximate the distal end and a second end opposite from the first end, the working channel including a fitting attached to the second end.  
   
   
       143 . The method of  claim 139  wherein providing a working channel attached to the body portion comprises providing a working channel having a first end proximate the distal end and a second end opposite from the first end, the working channel including a fitting attached to the second end, the method further comprising slideably receiving and guiding the fitting when the working channel is subjected to the axial force.  
   
   
       144 . The method of  claim 143  wherein slideably receiving and guiding the fitting comprises slideably receiving and guiding the fitting within a collar attached to the body portion of the sheath.  
   
   
       145 . The method of  claim 139  wherein exerting an axial force on the working channel comprises articulating a bending section of the insertion tube to apply the axial force on the working channel.  
   
   
       146 . The method of  claim 139  wherein exerting an axial force on the working channel comprises stretching the body portion of the sheath assembly onto the insertion tube to apply an axial tension force on the working channel.  
   
   
       147 . The method of  claim 139 , further comprising inserting a medical device through the working channel.  
   
   
       148 . The method of  claim 139  wherein providing a working channel includes providing a working channel having an enlarged end portion, further comprising drawing a medical device into the enlarged end portion of working channel.  
   
   
       149 . The method of  claim 139 , further comprising inserting working end of the insertion tube into a patient.  
   
   
       150 - 163 . (canceled)