Endoscope assemblies having working channels with reduced bending and stretching resistance

An endoscopic assembly, comprising:

• an elongated insertion tube having a working end;
• a sheath assembly including a body portion that encapsulates a substantial portion of the insertion tube, including the working end of the insertion tube, the body portion having a distal end proximate the working end of the insertion tube;
• and
• a working channel attached to the body portion proximate the distal end and having a sliding portion extending along at least a 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.

An endoscopic assembly, comprising:

• an elongated insertion tube having a working end adapted to be insertable into a patient and a proximal end adapted to remain external to the patient;
• a sheath assembly comprising a body portion that encapsulates a substantial portion of the insertion tube, including the working end of the insertion tube, the body portion having first and second ends proximate the working and proximal ends, respectively, of the insertion tube;
• and
• a working channel attached to the body portion proximate the first end, the working channel having a sliding portion extending along a first part of the body portion, the sliding portion being axially slideable along the first part of the body portion when the working channel is subjected to an axial force, the working channel further including an expansion section coupled between the sliding portion and the second end, the expansion section including an expansion member that is axially expandable when the working channel is subjected to the axial force.

A method of performing a procedure using an endoscopic insertion tube having a working end adapted to be insertable into a patient and a proximal end adapted to remain external to the patient, comprising:

• providing a sheath assembly having a body portion that encapsulates a substantial portion of the insertion tube, including the working end of the 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 a first part of the body portion, the sliding portion being axially slideable along the first part of the body portion when the working channel is subjected to an axial force, the working channel further including an expansion section coupled between the sliding portion and the second end, the expansion section including an expansion member that is axially expandable when the working channel is subjected to the axial force;
• and
• exerting an axial force on the working channel to axially slide the sliding portion of the working channel along the first part of the body portion and to axially expand the expansion member.