Endoscopic instruments having low friction sheath

摘要

A low friction sheath for endoscopic instruments is made from an extrusion grade of high density polyethylene (HDPE). The sheath is formed as an extruded polyethylene tube having an inner diameter slightly smaller than the outer diameter of the instrument it will cover. In order to place the sheath over the instrument, a containment sleeve is placed over the sheath and a source of pressurized gas is coupled to one end of the sheath. The endoscopic instrument tube is sealed and inserted into the other end of the sheath. The polyethylene sheath is filled with gas so that it expands against the containment sleeve and the endoscopic instrument tube is pushed into the expanded polyethylene sheath. The gas is released from the polyethylene sheath and it contracts against the outer surface of the endoscopic instrument tube. The sheath is preferably made from a HDPE having a microfractured surface with 10-20 micron fractures.