Endoscopes are routinely used in medical procedures to allow internal visualization. Many of these endoscopes have an integral suction lumen, which may be used, among other things, to aspirate bodily fluids and/or foreign bodies. It is normal clinical practice to clean and sterilize these generally very expensive scopes between patients. The cleaning process is costly due to degradation of the scope during cleaning and the requirement for additional scopes to ensure availability while others are being reprocessed.
The use of a disposable sheath to protect the scope from contamination during use is well known. However, placing this sheath over the scope disables the ability of the user to utilize the scope's integral suction lumen. It is possible to design the sheath so that it incorporates one or more additional lumens through which suction can be drawn. There is currently at least one disposable sheath product on the market that provides such alternate suction capability. It is desirable that a sheath-specific suction lumen (or lumens) afford a cross-sectional area as large as possible (e.g., at least as large as the one integral to the scope). If multiple suction lumens are provided, it is also desirable that the cross-sectional area of any one of these be reasonably large so as to minimize the potential for occlusion.
Many endoscopes incorporate an articulating distal section that is controlled proximally by the user. It is important that a sheath does not appreciably impair the ability of the scope during articulation. Examples of endoscopes and endoscope sheaths are described in PCT Publication No. WO 2010/111461, U.S. Pat. No. 7,056,284, and U.S. Pat. No. 7,120,354, the entireties of which are hereby incorporated by reference.