Breathing circuit having an adjustable volume and length

摘要

A breathing circuit comprising first and second conduits is disclosed, wherein at least one of the conduits is a non-conventional conduit. A multilumen unilimb breathing circuit is also disclosed having first and second conduits, wherein when the proximal ends of said first and second conduits are each connected to an inlet and outlet fitting, respectively, movement of the distal end of the first conduit causes a corresponding movement of the distal end of the second conduit. In an embodiment, at least one of said conduits is coiled. In another embodiment, a coiled conduit is contained within an outer flexible conduit that is axially extendable and compressible, forming a unilimb multilumen respiratory circuit. The outer flexible conduit may be pleated to provide for axial extension and contraction. The multilumen respiratory circuit can provide a variable rebreathing volume. In an embodiment, at least one tube in a multilumen respiratory conduit is radially collapsible and radially expandable to a maximum radius for carrying respiratory gases to and from a patient. Also disclosed are methods and systems of optimizing utilization of fresh gases during artificial or assisted ventilation, including administering anesthesia.