| 摘要 |
A water separator is disclosed and which is specially suited for withdrawing dry gas from liquid/gas from a patient's exhalation for analysis thereof. The separator utilizes a conduit constructed of a gas permeable material, preferably expanded polytetrafluoroethylene, surrounded by a cylindrical, annular chamber. As the liquid/gas flows through the conduit at a predetermined flow, a negative pressure differential is created between the annular chamber and the conduit to draw the dry gas through the gas permeable material. The conduit is subject to radial expansion upon the patient's exhalation and the annular chamber has a predetermined minimum diameter that is sufficient to allow the conduit to expand without contact between the conduit and an inner surface forming the chamber. The minimum diameter also minimizes the volume of the annular chamber to resist the formation of dead air spaces in the annular chamber. Additionally, since the conduit may be formed with a pre-existing curvature, such as by poltetrafluoroethylene tubing unwound from a spool, the conduit may be subjected to a tensile preload force to eliminate the pre-existing curvature. Additionally, a seal is provided between the conduit and the cylindrical chamber at the ends thereof. The seal may comprise potting material formed by an epoxy which also may serve to maintain the conduit loaded with the tensile pre-load force.
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