| 摘要 |
An inhalation handset (1) is disclosed which is adapted to be held by a user and is formed with a mouthpiece (11) by which gas can be inhaled by the user from the handset (1) and exhaled by the user into the handset (1). The handset (1) is coupled to a supply conduit (12) fitted with a valve means (14) permitting flow of gas from the supply conduit (12) into the handset (1), and to an exhaust conduit (13) fitted with valve means (15) permitting flow of gas from the handset (1) into the exhaust conduit (13). A filter (18) is disposed within the handset (1) so as to partition the internal volume of the handset (1), the filter (18) being interposed in the flow of gas from the supply conduit (12) to the mouthpiece (11). In a further embodiment, the return flow (33, Fig 3) is around the inlet line (32). |
