| 摘要 |
<p>1,221,477. Monitoring respiratory apparatus. AIR REDUCTION CO. Inc. 6 Dec., 1968 [6 Dec., 1967], No. 58064/68. Heading A5T. [Also in Divisions G1 and G3] In an apparatus for monitoring the ultra violet absorption of a sample of respiratory gas, the sample is encompassed within a rotating drum having two diametrically opposite openings one of which contains a pane of fluorescent material, and the openings are aligned twice during each drum revolution with a source of ultra violet light, means being provided for reading the difference in light intensity passing through the sample and the two apertures when respective ones of the two apertures are adjacent the source. The apparatus is used for monitoring and/or controlling the amount of anaesthetic in a rebreathing system, the sample being held within a fixed container within the drum or in the drum itself. The sample is withdrawn by a pump, and the amount of anaesthetic is controlled by passing withdrawn gas through a vaporizer including a liquid halothane reservoir, the circuit including a pump, and solenoid valves controlled by a photocell responsive to the light passing through the drum apertures. The signals from photocell 32, Fig. 2, are gated to measurement and reference stores 38, 39, by reed switches 36 actuated by a magnet attached to the periphery of the drum, and the indication and control are made by meter 44, and meter relay 45 respectively. Source 31 is regulated by the detected reference signal and extreme conditions are arranged to operate appropriate alarms. The vapour concentration may be preset by a controller 46 and false alarm operation during a warming up period is prevented by a relay 61. An excess of halothane is also arranged to operate an alarm and in the event of alarm conditions the vapour control loop may be shut down.</p> |
