GB604558A - Improvements in apparatus for producing analgesia - Google Patents

Abstract

604,558. Anaesthetic apparatus; controlling gases, &c. DAVIS, SIR R. H., DAVIS. R. W. G., and SIEBE, GORMAN, & CO., Ltd. Nov. 27, 1945, No. 32011. [Class 81(ii)] Inhalation apparatus for producing analgesia of the kind in which inhaled air is first passed over or near, the surface of an analgesic liquid, so as to entrain vapour from the liquid, is characterised by a closed receptacle 1, Fig. 3, for the vapour-forming liquid having an air-inlet and an air-vapour outlet both extending well into the receptacle above the surface level of the liquid therein, to permit inversion of the receptacle without spilling liquid into either inlet or outlet tube. In the preferred embodiment the air-vapour outlet 12, Fig. 2, is concentric with air inlet 11, Fig. 2, and both are mounted in the screwed lid 5, Fig. 3, of the receptacle. The air-vapour outlet may be provided with a baffle disc 19, Fig. 2, in combination with a flange 15, Fig. 2, on the lower end, the latter deflects the air over the liquid. Fresh liquid may be put into the receptacle, by inversion, via the filler 6, Fig. 3. The apparatus may be provided with a supplementary air inlet through the opening 25, Fig. 3, by rotary valve element 26, Fig. 4, adjustable by a key which key may also be used for releasing locking means provided for lid 5, to prevent unauthorized interference with these items. The air-vapour mixture is led through non-return valve 36, Fig. 3, to a face mask or the like 2, Fig. 4, via flexible tube 3, and an exhaust valve 35, Fig. 3, is also provided. The receptacle may be mounted on the clamp 44, Fig. 4, in such a way that it may be angularly adjusted, while the clamp is secured to some suitable object, such as the head of the bed. By calibrating the supplementary valve member 26, it is possible to change from analgesia production to to anaesthetic production by setting it back to zero on the scale. It is also stated, that the receptacle cannot be overfilled, and the proportion of air to vapour cannot be altered by depth of breathing owing to the construction of the apparatus.