Oxford Inflating Bellows
Date of manufacture:
Described in 1953 by Macintosh, the Oxford Inflating Bellows was developed by the Nuffield Department of Anaesthetics as the basis of a versatile, artificial ventilation and anaesthetic system. The bellows, moulded from antistatic black rubber, contains a spring that causes it to self inflate to approximately half full. For transport, the bellows can be fully depressed when it locates with an internal sprung catch that secures it. Once released, the bellows acts as a flexible reservoir permitting spontaneous or manually assisted ventilation. The bellows is interposed between a pair of unidirectional, low resistance, gravity operated disc valves which are orientated to permit gas to enter the bellows from the 'INLET' port and to be expelled via the exit 'TO PATIENT' port. The latter valve can be lifted and disabled by a small magnet when it is optionally mounted on its bracket. The complete system includes a mask, angle piece, a Heidbrink-type variable orifice spill valve and a length of corrugated antistatic rubber hose. An oxygen inlet, fitted with a spring-loaded unidirectional valve, admits a supply of oxygen to the bellows whilst preventing leakage. The main assembly is housed in a free-standing metal casting. With the magnet in place and oxygen flowing, the assembled system constitutes a Mapleson 'A' partial rebreathing configuration whilst a non- rebreathing characteristic is achieved by removing the magnet. Manual ventilation is made possible by partially closing the Heidbringk valve or by replacing it with a Cardiff or similar inflating valve. The inlet port is provided with a taper to permit attachment of breathing system components.
Macintosh, R.R., 'Oxford Inflating Bellows', BMJ, 25 July 1953, 202.
Mushin, W.W., 'Cardiff Inflating Valve', BMJ, 25. July, 1953, 202.