| 摘要 |
1,212,527. Lung ventilators. F. M. BIRD and H. L. POHNDORF. 7 Dec., 1967 [14 Dec., 1966], No. 55618/67. Heading A5T. A lung ventilating assembly in which the expiratory and inspiratory times are each con trolled by a metering valve 52 supplying fluid to a fluid-operated means (e.g. a diaphragm 33) controlling a flow control valve 32, one of the valves being a gas supply valve which when opened by one fluid operated means permits supply of respiratory gas and the other flow control valve 32 being a vent valve opened by the other fluid operated means to vent the first metering valve and cause closure of the gas supply valve and opening of a vent valve 74 associated with the second metering valve resulting in closure of the other valve, both flow control valves being in closed position during the expiratory phase and open position during a portion of the inspiratory phase. The device comprises an expiratory cartridge 17, and an inspiratory cartridge 16, each of the cartridges comprising a flow control valve 32 which is opened against a spring 37 in response to fluid pressure on a diaphragm 33. For opening each valve pressure is built up in a diaphragm control chamber 36 through an adjustable needle valve 52. A gas source is connected through a cock 26 and inlet fittings 23 including a filter 20 to nipples 67, 68 of the expiratory cartridge. At the end of the inspiratory phase the valves 32 of both cartridges are closed so that gas supply to a flow pressure control assembly 18 and an outlet fitting 24 is cut off. Gas supplied to the nipple 68 flows through the needle valve 52 of the expiratory cartridge, which is adjustable to determine the expiratory time, to the diaphragm chamber 36 of the expiratory cartridge where pressure builds until the valve 32 of the expiratory cartridge opens to terminate the expiratory phase. Gas them flows via valve 32 of the expiratory cartridge to the outlet fitting 24 and also through the needle valve 52 of the inspiratory cartridge to the diaphragm chamber 36 of the inspiratory cartridge and to a diaphragm chamber 87 to close the vent valve 74. Pressure builds up in the chamber 36 of the inspiratory cartridge so that at the end of the inspiratory time, as determined by the needle valve 52 of the inspiratory cartridge, valve 32 of the inspiratory cartridge is opened to vent the needle valve 52 of the expiratory cartridge through a nipple 71 and cause closure of the valve 32 of the expiratory cartridge. The vent valve 74 then opens to vent the diaphragm chamber 36 of the inspiratory cartridge, the assembly 18 and apparatus connected to. the outlet fitting 24. |
