摘要 |
An anesthesia ventilator is disclosed for controlling the flow of air and/or oxygen through a plurality of binary weighted valves from a fluid regulator source to a bellows assembly. Directly-set minute volume, breath rate and inspiration to expiration ratio controls operate electronic circuitry which adjusts the magnitude of the flow, the tidal volume and the inhalation to exhalation times. The circuitry includes alarm detecting devices for alerting personnel that a patient should be ventilated manually, that a patient is disconnected from the instrument, that control settings exceed specifications for the instrument, that undesired low gas pressure exists and that actual inspiration to expiration is less than that of the control setting. Flow and tidal volume limiting apparatus is provided, together with sigh circuitry and devices for correcting for altitude and gas parameters. |