| 摘要 |
<p>A medical ventilator comprises a ventilator duct (1) having an inlet (7) for respiratory fresh gas. The pressure at which the respiratory fresh gas is supplied to the patient (4) is determined by a driving jet (10) disposed in the ventilator duct at a distance from the inlet so that an intervening column of gas acts as a pneumatic piston. The supply of driving gas to the jet is initially set by a regulator (16) to obtain a desired value of a respiratory parameter, such as the volume of gas ventilating the patient's lungs during the breathing cycle. The volume of gas expelled from the patient's lungs is monitored during operation by detecting means (8, 15) and the regulator is adjusted by a servomotor (29) in response to any change in the measured parameter in order to maintain the parameter at the desired value.</p> |
