초록 ▼

Lung ventilation equipment comprising a gas pulse source delivering pulses of breathable gas to a patient valve for introduction into the respiratory system of a patient for resuscitation or anaesthetic purposes is characterized by a restrictor in the pulse delivery line from the pulse source to the

Lung ventilation equipment comprising a gas pulse source delivering pulses of breathable gas to a patient valve for introduction into the respiratory system of a patient for resuscitation or anaesthetic purposes is characterized by a restrictor in the pulse delivery line from the pulse source to the patient valve, the restrictor being constructed to operate in a sonic-flow “choked”condition during passage of a gas pulse therethrough so that system pressures and resistances downstream of the restrictor cannot affect operation of the pulse source. Downstream of such a restrictor, therefore, conduits may be of small bore while the patient valve may be of the low-pressure type that normally requires a large-bore supply conduit.

대표청구항 ▼

Lung ventilation equipment comprising: an upstream gas pulse source adapted to deliver pulses of breathable gas under pressure at an operating flow rate; downstream patient valve; a line connecting the gas pulse source to the patient valve for delivering the gas pulses from the source to the patient

Lung ventilation equipment comprising: an upstream gas pulse source adapted to deliver pulses of breathable gas under pressure at an operating flow rate; downstream patient valve; a line connecting the gas pulse source to the patient valve for delivering the gas pulses from the source to the patient valve; and a sonic-flow restrictor in the line, the restrictor being adjustable for control of the flow rate and having means causing a pressure drop during each breathable gas pulse delivered by the pulse source through the line to the patient valve, the means being arranged to cause the pressure drop predominantly due to choking as a result of sonic flow velocity and negligibly due to resistive impedance, the flow thus being independent of changes in the downstream pressure.