GB1494618A - Ventilator for administering a gas to a patient - Google Patents

Abstract

1494618 Ventilators CAPE ENG CO Ltd 31 Dec 1974 [7 Dec 1973] 56819/73 Addition to 1374583 Heading A5T A ventilator for administering gas to a patient comprises a chamber 2 containing a deflatable and self-inflatable container 1 which is closed to the interior of the chamber and has a non-return inlet 12 through which gas will flow into the container during its inflation, and a non-return outlet 13 through which gas will be inspired by the patient during deflation of the container, the chamber being connected externally of the container to pumping means capable of - alternately introducing a fluid under pressure into the chamber to deflate the container and allowing the container to inflate under its own weight, and also includes a pressure operable exhalation valve 26 removably connected to an exhalation duct 21 leading from the patient, the exhalation valve having an outlet and being controlled by a pressure signal derived from the pumping means in timed relation to the inflation and deflation strokes of the container, the exhalation valve being closed during each inhalation phase of the ventilator, and means for connecting the outlet of the pressure-operable exhalation valve to the non-return inlet, whereby the ventilator will operate with a closed respiratory circuit to recirculate gas, expired by the patient, for re-inspiration. The connecting means comprises a pipe 24, hose 85, reservoir bag 101, and a flexible hose 100 including a purifier device 102 to extract carbon dioxide from the expired gases. The hose 100 is connected to an inlet valve 80 in the inlet circuit of the ventilator. A selector valve (not shown) may be included in the pipe 24 to enable either closed-circuit or open circuit operation to be achieved.