Respiratory ventilation machine

Abstract

Abstract 1,237,273. Artificial respiration. BLEASE MEDICAL EQUIPMENT Ltd. 5 July, 1968, No. 32259/68. Heading A5T. A ventilation machine comprises a variable volume chamber 10 adapted to be connected to a face mask 84 and to be contracted to force gas to the user by pressure of gas within a variable volume control chamber 16, inhalation and exhalation tubes 82, 86, and an over-centre toggle mechanism 28, 40 responsive to the control chamber volume and arranged to actuate a first valve 34 which can allow gas into the control chamber, there being a second valve 50 which can be actuated to allow exit of gas from the control chamber and there being a venturi arrangement 92 connected to the exhalation tube for assisting exhalation. As shown, in the inspiration phase, gas is supplied from a pump to an inlet 64 and from thence through conduits 68, 72 to the first valve 34, which is open, and into the control chamber. The gas also passes through conduits 66, 102, 106 to venturi nozzles 94, 96 and through conduits 68, 74 to an expansible valve operating chamber 60. During inspiration driving gas flows into the control chamber 16 through the valve 34 and by compressing the chamber 10 drives breathing gas (air, oxygen, or an anaesthetic mixture) to the user. After a period determined by the setting of a bleed valve 20 a diaphragm 18 moves against a spring 24 and the pressure in a chamber 22 to actuate the over-centre toggle mechanism through a rod 44 and to close the valve 34. The driving gas is then able to expand the chamber 60 causing the second valve 50 to open and allow the exit of gas from the chamber, the chamber 10 then expanding and drawing in breathing gas from a source 89 while the user exhales into a duct 86 through a filter 89 and the double venturi 92 into the control chamber. Exhalation may be assisted or limited by the adjustment of a tap 104 which by controlling the operation of the venturi nozzles 94, 96 provides a positive or negative pressure in the exhalation ducts. The duration of the expiratory phase is determined by the setting of a bleed valve 30 to the chamber 22 and the machine reverts to inspiration when pressure in the control chamber 16 has fallen such that the diphragm, moved by the spring 24, actuates the overcentre mechanism to open the valve 34. The inspiratory pressure may be controlled by adjusting the compression in the spring 24.

Inventors

• 👤 Roger Edward Wentworth Manley

Bibliographic Details