Squeeze bag type resuscitator apparatus

In resuscitator apparatus:

• a manually distortable resilient, hollow squeeze bag assembly having a bag chamber therewithin whose volume varies with distortion thereof,
• said bag assembly being provided with a pair of separate openings respectively adjacent opposite extremities thereof and in communication with said bag chamber;
• a non-rebreathing valve assembly mounted on said bag assembly adjacent one of said extremities of the latter and having a first fluid port in communication with said bag chamber through one of said bag openings and a second fluid port;
• a patient interfacing assembly in communication with said second port of said non-rebreathing valve assembly;
• and
• a demand type oxygen supply valve assembly mounted on said bag assembly adjacent the other of said extremities of the latter and having an oxygen inlet adapted for connection with a source of oxygen under pressure, and an oxygen outlet arranged to communicate with said bag chamber through the other of said bag openings, said supply valve assembly including
• housing structure having a hollow interior, a fluid inlet port adapted for coupling with a source of oxygen under pressure, a fluid outlet port adapted for communicating with an outlet chamber subject to fluid pressure variation therewithin in response to the withdrawal of fluid therefrom, and first and second atmospheric vent ports for communicating with the exterior of said housing structure;
• means including a partition and a pair of differential pressure responsive diaphragms dividing the interior of said housing structure into a plurality of internal chambers,
• one of said diaphragms being between the first and second of said internal chambers,
• said partition being between the second and third of said internal chambers,
• the other of said diaphragms being between the third and fourth of said internal chambers,
• said inlet port being in continuous communication with said fourth internal chamber;
• first valve means including a valve member carried by said one diaphragm and a valve passage through said partition for selectively placing said second internal chamber in fluid communication with said third internal chamber;
• second valve means including a valve member carried by the other of said diaphragms and a valve passage through said housing structure for selectively placing said fourth internal chamber in fluid communication with said outlet chamber;
• a fluid passage within said housing structure for placing said first internal chamber in fluid communication with said outlet chamber;
• a fluid passage within said housing structure for placing said second internal chamber in fluid communication with said first vent port;
• a fluid passage within said housing structure for placing said outlet chamber in fluid communication with said second vent port;
• and
• differential pressure responsive valve means oppositely communicating with said fourth internal chamber and said outlet chamber, also oppositely communicating with said fourth internal chamber and said second vent port, responsive to a positive pressure of at least a predetermined level within said fourth internal chamber for normally closing said passage between said outlet chamber and said second vent port, and responsive to a pressure of less than said predetermined level within said fourth internal chamber for opening said passage between said outlet chamber and said second vent port.