1953 -'Ambu' bags i.e. 'bag valve masks' They are as simple as it gets but have saved millions of lives. https://en.m.wikipedia.org/wiki/Bag_valve_mask https:

1953 -'Ambu' bags i.e. 'bag valve masks' They are as simple as it gets but have saved millions of lives. https://en.m.wikipedia.org/wiki/Bag_valve_mask https://en.m.wikipedia.org/wiki/Bag_valve_mask