As to the question of rules regarding when and where peaceful protests may be held, that's highly dependent on the specific location of the protest.
The venturi mask, also known as an air-entrainment mask (and sometimes by the brand name VentimaskÂ®), is a medical device to deliver a known oxygen concentration to patients on controlled oxygen therapy.
Bag-valve mask (BVM) ventilation is a life-saving skill that can easily be overlooked because of its apparent simplicity. Poor BVM ventilation technique can lead to the need for more invasive means of airway management and their inherent complications.