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.
When treating a patient with active TB, dental health care personnel should use respiratory protection (e.g., fitted, disposable N-95 respirators). Standard surgical face masks are not designed to protect against TB transmission.