Mask brackets specially adapted for placement underneath {disposable, cloth} sanitary masks for protection against viral infection; Medical apparatus, namely, bi-level positive airway pressure (BPAP) devices; Medical apparatus, namely, continuous positive airway pressure (CPAP) devices; Medical apparatus, namely, variable positive airway pressure devices (VPAP); Medical ventilators; Nebulizers for medical purposes; Patient breathing system comprising a breathing circuit, connections to patien...