Medical apparatus for the treatment of obstructive sleep apnea; Medical apparatus, namely, non-invasive ventilation apparatus and instruments; Medical respiratory masks for use in treating obstructive sleep apnea; Breathing masks for use in treating obstructive sleep apnea; Seals and connectors for medical respiratory masks; Medical apparatus, namely, continuous positive airway pressure (CPAP) devices, bi-level positive air pressure (BiPAP) devices, variable positive airway pressure (VPAP) de...