Willingness to participate in the study Age 20 -60 y/o No history of cardiovascular disease such as hypertension, liver, kidney according to self-declaration Need to prescribe oxygen and candidate for non-invasive respiratory assistance (NIV) according to physician (no need for intubation) No ban on the use of masks Definitive diagnosis of coronavirus infection by physician and laboratory results

Willingness to participate in the study Age 20 -60 y/o No history of cardiovascular disease such as hypertension, liver, kidney according to self-declaration Need to prescribe oxygen and candidate for non-invasive respiratory assistance (NIV) according to physician (no need for intubation) No ban on the use of masks Definitive diagnosis of coronavirus infection by physician and laboratory results