Inclusion Criteria:  Patients admitted for unexpected respiratory difficulty Patient admitted to the emergency department One of the following 3 criteria have to be present at admission to the ER: O2 < or = 95% Respiratory rate RR > or = 20 Suffocation sensation  Exclusion Criteria:  Patients <18 years old and> 85 years' old Pregnancy History of allergic asthma at early age Diagnosis retained of pulmonary embolism Patients with heart failure (HF) with left ventricular ejection fraction LVEF <40% are known beforehand or discovered at admission to ER known Allergy for Polyamide; Polyester; Elastane; Silicone; Silver; Synthetic material Cardiorespiratory disorders which may be aggravated by the slight compression of the thorax Open wound on the skin, at the level of the trunk