The Simeox device is necessary for patients who require assistance in clearing their airways because their mucociliary transport is not functional, resulting in mucus accumulation and stagnation. These patients may cough but cannot effectively mobilize secretions. Here we primarily refer to patients with chronic obstructive pulmonary disease, chronic bronchitis, bronchiectasis, cystic fibrosis, primary ciliary dyskinesia, and severe forms of asthma.